Parker Travis A, Lo Sassoum, Gepts Paul
Department of Plant Sciences/MS1, Section of Crop & Ecosystem Sciences, University of California, 1 Shields Avenue, Davis, CA 95616-8780.
Plant Cell. 2021 Apr 17;33(2):179-199. doi: 10.1093/plcell/koaa025.
A reduction in pod shattering is one of the main components of grain legume domestication. Despite this, many domesticated legumes suffer serious yield losses due to shattering, particularly under arid conditions. Mutations related to pod shattering modify the twisting force of pod walls or the structural strength of the dehiscence zone in pod sutures. At a molecular level, a growing body of evidence indicates that these changes are controlled by a relatively small number of key genes that have been selected in parallel across grain legume species, supporting partial molecular convergence. Legume homologs of Arabidopsis thaliana silique shattering genes play only minor roles in legume pod shattering. Most domesticated grain legume species contain multiple shattering-resistance genes, with mutants of each gene typically showing only partial shattering resistance. Hence, crosses between varieties with different genes lead to transgressive segregation of shattering alleles, producing plants with either enhanced shattering resistance or atavistic susceptibility to the trait. The frequency of these resistance pod-shattering alleles is often positively correlated with environmental aridity. The continued development of pod-shattering-related functional information will be vital for breeding crops that are suited to the increasingly arid conditions expected in the coming decades.
豆荚易裂性的降低是豆科粮食作物驯化的主要组成部分之一。尽管如此，许多驯化的豆科植物仍因豆荚易裂而遭受严重的产量损失，特别是在干旱条件下。与豆荚易裂相关的突变会改变豆荚壁的扭曲力或豆荚缝线处开裂区的结构强度。在分子水平上，越来越多的证据表明，这些变化由相对较少的关键基因控制，这些基因在不同的豆科粮食作物物种中被平行选择，这支持了部分分子趋同现象。拟南芥角果开裂基因的豆科同源物在豆科植物豆荚开裂中仅起次要作用。大多数驯化的豆科粮食作物物种含有多个抗裂基因，每个基因的突变体通常仅表现出部分抗裂性。因此，具有不同基因的品种之间杂交会导致开裂等位基因的超亲分离，产生具有增强抗裂性或返祖易裂性的植株。这些抗裂豆荚等位基因的频率通常与环境干旱程度呈正相关。持续开展与豆荚开裂相关的功能信息研究对于培育适应未来几十年预期日益干旱条件的作物至关重要。
