@article{Martinez2024,

title = {Comparative Analysis of Two Neighboring Conducive and Suppressive Soils Toward Plant Parasitism Caused by \textit{Phelipanche ramosa} on \textit{Brassica napus}},

author = {Lisa Martinez and Jean-Bernard Pouvreau and Christophe Jestin and Gregory Montiel and Antoine Gravot and Solenne Berardocco and Nathalie Marnet and Alain Bouchereau and Erwan Delage and Philippe Simier and Lucie Poulin},

doi = {10.1094/pbiomes-12-23-0140-r},

issn = {2471-2906},

year  = {2024},

date = {2024-11-00},

urldate = {2024-11-00},

journal = {Phytobiomes Journal},

volume = {8},

number = {4},

pages = {425--445},

publisher = {Scientific Societies},

abstract = {<jats:p> In Western France, rapeseed ( Brassica napus) cultivation faces substantial yield losses due to the root holoparasitic plant Phelipanche ramosa. However, recent observations have shown a reduction in parasitism within previously heavily infested fields. This study investigates two neighboring rapeseed soils with distinct levels of parasitic infestation, considered suppressive and conducive. Using a cocultivation system of Brassica napus and P. ramosa, we comprehensively examined rhizosphere exudates, parasitic plant attachment, and rhizosphere soil microbiota. Our findings revealed that the suppressive soil effectively reduced parasitism by impeding broomrape attachment and development, as well as inducing necrosis of tubercles. This suppressive effect was specific to postattachment stages, leaving germination and haustoriogenesis preattachment stages unaffected. Analysis of microbial structures suggested that the suppression of parasitism is predominantly of fungal rather than bacterial origin. Correlation network analyses identified three groups of amplicon sequence variants (ASVs) associated with suppression. Notably, seven ASVs were inversely correlated with parasitic attachments, and only one ASV, identified as Berkeleyomyces, a necrotrophic fungus responsible for black root rot, was positively correlated with necrosis and was more abundant in the suppressive soil. This study demonstrates the contrasting parasitic plant development on two physicochemically similar soils, highlighting the central role of fungal dynamics in the rhizosphere. These results provide valuable insights into the mechanisms underlying soil-mediated suppression of P. ramosa, offering potential strategies for mitigating the impact of this root holoparasite on rapeseed yields in the region. </jats:p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Veronesi2024b,

title = {(±)‐Catechins inhibit prehaustorium formation in the parasitic weed <scp>\textit{Phelipanche ramosa}</scp> and reduce tomato infestation},

author = {Christophe Veronesi and Estelle Billard and Philippe Delavault and Philippe Simier},

doi = {10.1002/ps.8472},

issn = {1526-4998},

year  = {2024},

date = {2024-10-05},

urldate = {2024-10-05},

journal = {Pest Management Science},

publisher = {Wiley},

abstract = {<jats:title>Abstract</jats:title><jats:sec><jats:title>BACKGROUND</jats:title><jats:p><jats:italic>Phelipanche ramosa</jats:italic> L. (Pomel) is a noxious parasitic weed in field and vegetable crops in Mediterranean countries. Control of this pest is complex and far from being achieved, and new environmentally‐friendly strategies are being sought. The present study evaluates the possibility of using (±)‐catechins as a natural herbicide against broomrapes.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>The results show that (±)‐catechins have no effect on GR24‐induced germination over a wide concentration range (10<jats:sup>−4</jats:sup> to 10<jats:sup>−10</jats:sup> <jats:sc>m</jats:sc>), nor on radicle elongation after germination, but strongly inhibit, at 10<jats:sup>−4</jats:sup> and 10<jats:sup>−5</jats:sup> <jats:sc>m</jats:sc>, prehaustorium formation in response to the haustorium‐inducing factor, <jats:italic>cis/trans</jats:italic>‐zeatin. Accordingly, pot experiments involving the supplies of 10<jats:sup>−5</jats:sup> <jats:sc>m</jats:sc> of (±)‐catechins to tomato plants infested or not with <jats:italic>P</jats:italic>. <jats:italic>ramosa</jats:italic> demonstrate that (±)‐catechins do not influence growth of non‐parasitized tomato plants and prevent heavy infestation by strongly reducing parasite attachments and inducing parasite necrosis once they are attached.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSION</jats:title><jats:p>This study points the potential use of (±)‐catechins for parasitic weed control. It raises also the question of the mechanisms involved in the inhibition of prehaustorium formation and the necrosis of parasite attachments in response to (±)‐catechins application. © 2024 The Author(s). <jats:italic>Pest Management Science</jats:italic> published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.</jats:p></jats:sec>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Grandjean2024d,

title = {Pectin Remodeling and Involvement of AtPME3 in the Parasitic Plant–Plant Interaction, Phelipanche ramosa–Arabidospis thaliana},

author = {Cyril Grandjean and Christophe Veronesi and Christine Rusterucci and Charlotte Gautier and Yannis Maillot and Maïté Leschevin and Françoise Fournet and Jan Drouaud and Paulo Marcelo and Luciane Zabijak and Philippe Delavault and Philippe Simier and Sophie Bouton and Karine Pageau},

doi = {10.3390/plants13152168},

issn = {2223-7747},

year  = {2024},

date = {2024-08-00},

urldate = {2024-08-00},

journal = {Plants},

volume = {13},

number = {15},

publisher = {MDPI AG},

abstract = {<jats:p>Phelipanche ramosa is a root parasitic plant fully dependent on host plants for nutrition and development. Upon germination, the parasitic seedling develops inside the infected roots a specific organ, the haustorium, thanks to the cell wall-degrading enzymes of haustorial intrusive cells, and induces modifications in the host’s cell walls. The model plant Arabidopsis thaliana is susceptible to P. ramosa; thus, mutants in cell wall metabolism, particularly those involved in pectin remodeling, like Atpme3-1, are of interest in studying the involvement of cell wall-degrading enzymes in the establishment of plant–plant interactions. Host–parasite co-cultures in mini-rhizotron systems revealed that parasite attachments are twice as numerous and tubercle growth is quicker on Atpme3-1 roots than on WT roots. Compared to WT, the increased susceptibility in AtPME3-1 is associated with reduced PME activity in the roots and a lower degree of pectin methylesterification at the host–parasite interface, as detected immunohistochemically in infected roots. In addition, both WT and Atpme3-1 roots responded to infestation by modulating the expression of PAE- and PME-encoding genes, as well as related global enzyme activities in the roots before and after parasite attachment. However, these modulations differed between WT and Atpme3-1, which may contribute to different pectin remodeling in the roots and contrasting susceptibility to P. ramosa. With this integrative study, we aim to define a model of cell wall response to this specific biotic stress and indicate, for the first time, the role of PME3 in this parasitic plant–plant interaction.</jats:p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@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},

url = {https://nantes-universite.hal.science/hal-04370677v1 },

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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}