Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy (DISAA), Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy.
Int J Mol Sci. 2020 Feb 11;21(4):1191. doi: 10.3390/ijms21041191.
The most consistent phenotype of the brassinosteroid (BR)-related mutants is the dwarf habit. This observation has been reported in every species in which BR action has been studied through a mutational approach. On this basis, a significant role has been attributed to BRs in promoting plant growth. In this review, we summarize the work conducted in rice, maize, and barley for the genetic dissection of the pathway and the functional analysis of the genes involved. Similarities and differences detected in these species for the BR role in plant development are presented. BR promotes plant cell elongation through a complex signalling cascade that modulates the activities of growth-related genes and through the interaction with gibberellins (GAs), another class of important growth-promoting hormones. Evidence of BR-GA cross-talk in controlling plant height has been collected, and mechanisms of interaction have been studied in detail in and in rice (). The complex picture emerging from the studies has highlighted points of interaction involving both metabolic and signalling pathways. Variations in plant stature influence plant performance in terms of stability and yield. The comprehension of BR's functional mechanisms will therefore be fundamental for future applications in plant-breeding programs.
植物激素油菜素内酯（BR）相关突变体最一致的表型是矮化习性。通过突变体的方法研究 BR 作用的每一种物种中都报告了这一观察结果。在此基础上，BR 在促进植物生长方面被赋予了重要作用。在这篇综述中，我们总结了在水稻、玉米和大麦中进行的遗传剖析途径和所涉及基因的功能分析的工作。介绍了这些物种中 BR 在植物发育中的作用的相似性和差异。BR 通过调节与生长相关基因的活性以及与赤霉素（GA）的相互作用，促进植物细胞伸长，GA 是另一类重要的促进生长的激素。已经收集了 BR-GA 相互作用在控制株高方面的证据，并在 和水稻（）中详细研究了相互作用的机制。从研究中出现的复杂情况突出了涉及代谢和信号通路的相互作用点。株高的变化会影响植物的稳定性和产量。因此，对 BR 功能机制的理解将是未来在植物育种计划中应用的基础。
