Domestication imposed radical selection pressures on plants,transforming them into crops that support global populations today.In this study,we investigate the loss of seed dispersal via pod shattering during common b...Domestication imposed radical selection pressures on plants,transforming them into crops that support global populations today.In this study,we investigate the loss of seed dispersal via pod shattering during common bean(Phaseolus vulgaris L.)domestication.We identified PvMYB26 mutations in all three main gene pools of common bean,including an 8 kb deletion in Middle American lines eliminating the gene’s transcription start site and promoter,a frameshift/truncation deletion in the independently domesticated Andean population,and another frameshift/truncation insertion in the genetic background of the‘‘undomesticated’’debouckii population.Mutants with the 8 kb deletion express PvMYB26 at<1%of the level of wild types and produce 44%less pod lignin.RNA in situ hybridization and fluorescence microscopy showed that PvMYB26 is expressed in the lignified fiber layer of pods,while mutants showed no visible expression and a greatly reduced fiber layer.Sequencing of 327 accessions revealed that the mutation is nearly diagnostic for domestication status among Middle American common bean and identified a 125 kb hard selective sweep,indicating the gene’s importance in domestication.The main Andean frameshift mutation was found in 84.5%of Andean domesticates but 0%of wild lines,while the debouckii truncation was identified in six domesticated lines of race Peru,suggesting that a third proto-domestication of common bean may have occurred in Ecuador and/or northern Peru.Wild haplotypes most like Middle American domesticates were found in eastern Jalisco,Mexico,strongly suggesting west-central Mexico as the site of common bean domestication and the rise of agriculture in Middle America.展开更多
Anther dehiscence is a crucial event in plant reproduction,tightly regulated and dependent on the lignification of the anther endothecium.In this study,we investigated the rapid lignification process that ensures time...Anther dehiscence is a crucial event in plant reproduction,tightly regulated and dependent on the lignification of the anther endothecium.In this study,we investigated the rapid lignification process that ensures timely anther dehiscence in Arabidopsis.Our findings reveal that endothecium lignification can be divided into two distinct phases.During Phase Ⅰ,lignin precursors are synthesized without polymerization,while Phase Ⅱ involves simultaneous synthesis of lignin precursors and polymerization.The transcription factors MYB26,NST1/2,and ARF17 specifically regulate the pathway responsible for the synthesis and polymerization of lignin monomers in Phase Ⅱ.MYB26-NST1/2 is the key regulatory pathway responsible for endothecium lignification,while ARF17 facilitates this process by interacting with MYB26.Interestingly,our results demonstrate that the lignification of the endothecium,which occurs within approximately 26 h,is much faster than that of the vascular tissue.These findings provide valuable insights into the regulation mechanism of rapid lignification in the endothecium,which enables timely anther dehiscence and successful pollen release during plant reproduction.展开更多
基金funded by Kirkhouse Trust A23-1518-001 to T.A.P.and USDA-AFRI award 2023-67013-40001 to T.A.P.X.X.acknowledges support from the University of California,Davis new faculty start-up funds and California Agricultural Experiment Station/National Institute of Food and Agriculture(CA-D-PLB-2850-H)Sequencing and analysis conducted by J.R.and P.E.M.were funded by Predictive Crop Performance Research Initiative award 58-3060-3-016,US Department of Agriculture,Agricultural Research Service.
文摘Domestication imposed radical selection pressures on plants,transforming them into crops that support global populations today.In this study,we investigate the loss of seed dispersal via pod shattering during common bean(Phaseolus vulgaris L.)domestication.We identified PvMYB26 mutations in all three main gene pools of common bean,including an 8 kb deletion in Middle American lines eliminating the gene’s transcription start site and promoter,a frameshift/truncation deletion in the independently domesticated Andean population,and another frameshift/truncation insertion in the genetic background of the‘‘undomesticated’’debouckii population.Mutants with the 8 kb deletion express PvMYB26 at<1%of the level of wild types and produce 44%less pod lignin.RNA in situ hybridization and fluorescence microscopy showed that PvMYB26 is expressed in the lignified fiber layer of pods,while mutants showed no visible expression and a greatly reduced fiber layer.Sequencing of 327 accessions revealed that the mutation is nearly diagnostic for domestication status among Middle American common bean and identified a 125 kb hard selective sweep,indicating the gene’s importance in domestication.The main Andean frameshift mutation was found in 84.5%of Andean domesticates but 0%of wild lines,while the debouckii truncation was identified in six domesticated lines of race Peru,suggesting that a third proto-domestication of common bean may have occurred in Ecuador and/or northern Peru.Wild haplotypes most like Middle American domesticates were found in eastern Jalisco,Mexico,strongly suggesting west-central Mexico as the site of common bean domestication and the rise of agriculture in Middle America.
基金supported by grants from the National Key R&D Program of China (2022YFF1003502)the National Natural Science Foundation of China (31930009, 31900165)the Innovation Program of Shanghai Municipal Education Commission (2019-01-07-00-02-E00006)。
文摘Anther dehiscence is a crucial event in plant reproduction,tightly regulated and dependent on the lignification of the anther endothecium.In this study,we investigated the rapid lignification process that ensures timely anther dehiscence in Arabidopsis.Our findings reveal that endothecium lignification can be divided into two distinct phases.During Phase Ⅰ,lignin precursors are synthesized without polymerization,while Phase Ⅱ involves simultaneous synthesis of lignin precursors and polymerization.The transcription factors MYB26,NST1/2,and ARF17 specifically regulate the pathway responsible for the synthesis and polymerization of lignin monomers in Phase Ⅱ.MYB26-NST1/2 is the key regulatory pathway responsible for endothecium lignification,while ARF17 facilitates this process by interacting with MYB26.Interestingly,our results demonstrate that the lignification of the endothecium,which occurs within approximately 26 h,is much faster than that of the vascular tissue.These findings provide valuable insights into the regulation mechanism of rapid lignification in the endothecium,which enables timely anther dehiscence and successful pollen release during plant reproduction.
