Water deficit is a major worldwide constraint to common bean(Phaseolus vulgaris L.)production,being photosynthesis one of the most affected physiological processes.To gain insights into the genetic basis of the photos...Water deficit is a major worldwide constraint to common bean(Phaseolus vulgaris L.)production,being photosynthesis one of the most affected physiological processes.To gain insights into the genetic basis of the photosynthetic response of common bean under water-limited conditions,a collection of 158 Portuguese accessions was grown under both well-watered and water-deficit regimes.Leaf gas-exchange parameters were measured and photosynthetic pigments quantified.The same collection was genotyped using SNP arrays,and SNP-trait associations tested considering a linear mixed model accounting for the genetic relatedness among accessions.A total of 133 SNP-trait associations were identified for net CO 2 assimilation rate,transpiration rate,stomatal conductance,and chlorophylls a and b,carotenes,and xanthophyll contents.Ninety of these associations were detected under water-deficit and 43 under well-watered conditions,with only two associations common to both treatments.Identified candidate genes revealed that stomatal regulation,protein translocation across membranes,redox mechanisms,hormone,and osmotic stress signaling were the most relevant processes involved in common bean response to water-limited conditions.These candidates are now preferential targets for common bean water-deficit-tolerance breeding.Additionally,new sources of water-deficit tolerance of Andean,Mesoamerican,and admixed origin were detected as accessions valuable for breeding,and not yet explored.展开更多
The knowledge on post-transcriptional regulation mechanisms implicated in seed development(SD)is still limited,particularly in one of the most consumed grain legumes,Phaseolus vulgaris L.We explore for the first time ...The knowledge on post-transcriptional regulation mechanisms implicated in seed development(SD)is still limited,particularly in one of the most consumed grain legumes,Phaseolus vulgaris L.We explore for the first time the miRNA expression dynamics in P.vulgaris developing seeds.Seventy-two known and 39 new miRNAs were found expressed in P.vulgaris developing seeds.Most of the miRNAs identified were more abundant at 10 and 40 days after anthesis,suggesting that late embryogenesis/early filling and desiccation were SD stages in which miRNA action is more pronounced.Degradome analysis and target prediction identified targets for 77 expressed miRNAs.While several known miRNAs were predicted to target HD-ZIP,ARF,SPL,and NF-Y transcription factors families,most of the predicted targets for new miRNAs encode for functional proteins.MiRNAs-targets expression profiles evidenced that these miRNAs could tune distinct seed developmental stages.MiRNAs more accumulated at early SD stages were implicated in regulating the end of embryogenesis,postponing the seed maturation program,storage compound synthesis and allocation.MiRNAs more accumulated at late SD stages could be implicated in seed quiescence,desiccation tolerance,and longevity with still uncovered roles in germination.The miRNAs herein described represent novel P.vulgaris resources with potential application in future biotechnological approaches to modulate the expression of genes implicated in legume seed traits with impact in horticultural production systems.展开更多
Common bean(Phaseolus vulgaris L.),one of the most consumed food legumes worldwide,is threatened by two main constraints that are found frequently together in nature,water deficit(WD)and fusarium wilt(Fop).To understa...Common bean(Phaseolus vulgaris L.),one of the most consumed food legumes worldwide,is threatened by two main constraints that are found frequently together in nature,water deficit(WD)and fusarium wilt(Fop).To understand the shared and unique responses of common bean to Fop and WD,we analyzed the transcriptomic changes and phenotypic responses in two accessions,one resistant and one susceptible to both stresses,exposed to single and combined stresses.Physiological responses(photosynthetic performance and pigments quantification)and disease progression were also assessed.The combined FopWD imposition negatively affected the photosynthetic performance and increased the susceptible accession disease symptoms.The susceptible accession revealed a higher level of transcriptional changes than the resistant one,and WD single stress triggered the highest transcriptional changes.While 89 differentially expressed genes were identified exclusively in combined stresses for the susceptible accession,35 were identified in the resistant one.These genes belong mainly to“stress”,“signaling”,“cell wall”,“hormone metabolism”,and“secondary metabolism”functional categories.Among the up-regulated genes with higher expression in the resistant accession,the cysteine-rich secretory,antigen 5 and Pr-1(CAP)superfamily protein,a ribulose bisphosphate carboxylase family protein,and a chitinase A seem promising targets for multiple stress breeding.展开更多
文摘Water deficit is a major worldwide constraint to common bean(Phaseolus vulgaris L.)production,being photosynthesis one of the most affected physiological processes.To gain insights into the genetic basis of the photosynthetic response of common bean under water-limited conditions,a collection of 158 Portuguese accessions was grown under both well-watered and water-deficit regimes.Leaf gas-exchange parameters were measured and photosynthetic pigments quantified.The same collection was genotyped using SNP arrays,and SNP-trait associations tested considering a linear mixed model accounting for the genetic relatedness among accessions.A total of 133 SNP-trait associations were identified for net CO 2 assimilation rate,transpiration rate,stomatal conductance,and chlorophylls a and b,carotenes,and xanthophyll contents.Ninety of these associations were detected under water-deficit and 43 under well-watered conditions,with only two associations common to both treatments.Identified candidate genes revealed that stomatal regulation,protein translocation across membranes,redox mechanisms,hormone,and osmotic stress signaling were the most relevant processes involved in common bean response to water-limited conditions.These candidates are now preferential targets for common bean water-deficit-tolerance breeding.Additionally,new sources of water-deficit tolerance of Andean,Mesoamerican,and admixed origin were detected as accessions valuable for breeding,and not yet explored.
文摘The knowledge on post-transcriptional regulation mechanisms implicated in seed development(SD)is still limited,particularly in one of the most consumed grain legumes,Phaseolus vulgaris L.We explore for the first time the miRNA expression dynamics in P.vulgaris developing seeds.Seventy-two known and 39 new miRNAs were found expressed in P.vulgaris developing seeds.Most of the miRNAs identified were more abundant at 10 and 40 days after anthesis,suggesting that late embryogenesis/early filling and desiccation were SD stages in which miRNA action is more pronounced.Degradome analysis and target prediction identified targets for 77 expressed miRNAs.While several known miRNAs were predicted to target HD-ZIP,ARF,SPL,and NF-Y transcription factors families,most of the predicted targets for new miRNAs encode for functional proteins.MiRNAs-targets expression profiles evidenced that these miRNAs could tune distinct seed developmental stages.MiRNAs more accumulated at early SD stages were implicated in regulating the end of embryogenesis,postponing the seed maturation program,storage compound synthesis and allocation.MiRNAs more accumulated at late SD stages could be implicated in seed quiescence,desiccation tolerance,and longevity with still uncovered roles in germination.The miRNAs herein described represent novel P.vulgaris resources with potential application in future biotechnological approaches to modulate the expression of genes implicated in legume seed traits with impact in horticultural production systems.
文摘Common bean(Phaseolus vulgaris L.),one of the most consumed food legumes worldwide,is threatened by two main constraints that are found frequently together in nature,water deficit(WD)and fusarium wilt(Fop).To understand the shared and unique responses of common bean to Fop and WD,we analyzed the transcriptomic changes and phenotypic responses in two accessions,one resistant and one susceptible to both stresses,exposed to single and combined stresses.Physiological responses(photosynthetic performance and pigments quantification)and disease progression were also assessed.The combined FopWD imposition negatively affected the photosynthetic performance and increased the susceptible accession disease symptoms.The susceptible accession revealed a higher level of transcriptional changes than the resistant one,and WD single stress triggered the highest transcriptional changes.While 89 differentially expressed genes were identified exclusively in combined stresses for the susceptible accession,35 were identified in the resistant one.These genes belong mainly to“stress”,“signaling”,“cell wall”,“hormone metabolism”,and“secondary metabolism”functional categories.Among the up-regulated genes with higher expression in the resistant accession,the cysteine-rich secretory,antigen 5 and Pr-1(CAP)superfamily protein,a ribulose bisphosphate carboxylase family protein,and a chitinase A seem promising targets for multiple stress breeding.