Christophe Bailly - Academia.edu (original) (raw)
Papers by Christophe Bailly
International Journal of Molecular Sciences
A timely and efficient seed germination is critical for plantlets’ establishment and robustness a... more A timely and efficient seed germination is critical for plantlets’ establishment and robustness as well as plant development and plant performance in both natural ecosystems and agrosystems [...]
Plants, 2022
In recent years, several reports pointed out the role of protein oxidation in seed longevity, not... more In recent years, several reports pointed out the role of protein oxidation in seed longevity, notably regarding the oxidation of methionine (Met) residues to methionine sulfoxide (MetO) in proteins. To further consider this question, we present a handy proteomic method based on the use of two-dimensional diagonal electrophoresis (2Dd) and cyanogen bromide (CNBr) cleavage, which we refer to as 2Dd-CNBr. CNBr treatment of proteins causes the non-enzymatic hydrolysis of peptide bonds on the carboxyl side of reduced Met residues. However, Met oxidation causes a lack of cleavage, thus modifying the electrophoretic mobility of CNBr-induced peptides. This approach was first validated using bovine serum albumin as a model protein, which confirmed the possibility of distinguishing between oxidized and non-oxidized forms of Met-containing peptides in gels. Then, the 2Dd-CNBr method was applied to the Arabidopsis thaliana seed protein extract in a control (non-oxidized) condition and in an oxi...
Plants, 2020
Seed vigor is an important trait that determines seed performance in the field, which corresponds... more Seed vigor is an important trait that determines seed performance in the field, which corresponds to seed germination rate and seedling establishment. Previous works brought helpful equations to calculate several parameters allowing vigor characterization. In this work we used base water potential (Ψb), base temperature (Tb) and seed lot (Ki) constants to characterize the vigor of 44 sunflower seed lots. Contrasting responses to water or temperature stress and storage potential were recorded within this population, the most interesting being the opposite responses between Ψb and Ki. The genotypes that were resistant to water stress presented low ability for storage and vice versa. Furthermore, Ψb and Ki presented narrow ranges while Tb showed important variability within the 44 genotypes. The analysis of the whole dataset showed that these constants are not correlated to each other or to the seed size, suggesting that genetic background is the most important determining factor in se...
BMC Biology, 2020
Background Upon water uptake and release of seed dormancy, embryonic plant cells expand, while be... more Background Upon water uptake and release of seed dormancy, embryonic plant cells expand, while being mechanically constrained by the seed coat. Cortical microtubules (CMTs) are key players of cell elongation in plants: their anisotropic orientation channels the axis of cell elongation through the guidance of oriented deposition of load-bearing cellulose microfibrils in the cell wall. Interestingly, CMTs align with tensile stress, and consistently, they reorient upon compressive stress in growing hypocotyls. How CMTs first organise in germinating embryos is unknown, and their relation with mechanical stress has not been investigated at such an early developing stage. Results Here, we analysed CMT dynamics in dormant and non-dormant Arabidopsis seeds by microscopy of fluorescently tagged microtubule markers at different developmental time points and in response to abscisic acid and gibberellins. We found that CMTs first appear as very few thick bundles in dormant seeds. Consistently, ...
Frontiers in Plant Science, 2016
PLoS genetics, 2015
Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared earl... more Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared early and late during plant evolution, respectively. The cuticle is a waterproof film covering plant aerial organs preventing excessive water loss and protecting against biotic and abiotic stresses. Cutin, consisting of crosslinked fatty acid monomers, is the most abundant and studied cuticular component. Seeds are dry, metabolically inert structures promoting plant dispersal by keeping the plant embryo in an arrested protected state. In Arabidopsis thaliana seeds, the embryo is surrounded by a single cell endosperm layer itself surrounded by a seed coat layer, the testa. Whole genome analyses lead us to identify cutin biosynthesis genes as regulatory targets of the phytohormones gibberellins (GA) and abscisic acid (ABA) signaling pathways that control seed germination. Cutin-containing layers are present in seed coats of numerous species, including Arabidopsis, where they regulate permeabil...
Journal of Experimental Botany, 2015
The Plant Cell, 2011
After-ripening is the mechanism by which dormant seeds become nondormant during their dry storage... more After-ripening is the mechanism by which dormant seeds become nondormant during their dry storage after harvest. The absence of free water in mature seeds does not allow detectable metabolism; thus, the processes associated with dormancy release under these conditions are largely unknown. We show here that sunflower (Helianthus annuus) seed alleviation of dormancy during after-ripening is associated with mRNA oxidation and that this oxidation is prevented when seeds are maintained dormant. In vitro approaches demonstrate that mRNA oxidation results in artifacts in cDNA–amplified fragment length polymorphim analysis and alters protein translation. The oxidation of transcripts is not random but selective, and, using microarrays, we identified 24 stored mRNAs that became highly oxidized during after-ripening. Oxidized transcripts mainly correspond to genes involved in responses to stress and in cell signaling. Among them, protein phosphatase 2C PPH1, mitogen-activated protein kinase ph...
Plant, Cell & Environment, 2009
Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-i... more Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-intolerant 'recalcitrant' seeds. However, it is unknown if and how ROS are produced in the apoplast and if they play a role in stress signalling during desiccation. We studied intracellular damage and extracellular superoxide (O(2)(.-)) production upon desiccation in Castanea sativa seeds, mechanisms of O(2)(.-) production and the effect of exogenously supplied ROS. A transient increase in extracellular O(2)(.-) production by the embryonic axes preceded significant desiccation-induced viability loss. Thereafter, progressively more oxidizing intracellular conditions, as indicated by a significant shift in glutathione half-cell reduction potential, accompanied cell and axis death, coinciding with the disruption of nuclear membranes. Most hydrogen peroxide (H(2)O(2))-dependent O(2)(.-) production was found in a cell wall fraction that contained extracellular peroxidases (ECPOX) with molecular masses of approximately 50 kDa. Cinnamic acid was identified as a potential reductant required for ECPOX-mediated O(2)(.-) production. H(2)O(2), applied exogenously to mimic the transient ROS burst at the onset of desiccation, counteracted viability loss of sub-lethally desiccation-stressed seeds and of excised embryonic axes grown in tissue culture. Hence, extracellular ROS produced by embryonic axes appear to be important signalling components involved in wound response, regeneration and growth.
Plant Signaling & Behavior, 2008
Biochemical Journal, 2019
Reactive oxygen species (ROS) are versatile compounds which can have toxic or signalling effects ... more Reactive oxygen species (ROS) are versatile compounds which can have toxic or signalling effects in a wide range living organisms, including seeds. They have been reported to play a pivotal role in the regulation of seed germination and dormancy but their mechanisms of action are still far from being fully understood. In this review, we sum-up the major findings that have been carried out this last decade in this field of research and which altogether shed a new light on the signalling roles of ROS in seed physiology. ROS participate in dormancy release during seed dry storage through the direct oxidation of a subset of biomolecules. During seed imbibition, the controlled generation of ROS is involved in the perception and transduction of environmental conditions that control germination. When these conditions are permissive for germination, ROS levels are maintained at a level which triggers cellular events associated with germination, such as hormone signalling. Here we propose th...
The biology of seeds: recent research advances. Proceedings of the Seventh International Workshop on Seeds, Salamanca, Spain, 2002, 2003
Plant Physiology, 2015
Dormancy is a complex evolutionary trait that temporally prevents seed germination, thus allowing... more Dormancy is a complex evolutionary trait that temporally prevents seed germination, thus allowing seedling growth at a favorable season. High-throughput analyses of transcriptomes have led to significant progress in understanding the molecular regulation of this process, but the role of posttranscriptional mechanisms has received little attention. In this work, we have studied the dynamics of messenger RNA association with polysomes and compared the transcriptome with the translatome in dormant and nondormant seeds of Arabidopsis (Arabidopsis thaliana) during their imbibition at 25°C in darkness, a temperature preventing germination of dormant seeds only. DNA microarray analysis revealed that 4,670 and 7,028 transcripts were differentially abundant in dormant and nondormant seeds in the transcriptome and the translatome, respectively. We show that there is no correlation between transcriptome and translatome and that germination regulation is also largely translational, implying a selective and dynamic recruitment of messenger RNAs to polysomes in both dormant and nondormant seeds. The study of 5' untranslated region features revealed that GC content and the number of upstream open reading frames could play a role in selective translation occurring during germination. Gene Ontology clustering showed that the functions of polysome-associated transcripts differed between dormant and nondormant seeds and revealed actors in seed dormancy and germination. In conclusion, our results demonstrate the essential role of selective polysome loading in this biological process.
Methods in molecular biology (Clifton, N.J.), 2011
Evidence is emerging that reactive oxygen species (ROS) and antioxidants, together with plant hor... more Evidence is emerging that reactive oxygen species (ROS) and antioxidants, together with plant hormones and other reactive species, such as reactive nitrogen species, are part of signalling networks pertinent to plant stress responses, cell division, and cell death. Consequently, they play pivotal roles in the regulation of seed development and maturation, germination and dormancy, seedling establishment, and seed ageing. Importantly, ROS, although essentially required at low concentrations, must be kept under stringent control by antioxidants. If the balance between pro- and antioxidative processes is lost and ROS production prevails, oxidative stress is the result, which can induce cell death and ultimately seed death. This chapter offers a variety of protocols for the determination of ROS, antioxidants, and stress markers aimed at enabling the reader to quantify these compounds. Protocols are also described to visualize ROS and localize the sites of ROS production, hoping to stimu...
Journal of experimental botany, 2001
Seeds of bean (Phaseolus vulgaris cv. Vernel) were collected throughout their development on the ... more Seeds of bean (Phaseolus vulgaris cv. Vernel) were collected throughout their development on the plant and dried at 15 degrees C and 75% relative humidity to a final moisture content of about 16% (fresh weight basis) to determine whether the onset of tolerance to this drying condition was related to changes in soluble sugars or the activities of the main antioxidant enzymes, namely superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR). Measurements of soluble sugars and enzyme activities were made after drying the seeds, and drying tolerance was evaluated by the ability of dried seeds to germinate and to produce normal seedlings. Seeds became tolerant to drying at 45 d after anthesis, a time marking physiological maturity. At physiological maturity, the moisture content of seeds was about 50-55% (fresh weight basis) and seed dry matter reached about 190 mg per seed. Seed vigour, evaluated by controlled deterioration and conductivity m...
Reactive Oxygen Species (ROS) are continuously produced during seed development, from embryogenes... more Reactive Oxygen Species (ROS) are continuously produced during seed development, from embryogenesis to germination, but also during seed storage. ROS play a dual role in seed physiology behaving, on the one hand, as actors of cellular signaling pathways and, on the other hand, as toxic products that accumulate under stress conditions. ROS, provided that their amount is tightly regulated by
Frontiers in Plant Science, 2014
Plant Signaling & Behavior, 2007
Frontiers in Plant Science, 2013
International Journal of Molecular Sciences
A timely and efficient seed germination is critical for plantlets’ establishment and robustness a... more A timely and efficient seed germination is critical for plantlets’ establishment and robustness as well as plant development and plant performance in both natural ecosystems and agrosystems [...]
Plants, 2022
In recent years, several reports pointed out the role of protein oxidation in seed longevity, not... more In recent years, several reports pointed out the role of protein oxidation in seed longevity, notably regarding the oxidation of methionine (Met) residues to methionine sulfoxide (MetO) in proteins. To further consider this question, we present a handy proteomic method based on the use of two-dimensional diagonal electrophoresis (2Dd) and cyanogen bromide (CNBr) cleavage, which we refer to as 2Dd-CNBr. CNBr treatment of proteins causes the non-enzymatic hydrolysis of peptide bonds on the carboxyl side of reduced Met residues. However, Met oxidation causes a lack of cleavage, thus modifying the electrophoretic mobility of CNBr-induced peptides. This approach was first validated using bovine serum albumin as a model protein, which confirmed the possibility of distinguishing between oxidized and non-oxidized forms of Met-containing peptides in gels. Then, the 2Dd-CNBr method was applied to the Arabidopsis thaliana seed protein extract in a control (non-oxidized) condition and in an oxi...
Plants, 2020
Seed vigor is an important trait that determines seed performance in the field, which corresponds... more Seed vigor is an important trait that determines seed performance in the field, which corresponds to seed germination rate and seedling establishment. Previous works brought helpful equations to calculate several parameters allowing vigor characterization. In this work we used base water potential (Ψb), base temperature (Tb) and seed lot (Ki) constants to characterize the vigor of 44 sunflower seed lots. Contrasting responses to water or temperature stress and storage potential were recorded within this population, the most interesting being the opposite responses between Ψb and Ki. The genotypes that were resistant to water stress presented low ability for storage and vice versa. Furthermore, Ψb and Ki presented narrow ranges while Tb showed important variability within the 44 genotypes. The analysis of the whole dataset showed that these constants are not correlated to each other or to the seed size, suggesting that genetic background is the most important determining factor in se...
BMC Biology, 2020
Background Upon water uptake and release of seed dormancy, embryonic plant cells expand, while be... more Background Upon water uptake and release of seed dormancy, embryonic plant cells expand, while being mechanically constrained by the seed coat. Cortical microtubules (CMTs) are key players of cell elongation in plants: their anisotropic orientation channels the axis of cell elongation through the guidance of oriented deposition of load-bearing cellulose microfibrils in the cell wall. Interestingly, CMTs align with tensile stress, and consistently, they reorient upon compressive stress in growing hypocotyls. How CMTs first organise in germinating embryos is unknown, and their relation with mechanical stress has not been investigated at such an early developing stage. Results Here, we analysed CMT dynamics in dormant and non-dormant Arabidopsis seeds by microscopy of fluorescently tagged microtubule markers at different developmental time points and in response to abscisic acid and gibberellins. We found that CMTs first appear as very few thick bundles in dormant seeds. Consistently, ...
Frontiers in Plant Science, 2016
PLoS genetics, 2015
Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared earl... more Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared early and late during plant evolution, respectively. The cuticle is a waterproof film covering plant aerial organs preventing excessive water loss and protecting against biotic and abiotic stresses. Cutin, consisting of crosslinked fatty acid monomers, is the most abundant and studied cuticular component. Seeds are dry, metabolically inert structures promoting plant dispersal by keeping the plant embryo in an arrested protected state. In Arabidopsis thaliana seeds, the embryo is surrounded by a single cell endosperm layer itself surrounded by a seed coat layer, the testa. Whole genome analyses lead us to identify cutin biosynthesis genes as regulatory targets of the phytohormones gibberellins (GA) and abscisic acid (ABA) signaling pathways that control seed germination. Cutin-containing layers are present in seed coats of numerous species, including Arabidopsis, where they regulate permeabil...
Journal of Experimental Botany, 2015
The Plant Cell, 2011
After-ripening is the mechanism by which dormant seeds become nondormant during their dry storage... more After-ripening is the mechanism by which dormant seeds become nondormant during their dry storage after harvest. The absence of free water in mature seeds does not allow detectable metabolism; thus, the processes associated with dormancy release under these conditions are largely unknown. We show here that sunflower (Helianthus annuus) seed alleviation of dormancy during after-ripening is associated with mRNA oxidation and that this oxidation is prevented when seeds are maintained dormant. In vitro approaches demonstrate that mRNA oxidation results in artifacts in cDNA–amplified fragment length polymorphim analysis and alters protein translation. The oxidation of transcripts is not random but selective, and, using microarrays, we identified 24 stored mRNAs that became highly oxidized during after-ripening. Oxidized transcripts mainly correspond to genes involved in responses to stress and in cell signaling. Among them, protein phosphatase 2C PPH1, mitogen-activated protein kinase ph...
Plant, Cell & Environment, 2009
Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-i... more Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-intolerant 'recalcitrant' seeds. However, it is unknown if and how ROS are produced in the apoplast and if they play a role in stress signalling during desiccation. We studied intracellular damage and extracellular superoxide (O(2)(.-)) production upon desiccation in Castanea sativa seeds, mechanisms of O(2)(.-) production and the effect of exogenously supplied ROS. A transient increase in extracellular O(2)(.-) production by the embryonic axes preceded significant desiccation-induced viability loss. Thereafter, progressively more oxidizing intracellular conditions, as indicated by a significant shift in glutathione half-cell reduction potential, accompanied cell and axis death, coinciding with the disruption of nuclear membranes. Most hydrogen peroxide (H(2)O(2))-dependent O(2)(.-) production was found in a cell wall fraction that contained extracellular peroxidases (ECPOX) with molecular masses of approximately 50 kDa. Cinnamic acid was identified as a potential reductant required for ECPOX-mediated O(2)(.-) production. H(2)O(2), applied exogenously to mimic the transient ROS burst at the onset of desiccation, counteracted viability loss of sub-lethally desiccation-stressed seeds and of excised embryonic axes grown in tissue culture. Hence, extracellular ROS produced by embryonic axes appear to be important signalling components involved in wound response, regeneration and growth.
Plant Signaling & Behavior, 2008
Biochemical Journal, 2019
Reactive oxygen species (ROS) are versatile compounds which can have toxic or signalling effects ... more Reactive oxygen species (ROS) are versatile compounds which can have toxic or signalling effects in a wide range living organisms, including seeds. They have been reported to play a pivotal role in the regulation of seed germination and dormancy but their mechanisms of action are still far from being fully understood. In this review, we sum-up the major findings that have been carried out this last decade in this field of research and which altogether shed a new light on the signalling roles of ROS in seed physiology. ROS participate in dormancy release during seed dry storage through the direct oxidation of a subset of biomolecules. During seed imbibition, the controlled generation of ROS is involved in the perception and transduction of environmental conditions that control germination. When these conditions are permissive for germination, ROS levels are maintained at a level which triggers cellular events associated with germination, such as hormone signalling. Here we propose th...
The biology of seeds: recent research advances. Proceedings of the Seventh International Workshop on Seeds, Salamanca, Spain, 2002, 2003
Plant Physiology, 2015
Dormancy is a complex evolutionary trait that temporally prevents seed germination, thus allowing... more Dormancy is a complex evolutionary trait that temporally prevents seed germination, thus allowing seedling growth at a favorable season. High-throughput analyses of transcriptomes have led to significant progress in understanding the molecular regulation of this process, but the role of posttranscriptional mechanisms has received little attention. In this work, we have studied the dynamics of messenger RNA association with polysomes and compared the transcriptome with the translatome in dormant and nondormant seeds of Arabidopsis (Arabidopsis thaliana) during their imbibition at 25°C in darkness, a temperature preventing germination of dormant seeds only. DNA microarray analysis revealed that 4,670 and 7,028 transcripts were differentially abundant in dormant and nondormant seeds in the transcriptome and the translatome, respectively. We show that there is no correlation between transcriptome and translatome and that germination regulation is also largely translational, implying a selective and dynamic recruitment of messenger RNAs to polysomes in both dormant and nondormant seeds. The study of 5' untranslated region features revealed that GC content and the number of upstream open reading frames could play a role in selective translation occurring during germination. Gene Ontology clustering showed that the functions of polysome-associated transcripts differed between dormant and nondormant seeds and revealed actors in seed dormancy and germination. In conclusion, our results demonstrate the essential role of selective polysome loading in this biological process.
Methods in molecular biology (Clifton, N.J.), 2011
Evidence is emerging that reactive oxygen species (ROS) and antioxidants, together with plant hor... more Evidence is emerging that reactive oxygen species (ROS) and antioxidants, together with plant hormones and other reactive species, such as reactive nitrogen species, are part of signalling networks pertinent to plant stress responses, cell division, and cell death. Consequently, they play pivotal roles in the regulation of seed development and maturation, germination and dormancy, seedling establishment, and seed ageing. Importantly, ROS, although essentially required at low concentrations, must be kept under stringent control by antioxidants. If the balance between pro- and antioxidative processes is lost and ROS production prevails, oxidative stress is the result, which can induce cell death and ultimately seed death. This chapter offers a variety of protocols for the determination of ROS, antioxidants, and stress markers aimed at enabling the reader to quantify these compounds. Protocols are also described to visualize ROS and localize the sites of ROS production, hoping to stimu...
Journal of experimental botany, 2001
Seeds of bean (Phaseolus vulgaris cv. Vernel) were collected throughout their development on the ... more Seeds of bean (Phaseolus vulgaris cv. Vernel) were collected throughout their development on the plant and dried at 15 degrees C and 75% relative humidity to a final moisture content of about 16% (fresh weight basis) to determine whether the onset of tolerance to this drying condition was related to changes in soluble sugars or the activities of the main antioxidant enzymes, namely superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR). Measurements of soluble sugars and enzyme activities were made after drying the seeds, and drying tolerance was evaluated by the ability of dried seeds to germinate and to produce normal seedlings. Seeds became tolerant to drying at 45 d after anthesis, a time marking physiological maturity. At physiological maturity, the moisture content of seeds was about 50-55% (fresh weight basis) and seed dry matter reached about 190 mg per seed. Seed vigour, evaluated by controlled deterioration and conductivity m...
Reactive Oxygen Species (ROS) are continuously produced during seed development, from embryogenes... more Reactive Oxygen Species (ROS) are continuously produced during seed development, from embryogenesis to germination, but also during seed storage. ROS play a dual role in seed physiology behaving, on the one hand, as actors of cellular signaling pathways and, on the other hand, as toxic products that accumulate under stress conditions. ROS, provided that their amount is tightly regulated by
Frontiers in Plant Science, 2014
Plant Signaling & Behavior, 2007
Frontiers in Plant Science, 2013