Patience et persévérance
Christophe VERONESI
Maître de conférences Université
section 66
| Équipe : |
Thèmes de recherche
Etude des interactions plantes (Arabidopsis thaliana, Colza, Tournesol, Tomate, Sorgho,..)/plantes parasites (Orobanche, Striga).
Projets
Parcours universitaire
Licence de Biochimie (1989), Université Paul Sabatier de Toulouse.
Master 1 (ex Maîtrise) de Biologie Cellulaire, option Microbiologie (1990), Université Paul Sabatier de Toulouse.
Master 2 (ex DEA) de Biologie et Technologie Végétales (1991), Université Paul Sabatier de Toulouse.
Doctorat en Biologie Cellulaire et Moléculaire Végétales (1995), Université Paul Sabatier de Toulouse.
Habilitation à Diriger des Recherches en Sciences Agronomiques et Ecologiques (2017), Université de Nantes.
Publications
1 publication
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.
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.
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.
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.