Guillaume BRUN
Maître de conférences Université
section 66
| Équipe : |
Thèmes de recherche
Étude du développement germinatif et post-germinatif des plantes parasites de la famille des Orobanchacées :
- Caractérisation de la diversité des signaux rhizosphériques régissant le conditionnement, la germination, et/ou l’haustoriogénèse
- Identification des voies de signalisation moléculaires impliquées dans la réponse à ces signaux rhizosphériques
- Modélisation des scénarios éco-évolutifs conduisant à la transition vers l’hétérotrophie chez les plantes parasites
Approches méthodologiques : analyses « omiques », biologie moléculaire, biochimie des protéines, tests d’activités biologiques, validation fonctionnelle
Encadrements de thèse :
- Candice Chesnais – 2025-2028
Enseignements : Biologie cellulaire, biologie végétale, biotechnologies, génétique formelle, mécanismes de l’évolution, systématique végétale
Projets
Parcours universitaire
- 2025 – Maître de Conférences. Nantes Université.
- 2019-2025 – Post-doctorat. Université de Münster (2019-2020 et 2024-2025) et Université Humboldt de Berlin (2020-2024). « Genetic reconfigurations en route to a holoparasitic lifestyle in plants ».
- 2017-2018 – ATER. Université de Nantes.
- 2017 – Doctorat en sciences du végétal. Université de Nantes. « Mécanismes moléculaires impliqués dans la germination des plantes en réponse aux strigolactones ».
- 2014 – Master Biologie Végétale Intégrative : Gène, Plante, Agrosystème (parcours Génétique et Génomique). Université de Nantes.
- 2012 – Licence Biologie-Biochimie (parcours Physiologie Cellulaire et Moléculaire Végétales). Université de Nantes.
Publications
1 publication
Brun, Guillaume; Billard, Estelle; Hýlová, Adéla; Montiel, Grégory; Plačková, Lenka; Doležal, Karel; Puech-Pagès, Virginie; Simier, Philippe; Wicke, Susann; Spíchal, Lukáš; Delavault, Philippe; Pouvreau, Jean-Bernard
Divergent control of seed germination by cytokinins in weedy broomrapes and witchweeds Article de journal
Dans: Plant and Cell Physiology, vol. 67, no. 4, p. 469-478, 2026, ISSN: 1471-9053.
@article{10.1093/pcp/pcaf032,
title = {Divergent control of seed germination by cytokinins in weedy broomrapes and witchweeds},
author = {Guillaume Brun and Estelle Billard and Adéla Hýlová and Grégory Montiel and Lenka Plačková and Karel Doležal and Virginie Puech-Pagès and Philippe Simier and Susann Wicke and Lukáš Spíchal and Philippe Delavault and Jean-Bernard Pouvreau},
url = {https://doi.org/10.1093/pcp/pcaf032},
doi = {10.1093/pcp/pcaf032},
issn = {1471-9053},
year = {2026},
date = {2026-01-01},
urldate = {2026-01-01},
journal = {Plant and Cell Physiology},
volume = {67},
number = {4},
pages = {469-478},
abstract = {Broomrapes (Phelipanche and Orobanche spp.) and witchweeds (Striga spp.) are parasitic weeds that are increasingly threatening crops worldwide. Seeds of these species rely on host-derived signals such as strigolactones (SL) to germinate. While cytokinins (CKs) were also reported as germination inducers of witchweeds, their role during the germination of broomrapes remains unexplored. Our study shows that some but not all CKs stimulate Striga hermonthica germination independently of SL and that high concentrations of bioactive CKs trigger Striga seedlings to differentiate into fully extruded embryo-like structures. In contrast, CK-free bases but not ribosylated or glycosylated conjugates are extremely potent inhibitors of broomrapes germination. Germination inhibition upon the CK signaling inhibitor PI-55 and inhibitor of CK degradation INCYDE suggest that the CK perception and degradation machinery is conserved in parasitic weeds. In Phelipanche ramosa, gene expression analyses combined with targeted quantification of CK contents revealed that SL first induce an increase in abscisic acid catabolism, then a modification of the CK endogenous pool in favor of inactive conjugates. Overall, this study provides valuable insights into the hormonal interplay governing seed germination in broomrapes and witchweeds, paving the way for future studies aimed at developing novel strategies for parasitic weed control.},
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pubstate = {published},
tppubtype = {article}
}
Broomrapes (Phelipanche and Orobanche spp.) and witchweeds (Striga spp.) are parasitic weeds that are increasingly threatening crops worldwide. Seeds of these species rely on host-derived signals such as strigolactones (SL) to germinate. While cytokinins (CKs) were also reported as germination inducers of witchweeds, their role during the germination of broomrapes remains unexplored. Our study shows that some but not all CKs stimulate Striga hermonthica germination independently of SL and that high concentrations of bioactive CKs trigger Striga seedlings to differentiate into fully extruded embryo-like structures. In contrast, CK-free bases but not ribosylated or glycosylated conjugates are extremely potent inhibitors of broomrapes germination. Germination inhibition upon the CK signaling inhibitor PI-55 and inhibitor of CK degradation INCYDE suggest that the CK perception and degradation machinery is conserved in parasitic weeds. In Phelipanche ramosa, gene expression analyses combined with targeted quantification of CK contents revealed that SL first induce an increase in abscisic acid catabolism, then a modification of the CK endogenous pool in favor of inactive conjugates. Overall, this study provides valuable insights into the hormonal interplay governing seed germination in broomrapes and witchweeds, paving the way for future studies aimed at developing novel strategies for parasitic weed control.
3 publications
Brun, Guillaume; Schindler, Florian; Bouyrakhen, Amal; Dayou, Olivier; Weckwerth, Wolfram; Wicke, Susann
Seed metabolites headstart haustoriogenesis and potentiate aggressiveness of parasitic weeds Article de journal
Dans: Science Advances, vol. 11, no. 50, p. eaea1449, 2025.
@article{<LineBreak>doi:10.1126/sciadv.aea1449,
title = {Seed metabolites headstart haustoriogenesis and potentiate aggressiveness of parasitic weeds},
author = {Guillaume Brun and Florian Schindler and Amal Bouyrakhen and Olivier Dayou and Wolfram Weckwerth and Susann Wicke},
url = {https://www.science.org/doi/abs/10.1126/sciadv.aea1449},
doi = {10.1126/sciadv.aea1449},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {Science Advances},
volume = {11},
number = {50},
pages = {eaea1449},
abstract = {Agricultural pests like parasitic broomrapes and witchweeds differentiate a haustorium that penetrates another plant’s root for nutrient acquisition. We demonstrate that during imbibition and postgermination growth, parasite seeds produce bioactive haustorium-inducing factors (HIFs) to differentiate their haustorium independently of host signals, thereby challenging the paradigm of host-induced haustoriogenesis. Metabolome profiling of this seed “leachate” unraveled synergistic haustoriogenic potential of possibly canonical HIF classes at hormonal concentrations, including cytokinins, sterols, quinones, and flavonoids. We suggest that early lignin neosynthesis serves as a template for HIF production through postgerminative oxidative stress and microbial ligninolytic activity. Seedlings with host-independently formed haustoria attached faster to and produced more tubercles on compatible hosts. Thus, haustorium differentiation via a coopted autonomous developmental program potentiates the eco-evolutionary success of obligate parasitic plants. Parasitic weeds self-activate their feeding organs, challenging the paradigm of host-triggered parasitism.},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Agricultural pests like parasitic broomrapes and witchweeds differentiate a haustorium that penetrates another plant’s root for nutrient acquisition. We demonstrate that during imbibition and postgermination growth, parasite seeds produce bioactive haustorium-inducing factors (HIFs) to differentiate their haustorium independently of host signals, thereby challenging the paradigm of host-induced haustoriogenesis. Metabolome profiling of this seed “leachate” unraveled synergistic haustoriogenic potential of possibly canonical HIF classes at hormonal concentrations, including cytokinins, sterols, quinones, and flavonoids. We suggest that early lignin neosynthesis serves as a template for HIF production through postgerminative oxidative stress and microbial ligninolytic activity. Seedlings with host-independently formed haustoria attached faster to and produced more tubercles on compatible hosts. Thus, haustorium differentiation via a coopted autonomous developmental program potentiates the eco-evolutionary success of obligate parasitic plants. Parasitic weeds self-activate their feeding organs, challenging the paradigm of host-triggered parasitism.
Brun, Guillaume; Leman, Julia K. H.; Wicke, Susann
Comparative gene expression analysis of differentiated terminal and lateral haustoria of the obligate root parasitic plant Phelipanche ramosa (Orobanchaceae) Article de journal
Dans: PLANTS, PEOPLE, PLANET, vol. 7, no. 2, p. 360-366, 2025.
@article{https://doi.org/10.1002/ppp3.10464,
title = {Comparative gene expression analysis of differentiated terminal and lateral haustoria of the obligate root parasitic plant Phelipanche ramosa (Orobanchaceae)},
author = {Guillaume Brun and Julia K. H. Leman and Susann Wicke},
url = {https://nph.onlinelibrary.wiley.com/doi/abs/10.1002/ppp3.10464},
doi = {https://doi.org/10.1002/ppp3.10464},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {PLANTS, PEOPLE, PLANET},
volume = {7},
number = {2},
pages = {360-366},
abstract = {Societal Impact Statements The parasitic weed Phelipanche ramosa thrives on a broad spectrum of cash crops over the Northern Hemisphere. Unfortunately, current management practices are inefficient in controlling its devastating impacts and spread. Here, valuable insights are provided on an understudied aspect of its biology, the formation of a feeding organ network on the rudimentary roots of the parasite tubercle, which will help refine our general knowledge of how parasitic plants develop on their hosts. This research sets the path for a thorough understanding of the biology of parasitic plants, which in the long run will help design integrated control methods.},
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Societal Impact Statements The parasitic weed Phelipanche ramosa thrives on a broad spectrum of cash crops over the Northern Hemisphere. Unfortunately, current management practices are inefficient in controlling its devastating impacts and spread. Here, valuable insights are provided on an understudied aspect of its biology, the formation of a feeding organ network on the rudimentary roots of the parasite tubercle, which will help refine our general knowledge of how parasitic plants develop on their hosts. This research sets the path for a thorough understanding of the biology of parasitic plants, which in the long run will help design integrated control methods.
Brun, Guillaume; Pöhl, Jonathan; Wicke, Susann
Aging seeds of weedy broomrapes and witchweeds lose sensitivity to strigolactones as DNA demethylates Article de journal
Dans: PLANTS, PEOPLE, PLANET, vol. 7, no. 2, p. 476-485, 2025.
@article{https://doi.org/10.1002/ppp3.10465,
title = {Aging seeds of weedy broomrapes and witchweeds lose sensitivity to strigolactones as DNA demethylates},
author = {Guillaume Brun and Jonathan Pöhl and Susann Wicke},
url = {https://nph.onlinelibrary.wiley.com/doi/abs/10.1002/ppp3.10465},
doi = {https://doi.org/10.1002/ppp3.10465},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {PLANTS, PEOPLE, PLANET},
volume = {7},
number = {2},
pages = {476-485},
abstract = {Societal Impact Statement Broomrapes and witchweeds have devastating effects on crops in parts of Europe, Africa, and Asia. The key to their success is the production of copious, long-lived seeds, which germinate in response to the perception of chemicals released by their hosts' roots. Here, it is proposed that the success of a parasite population will decrease as its seed bank ages due to the gradual decrease in sensitivity to the host signals in correlation with alterations of the seeds' epigenetic landscape, which is the set of non-hard-coded genetic information that influences gene function. This research provides important information toward a better understanding of parasite seed bank dynamics, which must be accounted for in future control strategies. Summary Broomrapes (Phelipanche and Orobanche spp.) and witchweeds (Striga and Alectra spp.) are obligate root parasitic weeds responsible for major crop yield losses worldwide. Their success in agricultural landscapes is attributable to their ability to produce thousands of long-lived minute seeds that coordinate their germination with the presence of nearby hosts by perceiving host-derived strigolactones. The processes underlying the alleged decade(s)-long persistence in the field are understudied. Here, we used an accelerated seed aging method coupled with germination bioassays and an enzyme-linked immunosorbent assay (ELISA), which allowed studying seed aging in Orobanchaceae in a comparative manner. We show that the losses of seed viability and germinability associated with seed aging are accompanied by a decrease in both strigolactone sensitivity and global DNA methylation. Our results also suggest that seeds of broomrapes are longer-lived than those of witchweeds. Overall, this emphasizes the need for further research into how epigenetic mechanisms contribute to alterations in seed viability in parasitic weeds and how seed aging influences seed responses to their environment.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Societal Impact Statement Broomrapes and witchweeds have devastating effects on crops in parts of Europe, Africa, and Asia. The key to their success is the production of copious, long-lived seeds, which germinate in response to the perception of chemicals released by their hosts' roots. Here, it is proposed that the success of a parasite population will decrease as its seed bank ages due to the gradual decrease in sensitivity to the host signals in correlation with alterations of the seeds' epigenetic landscape, which is the set of non-hard-coded genetic information that influences gene function. This research provides important information toward a better understanding of parasite seed bank dynamics, which must be accounted for in future control strategies. Summary Broomrapes (Phelipanche and Orobanche spp.) and witchweeds (Striga and Alectra spp.) are obligate root parasitic weeds responsible for major crop yield losses worldwide. Their success in agricultural landscapes is attributable to their ability to produce thousands of long-lived minute seeds that coordinate their germination with the presence of nearby hosts by perceiving host-derived strigolactones. The processes underlying the alleged decade(s)-long persistence in the field are understudied. Here, we used an accelerated seed aging method coupled with germination bioassays and an enzyme-linked immunosorbent assay (ELISA), which allowed studying seed aging in Orobanchaceae in a comparative manner. We show that the losses of seed viability and germinability associated with seed aging are accompanied by a decrease in both strigolactone sensitivity and global DNA methylation. Our results also suggest that seeds of broomrapes are longer-lived than those of witchweeds. Overall, this emphasizes the need for further research into how epigenetic mechanisms contribute to alterations in seed viability in parasitic weeds and how seed aging influences seed responses to their environment.
1 publication
Dayou, Olivier; Brun, Guillaume; Gennat, Charline; Wicke, Susann
Acclimation kinetics of the holoparasitic weed Phelipanche ramosa (Orobanchaceae) during excessive light and heat conditions Article de journal
Dans: bioRxiv, 2023.
@article{Dayou2023.11.30.569309,
title = {Acclimation kinetics of the holoparasitic weed Phelipanche ramosa (Orobanchaceae) during excessive light and heat conditions},
author = {Olivier Dayou and Guillaume Brun and Charline Gennat and Susann Wicke},
url = {https://www.biorxiv.org/content/early/2023/12/01/2023.11.30.569309},
doi = {10.1101/2023.11.30.569309},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
journal = {bioRxiv},
publisher = {Cold Spring Harbor Laboratory},
abstract = {Holoparasitic plants, such as broomrape, have abandoned a photosynthesis, relying entirely on the resources of host plants. This departure from an autotrophic lifestyle necessitates significant genetic and metabolic adaptations, offering a unique model system to elucidate responses independent of canonical plastid functions in green plants. In this study, we examined the acclimation kinetics of the holoparasitic weed Phelipanche ramosa (broomrape) under unfavorable temperature and excessive light conditions through a comprehensive time-course analysis of RNA sequence data and physiological monitoring. Our work unveils that suboptimal abiotic conditions induce transcriptional changes in the parasitic plant, involving coordinated expression of nuclear and plastid-encoded genes. Notably, magnesium transporters, critical for heat-induced chlorophyll conversion, were enriched among heat-repressed genes. Additionally, multiple copies of chloroplast-targeted DnaJ proteins, responsible for maintaining CO2 assimilation capacity in non-parasitic plants, were identified. Comparative expression analysis with the parasite’s host plants, tomato and Arabidopsis, revealed distinct patterns for certain plastid genes in Phelipanche. Furthermore, an elevation in reactive oxygen species (ROS) in the parasite coincided with the upregulation of numerous heat shock protein (HSP) genes, including HSP21, which associates with thylakoid membranes in photosynthetic plants; noteworthily, thylakoids are absent from Phelipanche’s plastids. Collectively, our findings suggest that plastids of the nonphotosynthetic model plant retains their ancestral role as environmental sensors. This research opens new avenues for functional-genetic research into the nuanced roles of plastids in the lifecycles of parasitic plants.Competing Interest StatementThe authors have declared no competing interest.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Holoparasitic plants, such as broomrape, have abandoned a photosynthesis, relying entirely on the resources of host plants. This departure from an autotrophic lifestyle necessitates significant genetic and metabolic adaptations, offering a unique model system to elucidate responses independent of canonical plastid functions in green plants. In this study, we examined the acclimation kinetics of the holoparasitic weed Phelipanche ramosa (broomrape) under unfavorable temperature and excessive light conditions through a comprehensive time-course analysis of RNA sequence data and physiological monitoring. Our work unveils that suboptimal abiotic conditions induce transcriptional changes in the parasitic plant, involving coordinated expression of nuclear and plastid-encoded genes. Notably, magnesium transporters, critical for heat-induced chlorophyll conversion, were enriched among heat-repressed genes. Additionally, multiple copies of chloroplast-targeted DnaJ proteins, responsible for maintaining CO2 assimilation capacity in non-parasitic plants, were identified. Comparative expression analysis with the parasite’s host plants, tomato and Arabidopsis, revealed distinct patterns for certain plastid genes in Phelipanche. Furthermore, an elevation in reactive oxygen species (ROS) in the parasite coincided with the upregulation of numerous heat shock protein (HSP) genes, including HSP21, which associates with thylakoid membranes in photosynthetic plants; noteworthily, thylakoids are absent from Phelipanche’s plastids. Collectively, our findings suggest that plastids of the nonphotosynthetic model plant retains their ancestral role as environmental sensors. This research opens new avenues for functional-genetic research into the nuanced roles of plastids in the lifecycles of parasitic plants.Competing Interest StatementThe authors have declared no competing interest.
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.},
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pubstate = {published},
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}
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.},
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pubstate = {published},
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One-sentence summary Recent advances provide insight into the molecular mechanisms underlying host-dependent seed germination and haustorium formation in parasitic plants.
1 publication
Brun, Guillaume
At the crossroads of strigolactones and abscisic acid pathways: A role for miR156 Article de journal
Dans: Plant, Cell & Environment, vol. 43, no. 7, p. 1609-1612, 2020.
@article{https://doi.org/10.1111/pce.13787,
title = {At the crossroads of strigolactones and abscisic acid pathways: A role for miR156},
author = {Guillaume Brun},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/pce.13787},
doi = {https://doi.org/10.1111/pce.13787},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Plant, Cell & Environment},
volume = {43},
number = {7},
pages = {1609-1612},
abstract = {This article comments on: A novel strigolactone-miR156 module controls stomatal behaviour during drought recovery},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This article comments on: A novel strigolactone-miR156 module controls stomatal behaviour during drought recovery
1 publication
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.},
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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.
1 publication
Brun, Guillaume; Braem, Lukas; Thoiron, Séverine; Gevaert, Kris; Goormachtig, Sophie; Delavault, Philippe
Seed germination in parasitic plants: what insights can we expect from strigolactone research? Article de journal
Dans: J Exp Bot, vol. 69, no. 9, p. 2265-2280, 2018, ISSN: 0022-0957.
@article{RN5,
title = {Seed germination in parasitic plants: what insights can we expect from strigolactone research?},
author = {Guillaume Brun and Lukas Braem and Séverine Thoiron and Kris Gevaert and Sophie Goormachtig and Philippe Delavault},
url = {https://watermark.silverchair.com/erx472.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAt4wggLaBgkqhkiG9w0BBwagggLLMIICxwIBADCCAsAGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQM1yniRk8_noMBOyNMAgEQgIICkQSx0NkVWTLILIUWSlmnkftHgPP-m5t-cQPJknvKituLwilM0lvjYzZ8hS9XgfOcZXtWI5s8xbpatlB8cdpZP9UIDbsBGHsUHt7S7HlpuAZMTQ45haVuNqJvyuKge5jMk7hS88X3g81iv7EI3sBpzHd2YIKMfNhaf48kbTwwrzS4DRYGNAvL4WBc-raLQpiuWzkwcigfD-aABZkBD1-gFe8IEUnOb2RkmjlUr_liOJU7PFy_Cx4vIQEP2JYFSTWPLCUjkUom_5WQQc6OEtCE9DM41tXRLSckgbL81--d43m9Fej8gsZ4BfyxtqW2HQeS-iOmIDEWFFSwij_htBntsNJyL2q_vklyiqNPmXnr7aAG5USvV7SKNyBXBLiZMhcK4LNAPAEXOmSdSzYuMfXoO0kbljSM6ht_Z5lxwGuDDEByCqSieqyirwwsSP5G7zjEwBgLyWku3qPSVQlSht3Zw5syxIR8XT1sWmvYDcKEttmpmlsNbJCFK8vfRSi8KeAAbs1zSzg17FzgpZCOkqRY5GKdESZfeVuNdyzEA5rlbuLLEKwV2LRm2RAg8b2ygsderPTNrSDDfwLwbN5VRWZF7lyhSHemRqDOnYU59ezeS882026E4kS2LpG_zwSjma0HyCHEE2GNywtVrwKfa_0_gKE1Q-OQ8INzeshP-lrHHZqa8Q4bZLCQXLfyE1qlJnLTroDX4UIpRRhA1Ildrf_lGv2vFlPxs9DzFqjLPoqsmb5cBVdv819hiJTgqzR4v-Nm2sw1H5Vp2V8l6aPIab9ijg3ZIlpm-B6VUnUsjZA5gxKdSDHHZzIQluh9wxsUc6c_WYBWNA20_EOSP9ALg-sQsplZk3VAb1WhQh7antobYSAx_A},
doi = {10.1093/jxb/erx472},
issn = {0022-0957},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {J Exp Bot},
volume = {69},
number = {9},
pages = {2265-2280},
abstract = {Obligate root-parasitic plants belonging to the Orobanchaceae family are deadly pests for major crops all over the world. Because these heterotrophic plants severely damage their hosts even before emerging from the soil, there is an unequivocal need to design early and efficient methods for their control. The germination process of these species has probably undergone numerous selective pressure events in the course of evolution, in that the perception of host-derived molecules is a necessary condition for seeds to germinate. Although most of these molecules belong to the strigolactones, structurally different molecules have been identified. Since strigolactones are also classified as novel plant hormones that regulate several physiological processes other than germination, the use of autotrophic model plant species has allowed the identification of many actors involved in the strigolactone biosynthesis, perception, and signal transduction pathways. Nevertheless, many questions remain to be answered regarding the germination process of parasitic plants. For instance, how did parasitic plants evolve to germinate in response to a wide variety of molecules, while autotrophic plants do not? What particular features are associated with their lack of spontaneous germination? In this review, we attempt to illustrate to what extent conclusions from research into strigolactones could be applied to better understand the biology of parasitic plants.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Obligate root-parasitic plants belonging to the Orobanchaceae family are deadly pests for major crops all over the world. Because these heterotrophic plants severely damage their hosts even before emerging from the soil, there is an unequivocal need to design early and efficient methods for their control. The germination process of these species has probably undergone numerous selective pressure events in the course of evolution, in that the perception of host-derived molecules is a necessary condition for seeds to germinate. Although most of these molecules belong to the strigolactones, structurally different molecules have been identified. Since strigolactones are also classified as novel plant hormones that regulate several physiological processes other than germination, the use of autotrophic model plant species has allowed the identification of many actors involved in the strigolactone biosynthesis, perception, and signal transduction pathways. Nevertheless, many questions remain to be answered regarding the germination process of parasitic plants. For instance, how did parasitic plants evolve to germinate in response to a wide variety of molecules, while autotrophic plants do not? What particular features are associated with their lack of spontaneous germination? In this review, we attempt to illustrate to what extent conclusions from research into strigolactones could be applied to better understand the biology of parasitic plants.
1 publication
Delavault, Philippe; Montiel, Gregory; Brun, Guillaume; Pouvreau, Jean-Bernard; Thoiron, Séverine; Simier, Philippe
Chapter Three - Communication Between Host Plants and Parasitic Plants Book Section
Dans: Becard, Guillaume (Ed.): How Plants Communicate with their Biotic Environment, vol. 82, p. 55-82, Academic Press, 2017, ISSN: 0065-2296.
@incollection{DELAVAULT201755,
title = {Chapter Three - Communication Between Host Plants and Parasitic Plants},
author = {Philippe Delavault and Gregory Montiel and Guillaume Brun and Jean-Bernard Pouvreau and Séverine Thoiron and Philippe Simier},
editor = {Guillaume Becard},
url = {https://www.sciencedirect.com/science/article/pii/S0065229616301148},
doi = {https://doi.org/10.1016/bs.abr.2016.10.006},
issn = {0065-2296},
year = {2017},
date = {2017-01-01},
urldate = {2017-01-01},
booktitle = {How Plants Communicate with their Biotic Environment},
volume = {82},
pages = {55-82},
publisher = {Academic Press},
series = {Advances in Botanical Research},
abstract = {Parasitic plants are usually considered as botanical curiosities because of their shapes and colours. However, in some cases, they are proving to be terrible bioagressors in man-made ecosystems. Parasitic plants have indeed the capacity to connect intimately with other plants to exploit their resources (water, nutrients, growth regulators…) for their development. Thus, these plants are the result of an evolutionary transition from autotrophism to heterotrophism. The underlying process of this trophic exploitation, governed by a fine-tuned molecular dialogue between both partners, is an extraordinary example of adaptive plant biology operated by these parasitic organisms in the course of evolution. This transition is associated with remarkable morphological and physiological adaptations, and these adaptive strategies have led some parasitic plants to become deadly pests for crops against which no efficient control methods are yet available, especially in terms of sustainability. This chapter highlights the actual knowledge regarding the molecular aspects of these intimate and intriguing communications between host plants and parasitic plants, with a special focus on root parasitic plants.},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}
Parasitic plants are usually considered as botanical curiosities because of their shapes and colours. However, in some cases, they are proving to be terrible bioagressors in man-made ecosystems. Parasitic plants have indeed the capacity to connect intimately with other plants to exploit their resources (water, nutrients, growth regulators…) for their development. Thus, these plants are the result of an evolutionary transition from autotrophism to heterotrophism. The underlying process of this trophic exploitation, governed by a fine-tuned molecular dialogue between both partners, is an extraordinary example of adaptive plant biology operated by these parasitic organisms in the course of evolution. This transition is associated with remarkable morphological and physiological adaptations, and these adaptive strategies have led some parasitic plants to become deadly pests for crops against which no efficient control methods are yet available, especially in terms of sustainability. This chapter highlights the actual knowledge regarding the molecular aspects of these intimate and intriguing communications between host plants and parasitic plants, with a special focus on root parasitic plants.
1 publication
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.
Stagiaires encadrés :
- Gildas GUILLEMER, Master 2 Biologie Végétale, Faculté Sciences et Ingénierie Université de Toulouse