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Antoine Gravot - One of the best experts on this subject based on the ideXlab platform.
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Clubroot resistance QTL are modulated by nitrogen input in Brassica napus
TAG Theoretical and Applied Genetics, 2017Co-Authors: Anne Laperche, Marine Ollier, Solenn Guichard, Antoine Gravot, Yoann Aigu, Mélanie Jubault, Stephen E. Strelkov, Pascal Glory, Maria Manzanares-dauleuxAbstract:Nitrogen levels can modulate the effectiveness of Clubroot resistance in an isolate- and host-specific manner. While the same QTL were detected under high and low nitrogen, their effects were altered.Clubroot, caused by Plasmodiophora brassicae, is one of the most damaging diseases of oilseed rape and is known to be affected by nitrogen fertilization. However, the genetic factors involved in Clubroot resistance have not been characterized under nitrogen-limiting conditions. This study aimed to assess the variability of Clubroot resistance under different nitrogen levels and to characterize the impact of nitrogen supply on genetic resistance factors. Linkage analyses and a genome-wide association study were conducted to detect QTL for Clubroot resistance and evaluate their sensitivity to nitrogen. The Clubroot response of a set of 92 diverse oilseed rape accessions and 108 lines derived from a cross between 'Darmor-bzh' (resistant) and 'Yudal' (susceptible) was studied in the greenhouse under high- and low-nitrogen conditions, following inoculation with the P. brassicae isolates eH and K92-16. Resistance to each isolate was controlled by a major QTL and a few small-effects QTL. While the same QTL were detected under both high and low nitrogen, their effects were altered. Clubroot resistance to isolate eH, but not K92-16, was greater under a low-N supply versus a high-N supply. New sources of resistance were found among the oilseed rape accessions under both low and high-N conditions. The results are discussed relative to the literature and from a crop improvement perspective.
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Flooding affects the development of Plasmodiophora brassicae in Arabidopsis roots during the secondary phase of infection
Plant Pathology, 2016Co-Authors: Antoine Gravot, Christine Lariagon, Séverine Lemarié, Gautier Richard, Tanguy Lime, Maria Manzanares-dauleuxAbstract:Clubroot, a disease of Brassicaceae species, is caused by the soilborne pathogen Plasmodiophora brassicae. High soil water content was previously described to favour the motility of zoospores and their penetration into root cells. In this study, the effect of irrigation regimes on Clubroot development during the post-invasive secondary phase of infection was investigated. Three irrigation regimes (low, standard, high) were tested on two Arabidopsis accessions, Col-0 (susceptible) and Bur-0, a partially resistant line. In Col-0, Clubroot symptoms and resting spore content were higher under the low irrigation' regime than the other two regimes, thus enhancing the phenotypic contrast between the two Arabidopsis accessions. Clubroot severity under high and low irrigation regimes was evaluated in near-isogenic lines derived from a Col-0x Bur-0 cross, to assess the effect of soil moisture on the expression of each of four quantitative trait loci (QTL) controlling partial resistance. The presence of the Bur-0 allele at the QTL PbAt5.2 resulted in reduced severity only under low irrigation, whereas the Bur-0 allele at QTL PbAt5.1 was associated with partial resistance only under high irrigation. QTL PbAt4 reduced the number of resting spores in infected roots, but was not associated with reduced Clubroot symptoms. The results indicated that soil moisture could have consequences for the secondary phase of Clubroot development, depending on plant genotype. Future genetic studies may benefit from using combinations of watering conditions during the secondary stage of infection, thus opening up the possibility of identifying genetic factors expressed under specific environmental conditions.
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Both the Jasmonic Acid and the Salicylic Acid Pathways Contribute to Resistance to the Biotrophic Clubroot Agent [i]Plasmodiophora brassicae[/i] in Arabidopsis.
Plant and Cell Physiology, 2015Co-Authors: Séverine Lemarié, Maria Manzanares-dauleux, Mélanie Jubault, Christine Lariagon, Alexandre Robert-seilaniantz, Jocelyne Lemoine, Nathalie Marnet, Antoine GravotAbstract:The role of salicylic acid (SA) and jasmonic acid (JA) signaling in resistance to root pathogens has been poorly documented. We assessed the contribution of SA and JA to basal and partial resistance of Arabidopsis to the biotrophic Clubroot agent Plasmodiophora brassicae. SA and JA levels as well as the expression of the SA-responsive genes PR2 and PR5 and the JA-responsive genes ARGAH2 and THI2.1 were monitored in infected roots of the accessions Col-0 (susceptible) and Bur-0 (partially resistant). SA signaling was activated in Bur-0 but not in Col-0. The JA pathway was weakly activated in Bur-0 but was strongly induced in Col-0. The contribution of both pathways to Clubroot resistance was then assessed using exogenous phytohormone application and mutants affected in SA or JA signaling. Exogenous SA treatment decreased Clubroot symptoms in the two Arabidopsis accessions, whereas JA treatment reduced Clubroot symptoms only in Col-0. The cpr5-2 mutant, in which SA responses are constitutively induced, was more resistant to Clubroot than the corresponding wild type, and the JA signaling-deficient mutant jar1 was more susceptible. Finally, we showed that the JA-mediated induction of NATA1 drove N(δ)-acetylornithine biosynthesis in infected Col-0 roots. The 35S::NATA1 and nata1 lines displayed reduced or enhanced Clubroot symptoms, respectively, thus suggesting that in Col-0 this pathway was involved in the JA-mediated basal Clubroot resistance. Overall, our data support the idea that, depending on the Arabidopsis accession, both SA and JA signaling can play a role in partial inhibition of Clubroot development in compatible interactions with P. brassicae.
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Camalexin contributes to the partial resistance of [i]Arabidopsis thaliana[/i] to the biotrophic soilborne protist [i]Plasmodiophora brassicae[/i].
Frontiers in Plant Science, 2015Co-Authors: Séverine Lemarié, Mélanie Jubault, Christine Lariagon, Alexandre Robert-seilaniantz, Jocelyne Lemoine, Nathalie Marnet, Anne Levrel, Maria Manzanares-dauleux, Antoine GravotAbstract:Camalexin has been reported to play defensive functions against several pathogens in Arabidopsis. In this study, we investigated the possible role of camalexin accumulation in two Arabidopsis genotypes with different levels of basal resistance to the compatible eH strain of the Clubroot agent Plasmodiophora brassicae. Camalexin biosynthesis was induced in infected roots of both Col-0 (susceptible) and Bur-0 (partially resistant) accessions during the secondary phase of infection. However, the level of accumulation was four-to-seven times higher in Bur-0 than Col-0. This was associated with the enhanced transcription of a set of camalexin biosynthetic P450 genes in Bur-0: CYP71A13, CYP71A12, and CYP79B2. This induction correlated with slower P. brassicae growth in Bur-0 compared to Col-0, thus suggesting a relationship between the levels of camalexin biosynthesis and the different levels of resistance. Clubroot-triggered biosynthesis of camalexin may also participate in basal defense in Col-0, as gall symptoms and pathogen development were enhanced in the pad3 mutant (Col-0 genetic background), which is defective in camalexin biosynthesis. Clubroot and camalexin responses were then studied in Heterogeneous Inbred Families (HIF) lines derived from a cross between Bur-0 and Col-0. The Bur/Col allelic substitution in the region of the previously identified Clubroot resistance QTL PbAt5.2 (Chromosome 5) was associated with both the enhanced Clubroot-triggered induction of camalexin biosynthesis and the reduced P. brassicae development. Altogether, our results suggest that high levels of Clubroot-triggered camalexin biosynthesis play a role in the quantitative control of partial resistance of Arabidopsis to Clubroot.
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arginase induction represses gall development during Clubroot infection in arabidopsis
Plant and Cell Physiology, 2012Co-Authors: Antoine Gravot, Christopher D Todd, Carole Deleu, G Wagner, Christine Lariagon, Raphael Lugan, David Wendehenne, Regine Delourme, Alain BouchereauAbstract:Arginase induction can play a defensive role through the reduction of arginine availability for phytophageous insects. Arginase activity is also induced during gall growth caused by Plasmodiophora brassicae infection in roots of Arabidopsis thaliana; however, its possible role in this context has been unclear. We report here that the mutation of the arginase-encoding gene ARGAH2 abrogates Clubroot-induced arginase activity and results in enhanced gall size in infected roots, suggesting that arginase plays a defensive role. Induction of arginase activity in infected roots was impaired in the jar1 mutant, highlighting a link between the arginase response to Clubroot and jasmonate signaling. Clubroot-induced accumulation of the principal amino acids in galls was not affected by the argah2 mutation. Because ARGAH2 was previously reported to control auxin response, we investigated the role of ARGAH2 in callus induction. ARGAH2 was found to be highly induced in auxin/cytokinin-triggered aseptic plant calli, and callus development was enhanced in argah2 in the absence of the pathogen. We hypothesized that arginase contributes to a negative control over Clubroot symptoms, by reducing hormone-triggered cellular proliferation.
Christine Lariagon - One of the best experts on this subject based on the ideXlab platform.
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Flooding affects the development of Plasmodiophora brassicae in Arabidopsis roots during the secondary phase of infection
Plant Pathology, 2016Co-Authors: Antoine Gravot, Christine Lariagon, Séverine Lemarié, Gautier Richard, Tanguy Lime, Maria Manzanares-dauleuxAbstract:Clubroot, a disease of Brassicaceae species, is caused by the soilborne pathogen Plasmodiophora brassicae. High soil water content was previously described to favour the motility of zoospores and their penetration into root cells. In this study, the effect of irrigation regimes on Clubroot development during the post-invasive secondary phase of infection was investigated. Three irrigation regimes (low, standard, high) were tested on two Arabidopsis accessions, Col-0 (susceptible) and Bur-0, a partially resistant line. In Col-0, Clubroot symptoms and resting spore content were higher under the low irrigation' regime than the other two regimes, thus enhancing the phenotypic contrast between the two Arabidopsis accessions. Clubroot severity under high and low irrigation regimes was evaluated in near-isogenic lines derived from a Col-0x Bur-0 cross, to assess the effect of soil moisture on the expression of each of four quantitative trait loci (QTL) controlling partial resistance. The presence of the Bur-0 allele at the QTL PbAt5.2 resulted in reduced severity only under low irrigation, whereas the Bur-0 allele at QTL PbAt5.1 was associated with partial resistance only under high irrigation. QTL PbAt4 reduced the number of resting spores in infected roots, but was not associated with reduced Clubroot symptoms. The results indicated that soil moisture could have consequences for the secondary phase of Clubroot development, depending on plant genotype. Future genetic studies may benefit from using combinations of watering conditions during the secondary stage of infection, thus opening up the possibility of identifying genetic factors expressed under specific environmental conditions.
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Both the Jasmonic Acid and the Salicylic Acid Pathways Contribute to Resistance to the Biotrophic Clubroot Agent [i]Plasmodiophora brassicae[/i] in Arabidopsis.
Plant and Cell Physiology, 2015Co-Authors: Séverine Lemarié, Maria Manzanares-dauleux, Mélanie Jubault, Christine Lariagon, Alexandre Robert-seilaniantz, Jocelyne Lemoine, Nathalie Marnet, Antoine GravotAbstract:The role of salicylic acid (SA) and jasmonic acid (JA) signaling in resistance to root pathogens has been poorly documented. We assessed the contribution of SA and JA to basal and partial resistance of Arabidopsis to the biotrophic Clubroot agent Plasmodiophora brassicae. SA and JA levels as well as the expression of the SA-responsive genes PR2 and PR5 and the JA-responsive genes ARGAH2 and THI2.1 were monitored in infected roots of the accessions Col-0 (susceptible) and Bur-0 (partially resistant). SA signaling was activated in Bur-0 but not in Col-0. The JA pathway was weakly activated in Bur-0 but was strongly induced in Col-0. The contribution of both pathways to Clubroot resistance was then assessed using exogenous phytohormone application and mutants affected in SA or JA signaling. Exogenous SA treatment decreased Clubroot symptoms in the two Arabidopsis accessions, whereas JA treatment reduced Clubroot symptoms only in Col-0. The cpr5-2 mutant, in which SA responses are constitutively induced, was more resistant to Clubroot than the corresponding wild type, and the JA signaling-deficient mutant jar1 was more susceptible. Finally, we showed that the JA-mediated induction of NATA1 drove N(δ)-acetylornithine biosynthesis in infected Col-0 roots. The 35S::NATA1 and nata1 lines displayed reduced or enhanced Clubroot symptoms, respectively, thus suggesting that in Col-0 this pathway was involved in the JA-mediated basal Clubroot resistance. Overall, our data support the idea that, depending on the Arabidopsis accession, both SA and JA signaling can play a role in partial inhibition of Clubroot development in compatible interactions with P. brassicae.
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Camalexin contributes to the partial resistance of [i]Arabidopsis thaliana[/i] to the biotrophic soilborne protist [i]Plasmodiophora brassicae[/i].
Frontiers in Plant Science, 2015Co-Authors: Séverine Lemarié, Mélanie Jubault, Christine Lariagon, Alexandre Robert-seilaniantz, Jocelyne Lemoine, Nathalie Marnet, Anne Levrel, Maria Manzanares-dauleux, Antoine GravotAbstract:Camalexin has been reported to play defensive functions against several pathogens in Arabidopsis. In this study, we investigated the possible role of camalexin accumulation in two Arabidopsis genotypes with different levels of basal resistance to the compatible eH strain of the Clubroot agent Plasmodiophora brassicae. Camalexin biosynthesis was induced in infected roots of both Col-0 (susceptible) and Bur-0 (partially resistant) accessions during the secondary phase of infection. However, the level of accumulation was four-to-seven times higher in Bur-0 than Col-0. This was associated with the enhanced transcription of a set of camalexin biosynthetic P450 genes in Bur-0: CYP71A13, CYP71A12, and CYP79B2. This induction correlated with slower P. brassicae growth in Bur-0 compared to Col-0, thus suggesting a relationship between the levels of camalexin biosynthesis and the different levels of resistance. Clubroot-triggered biosynthesis of camalexin may also participate in basal defense in Col-0, as gall symptoms and pathogen development were enhanced in the pad3 mutant (Col-0 genetic background), which is defective in camalexin biosynthesis. Clubroot and camalexin responses were then studied in Heterogeneous Inbred Families (HIF) lines derived from a cross between Bur-0 and Col-0. The Bur/Col allelic substitution in the region of the previously identified Clubroot resistance QTL PbAt5.2 (Chromosome 5) was associated with both the enhanced Clubroot-triggered induction of camalexin biosynthesis and the reduced P. brassicae development. Altogether, our results suggest that high levels of Clubroot-triggered camalexin biosynthesis play a role in the quantitative control of partial resistance of Arabidopsis to Clubroot.
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arginase induction represses gall development during Clubroot infection in arabidopsis
Plant and Cell Physiology, 2012Co-Authors: Antoine Gravot, Christopher D Todd, Carole Deleu, G Wagner, Christine Lariagon, Raphael Lugan, David Wendehenne, Regine Delourme, Alain BouchereauAbstract:Arginase induction can play a defensive role through the reduction of arginine availability for phytophageous insects. Arginase activity is also induced during gall growth caused by Plasmodiophora brassicae infection in roots of Arabidopsis thaliana; however, its possible role in this context has been unclear. We report here that the mutation of the arginase-encoding gene ARGAH2 abrogates Clubroot-induced arginase activity and results in enhanced gall size in infected roots, suggesting that arginase plays a defensive role. Induction of arginase activity in infected roots was impaired in the jar1 mutant, highlighting a link between the arginase response to Clubroot and jasmonate signaling. Clubroot-induced accumulation of the principal amino acids in galls was not affected by the argah2 mutation. Because ARGAH2 was previously reported to control auxin response, we investigated the role of ARGAH2 in callus induction. ARGAH2 was found to be highly induced in auxin/cytokinin-triggered aseptic plant calli, and callus development was enhanced in argah2 in the absence of the pathogen. We hypothesized that arginase contributes to a negative control over Clubroot symptoms, by reducing hormone-triggered cellular proliferation.
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Genetic and physiological analysis of the relationship between partial resistance to Clubroot and tolerance to trehalose in Arabidopsis thaliana
The New phytologist, 2011Co-Authors: Antoine Gravot, Mélanie Jubault, Carole Deleu, Christine Lariagon, Regine Delourme, Alain Bouchereau, Louis Grillet, Geoffrey Wagner, Cécile Baron, Maria Manzanares-dauleuxAbstract:In Arabidopsis thaliana the induction of plant trehalase during Clubroot disease was proposed to act as a defense mechanism in the susceptible accession Col-0, which could thereby cope with the accumulation of pathogen-synthesized trehalose. In the present study, we assessed trehalose activity and tolerance to trehalose in the Clubroot partially resistant accession Bur-0. We compared both accessions for several trehalose-related physiological traits during Clubroot infection. A quantitative trait loci (QTLs) analysis of tolerance to exogenous trehalose was also conducted on a Bur-0xCol-0 RIL progeny. Trehalase activity was not induced by Clubroot in Bur-0 and the inhibition of trehalase by validamycin treatments resulted in the enhancement of Clubroot symptoms only in Col-0. In pathogen-free cultures, Bur-0 showed less trehalose-induced toxicity symptoms than Col-0. A QTL analysis identified one locus involved in tolerance to trehalose overlapping the confidence interval of a QTL for resistance to Plasmodiophora brassicae. This colocalization was confirmed using heterogeneous inbred family (HIF) lines. Although not based on trehalose catabolism capacity, partial resistance to Clubroot is to some extent related to the tolerance to trehalose accumulation in Bur-0. These findings support an original model where contrasting primary metabolism-related regulations could contribute to the partial resistance to a plant pathogen.
Jutta Ludwig-müller - One of the best experts on this subject based on the ideXlab platform.
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New kid on the block – the Clubroot pathogen genome moves the plasmodiophorids into the genomic era
European Journal of Plant Pathology, 2016Co-Authors: Arne Schwelm, Christina Dixelius, Jutta Ludwig-müllerAbstract:Plasmodiophora brassicae causes Clubroot on cruciferous plants and causes worldwide huge economical losses on important Brassica crops. P. brassicae infection produces large root galls, the Clubroots, which can also affect the upper plant parts by reduced water and nutrient uptake and redirection of assimilates from leaves to roots. P. brassicae is an obligate biotrophic protist in the plasmodiophorids within the eukaryote supergroup of Rhizaria and is unrelated to other known plant pathogens. Plasmodiophorids can be parasites of plants and oomycetes. The recently released genome of P. brassicae is only the third in the poorly studied Rhizaria and the first plant pathogenic genome of this eukaryotic group. The P. brassicae genome was estimated to be 25.5 Mb in size and predicted to contain 9730 gene models. A transcriptome of P. brassicae and Spongospora subterranea , the potato scab pathogen was also presented. Consequently, for the first time large scale data for a eukaryotic plant pathogen group outside the fungi and oomycetes are now available. This review highlights selected characteristics of the P. brassicae genome including molecular events shown or predicted to take place in each phase of its life-cycle, such as manipulation of: 1) host primary metabolism, 2) plant hormone homeostasis, and 3) plant defense. Further, future directions and challenges in the P. brassicae and plasmodiophorid genomic research are discussed.
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Belowground Defence Strategies Against Clubroot (Plasmodiophora brassicae)
Belowground Defence Strategies in Plants, 2016Co-Authors: Jutta Ludwig-müllerAbstract:The Clubroot disease is one of the most devastating root-borne diseases of brassica crops. While breeding of resistant cultivars is still a method of choice, the control of Clubroot by either biocontrol agents or even plant strengtheners could be improved. More environmentally friendly alternatives or additional means to make the resistance response of crop plants more durable are needed. Chemical control of Clubroot is in many cases not successful; only liming has been used traditionally with good success. In some cases, the model plant Arabidopsis thaliana has been used; a plethora of work however has been done on oilseed rape/canola (in this chapter, the common name for Brassica napus will be chosen according to the name in the respective publications, mainly canola in Canada and oilseed rape in Europe) (Brassica napus). The Clubroot pathogen is called Plasmodiophora brassicae and constitutes an obligate biotrophic protist that lives in close relationship with its host cell. The roots of the host plants are colonized, and the plant growth is altered upon infection. While shoots can be stunted and show wilt symptoms after longer infection periods, the root system is converted to a tumorous root tissue, called “Clubroot” by alterations of plant hormones and metabolic pathways essential for pathogen nutrition. In this chapter, the major focus will, however, be on biocontrol of Clubroot by either endophytic organisms or by plant strengtheners or plant growth regulators; and some mechanisms behind it, independent of which host plant was employed, will be discussed.
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Metabolism and Plant Hormone Action During Clubroot Disease
Journal of Plant Growth Regulation, 2009Co-Authors: Jutta Ludwig-müller, Els Prinsen, Stephen A. Rolfe, Julie D. ScholesAbstract:Infection of Brassicaceae with the obligate biotrophic pathogen Plasmodiophora brassicae results in the development of root galls (Clubroots). During the transformation of a healthy root to a root gall a plethora of changes in primary and secondary metabolism occur. The upper part of an infected plant is retarded in growth due to redirection of assimilates from the shoot to the root. In addition, changes in the levels of plant growth regulators, especially auxins and cytokinins, contribute to the hypertrophy of infected roots. Also, defense reactions are manipulated after inoculation of suitable host plants with P. brassicae . This review summarizes our current knowledge on the changes in these parameters. A model is presented for how primary metabolism and secondary metabolism, including plant hormones, interact to induce Clubroot formation.
Maria Manzanares-dauleux - One of the best experts on this subject based on the ideXlab platform.
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Clubroot resistance QTL are modulated by nitrogen input in Brassica napus
TAG Theoretical and Applied Genetics, 2017Co-Authors: Anne Laperche, Marine Ollier, Solenn Guichard, Antoine Gravot, Yoann Aigu, Mélanie Jubault, Stephen E. Strelkov, Pascal Glory, Maria Manzanares-dauleuxAbstract:Nitrogen levels can modulate the effectiveness of Clubroot resistance in an isolate- and host-specific manner. While the same QTL were detected under high and low nitrogen, their effects were altered.Clubroot, caused by Plasmodiophora brassicae, is one of the most damaging diseases of oilseed rape and is known to be affected by nitrogen fertilization. However, the genetic factors involved in Clubroot resistance have not been characterized under nitrogen-limiting conditions. This study aimed to assess the variability of Clubroot resistance under different nitrogen levels and to characterize the impact of nitrogen supply on genetic resistance factors. Linkage analyses and a genome-wide association study were conducted to detect QTL for Clubroot resistance and evaluate their sensitivity to nitrogen. The Clubroot response of a set of 92 diverse oilseed rape accessions and 108 lines derived from a cross between 'Darmor-bzh' (resistant) and 'Yudal' (susceptible) was studied in the greenhouse under high- and low-nitrogen conditions, following inoculation with the P. brassicae isolates eH and K92-16. Resistance to each isolate was controlled by a major QTL and a few small-effects QTL. While the same QTL were detected under both high and low nitrogen, their effects were altered. Clubroot resistance to isolate eH, but not K92-16, was greater under a low-N supply versus a high-N supply. New sources of resistance were found among the oilseed rape accessions under both low and high-N conditions. The results are discussed relative to the literature and from a crop improvement perspective.
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Both the Jasmonic Acid and the Salicylic Acid Pathways Contribute to Resistance to the Biotrophic Clubroot Agent [i]Plasmodiophora brassicae[/i] in Arabidopsis.
Plant and Cell Physiology, 2015Co-Authors: Séverine Lemarié, Maria Manzanares-dauleux, Mélanie Jubault, Christine Lariagon, Alexandre Robert-seilaniantz, Jocelyne Lemoine, Nathalie Marnet, Antoine GravotAbstract:The role of salicylic acid (SA) and jasmonic acid (JA) signaling in resistance to root pathogens has been poorly documented. We assessed the contribution of SA and JA to basal and partial resistance of Arabidopsis to the biotrophic Clubroot agent Plasmodiophora brassicae. SA and JA levels as well as the expression of the SA-responsive genes PR2 and PR5 and the JA-responsive genes ARGAH2 and THI2.1 were monitored in infected roots of the accessions Col-0 (susceptible) and Bur-0 (partially resistant). SA signaling was activated in Bur-0 but not in Col-0. The JA pathway was weakly activated in Bur-0 but was strongly induced in Col-0. The contribution of both pathways to Clubroot resistance was then assessed using exogenous phytohormone application and mutants affected in SA or JA signaling. Exogenous SA treatment decreased Clubroot symptoms in the two Arabidopsis accessions, whereas JA treatment reduced Clubroot symptoms only in Col-0. The cpr5-2 mutant, in which SA responses are constitutively induced, was more resistant to Clubroot than the corresponding wild type, and the JA signaling-deficient mutant jar1 was more susceptible. Finally, we showed that the JA-mediated induction of NATA1 drove N(δ)-acetylornithine biosynthesis in infected Col-0 roots. The 35S::NATA1 and nata1 lines displayed reduced or enhanced Clubroot symptoms, respectively, thus suggesting that in Col-0 this pathway was involved in the JA-mediated basal Clubroot resistance. Overall, our data support the idea that, depending on the Arabidopsis accession, both SA and JA signaling can play a role in partial inhibition of Clubroot development in compatible interactions with P. brassicae.
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Genetic and physiological analysis of the relationship between partial resistance to Clubroot and tolerance to trehalose in Arabidopsis thaliana
The New phytologist, 2011Co-Authors: Antoine Gravot, Mélanie Jubault, Carole Deleu, Christine Lariagon, Regine Delourme, Alain Bouchereau, Louis Grillet, Geoffrey Wagner, Cécile Baron, Maria Manzanares-dauleuxAbstract:In Arabidopsis thaliana the induction of plant trehalase during Clubroot disease was proposed to act as a defense mechanism in the susceptible accession Col-0, which could thereby cope with the accumulation of pathogen-synthesized trehalose. In the present study, we assessed trehalose activity and tolerance to trehalose in the Clubroot partially resistant accession Bur-0. We compared both accessions for several trehalose-related physiological traits during Clubroot infection. A quantitative trait loci (QTLs) analysis of tolerance to exogenous trehalose was also conducted on a Bur-0xCol-0 RIL progeny. Trehalase activity was not induced by Clubroot in Bur-0 and the inhibition of trehalase by validamycin treatments resulted in the enhancement of Clubroot symptoms only in Col-0. In pathogen-free cultures, Bur-0 showed less trehalose-induced toxicity symptoms than Col-0. A QTL analysis identified one locus involved in tolerance to trehalose overlapping the confidence interval of a QTL for resistance to Plasmodiophora brassicae. This colocalization was confirmed using heterogeneous inbred family (HIF) lines. Although not based on trehalose catabolism capacity, partial resistance to Clubroot is to some extent related to the tolerance to trehalose accumulation in Bur-0. These findings support an original model where contrasting primary metabolism-related regulations could contribute to the partial resistance to a plant pathogen.
Mélanie Jubault - One of the best experts on this subject based on the ideXlab platform.
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Clubroot resistance QTL are modulated by nitrogen input in Brassica napus
TAG Theoretical and Applied Genetics, 2017Co-Authors: Anne Laperche, Marine Ollier, Solenn Guichard, Antoine Gravot, Yoann Aigu, Mélanie Jubault, Stephen E. Strelkov, Pascal Glory, Maria Manzanares-dauleuxAbstract:Nitrogen levels can modulate the effectiveness of Clubroot resistance in an isolate- and host-specific manner. While the same QTL were detected under high and low nitrogen, their effects were altered.Clubroot, caused by Plasmodiophora brassicae, is one of the most damaging diseases of oilseed rape and is known to be affected by nitrogen fertilization. However, the genetic factors involved in Clubroot resistance have not been characterized under nitrogen-limiting conditions. This study aimed to assess the variability of Clubroot resistance under different nitrogen levels and to characterize the impact of nitrogen supply on genetic resistance factors. Linkage analyses and a genome-wide association study were conducted to detect QTL for Clubroot resistance and evaluate their sensitivity to nitrogen. The Clubroot response of a set of 92 diverse oilseed rape accessions and 108 lines derived from a cross between 'Darmor-bzh' (resistant) and 'Yudal' (susceptible) was studied in the greenhouse under high- and low-nitrogen conditions, following inoculation with the P. brassicae isolates eH and K92-16. Resistance to each isolate was controlled by a major QTL and a few small-effects QTL. While the same QTL were detected under both high and low nitrogen, their effects were altered. Clubroot resistance to isolate eH, but not K92-16, was greater under a low-N supply versus a high-N supply. New sources of resistance were found among the oilseed rape accessions under both low and high-N conditions. The results are discussed relative to the literature and from a crop improvement perspective.
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Both the Jasmonic Acid and the Salicylic Acid Pathways Contribute to Resistance to the Biotrophic Clubroot Agent [i]Plasmodiophora brassicae[/i] in Arabidopsis.
Plant and Cell Physiology, 2015Co-Authors: Séverine Lemarié, Maria Manzanares-dauleux, Mélanie Jubault, Christine Lariagon, Alexandre Robert-seilaniantz, Jocelyne Lemoine, Nathalie Marnet, Antoine GravotAbstract:The role of salicylic acid (SA) and jasmonic acid (JA) signaling in resistance to root pathogens has been poorly documented. We assessed the contribution of SA and JA to basal and partial resistance of Arabidopsis to the biotrophic Clubroot agent Plasmodiophora brassicae. SA and JA levels as well as the expression of the SA-responsive genes PR2 and PR5 and the JA-responsive genes ARGAH2 and THI2.1 were monitored in infected roots of the accessions Col-0 (susceptible) and Bur-0 (partially resistant). SA signaling was activated in Bur-0 but not in Col-0. The JA pathway was weakly activated in Bur-0 but was strongly induced in Col-0. The contribution of both pathways to Clubroot resistance was then assessed using exogenous phytohormone application and mutants affected in SA or JA signaling. Exogenous SA treatment decreased Clubroot symptoms in the two Arabidopsis accessions, whereas JA treatment reduced Clubroot symptoms only in Col-0. The cpr5-2 mutant, in which SA responses are constitutively induced, was more resistant to Clubroot than the corresponding wild type, and the JA signaling-deficient mutant jar1 was more susceptible. Finally, we showed that the JA-mediated induction of NATA1 drove N(δ)-acetylornithine biosynthesis in infected Col-0 roots. The 35S::NATA1 and nata1 lines displayed reduced or enhanced Clubroot symptoms, respectively, thus suggesting that in Col-0 this pathway was involved in the JA-mediated basal Clubroot resistance. Overall, our data support the idea that, depending on the Arabidopsis accession, both SA and JA signaling can play a role in partial inhibition of Clubroot development in compatible interactions with P. brassicae.
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Camalexin contributes to the partial resistance of [i]Arabidopsis thaliana[/i] to the biotrophic soilborne protist [i]Plasmodiophora brassicae[/i].
Frontiers in Plant Science, 2015Co-Authors: Séverine Lemarié, Mélanie Jubault, Christine Lariagon, Alexandre Robert-seilaniantz, Jocelyne Lemoine, Nathalie Marnet, Anne Levrel, Maria Manzanares-dauleux, Antoine GravotAbstract:Camalexin has been reported to play defensive functions against several pathogens in Arabidopsis. In this study, we investigated the possible role of camalexin accumulation in two Arabidopsis genotypes with different levels of basal resistance to the compatible eH strain of the Clubroot agent Plasmodiophora brassicae. Camalexin biosynthesis was induced in infected roots of both Col-0 (susceptible) and Bur-0 (partially resistant) accessions during the secondary phase of infection. However, the level of accumulation was four-to-seven times higher in Bur-0 than Col-0. This was associated with the enhanced transcription of a set of camalexin biosynthetic P450 genes in Bur-0: CYP71A13, CYP71A12, and CYP79B2. This induction correlated with slower P. brassicae growth in Bur-0 compared to Col-0, thus suggesting a relationship between the levels of camalexin biosynthesis and the different levels of resistance. Clubroot-triggered biosynthesis of camalexin may also participate in basal defense in Col-0, as gall symptoms and pathogen development were enhanced in the pad3 mutant (Col-0 genetic background), which is defective in camalexin biosynthesis. Clubroot and camalexin responses were then studied in Heterogeneous Inbred Families (HIF) lines derived from a cross between Bur-0 and Col-0. The Bur/Col allelic substitution in the region of the previously identified Clubroot resistance QTL PbAt5.2 (Chromosome 5) was associated with both the enhanced Clubroot-triggered induction of camalexin biosynthesis and the reduced P. brassicae development. Altogether, our results suggest that high levels of Clubroot-triggered camalexin biosynthesis play a role in the quantitative control of partial resistance of Arabidopsis to Clubroot.
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Genetic and physiological analysis of the relationship between partial resistance to Clubroot and tolerance to trehalose in Arabidopsis thaliana
The New phytologist, 2011Co-Authors: Antoine Gravot, Mélanie Jubault, Carole Deleu, Christine Lariagon, Regine Delourme, Alain Bouchereau, Louis Grillet, Geoffrey Wagner, Cécile Baron, Maria Manzanares-dauleuxAbstract:In Arabidopsis thaliana the induction of plant trehalase during Clubroot disease was proposed to act as a defense mechanism in the susceptible accession Col-0, which could thereby cope with the accumulation of pathogen-synthesized trehalose. In the present study, we assessed trehalose activity and tolerance to trehalose in the Clubroot partially resistant accession Bur-0. We compared both accessions for several trehalose-related physiological traits during Clubroot infection. A quantitative trait loci (QTLs) analysis of tolerance to exogenous trehalose was also conducted on a Bur-0xCol-0 RIL progeny. Trehalase activity was not induced by Clubroot in Bur-0 and the inhibition of trehalase by validamycin treatments resulted in the enhancement of Clubroot symptoms only in Col-0. In pathogen-free cultures, Bur-0 showed less trehalose-induced toxicity symptoms than Col-0. A QTL analysis identified one locus involved in tolerance to trehalose overlapping the confidence interval of a QTL for resistance to Plasmodiophora brassicae. This colocalization was confirmed using heterogeneous inbred family (HIF) lines. Although not based on trehalose catabolism capacity, partial resistance to Clubroot is to some extent related to the tolerance to trehalose accumulation in Bur-0. These findings support an original model where contrasting primary metabolism-related regulations could contribute to the partial resistance to a plant pathogen.