Zu Song-Hao, Jiang Yu-Tong, Hu Li-Qin, Zhang Yan-Jie, Chang Jin-Hui, Xue Hong-Wei, Lin Wen-Hui
School of Life Sciences and Biotechnology, The Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai, China.
School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
Front Plant Sci. 2019 Jul 26;10:980. doi: 10.3389/fpls.2019.00980. eCollection 2019.
Brassinosteroid (BR) is a family of bioactive steroid hormones that plays vital roles in plant growth and development. The BR-mediated regulation of plant growth and architecture has been well studied. However, relatively few studies have investigated the BR-related regulation of reproductive development because of the difficulties in excluding non-specific regulation and secondary responses from severe vegetative phenotypes and poor nutritional status. Furthermore, differentially regulating the BR signal in vegetative and reproductive organs is problematic. Thus, establishing a method for modulating the BR signal only in reproductive organs or during reproductive developmental stages will be beneficial. Additionally, the utility of BR applications for crop production is limited because of deleterious side-effects, including the associated decrease in the planting density and lodging resistance. Moreover, enhancing the BR signal may lead to feedback inhibition. In this study, we developed a transformation system for modulating the BR signal differentially during reproductive and vegetative developmental stages. This system involves transformations with different combinations of a reproductive tissue-specific promoter, coding sequences that increase or decrease the BR signal, and various genotypic backgrounds with enhanced or decreased BR signals. The enhanced BR signal generated in transformants was targeted to reproductive organs without affecting vegetative organs. This system may be useful for studying the BR-specific regulation of plant reproductive development and shows promise for optimizing seed yield.
油菜素内酯（BR）是一类生物活性甾体激素，在植物生长发育中起着至关重要的作用。BR介导的植物生长和形态调控已得到充分研究。然而，由于难以从严重的营养表型和不良营养状况中排除非特异性调控和次级反应，相对较少的研究调查了BR相关的生殖发育调控。此外，在营养器官和生殖器官中差异调节BR信号存在问题。因此，建立一种仅在生殖器官或生殖发育阶段调节BR信号的方法将是有益的。此外，由于包括种植密度和抗倒伏性降低等有害副作用，BR在作物生产中的应用效用有限。此外，增强BR信号可能会导致反馈抑制。在本研究中，我们开发了一种转化系统，用于在生殖和营养发育阶段差异调节BR信号。该系统涉及用生殖组织特异性启动子、增加或降低BR信号的编码序列以及具有增强或降低BR信号的各种基因型背景的不同组合进行转化。转化体中产生的增强BR信号靶向生殖器官而不影响营养器官。该系统可能有助于研究植物生殖发育的BR特异性调控，并有望优化种子产量。
