植物学报 ›› 2019, Vol. 54 ›› Issue (2): 185-193.DOI: 10.11983/CBB19013

所属专题: 逆境生物学专辑 (2019年54卷2期)

• 研究报告 • 上一篇    下一篇

油菜素甾醇调控水稻盐胁迫应答的作用研究

栗露露,殷文超,牛梅,孟文静,张晓星,童红宁()   

  1. 农作物基因资源与基因改良国家重大科学工程/中国农业科学院作物科学研究所, 北京 100081
  • 收稿日期:2019-01-18 接受日期:2019-03-19 出版日期:2019-03-10 发布日期:2019-09-01
  • 通讯作者: 童红宁
  • 基金资助:
    国家自然科学基金(91735302);国家自然科学基金(31871587);国家自然科学基金(31722037)

Functional Analysis of Brassinosteroids in Salt Stress Responses in Rice

Lulu Li,Wenchao Yin,Mei Niu,Wenjing Meng,Xiaoxing Zhang,Hongning Tong()   

  1. Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Beijing 100081, China
  • Received:2019-01-18 Accepted:2019-03-19 Online:2019-03-10 Published:2019-09-01
  • Contact: Hongning Tong

摘要: 油菜素甾醇(BR)作为植物内源激素, 广泛参与植物的生长发育过程及逆境应答。虽然BR调控生长发育的分子机制目前已相对清楚, 但在水稻(Oryza sativa)中, BR在逆境反应中的功能还鲜有报道。该研究系统分析了BR在高盐胁迫过程中的作用, 表明盐胁迫和逆境激素脱落酸可抑制BR合成基因D2D11的表达, 典型的BR缺陷突变体(如d2-2d61-1)则表现出对盐胁迫敏感性增强。此外, 通过对BR核心转录因子OsBZR1的过表达株系进行分析, 发现BR可显著诱导OsBZR1的去磷酸化, 盐胁迫对OsBZR1蛋白的积累水平和磷酸化状态均有调控作用。转录组数据分析表明, BR处理前后差异表达基因中有38.4%同时受到盐胁迫调控, 其中91.5%受到BR和高盐一致调控, 并显著富集在应激反应过程中。研究结果表明, BR正调控水稻的耐盐性, 而盐胁迫通过抑制BR合成来限制水稻的生长。

关键词: 油菜素甾醇, 水稻, 盐胁迫, 脱落酸, OsBZR1

Abstract: Brassinosteroids (BRs) are a class of steroid phytohormones that play diverse roles in plant growth and development and stress responses. Rapid progresses have been made in how BRs regulate plant growth and development in recent years. However, the roles of BRs in stress response in Oryza sativa remain unclear. Here, we investigated the relation between salinity stress and BR synthesis in rice. Both salt stress and abscisic acid, the well-known stress hormone, strongly inhibited the expression of two BR-synthetic genes, D2 and D11. In addition, both d2-2, the BR synthetic mutant, and d61-1, the BR receptor mutant, showed impaired tolerance to salt stress. Moreover, by using transgenic plants overexpressing OsBZR1, the key BR signaling transcriptional factor, we found that BRs strongly induced dephosphorylation of OsBZR1, but high concentrations of salt suppressed OsBZR1 protein accumulation as well as its dephosphorylation. Furthermore, transcriptome analyses revealed that 38.4% of BR-regulated genes were also regulated by high concentrations of salt, and importantly, 91.5% of the co-regulated genes are consistently up- or downregulated by both BR and salt. Gene Ontology analyses revealed that these overlapping genes were highly enriched in the biological process “response to stimulus”. Taken together, our results suggest that BRs contribute to salt stress tolerance, and salt stress suppresses BR synthesis to restrict rice growth.

Key words: brassinosteroid, rice, salt stress, abscisic acid, OsBZR1