文献类型：期刊文献

英文题名：Exogenous applications of brassinosteroids promote secondary xylem differentiation in Eucalyptus grandis

作者：Zhou, Fangping[1,2] Hu, Bing[1] Li, Juan[1] Yan, Huifang[3] Liu, Qianyu[4] Zeng, Bingshan[1] Fan, Chunjie[1,2]

第一作者：Zhou, Fangping

通信作者：Fan, CJ[1];Fan, CJ[2]

机构：[1]Chinese Acad Forestry, Res Inst Trop Forestry, Key Lab State Forestry Adm Trop Forestry, Guangzhou, Peoples R China;[2]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Beijing, Peoples R China;[3]Fudan Univ, Sch Life Sci, Shanghai, Peoples R China;[4]South China Agr Univ, State Key Lab Conservat & Utilizat Subtrop Agrobio, Guangzhou 510642, Peoples R China

年份：2024

卷号：12

外文期刊名：PEERJ

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001140597700004)】；

基金：Funding This work was supported by the Natural Science Foundation of Guangdong Province (2020A1515011059) and the National Natural Science Foundation of China (Grant No. 31400554) . The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

语种：英文

外文关键词：Brassinosteroids; Eucalyptus grandis; Xylem; Gene expression

摘要：Brassinosteroids (BRs) play many pivotal roles in plant growth and development, especially in cell elongation and vascular development. Although its biosynthetic and signal transduction pathway have been well characterized in model plants, their biological roles in Eucalyptus grandis, a major hardwood tree providing fiber and energy worldwide, remain unclear. Here, we treated E. grandis plantlets with 24-epibrassinolide (EBL), the most active BR and/or BR biosynthesis inhibitor brassinazole. We recorded the plant growth and analyzed the cell structure of the root and stem with histochemical methods; then, we performed a secondary growth, BR synthesis, and signaling-related gene expression analysis. The results showed that the BRs dramatically increased the shoot length and diameter, and the exogenous BR increased the xylem area of the stem and root. In this process, EgrBRI1, EgrBZR1, and EgrBZR2 expression were induced by the BR treatment, and the expressions of HD-ZIPIII and cellulose synthase genes were also altered. To further verify the effect of BRs in secondary xylem development in Eucalyptus, we used six-month-old plants as the material and directly applied EBL to the xylem and cambium of the vertical stems. The xylem area, fiber cell length, and cell numbers showed considerable increases. Several key BR-signaling genes, secondary xylem development-related transcription factor genes, and cellulose and lignin biosynthetic genes were also considerably altered. Thus, BR had regulatory roles in secondary xylem development and differentiation via the BR-signaling pathway in this woody plant.