Philippe SIMIER
Professeur Université
section 66
| Équipe : |
Thèmes de recherche
Etude des déterminants (génétiques, moléculaires et chimiques) des interactions plante – plante parasite. Application dans un contexte de protection des grandes cultures (colza et tournesol essentiellement…) contre l’orobanche, une plante adventice parasite. Trois objectifs majeurs :
- Caractérisation des composés allélopathiques de la rhizosphère des plantes hôtes (Arabidopsis, colza …) inducteurs de la formation de l’haustorium de l’orobanche
- Caractérisation des voies de signalisation de ces composés chez l’orobanche
- Recherche de nouvelles sources de résistance à l’orobanche chez Brassica
Projets
Parcours universitaire
- 1991 Master Recherche en Productions Végétales et Alimentaires, Université de Nantes
- 1994 Doctorat. Spécialité : Physiologie Végétales. Université de Nantes
Titre : Importance physiologique et métabolique du mannitol dans le parasitisme des angiospermes et perspectives d’application en agronomie. Sous la Direction du Professeur A. FER. - 2000 Habilitation à Diriger des Recherches, Université de Nantes
Titre : Particularités physiologiques, métaboliques et moléculaires des angiospermes parasites. Recherche de cibles métaboliques pour l’établissement de nouvelles méthodes de lutte chimique.
Publications
1 publication
Martinez, Lisa; Pouvreau, Jean-Bernard; Montiel, Gregory; Jestin, Christophe; Delavault, Philippe; Simier, Philippe; Poulin, Lucie
Soil microbiota promotes early developmental stages of Phelipanche ramosa L. Pomel during plant parasitism on Brassica napus L. Article de journal
Dans: Plant and Soil, vol. 483, p. 667–691 , 2022.
@article{martinez2022soil,
title = {Soil microbiota promotes early developmental stages of Phelipanche ramosa L. Pomel during plant parasitism on Brassica napus L.},
author = {Lisa Martinez and Jean-Bernard Pouvreau and Gregory Montiel and Christophe Jestin and Philippe Delavault and Philippe Simier and Lucie Poulin},
doi = {https://doi.org/10.1007/s11104-022-05822-6},
year = {2022},
date = {2022-12-08},
urldate = {2022-12-08},
journal = {Plant and Soil},
volume = {483},
pages = {667–691 },
publisher = {Springer},
abstract = {Purpose
The root holoparasitic plant Phelipanche ramosa has become a major constraint for rapeseed cultivation in western France for the last decades and its control remains challenging. To date, few studies have considered soil microbiota as a third partner of the parasitic plant-plant interaction. Therefore, we here addressed the question of how soil microbiota interferes with host-derived signal metabolites required for host plant recognition by the parasitic plant.
Methods
Using a branched broomrape infested soil (genetic group 1) from a rapeseed field, we first provided soil physicochemical and microbiological descriptions by metabarcoding, followed by P. ramosa seed germination and prehaustorium formation bioassays, and by in vitro co-cultivation with Brassica napus.
Results
Co-cultivation in presence of soil microorganisms promoted parasitic plant seed germination and attachments to host’s roots. Seed germination assays showed that only the combination of gluconasturtiin (main rapeseed glucosinolate) with soil extracts stimulated broomrape germination. This suggests a microbial conversion of gluconasturtiin into germination stimulants via soil microbial myrosinase enzymes. Furthermore, soil bacteria Arthrobacter, Ralstonia, Actinobacterium, Proteobacterium spp. and fungus Penicillium spp. were isolated and screened for myrosinase activity. Pre-germinated seeds treated with soil extracts or differentially filtrated soil extracts also promoted the formation of P. ramosa prehaustorium and led to more parasitic attachments on rapeseed roots in co-cultivation assays. This thus suggests that this enhancement of parasitic attachments could also be partly attributed to soil microbial production of haustorium inducing factors.
Conclusion
Soil microbiota influences B. napus - P. ramosa interaction by altering direct and indirect recognition signals.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Purpose
The root holoparasitic plant Phelipanche ramosa has become a major constraint for rapeseed cultivation in western France for the last decades and its control remains challenging. To date, few studies have considered soil microbiota as a third partner of the parasitic plant-plant interaction. Therefore, we here addressed the question of how soil microbiota interferes with host-derived signal metabolites required for host plant recognition by the parasitic plant.
Methods
Using a branched broomrape infested soil (genetic group 1) from a rapeseed field, we first provided soil physicochemical and microbiological descriptions by metabarcoding, followed by P. ramosa seed germination and prehaustorium formation bioassays, and by in vitro co-cultivation with Brassica napus.
Results
Co-cultivation in presence of soil microorganisms promoted parasitic plant seed germination and attachments to host’s roots. Seed germination assays showed that only the combination of gluconasturtiin (main rapeseed glucosinolate) with soil extracts stimulated broomrape germination. This suggests a microbial conversion of gluconasturtiin into germination stimulants via soil microbial myrosinase enzymes. Furthermore, soil bacteria Arthrobacter, Ralstonia, Actinobacterium, Proteobacterium spp. and fungus Penicillium spp. were isolated and screened for myrosinase activity. Pre-germinated seeds treated with soil extracts or differentially filtrated soil extracts also promoted the formation of P. ramosa prehaustorium and led to more parasitic attachments on rapeseed roots in co-cultivation assays. This thus suggests that this enhancement of parasitic attachments could also be partly attributed to soil microbial production of haustorium inducing factors.
Conclusion
Soil microbiota influences B. napus - P. ramosa interaction by altering direct and indirect recognition signals.
The root holoparasitic plant Phelipanche ramosa has become a major constraint for rapeseed cultivation in western France for the last decades and its control remains challenging. To date, few studies have considered soil microbiota as a third partner of the parasitic plant-plant interaction. Therefore, we here addressed the question of how soil microbiota interferes with host-derived signal metabolites required for host plant recognition by the parasitic plant.
Methods
Using a branched broomrape infested soil (genetic group 1) from a rapeseed field, we first provided soil physicochemical and microbiological descriptions by metabarcoding, followed by P. ramosa seed germination and prehaustorium formation bioassays, and by in vitro co-cultivation with Brassica napus.
Results
Co-cultivation in presence of soil microorganisms promoted parasitic plant seed germination and attachments to host’s roots. Seed germination assays showed that only the combination of gluconasturtiin (main rapeseed glucosinolate) with soil extracts stimulated broomrape germination. This suggests a microbial conversion of gluconasturtiin into germination stimulants via soil microbial myrosinase enzymes. Furthermore, soil bacteria Arthrobacter, Ralstonia, Actinobacterium, Proteobacterium spp. and fungus Penicillium spp. were isolated and screened for myrosinase activity. Pre-germinated seeds treated with soil extracts or differentially filtrated soil extracts also promoted the formation of P. ramosa prehaustorium and led to more parasitic attachments on rapeseed roots in co-cultivation assays. This thus suggests that this enhancement of parasitic attachments could also be partly attributed to soil microbial production of haustorium inducing factors.
Conclusion
Soil microbiota influences B. napus - P. ramosa interaction by altering direct and indirect recognition signals.
2 publications
Germain, Alexandre Saint; Jacobs, Anse; Brun, Guillaume; Pouvreau, Jean-Bernard; Braem, Lukas; Cornu, David; Clavé, Guillaume; Baudu, Emmanuelle; Steinmetz, Vincent; Servajean, Vincent; Wicke, Susann; Gevaert, Kris; Simier, Philippe; Goormachtig, Sophie; Delavault, Philippe; Boyer, François-Didier
A Phelipanche ramosa KAI2 protein perceives strigolactones and isothiocyanates enzymatically Article de journal
Dans: Plant Commun, vol. 2, no. 5, p. 100166, 2021, ISSN: 2590-3462.
@article{RN13,
title = {A Phelipanche ramosa KAI2 protein perceives strigolactones and isothiocyanates enzymatically},
author = {Alexandre Saint Germain and Anse Jacobs and Guillaume Brun and Jean-Bernard Pouvreau and Lukas Braem and David Cornu and Guillaume Clavé and Emmanuelle Baudu and Vincent Steinmetz and Vincent Servajean and Susann Wicke and Kris Gevaert and Philippe Simier and Sophie Goormachtig and Philippe Delavault and François-Didier Boyer},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8553955/pdf/main.pdf},
doi = {10.1016/j.xplc.2021.100166},
issn = {2590-3462},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Plant Commun},
volume = {2},
number = {5},
pages = {100166},
abstract = {Phelipanche ramosa is an obligate root-parasitic weed that threatens major crops in central Europe. In order to germinate, it must perceive various structurally divergent host-exuded signals, including isothiocyanates (ITCs) and strigolactones (SLs). However, the receptors involved are still uncharacterized. Here, we identify five putative SL receptors in P. ramosa and show that PrKAI2d3 is involved in the stimulation of seed germination. We demonstrate the high plasticity of PrKAI2d3, which allows it to interact with different chemicals, including ITCs. The SL perception mechanism of PrKAI2d3 is similar to that of endogenous SLs in non-parasitic plants. We provide evidence that PrKAI2d3 enzymatic activity confers hypersensitivity to SLs. Additionally, we demonstrate that methylbutenolide-OH binds PrKAI2d3 and stimulates P. ramosa germination with bioactivity comparable to that of ITCs. This study demonstrates that P. ramosa has extended its signal perception system during evolution, a fact that should be considered for the development of specific and efficient biocontrol methods.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Phelipanche ramosa is an obligate root-parasitic weed that threatens major crops in central Europe. In order to germinate, it must perceive various structurally divergent host-exuded signals, including isothiocyanates (ITCs) and strigolactones (SLs). However, the receptors involved are still uncharacterized. Here, we identify five putative SL receptors in P. ramosa and show that PrKAI2d3 is involved in the stimulation of seed germination. We demonstrate the high plasticity of PrKAI2d3, which allows it to interact with different chemicals, including ITCs. The SL perception mechanism of PrKAI2d3 is similar to that of endogenous SLs in non-parasitic plants. We provide evidence that PrKAI2d3 enzymatic activity confers hypersensitivity to SLs. Additionally, we demonstrate that methylbutenolide-OH binds PrKAI2d3 and stimulates P. ramosa germination with bioactivity comparable to that of ITCs. This study demonstrates that P. ramosa has extended its signal perception system during evolution, a fact that should be considered for the development of specific and efficient biocontrol methods.
Brun, Guillaume; Spallek, Thomas; Simier, Philippe; Delavault, Philippe
Molecular actors of seed germination and haustoriogenesis in parasitic weeds Article de journal
Dans: Plant Physiol, vol. 185, no. 4, p. 1270-1281, 2021, ISSN: 0032-0889 (Print) 0032-0889.
@article{RN8,
title = {Molecular actors of seed germination and haustoriogenesis in parasitic weeds},
author = {Guillaume Brun and Thomas Spallek and Philippe Simier and Philippe Delavault},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8133557/pdf/kiaa041.pdf},
doi = {10.1093/plphys/kiaa041},
issn = {0032-0889 (Print) 0032-0889},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Plant Physiol},
volume = {185},
number = {4},
pages = {1270-1281},
abstract = {One-sentence summary Recent advances provide insight into the molecular mechanisms underlying host-dependent seed germination and haustorium formation in parasitic plants.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
One-sentence summary Recent advances provide insight into the molecular mechanisms underlying host-dependent seed germination and haustorium formation in parasitic plants.
2 publications
Huet, Sarah; Pouvreau, Jean-Bernard; Delage, Erwan; Delgrange, Sabine; Marais, Coralie; Bahut, Muriel; Delavault, Philippe; Simier, Philippe; Poulin, Lucie
Populations of the Parasitic Plant Influence Their Seed Microbiota Article de journal
Dans: Front Plant Sci, vol. 11, p. 1075, 2020, ISSN: 1664-462X.
@article{pmid32765559,
title = {Populations of the Parasitic Plant Influence Their Seed Microbiota},
author = {Sarah Huet and Jean-Bernard Pouvreau and Erwan Delage and Sabine Delgrange and Coralie Marais and Muriel Bahut and Philippe Delavault and Philippe Simier and Lucie Poulin},
doi = {10.3389/fpls.2020.01075},
issn = {1664-462X},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Front Plant Sci},
volume = {11},
pages = {1075},
abstract = {Seeds of the parasitic weed are well adapted to their hosts because they germinate and form haustorial structures to connect to roots in response to diverse host-derived molecular signals. presents different genetic groups that are preferentially adapted to certain hosts. Since there are indications that microbes play a role in the interaction especially in the early stages of the interaction, we studied the microbial diversity harbored by the parasitic seeds with respect to their host and genetic group. Twenty-six seed lots from seven cropping plots of three different hosts-oilseed rape, tobacco, and hemp-in the west of France were characterized for their bacterial and fungal communities using 16S rRNA gene and ITS (Internal transcribed spacer) sequences, respectively. First seeds were characterized genetically using twenty microsatellite markers and phenotyped for their sensibility to various germination stimulants including strigolactones and isothiocyanates. This led to the distinction of three groups that corresponded to their host of origin. The observed seed diversity was correlated to the host specialization and germination stimulant sensitivity within species. Microbial communities were both clustered by host and plot of origin. The seed core microbiota was composed of seventeen species that were also retrieved from soil and was in lower abundances for bacteria and similar abundances for fungi compared to seeds. The host-related core microbiota of parasitic seeds was limited and presumably well adapted to the interaction with its hosts. Two microbial candidates of species and were especially identified in seeds from oilseed rape plots, suggesting their involvement in host recognition and specialization as well as seed fitness for by improving the production of isothiocyanates from glucosinolates in the rhizosphere of oilseed rape.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Seeds of the parasitic weed are well adapted to their hosts because they germinate and form haustorial structures to connect to roots in response to diverse host-derived molecular signals. presents different genetic groups that are preferentially adapted to certain hosts. Since there are indications that microbes play a role in the interaction especially in the early stages of the interaction, we studied the microbial diversity harbored by the parasitic seeds with respect to their host and genetic group. Twenty-six seed lots from seven cropping plots of three different hosts-oilseed rape, tobacco, and hemp-in the west of France were characterized for their bacterial and fungal communities using 16S rRNA gene and ITS (Internal transcribed spacer) sequences, respectively. First seeds were characterized genetically using twenty microsatellite markers and phenotyped for their sensibility to various germination stimulants including strigolactones and isothiocyanates. This led to the distinction of three groups that corresponded to their host of origin. The observed seed diversity was correlated to the host specialization and germination stimulant sensitivity within species. Microbial communities were both clustered by host and plot of origin. The seed core microbiota was composed of seventeen species that were also retrieved from soil and was in lower abundances for bacteria and similar abundances for fungi compared to seeds. The host-related core microbiota of parasitic seeds was limited and presumably well adapted to the interaction with its hosts. Two microbial candidates of species and were especially identified in seeds from oilseed rape plots, suggesting their involvement in host recognition and specialization as well as seed fitness for by improving the production of isothiocyanates from glucosinolates in the rhizosphere of oilseed rape.
Billard, Estelle; Goyet, Vincent; Delavault, Philippe; Simier, Philippe; Montiel, Grégory
Correction to: Cytokinin treated microcalli of Phelipanche ramosa: an efficient model for studying haustorium formation in holoparasitic plants Article de journal
Dans: Plant Cell, Tissue and Organ Culture (PCTOC), vol. 141, no. 3, p. 555-555, 2020, ISSN: 1573-5044.
@article{RN31,
title = {Correction to: Cytokinin treated microcalli of Phelipanche ramosa: an efficient model for studying haustorium formation in holoparasitic plants},
author = {Estelle Billard and Vincent Goyet and Philippe Delavault and Philippe Simier and Grégory Montiel},
url = {https://doi.org/10.1007/s11240-020-01832-3
https://link.springer.com/content/pdf/10.1007/s11240-020-01832-3.pdf},
doi = {10.1007/s11240-020-01832-3},
issn = {1573-5044},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Plant Cell, Tissue and Organ Culture (PCTOC)},
volume = {141},
number = {3},
pages = {555-555},
abstract = {The caption to Fig. 4 belonged to Fig. 5 and vice versa in the initial online publication. The original article has been corrected.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The caption to Fig. 4 belonged to Fig. 5 and vice versa in the initial online publication. The original article has been corrected.
2 publications
Brun, Guillaume; Thoiron, Séverine; Braem, Lukas; Pouvreau, Jean-Bernard; Montiel, Grégory; Lechat, Marc-Marie; Simier, Philippe; Gevaert, Kris; Goormachtig, Sophie; Delavault, Philippe
CYP707As are effectors of karrikin and strigolactone signalling pathways in Arabidopsis thaliana and parasitic plants Article de journal
Dans: Plant Cell Environ, vol. 42, no. 9, p. 2612-2626, 2019, ISSN: 0140-7791.
@article{RN7,
title = {CYP707As are effectors of karrikin and strigolactone signalling pathways in Arabidopsis thaliana and parasitic plants},
author = {Guillaume Brun and Séverine Thoiron and Lukas Braem and Jean-Bernard Pouvreau and Grégory Montiel and Marc-Marie Lechat and Philippe Simier and Kris Gevaert and Sophie Goormachtig and Philippe Delavault},
url = {https://onlinelibrary.wiley.com/doi/10.1111/pce.13594},
doi = {10.1111/pce.13594},
issn = {0140-7791},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
journal = {Plant Cell Environ},
volume = {42},
number = {9},
pages = {2612-2626},
abstract = {Karrikins stimulate Arabidopsis thaliana germination, whereas parasitic weeds of the Orobanchaceae family have evolved to respond to host-exuded compounds such as strigolactones, dehydrocostus lactone, and 2-phenylethyl isothiocyanate. In Phelipanche ramosa, strigolactone-induced germination was shown to require one of the CYP707A proteins involved in abscisic acid catabolism. Here, germination and gene expression were analysed to investigate the role of CYP707As in germination of both parasitic plants and Arabidopsis upon perception of germination stimulants, after using pharmacological inhibitors and Arabidopsis mutants disrupting germination signals. CYP707A genes were up-regulated upon treatment with effective germination stimulants in both parasitic plants and Arabidopsis. Obligate parasitic plants exhibited both intensified up-regulation of CYP707A genes and increased sensitivity to the CYP707A inhibitor abscinazole-E2B, whereas Arabidopsis cyp707a mutants still positively responded to germination stimulation. In Arabidopsis, CYP707A regulation required the canonical karrikin signalling pathway KAI2/MAX2/SMAX1 and the transcription factor WRKY33. Finally, CYP707As and WRKY33 also modulated Arabidopsis root architecture in response to the synthetic strigolactone rac-GR24, and wrky33-1 exhibited a shoot hyperbranched phenotype. This study suggests that the lack of host-independent germination in obligate parasites is associated with an exacerbated CYP707A induction and that CYP707As and WRKY33 are new players involved in a variety of strigolactone/karrikin responses.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Karrikins stimulate Arabidopsis thaliana germination, whereas parasitic weeds of the Orobanchaceae family have evolved to respond to host-exuded compounds such as strigolactones, dehydrocostus lactone, and 2-phenylethyl isothiocyanate. In Phelipanche ramosa, strigolactone-induced germination was shown to require one of the CYP707A proteins involved in abscisic acid catabolism. Here, germination and gene expression were analysed to investigate the role of CYP707As in germination of both parasitic plants and Arabidopsis upon perception of germination stimulants, after using pharmacological inhibitors and Arabidopsis mutants disrupting germination signals. CYP707A genes were up-regulated upon treatment with effective germination stimulants in both parasitic plants and Arabidopsis. Obligate parasitic plants exhibited both intensified up-regulation of CYP707A genes and increased sensitivity to the CYP707A inhibitor abscinazole-E2B, whereas Arabidopsis cyp707a mutants still positively responded to germination stimulation. In Arabidopsis, CYP707A regulation required the canonical karrikin signalling pathway KAI2/MAX2/SMAX1 and the transcription factor WRKY33. Finally, CYP707As and WRKY33 also modulated Arabidopsis root architecture in response to the synthetic strigolactone rac-GR24, and wrky33-1 exhibited a shoot hyperbranched phenotype. This study suggests that the lack of host-independent germination in obligate parasites is associated with an exacerbated CYP707A induction and that CYP707As and WRKY33 are new players involved in a variety of strigolactone/karrikin responses.
Stojanova, Bojana; Delourme, Régine; Duffé, Philippe; Delavault, Philippe; Simier, Philippe
Genetic differentiation and host preference reveal non-exclusive host races in the generalist parasitic weed Phelipanche ramosa Article de journal
Dans: Weed Research, vol. 59, no. 2, p. 107-118, 2019, ISSN: 0043-1737.
@article{RN32,
title = {Genetic differentiation and host preference reveal non-exclusive host races in the generalist parasitic weed Phelipanche ramosa},
author = {Bojana Stojanova and Régine Delourme and Philippe Duffé and Philippe Delavault and Philippe Simier},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/wre.12353
https://onlinelibrary.wiley.com/doi/10.1111/wre.12353},
doi = {https://doi.org/10.1111/wre.12353},
issn = {0043-1737},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
journal = {Weed Research},
volume = {59},
number = {2},
pages = {107-118},
abstract = {Summary We developed 20 microsatellite markers to genotype over 100 populations of the parasitic weed Phelipanche ramosa, which covers a wide host crop and geographic range. A representative core collection of 15 populations was also used in cross-infestation assays to study host preference during germination, attachment and shoot formation. We observed low genetic differentiation within most of the populations, but high genetic differentiation between populations partitioned into 3 genetic groups with different host preferences and geographic distributions. Genetic group 1 is detected exclusively in western France and on various host crops, notably winter oilseed rape (WOSR) and not hemp. Cross-infection assays confirmed its incompatibility with hemp and showed its preference for WOSR and tobacco in terms of germination and attachment success. The group 2 populations share a large geographic distribution in France and Europe, low germination success with WOSR and high germination success, attachment success and shoot formation with hemp, tobacco or tomato. The subclades 2a and 2b include most of the French populations in hemp crops in eastern France and in tobacco fields in several European countries respectively. The genetic analyses revealed the potential of the three groups to increase their geographic range in the future. Intermediate genetic groups showed higher intrapopulation diversity and represent potential stocks for new host race emergence. Those findings argue in favour of the existence of host races in P. ramosa and should be considered for appropriate management strategies, notably in breeding programmes for resistance against this parasitic weed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Summary We developed 20 microsatellite markers to genotype over 100 populations of the parasitic weed Phelipanche ramosa, which covers a wide host crop and geographic range. A representative core collection of 15 populations was also used in cross-infestation assays to study host preference during germination, attachment and shoot formation. We observed low genetic differentiation within most of the populations, but high genetic differentiation between populations partitioned into 3 genetic groups with different host preferences and geographic distributions. Genetic group 1 is detected exclusively in western France and on various host crops, notably winter oilseed rape (WOSR) and not hemp. Cross-infection assays confirmed its incompatibility with hemp and showed its preference for WOSR and tobacco in terms of germination and attachment success. The group 2 populations share a large geographic distribution in France and Europe, low germination success with WOSR and high germination success, attachment success and shoot formation with hemp, tobacco or tomato. The subclades 2a and 2b include most of the French populations in hemp crops in eastern France and in tobacco fields in several European countries respectively. The genetic analyses revealed the potential of the three groups to increase their geographic range in the future. Intermediate genetic groups showed higher intrapopulation diversity and represent potential stocks for new host race emergence. Those findings argue in favour of the existence of host races in P. ramosa and should be considered for appropriate management strategies, notably in breeding programmes for resistance against this parasitic weed.
1 publication
Goyet, Vincent; Billard, Estelle; Pouvreau, Jean-Bernard; Lechat, Marc-Marie; Pelletier, Sandra; Bahut, Muriel; Monteau, Fabrice; Spíchal, Lukas; Delavault, Philippe; Montiel, Grégory; Simier, Philippe
Haustorium initiation in the obligate parasitic plant Phelipanche ramosa involves a host-exudated cytokinin signal Article de journal
Dans: J Exp Bot, vol. 68, no. 20, p. 5539-5552, 2017, ISSN: 0022-0957 (Print) 0022-0957.
@article{RN11,
title = {Haustorium initiation in the obligate parasitic plant Phelipanche ramosa involves a host-exudated cytokinin signal},
author = {Vincent Goyet and Estelle Billard and Jean-Bernard Pouvreau and Marc-Marie Lechat and Sandra Pelletier and Muriel Bahut and Fabrice Monteau and Lukas Spíchal and Philippe Delavault and Grégory Montiel and Philippe Simier},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5853424/pdf/erx359.pdf},
doi = {10.1093/jxb/erx359},
issn = {0022-0957 (Print) 0022-0957},
year = {2017},
date = {2017-01-01},
urldate = {2017-01-01},
journal = {J Exp Bot},
volume = {68},
number = {20},
pages = {5539-5552},
abstract = {The heterotrophic lifestyle of parasitic plants relies on the development of the haustorium, a specific infectious organ required for attachment to host roots. While haustorium development is initiated upon chemodetection of host-derived molecules in hemiparasitic plants, the induction of haustorium formation remains largely unknown in holoparasitic species such as Phelipanche ramosa. This work demonstrates that the root exudates of the host plant Brassica napus contain allelochemicals displaying haustorium-inducing activity on P. ramosa germinating seeds, which increases the parasite aggressiveness. A de novo assembled transcriptome and microarray approach with P. ramosa during early haustorium formation upon treatment with B. napus root exudates allowed the identification of differentially expressed genes involved in hormone signaling. Bioassays using exogenous cytokinins and the specific cytokinin receptor inhibitor PI-55 showed that cytokinins induced haustorium formation and increased parasite aggressiveness. Root exudates triggered the expression of cytokinin-responsive genes during early haustorium development in germinated seeds, and bio-guided UPLC-ESI(+)-/MS/MS analysis showed that these exudates contain a cytokinin with dihydrozeatin characteristics. These results suggest that cytokinins constitutively exudated from host roots play a major role in haustorium formation and aggressiveness in P. ramosa.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The heterotrophic lifestyle of parasitic plants relies on the development of the haustorium, a specific infectious organ required for attachment to host roots. While haustorium development is initiated upon chemodetection of host-derived molecules in hemiparasitic plants, the induction of haustorium formation remains largely unknown in holoparasitic species such as Phelipanche ramosa. This work demonstrates that the root exudates of the host plant Brassica napus contain allelochemicals displaying haustorium-inducing activity on P. ramosa germinating seeds, which increases the parasite aggressiveness. A de novo assembled transcriptome and microarray approach with P. ramosa during early haustorium formation upon treatment with B. napus root exudates allowed the identification of differentially expressed genes involved in hormone signaling. Bioassays using exogenous cytokinins and the specific cytokinin receptor inhibitor PI-55 showed that cytokinins induced haustorium formation and increased parasite aggressiveness. Root exudates triggered the expression of cytokinin-responsive genes during early haustorium development in germinated seeds, and bio-guided UPLC-ESI(+)-/MS/MS analysis showed that these exudates contain a cytokinin with dihydrozeatin characteristics. These results suggest that cytokinins constitutively exudated from host roots play a major role in haustorium formation and aggressiveness in P. ramosa.
2 publications
Péron, Thomas; Candat, Adrien; Montiel, Grégory; Veronesi, Christophe; Macherel, David; Delavault, Philippe; Simier, Philippe
New Insights into Phloem Unloading and Expression of Sucrose Transporters in Vegetative Sinks of the Parasitic Plant Phelipanche ramosa L. (Pomel) Article de journal
Dans: Front Plant Sci, vol. 7, p. 2048, 2016, ISSN: 1664-462X (Print) 1664-462x.
@article{RN23,
title = {New Insights into Phloem Unloading and Expression of Sucrose Transporters in Vegetative Sinks of the Parasitic Plant Phelipanche ramosa L. (Pomel)},
author = {Thomas Péron and Adrien Candat and Grégory Montiel and Christophe Veronesi and David Macherel and Philippe Delavault and Philippe Simier},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5220101/pdf/fpls-07-02048.pdf},
doi = {10.3389/fpls.2016.02048},
issn = {1664-462X (Print) 1664-462x},
year = {2016},
date = {2016-01-01},
urldate = {2016-01-01},
journal = {Front Plant Sci},
volume = {7},
pages = {2048},
abstract = {The plant-parasitic plant interaction is a interesting model to study sink-source relationship and phloem unloading. The parasitic plants, such as the achlorophyllous plant Phelipanche ramosa, connect to the host phloem through the haustorium and act as supernumerary sinks for the host-derived photoassimilates, primarily sucrose. The application of the fluorescent symplastic tracer, carboxyfluorescein (CF) derived from carboxyfluorescein diacetate (CFDA), to the leaves of the host plant (Brassica napus) showed direct phloem connections at the host-parasite interface. These experiments also evidenced the dominant apoplastic pathway for phloem unloading in major vegetative sinks of the parasite, including tubercles and shoots, except the adventitious root apices. The CF experiments showed also the symplastic isolation of the phloem tissues from the sink tissues in tubercle and shoot of the parasite, then suggesting the pivotal role of sucrose transporters in sucrose unloading in P. ramosa sinks. Three cDNAs encoding sucrose transporters (PrSUT) were isolated from the parasitic plant. PrSUT1 transcripts accumulated at the same level in the tubercle throughout the parasite growth while a significant increase in transcript accumulation occurred after emergence in the flowering shoot, notably in the growing apical part. The in situ hybridization experiments revealed the PrSUT1 transcript accumulation in the mature phloem cells of both subterranean and flowering shoots, as well as in shoot terminal sinks corresponding to apical meristem, scale leaf primordia and immature vasculature. The transient expression experiments in Arabidopsis protoplasts showed that PrSUT1 was localized at the plasma membrane, suggesting its role in phloem functioning and sucrose uptake by the sink cells in P. ramosa. Conversely, the PrSUT2 transcript accumulation was constantly low in tubercles and shoots but PrSUT3 transcripts accumulated markedly in the subterranean and flowering shoots, in concordance with the PrSUT3 mRNA accumulation in multiple sink areas including apical meristem, scale-leaf primordia, immature vasculature and even storage parenchyma. However, the PrSUT3 transcripts did not accumulate in the mature phloem cells. The transient expression experiments in Arabidopsis protoplasts suggested a tonoplast localization of PrSUT3, for which nevertheless the involvement in intracellular sucrose transport needs clarification.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The plant-parasitic plant interaction is a interesting model to study sink-source relationship and phloem unloading. The parasitic plants, such as the achlorophyllous plant Phelipanche ramosa, connect to the host phloem through the haustorium and act as supernumerary sinks for the host-derived photoassimilates, primarily sucrose. The application of the fluorescent symplastic tracer, carboxyfluorescein (CF) derived from carboxyfluorescein diacetate (CFDA), to the leaves of the host plant (Brassica napus) showed direct phloem connections at the host-parasite interface. These experiments also evidenced the dominant apoplastic pathway for phloem unloading in major vegetative sinks of the parasite, including tubercles and shoots, except the adventitious root apices. The CF experiments showed also the symplastic isolation of the phloem tissues from the sink tissues in tubercle and shoot of the parasite, then suggesting the pivotal role of sucrose transporters in sucrose unloading in P. ramosa sinks. Three cDNAs encoding sucrose transporters (PrSUT) were isolated from the parasitic plant. PrSUT1 transcripts accumulated at the same level in the tubercle throughout the parasite growth while a significant increase in transcript accumulation occurred after emergence in the flowering shoot, notably in the growing apical part. The in situ hybridization experiments revealed the PrSUT1 transcript accumulation in the mature phloem cells of both subterranean and flowering shoots, as well as in shoot terminal sinks corresponding to apical meristem, scale leaf primordia and immature vasculature. The transient expression experiments in Arabidopsis protoplasts showed that PrSUT1 was localized at the plasma membrane, suggesting its role in phloem functioning and sucrose uptake by the sink cells in P. ramosa. Conversely, the PrSUT2 transcript accumulation was constantly low in tubercles and shoots but PrSUT3 transcripts accumulated markedly in the subterranean and flowering shoots, in concordance with the PrSUT3 mRNA accumulation in multiple sink areas including apical meristem, scale-leaf primordia, immature vasculature and even storage parenchyma. However, the PrSUT3 transcripts did not accumulate in the mature phloem cells. The transient expression experiments in Arabidopsis protoplasts suggested a tonoplast localization of PrSUT3, for which nevertheless the involvement in intracellular sucrose transport needs clarification.
Brahmi, Ines; Mabrouk, Yassine; Brun, Guillaume; Delavault, Philippe; Belhadj, Omrane; Simier, Philippe
Phenotypical and biochemical characterisation of resistance for parasitic weed (Orobanche foetida Poir.) in radiation-mutagenised mutants of chickpea Article de journal
Dans: Pest Manag Sci, vol. 72, no. 12, p. 2330-2338, 2016, ISSN: 1526-498x.
@article{RN16,
title = {Phenotypical and biochemical characterisation of resistance for parasitic weed (Orobanche foetida Poir.) in radiation-mutagenised mutants of chickpea},
author = {Ines Brahmi and Yassine Mabrouk and Guillaume Brun and Philippe Delavault and Omrane Belhadj and Philippe Simier},
url = {https://onlinelibrary.wiley.com/doi/10.1002/ps.4278},
doi = {10.1002/ps.4278},
issn = {1526-498x},
year = {2016},
date = {2016-01-01},
urldate = {2016-01-01},
journal = {Pest Manag Sci},
volume = {72},
number = {12},
pages = {2330-2338},
abstract = {BACKGROUND: Some radiation-mutagenised chickpea mutants potentially resistant to the broomrape, Orobanche foetida Poir., were selected through field trials. The objectives of this work were to confirm resistance under artificial infestation, in pots and mini-rhizotron systems, and to determine the developmental stages of broomrape affected by resistance and the relevant resistance mechanisms induced by radiation mutagenesis. RESULTS: Among 30 mutants tested for resistance to O. foetida, five shared strong resistance in both pot experiments and mini-rhizotron systems. Resistance was not complete, but the few individuals that escaped resistance displayed high disorders of shoot development. Results demonstrated a 2-3-fold decrease in stimulatory activity of root exudates towards broomrape seed germination in resistant mutants in comparison with non-irradiated control plants and susceptible mutants. Resistance was associated with an induction of broomrape necrosis early during infection. When infested, most of the resistant mutants shared enhanced levels of soluble phenolic contents, phenylalanine ammonia lyase activity, guaiacol peroxidase activity and polyphenol oxidase activity, in addition to glutathione and notably ascorbate peroxidase gene expression in roots. CONCLUSION: Results confirmed enhanced resistance in chickpea radiation-mutagenised mutants, and demonstrated that resistance is based on alteration of root exudation, presumed cell-wall reinforcement and change in root oxidative status in response to infection. © 2016 Society of Chemical Industry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Some radiation-mutagenised chickpea mutants potentially resistant to the broomrape, Orobanche foetida Poir., were selected through field trials. The objectives of this work were to confirm resistance under artificial infestation, in pots and mini-rhizotron systems, and to determine the developmental stages of broomrape affected by resistance and the relevant resistance mechanisms induced by radiation mutagenesis. RESULTS: Among 30 mutants tested for resistance to O. foetida, five shared strong resistance in both pot experiments and mini-rhizotron systems. Resistance was not complete, but the few individuals that escaped resistance displayed high disorders of shoot development. Results demonstrated a 2-3-fold decrease in stimulatory activity of root exudates towards broomrape seed germination in resistant mutants in comparison with non-irradiated control plants and susceptible mutants. Resistance was associated with an induction of broomrape necrosis early during infection. When infested, most of the resistant mutants shared enhanced levels of soluble phenolic contents, phenylalanine ammonia lyase activity, guaiacol peroxidase activity and polyphenol oxidase activity, in addition to glutathione and notably ascorbate peroxidase gene expression in roots. CONCLUSION: Results confirmed enhanced resistance in chickpea radiation-mutagenised mutants, and demonstrated that resistance is based on alteration of root exudation, presumed cell-wall reinforcement and change in root oxidative status in response to infection. © 2016 Society of Chemical Industry.
1 publication
Lechat, Marc-Marie; Brun, Guillaume; Montiel, Grégory; Véronési, Christophe; Simier, Philippe; Thoiron, Séverine; Pouvreau, Jean-Bernard; Delavault, Philippe
Seed response to strigolactone is controlled by abscisic acid-independent DNA methylation in the obligate root parasitic plant, Phelipanche ramosa L. Pomel Article de journal
Dans: J Exp Bot, vol. 66, no. 11, p. 3129-40, 2015, ISSN: 0022-0957 (Print) 0022-0957.
@article{RN22,
title = {Seed response to strigolactone is controlled by abscisic acid-independent DNA methylation in the obligate root parasitic plant, Phelipanche ramosa L. Pomel},
author = {Marc-Marie Lechat and Guillaume Brun and Grégory Montiel and Christophe Véronési and Philippe Simier and Séverine Thoiron and Jean-Bernard Pouvreau and Philippe Delavault},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449535/pdf/erv119.pdf},
doi = {10.1093/jxb/erv119},
issn = {0022-0957 (Print) 0022-0957},
year = {2015},
date = {2015-01-01},
urldate = {2015-01-01},
journal = {J Exp Bot},
volume = {66},
number = {11},
pages = {3129-40},
abstract = {Seed dormancy release of the obligate root parasitic plant, Phelipanche ramosa, requires a minimum 4-day conditioning period followed by stimulation by host-derived germination stimulants, such as strigolactones. Germination is then mediated by germination stimulant-dependent activation of PrCYP707A1, an abscisic acid catabolic gene. The molecular mechanisms occurring during the conditioning period that silence PrCYP707A1 expression and regulate germination stimulant response are almost unknown. Here, global DNA methylation quantification associated with pharmacological approaches and cytosine methylation analysis of the PrCYP707A1 promoter were used to investigate the modulation and possible role of DNA methylation during the conditioning period and in the PrCYP707A1 response to GR24, a synthetic strigolactone analogue. Active global DNA demethylation occurs during the conditioning period and is required for PrCYP707A1 activation by GR24 and for subsequent seed germination. Treatment with 5-azacytidine, a DNA-hypomethylating molecule, reduces the length of the conditioning period. Conversely, hydroxyurea, a hypermethylating agent, inhibits PrCYP707A1 expression and seed germination. Methylated DNA immunoprecipitation followed by PCR experiments and bisulfite sequencing revealed that DNA demethylation particularly impacts a 78-nucleotide sequence in the PrCYP707A1 promoter. The results here demonstrate that the DNA methylation status during the conditioning period plays a crucial role independently of abscisic acid in the regulation of P. ramosa seed germination by controlling the strigolactone-dependent expression of PrCYP707A1.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Seed dormancy release of the obligate root parasitic plant, Phelipanche ramosa, requires a minimum 4-day conditioning period followed by stimulation by host-derived germination stimulants, such as strigolactones. Germination is then mediated by germination stimulant-dependent activation of PrCYP707A1, an abscisic acid catabolic gene. The molecular mechanisms occurring during the conditioning period that silence PrCYP707A1 expression and regulate germination stimulant response are almost unknown. Here, global DNA methylation quantification associated with pharmacological approaches and cytosine methylation analysis of the PrCYP707A1 promoter were used to investigate the modulation and possible role of DNA methylation during the conditioning period and in the PrCYP707A1 response to GR24, a synthetic strigolactone analogue. Active global DNA demethylation occurs during the conditioning period and is required for PrCYP707A1 activation by GR24 and for subsequent seed germination. Treatment with 5-azacytidine, a DNA-hypomethylating molecule, reduces the length of the conditioning period. Conversely, hydroxyurea, a hypermethylating agent, inhibits PrCYP707A1 expression and seed germination. Methylated DNA immunoprecipitation followed by PCR experiments and bisulfite sequencing revealed that DNA demethylation particularly impacts a 78-nucleotide sequence in the PrCYP707A1 promoter. The results here demonstrate that the DNA methylation status during the conditioning period plays a crucial role independently of abscisic acid in the regulation of P. ramosa seed germination by controlling the strigolactone-dependent expression of PrCYP707A1.
2013
Pouvreau, Jean-Bernard; Gaudin, Zachary; Auger, Bathilde; Lechat, Marc-Marie; Gauthier, Mathieu; Delavault, Philippe; Simier, Philippe
A high-throughput seed germination assay for root parasitic plants Article de journal
Dans: Plant Methods, vol. 9, no. 1, p. 32, 2013, ISSN: 1746-4811.
@article{pmid23915294,
title = {A high-throughput seed germination assay for root parasitic plants},
author = {Jean-Bernard Pouvreau and Zachary Gaudin and Bathilde Auger and Marc-Marie Lechat and Mathieu Gauthier and Philippe Delavault and Philippe Simier},
doi = {10.1186/1746-4811-9-32},
issn = {1746-4811},
year = {2013},
date = {2013-08-01},
urldate = {2013-08-01},
journal = {Plant Methods},
volume = {9},
number = {1},
pages = {32},
abstract = {BACKGROUND: Some root-parasitic plants belonging to the Orobanche, Phelipanche or Striga genus represent one of the most destructive and intractable weed problems to agricultural production in both developed and developing countries. Compared with most of the other weeds, parasitic weeds are difficult to control by conventional methods because of their life style. The main difficulties that currently limit the development of successful control methods are the ability of the parasite to produce a tremendous number of tiny seeds that may remain viable in the soil for more than 15 years. Seed germination requires induction by stimulants present in root exudates of host plants. Researches performed on these minute seeds are until now tedious and time-consuming because germination rate is usually evaluated in Petri-dish by counting germinated seeds under a binocular microscope.
RESULTS: We developed an easy and fast method for germination rate determination based on a standardized 96-well plate test coupled with spectrophotometric reading of tetrazolium salt (MTT) reduction. We adapted the Mosmann's protocol for cell cultures to germinating seeds and determined the conditions of seed stimulation and germination, MTT staining and formazan salt solubilization required to obtain a linear relationship between absorbance and germination rate. Dose-response analyses were presented as applications of interest for assessing half maximal effective or inhibitory concentrations of germination stimulants (strigolactones) or inhibitors (ABA), respectively, using four parameter logistic curves.
CONCLUSION: The developed MTT system is simple and accurate. It yields reproducible results for germination bioassays of parasitic plant seeds. This method is adapted to high-throughput screenings of allelochemicals (stimulants, inhibitors) or biological extracts on parasitic plant seed germination, and strengthens the investigations of distinctive features of parasitic plant germination.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Some root-parasitic plants belonging to the Orobanche, Phelipanche or Striga genus represent one of the most destructive and intractable weed problems to agricultural production in both developed and developing countries. Compared with most of the other weeds, parasitic weeds are difficult to control by conventional methods because of their life style. The main difficulties that currently limit the development of successful control methods are the ability of the parasite to produce a tremendous number of tiny seeds that may remain viable in the soil for more than 15 years. Seed germination requires induction by stimulants present in root exudates of host plants. Researches performed on these minute seeds are until now tedious and time-consuming because germination rate is usually evaluated in Petri-dish by counting germinated seeds under a binocular microscope.
RESULTS: We developed an easy and fast method for germination rate determination based on a standardized 96-well plate test coupled with spectrophotometric reading of tetrazolium salt (MTT) reduction. We adapted the Mosmann's protocol for cell cultures to germinating seeds and determined the conditions of seed stimulation and germination, MTT staining and formazan salt solubilization required to obtain a linear relationship between absorbance and germination rate. Dose-response analyses were presented as applications of interest for assessing half maximal effective or inhibitory concentrations of germination stimulants (strigolactones) or inhibitors (ABA), respectively, using four parameter logistic curves.
CONCLUSION: The developed MTT system is simple and accurate. It yields reproducible results for germination bioassays of parasitic plant seeds. This method is adapted to high-throughput screenings of allelochemicals (stimulants, inhibitors) or biological extracts on parasitic plant seed germination, and strengthens the investigations of distinctive features of parasitic plant germination.
RESULTS: We developed an easy and fast method for germination rate determination based on a standardized 96-well plate test coupled with spectrophotometric reading of tetrazolium salt (MTT) reduction. We adapted the Mosmann's protocol for cell cultures to germinating seeds and determined the conditions of seed stimulation and germination, MTT staining and formazan salt solubilization required to obtain a linear relationship between absorbance and germination rate. Dose-response analyses were presented as applications of interest for assessing half maximal effective or inhibitory concentrations of germination stimulants (strigolactones) or inhibitors (ABA), respectively, using four parameter logistic curves.
CONCLUSION: The developed MTT system is simple and accurate. It yields reproducible results for germination bioassays of parasitic plant seeds. This method is adapted to high-throughput screenings of allelochemicals (stimulants, inhibitors) or biological extracts on parasitic plant seed germination, and strengthens the investigations of distinctive features of parasitic plant germination.
2012
Lechat, Marc-Marie; Pouvreau, Jean-Bernard; Péron, Thomas; Gauthier, Mathieu; Montiel, Grégory; Véronési, Christophe; Todoroki, Yasushi; Bizec, Bruno Le; Monteau, Fabrice; Macherel, David; Simier, Philippe; Thoiron, Séverine; Delavault, Philippe
PrCYP707A1, an ABA catabolic gene, is a key component of Phelipanche ramosa seed germination in response to the strigolactone analogue GR24 Article de journal
Dans: J Exp Bot, vol. 63, no. 14, p. 5311–5322, 2012, ISSN: 1460-2431.
@article{pmid22859674,
title = {PrCYP707A1, an ABA catabolic gene, is a key component of Phelipanche ramosa seed germination in response to the strigolactone analogue GR24},
author = {Marc-Marie Lechat and Jean-Bernard Pouvreau and Thomas Péron and Mathieu Gauthier and Grégory Montiel and Christophe Véronési and Yasushi Todoroki and Bruno Le Bizec and Fabrice Monteau and David Macherel and Philippe Simier and Séverine Thoiron and Philippe Delavault},
doi = {10.1093/jxb/ers189},
issn = {1460-2431},
year = {2012},
date = {2012-09-01},
urldate = {2012-09-01},
journal = {J Exp Bot},
volume = {63},
number = {14},
pages = {5311--5322},
abstract = {After a conditioning period, seed dormancy in obligate root parasitic plants is released by a chemical stimulus secreted by the roots of host plants. Using Phelipanche ramosa as the model, experiments conducted in this study showed that seeds require a conditioning period of at least 4 d to be receptive to the synthetic germination stimulant GR24. A cDNA-AFLP procedure on seeds revealed 58 transcript-derived fragments (TDFs) whose expression pattern changed upon GR24 treatment. Among the isolated TDFs, two up-regulated sequences corresponded to an abscisic acid (ABA) catabolic gene, PrCYP707A1, encoding an ABA 8'-hydroxylase. Using the rapid amplification of cDNA ends method, two full-length cDNAs, PrCYP707A1 and PrCYP707A2, were isolated from seeds. Both genes were always expressed at low levels during conditioning during which an initial decline in ABA levels was recorded. GR24 application after conditioning triggered a strong up-regulation of PrCYP707A1 during the first 18 h, followed by an 8-fold decrease in ABA levels detectable 3 d after treatment. In situ hybridization experiments on GR24-treated seeds revealed a specific PrCYP707A1 mRNA accumulation in the cells located between the embryo and the micropyle. Abz-E2B, a specific inhibitor of CYP707A enzymes, significantly impeded seed germination, proving to be a non-competitive antagonist of GR24 with reversible inhibitory activity. These results demonstrate that P. ramosa seed dormancy release relies on ABA catabolism mediated by the GR24-dependent activation of PrCYP707A1. In addition, in situ hybridization corroborates the putative location of cells receptive to the germination stimulants in seeds.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
After a conditioning period, seed dormancy in obligate root parasitic plants is released by a chemical stimulus secreted by the roots of host plants. Using Phelipanche ramosa as the model, experiments conducted in this study showed that seeds require a conditioning period of at least 4 d to be receptive to the synthetic germination stimulant GR24. A cDNA-AFLP procedure on seeds revealed 58 transcript-derived fragments (TDFs) whose expression pattern changed upon GR24 treatment. Among the isolated TDFs, two up-regulated sequences corresponded to an abscisic acid (ABA) catabolic gene, PrCYP707A1, encoding an ABA 8'-hydroxylase. Using the rapid amplification of cDNA ends method, two full-length cDNAs, PrCYP707A1 and PrCYP707A2, were isolated from seeds. Both genes were always expressed at low levels during conditioning during which an initial decline in ABA levels was recorded. GR24 application after conditioning triggered a strong up-regulation of PrCYP707A1 during the first 18 h, followed by an 8-fold decrease in ABA levels detectable 3 d after treatment. In situ hybridization experiments on GR24-treated seeds revealed a specific PrCYP707A1 mRNA accumulation in the cells located between the embryo and the micropyle. Abz-E2B, a specific inhibitor of CYP707A enzymes, significantly impeded seed germination, proving to be a non-competitive antagonist of GR24 with reversible inhibitory activity. These results demonstrate that P. ramosa seed dormancy release relies on ABA catabolism mediated by the GR24-dependent activation of PrCYP707A1. In addition, in situ hybridization corroborates the putative location of cells receptive to the germination stimulants in seeds.
Boyer, François-Didier; de Saint Germain, Alexandre; Pillot, Jean-Paul; Pouvreau, Jean-Bernard; Chen, Victor Xiao; Ramos, Suzanne; Stévenin, Arnaud; Simier, Philippe; Delavault, Philippe; Beau, Jean-Marie; Rameau, Catherine
Structure-activity relationship studies of strigolactone-related molecules for branching inhibition in garden pea: molecule design for shoot branching Article de journal
Dans: Plant Physiol, vol. 159, no. 4, p. 1524–1544, 2012, ISSN: 1532-2548.
@article{pmid22723084,
title = {Structure-activity relationship studies of strigolactone-related molecules for branching inhibition in garden pea: molecule design for shoot branching},
author = {François-Didier Boyer and Alexandre de Saint Germain and Jean-Paul Pillot and Jean-Bernard Pouvreau and Victor Xiao Chen and Suzanne Ramos and Arnaud Stévenin and Philippe Simier and Philippe Delavault and Jean-Marie Beau and Catherine Rameau},
doi = {10.1104/pp.112.195826},
issn = {1532-2548},
year = {2012},
date = {2012-08-01},
urldate = {2012-08-01},
journal = {Plant Physiol},
volume = {159},
number = {4},
pages = {1524--1544},
abstract = {Initially known for their role in the rhizosphere in stimulating the seed germination of parasitic weeds such as the Striga and Orobanche species, and later as host recognition signals for arbuscular mycorrhizal fungi, strigolactones (SLs) were recently rediscovered as a new class of plant hormones involved in the control of shoot branching in plants. Herein, we report the synthesis of new SL analogs and, to our knowledge, the first study of SL structure-activity relationships for their hormonal activity in garden pea (Pisum sativum). Comparisons with their action for the germination of broomrape (Phelipanche ramosa) are also presented. The pea rms1 SL-deficient mutant was used in a SL bioassay based on axillary bud length after direct SL application on the bud. This assay was compared with an assay where SLs were fed via the roots using hydroponics and with a molecular assay in which transcript levels of BRANCHED1, the pea homolog of the maize TEOSINTE BRANCHED1 gene were quantified in axillary buds only 6 h after application of SLs. We have demonstrated that the presence of a Michael acceptor and a methylbutenolide or dimethylbutenolide motif in the same molecule is essential. It was established that the more active analog 23 with a dimethylbutenolide as the D-ring could be used to control the plant architecture without strongly favoring the germination of P. ramosa seeds. Bold numerals refer to numbers of compounds.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Initially known for their role in the rhizosphere in stimulating the seed germination of parasitic weeds such as the Striga and Orobanche species, and later as host recognition signals for arbuscular mycorrhizal fungi, strigolactones (SLs) were recently rediscovered as a new class of plant hormones involved in the control of shoot branching in plants. Herein, we report the synthesis of new SL analogs and, to our knowledge, the first study of SL structure-activity relationships for their hormonal activity in garden pea (Pisum sativum). Comparisons with their action for the germination of broomrape (Phelipanche ramosa) are also presented. The pea rms1 SL-deficient mutant was used in a SL bioassay based on axillary bud length after direct SL application on the bud. This assay was compared with an assay where SLs were fed via the roots using hydroponics and with a molecular assay in which transcript levels of BRANCHED1, the pea homolog of the maize TEOSINTE BRANCHED1 gene were quantified in axillary buds only 6 h after application of SLs. We have demonstrated that the presence of a Michael acceptor and a methylbutenolide or dimethylbutenolide motif in the same molecule is essential. It was established that the more active analog 23 with a dimethylbutenolide as the D-ring could be used to control the plant architecture without strongly favoring the germination of P. ramosa seeds. Bold numerals refer to numbers of compounds.
Auger, Bathilde; Pouvreau, Jean-Bernard; Pouponneau, Karinne; Yoneyama, Kaori; Montiel, Grégory; Bizec, Bruno Le; Yoneyama, Koichi; Delavault, Philippe; Delourme, Régine; Simier, Philippe
Germination stimulants of Phelipanche ramosa in the rhizosphere of Brassica napus are derived from the glucosinolate pathway Article de journal
Dans: Mol Plant Microbe Interact, vol. 25, no. 7, p. 993–1004, 2012, ISSN: 0894-0282.
@article{pmid22414435,
title = {Germination stimulants of Phelipanche ramosa in the rhizosphere of Brassica napus are derived from the glucosinolate pathway},
author = {Bathilde Auger and Jean-Bernard Pouvreau and Karinne Pouponneau and Kaori Yoneyama and Grégory Montiel and Bruno Le Bizec and Koichi Yoneyama and Philippe Delavault and Régine Delourme and Philippe Simier},
doi = {10.1094/MPMI-01-12-0006-R},
issn = {0894-0282},
year = {2012},
date = {2012-07-01},
urldate = {2012-07-01},
journal = {Mol Plant Microbe Interact},
volume = {25},
number = {7},
pages = {993--1004},
abstract = {Phelipanche ramosa is a major parasitic weed of Brassica napus. The first step in a host-parasitic plant interaction is stimulation of parasite seed germination by compounds released from host roots. However, germination stimulants produced by B. napus have not been identified yet. In this study, we characterized the germination stimulants that accumulate in B. napus roots and are released into the rhizosphere. Eight glucosinolate-breakdown products were identified and quantified in B. napus roots by gas chromatography-mass spectrometry. Two (3-phenylpropanenitrile and 2-phenylethyl isothiocyanate [2-PEITC]) were identified in the B. napus rhizosphere. Among glucosinolate-breakdown products, P. ramosa germination was strongly and specifically triggered by isothiocyanates, indicating that 2-PEITC, in particular, plays a key role in the B. napus-P. ramosa interaction. Known strigolactones were not detected by ultraperformance liquid chromatography-tandem mass spectrometry, and seed of Phelipanche and Orobanche spp. that respond to strigolactones but not to isothiocyanates did not germinate in the rhizosphere of B. napus. Furthermore, both wild-type and strigolactone biosynthesis mutants of Arabidopsis thaliana Atccd7 and Atccd8 induced similar levels of P. ramosa seed germination, suggesting that compounds other than strigolactone function as germination stimulants for P. ramosa in other Brassicaceae spp. Our results open perspectives on the high adaptation potential of root-parasitic plants under host-driven selection pressures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Phelipanche ramosa is a major parasitic weed of Brassica napus. The first step in a host-parasitic plant interaction is stimulation of parasite seed germination by compounds released from host roots. However, germination stimulants produced by B. napus have not been identified yet. In this study, we characterized the germination stimulants that accumulate in B. napus roots and are released into the rhizosphere. Eight glucosinolate-breakdown products were identified and quantified in B. napus roots by gas chromatography-mass spectrometry. Two (3-phenylpropanenitrile and 2-phenylethyl isothiocyanate [2-PEITC]) were identified in the B. napus rhizosphere. Among glucosinolate-breakdown products, P. ramosa germination was strongly and specifically triggered by isothiocyanates, indicating that 2-PEITC, in particular, plays a key role in the B. napus-P. ramosa interaction. Known strigolactones were not detected by ultraperformance liquid chromatography-tandem mass spectrometry, and seed of Phelipanche and Orobanche spp. that respond to strigolactones but not to isothiocyanates did not germinate in the rhizosphere of B. napus. Furthermore, both wild-type and strigolactone biosynthesis mutants of Arabidopsis thaliana Atccd7 and Atccd8 induced similar levels of P. ramosa seed germination, suggesting that compounds other than strigolactone function as germination stimulants for P. ramosa in other Brassicaceae spp. Our results open perspectives on the high adaptation potential of root-parasitic plants under host-driven selection pressures.
Péron, Thomas; Véronési, Christophe; Mortreau, Eric; Pouvreau, Jean-Bernard; Thoiron, Séverine; Leduc, Nathalie; Delavault, Philippe; Simier, Philippe
Role of the sucrose synthase encoding PrSus1 gene in the development of the parasitic plant Phelipanche ramosa L. (Pomel) Article de journal
Dans: Mol Plant Microbe Interact, vol. 25, no. 3, p. 402–411, 2012, ISSN: 0894-0282.
@article{pmid22088196,
title = {Role of the sucrose synthase encoding PrSus1 gene in the development of the parasitic plant Phelipanche ramosa L. (Pomel)},
author = {Thomas Péron and Christophe Véronési and Eric Mortreau and Jean-Bernard Pouvreau and Séverine Thoiron and Nathalie Leduc and Philippe Delavault and Philippe Simier},
doi = {10.1094/MPMI-10-11-0260},
issn = {0894-0282},
year = {2012},
date = {2012-03-01},
urldate = {2012-03-01},
journal = {Mol Plant Microbe Interact},
volume = {25},
number = {3},
pages = {402--411},
abstract = {Phelipanche ramosa L. (Pomel) is a major root-parasitic weed attacking many important crops. Success in controlling this parasite is rare and a better understanding of its unique biology is needed to develop new specific control strategies. In the present study, quantitative polymerase chain reaction experiments showed that sucrose synthase encoding PrSus1 transcripts accumulate at their highest level once the parasite is connected to the host (tomato) vascular system, mainly in the parasite tubercles, which bear numerous adventitious roots. In situ hybridization experiments revealed strong PrSus1 expression in both shoot and root apices, especially in shoot apical meristems and in the vascular tissues of scale leaves and stems, and in the apical meristems and developing xylem in roots. In addition, immunolocalization experiments showed that a sucrose synthase protein co-localized with cell-wall thickening in xylem elements. These findings highlight the role of PrSus1 in the utilization of host-derived sucrose in meristematic areas and in cellulose biosynthesis in differentiating vascular elements. We also demonstrate that PrSus1 is downregulated in response to 2,3,5-triiodobenzoic acid-induced inhibition of polar auxin transport in the host stem, suggesting that PrSus1 activity in xylem maturation is controlled by host-derived auxin.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Phelipanche ramosa L. (Pomel) is a major root-parasitic weed attacking many important crops. Success in controlling this parasite is rare and a better understanding of its unique biology is needed to develop new specific control strategies. In the present study, quantitative polymerase chain reaction experiments showed that sucrose synthase encoding PrSus1 transcripts accumulate at their highest level once the parasite is connected to the host (tomato) vascular system, mainly in the parasite tubercles, which bear numerous adventitious roots. In situ hybridization experiments revealed strong PrSus1 expression in both shoot and root apices, especially in shoot apical meristems and in the vascular tissues of scale leaves and stems, and in the apical meristems and developing xylem in roots. In addition, immunolocalization experiments showed that a sucrose synthase protein co-localized with cell-wall thickening in xylem elements. These findings highlight the role of PrSus1 in the utilization of host-derived sucrose in meristematic areas and in cellulose biosynthesis in differentiating vascular elements. We also demonstrate that PrSus1 is downregulated in response to 2,3,5-triiodobenzoic acid-induced inhibition of polar auxin transport in the host stem, suggesting that PrSus1 activity in xylem maturation is controlled by host-derived auxin.
2011
Draie, Rida; Péron, Thomas; Pouvreau, Jean-Bernard; Véronési, Christophe; Jégou, Sandrine; Delavault, Philippe; Thoiron, Séverine; Simier, Philippe
Invertases involved in the development of the parasitic plant Phelipanche ramosa: characterization of the dominant soluble acid isoform, PrSAI1 Article de journal
Dans: Mol Plant Pathol, vol. 12, no. 7, p. 638–652, 2011, ISSN: 1364-3703.
@article{pmid21726369,
title = {Invertases involved in the development of the parasitic plant Phelipanche ramosa: characterization of the dominant soluble acid isoform, PrSAI1},
author = {Rida Draie and Thomas Péron and Jean-Bernard Pouvreau and Christophe Véronési and Sandrine Jégou and Philippe Delavault and Séverine Thoiron and Philippe Simier},
doi = {10.1111/j.1364-3703.2010.00702.x},
issn = {1364-3703},
year = {2011},
date = {2011-09-01},
urldate = {2011-09-01},
journal = {Mol Plant Pathol},
volume = {12},
number = {7},
pages = {638--652},
abstract = {Phelipanche ramosa L. parasitizes major crops, acting as a competitive sink for host photoassimilates, especially sucrose. An understanding of the mechanisms of sucrose utilization in parasites is an important step in the development of new control methods. Therefore, in this study, we characterized the invertase gene family in P. ramosa and analysed its involvement in plant development. Invertase-encoded cDNAs were isolated using degenerate primers corresponding to highly conserved regions of invertases. In addition to enzyme assays, gene expression was analysed using real-time quantitative reverse transcriptase-polymerase chain reaction during overall plant development. The dominant isoform was purified and sequenced using electrospray ionization-liquid chromatography-tandem mass spectrometry (ESI-LC-MS/MS). Five invertase-encoded cDNAs were thus characterized, including PrSai1 which encodes a soluble acid invertase (SAI). Of the five invertases, PrSai1 transcripts and SAI activity were dominant in growing organs. The most active invertase corresponded to the PrSai1 gene product. The purified PrSAI1 displayed low pI and optimal pH values, specificity for β-fructofuranosides and inhibition by metallic ions and competitive inhibition by fructose. PrSAI1 is a typical vacuolar SAI that is actively involved in growth following both germination and attachment to host roots. In addition, germinated seeds displayed enhanced cell wall invertase activity (PrCWI) in comparison with preconditioned seeds, suggesting the contribution of this activity in the sink strength of infected roots during the subsequent step of root penetration. Our results show that PrSAI1 and, possibly, PrCWI constitute good targets for the development of new transgenic resistance in host plants using proteinaceous inhibitors or silencing strategies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Phelipanche ramosa L. parasitizes major crops, acting as a competitive sink for host photoassimilates, especially sucrose. An understanding of the mechanisms of sucrose utilization in parasites is an important step in the development of new control methods. Therefore, in this study, we characterized the invertase gene family in P. ramosa and analysed its involvement in plant development. Invertase-encoded cDNAs were isolated using degenerate primers corresponding to highly conserved regions of invertases. In addition to enzyme assays, gene expression was analysed using real-time quantitative reverse transcriptase-polymerase chain reaction during overall plant development. The dominant isoform was purified and sequenced using electrospray ionization-liquid chromatography-tandem mass spectrometry (ESI-LC-MS/MS). Five invertase-encoded cDNAs were thus characterized, including PrSai1 which encodes a soluble acid invertase (SAI). Of the five invertases, PrSai1 transcripts and SAI activity were dominant in growing organs. The most active invertase corresponded to the PrSai1 gene product. The purified PrSAI1 displayed low pI and optimal pH values, specificity for β-fructofuranosides and inhibition by metallic ions and competitive inhibition by fructose. PrSAI1 is a typical vacuolar SAI that is actively involved in growth following both germination and attachment to host roots. In addition, germinated seeds displayed enhanced cell wall invertase activity (PrCWI) in comparison with preconditioned seeds, suggesting the contribution of this activity in the sink strength of infected roots during the subsequent step of root penetration. Our results show that PrSAI1 and, possibly, PrCWI constitute good targets for the development of new transgenic resistance in host plants using proteinaceous inhibitors or silencing strategies.
2009
de Zélicourt, Axel; Montiel, Grégory; Pouvreau, Jean-Bernard; Thoiron, Séverine; Delgrange, Sabine; Simier, Philippe; Delavault, Philippe
Susceptibility of Phelipanche and Orobanche species to AAL-toxin Article de journal
Dans: Planta, vol. 230, no. 5, p. 1047–1055, 2009, ISSN: 1432-2048.
@article{pmid19705146,
title = {Susceptibility of Phelipanche and Orobanche species to AAL-toxin},
author = {Axel de Zélicourt and Grégory Montiel and Jean-Bernard Pouvreau and Séverine Thoiron and Sabine Delgrange and Philippe Simier and Philippe Delavault},
doi = {10.1007/s00425-009-1008-1},
issn = {1432-2048},
year = {2009},
date = {2009-10-01},
urldate = {2009-10-01},
journal = {Planta},
volume = {230},
number = {5},
pages = {1047--1055},
abstract = {Fusarium and Alternaria spp. are phytopathogenic fungi which are known to be virulent on broomrapes and to produce sphinganine-analog mycotoxins (SAMs). AAL-toxin is a SAM produced by Alternaria alternata which causes the inhibition of sphinganine N-acyltransferase, a key enzyme in sphingolipid biosynthesis, leading to accumulation of sphingoid bases. These long chain bases (LCBs) are determinant in the occurrence of programmed cell death (PCD) in susceptible plants. We showed that broomrapes are sensitive to AAL-toxin, which is not common plant behavior, and that AAL-toxin triggers cell death at the apex of the radicle as well as LCB accumulation and DNA laddering. We also demonstrated that three Lag1 homologs, encoding components of sphinganine N-acyltransferase in yeast, are present in the Orobanche cumana genome and two of them are mutated leading to an enhanced susceptibility to AAL-toxin. We therefore propose a model for the molecular mechanism governing broomrape susceptibility to the fungus Alternaria alternata.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Fusarium and Alternaria spp. are phytopathogenic fungi which are known to be virulent on broomrapes and to produce sphinganine-analog mycotoxins (SAMs). AAL-toxin is a SAM produced by Alternaria alternata which causes the inhibition of sphinganine N-acyltransferase, a key enzyme in sphingolipid biosynthesis, leading to accumulation of sphingoid bases. These long chain bases (LCBs) are determinant in the occurrence of programmed cell death (PCD) in susceptible plants. We showed that broomrapes are sensitive to AAL-toxin, which is not common plant behavior, and that AAL-toxin triggers cell death at the apex of the radicle as well as LCB accumulation and DNA laddering. We also demonstrated that three Lag1 homologs, encoding components of sphinganine N-acyltransferase in yeast, are present in the Orobanche cumana genome and two of them are mutated leading to an enhanced susceptibility to AAL-toxin. We therefore propose a model for the molecular mechanism governing broomrape susceptibility to the fungus Alternaria alternata.