植物BZR家族基因调控非生物胁迫应答和生长发育的研究进展

由于固着生长的特性,植物在生长发育过程中会遭遇各种不利环境的影响,因此植物发展出复杂的调控机制来抵御胁迫危害。油菜素内酯(brassinosteroid,BR)是一类甾醇类植物内源激素,广泛参与植物生命周期中各种生命活动的调节。近年来,植物BR生物合成、代谢及信号转导过程相关研究已取得重要进展。油菜素唑抗性因子(brassinazole resistant,BZR)作为BR信号通路中特有的一类转录因子,在该通路中发挥重要作用。本文概述了植物BZR家族成员的基本结构及其生物学功能,重点阐述了BZR在植物非生物胁迫应答和生长发育中的调控作用,特别归纳了油料作物BZR研究进展,并对一些尚未明确的问题进行了探讨,旨在为深入理解BR介导的分子调控网络、改良作物抗逆性并提高作物生产力提供理论依据。     

Systemic Effect of a Brassinosteroid on Root Nodule Formation in Soybean as Revealed by the Application of Brassinolide and Brassinazole

Leguminous plants form nitrogen-fixing root nodules and the number of nodules is controlled by a self-regulating mechanism called autoregulation. However, signaling substances involved in nodule regulation have not been identified. In the present study, we used brassinolide, a most effective molecular species of plant hormone brassinosteroids, and brassinazole, an effective inhibitor of brassinosteroid biosynthesis to determine whether brassinolide played a role in systemic regulation of noduel formation in wild type soybean and its super-nodulating mutant. Foliar application or direct injection of brassinolide into the root base inhibited nodule formation and root development in the super-nodulating mutant (En6500), but not in the parent line (cv. Enrei). The internodes in the plants subjected to foliar application were significantly longer than those in the untreated plants. In contrast, the application of brassinazole on mature leaves or into the culture media resulted in the increase of the nodule number in Enrei. These treatments also inhibited internodal growth in Enrei. The results indicate that brassinosteroids may regulate the nodule number in soybean plants. The function of brassinosteroids for the systemic regulation of nodule formation was examined.