PDF(Pubmed)
Abstract：
Brassinosteroids (BRs) are a group of polyhydroxylated steroids for plant growth and development, regulating numerous physiological and biochemical processes and participating in multi-pathway signaling in plants. 24-Epibrassinolide (EBR) is the most commonly used BR for the investigation of the effects of exogenous steroidal phytohormones on plant physiology. Although SlSERK3B is considered a gene involved in the brassinosteroid (BR) signaling pathway, its specific role in plant growth and development has not been reported in detail. In this study, tomato (Solanum lycopersicum L.) seedlings treated with 0.05 μmol L-1 EBR showed a significant increase in plant height, stem diameter, and fresh weight, demonstrating that BR promotes the growth of tomato seedlings. EBR treatment increased the expression of the BR receptor gene SlBRI1, the co-receptor gene SlSERK3A and its homologs SlSERK3B, and SlBZR1. The SlSERK3B gene was silenced by TRV-mediated virus-induced gene silencing (VIGS) technology. The results showed that both brassinolide (BL) content and BR synthesis genes were significantly up-regulated in TRV-SlSERK3B-infected seedlings compared to the control seedlings. In contrast, plant height, stem diameter, fresh weight, leaf area and total root length were significantly reduced in silenced plants. These results suggest that silencing SlSERK3B may affect BR synthesis and signaling, thereby affecting the growth of tomato seedlings. Furthermore, the photosynthetic capacity of TRV-SlSERK3B-infected tomato seedlings was reduced, accompanied by decreased photosynthetic pigment content chlorophyll fluorescence, and photosynthesis parameters. The expression levels of chlorophyll-degrading genes were significantly up-regulated, and carotenoid-synthesising genes were significantly down-regulated in TRV-SlSERK3B-infected seedlings. In conclusion, silencing of SlSERK3B inhibited BR signaling and reduced photosynthesis in tomato seedlings, and this correlation suggests that SlSERK3B may be related to BR signaling and photosynthesis enhancement.
摘要：
油菜素类固醇（BRs）是一组多羟基类固醇，用于植物生长和发育，调节植物的许多生理和生化过程并参与多途径信号传导。24-表油菜素内酯（EBR）是最常用的BR，用于研究外源类固醇植物激素对植物生理的影响。尽管SlSERK3B被认为是参与油菜素类固醇（BR）信号通路的基因，其在植物生长发育中的具体作用尚未详细报道。在这项研究中,用0.05μmolL-1EBR处理的番茄（SolanumlycopersicumL.）幼苗显示出植物高度的显着增加，阀杆直径,和新鲜的重量，表明BR促进番茄幼苗的生长。EBR处理增加BR受体基因SlBRI1、共受体基因SlSERK3A及其同源物SlSERK3B的表达,和SlBZR1。通过TRV介导的病毒诱导基因沉默(VIGS)技术沉默SlSERK3B基因。结果表明，与对照幼苗相比，TRV-SlSERK3B感染的幼苗中油菜素内酯（BL）含量和BR合成基因均显着上调。相比之下,植物高度,阀杆直径,鲜重,在沉默的植物中，叶面积和总根长明显减少。这些结果表明，沉默SlSERK3B可能会影响BR的合成和信号传导，从而影响番茄幼苗的生长。此外，TRV-SlSERK3B感染番茄幼苗的光合能力降低，伴随着光合色素含量下降叶绿素荧光，和光合作用参数。叶绿素降解基因的表达水平显著上调,在TRV-SlSERK3B感染的幼苗中，类胡萝卜素合成基因显着下调。总之,SlSERK3B的沉默抑制了番茄幼苗的BR信号和减少的光合作用，这种相关性表明SlSERK3B可能与BR信号传导和光合作用增强有关。
