The RING Finger Ubiquitin E3 Ligase OsHTAS Enhances Heat Tolerance by Promoting H2O2-Induced Stomatal Closure in Rice
The RING Finger Ubiquitin E3 Ligase OsHTAS Enhances Heat Tolerance by Promoting H2O2-Induced Stomatal Closure in Rice
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RING Finger 泛素 E3 连接酶 OsHTAS 通过促进 H2O2 诱导的水稻气孔关闭来增强耐热性
DOI：
10.1104/pp.15.00879
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发表时间：
2016-01-01
期刊：
影响因子：
7.4
通讯作者：
Tu, Jumin
中科院分区：
文献类型：
--
作者：
Liu, Jianping;Zhang, Cuicui;Tu, Jumin
热胁迫经常导致过氧化氢等活性氧物种的产生，在脱落酸(ABA)介导的气孔关闭过程中扮演着重要的第二信使角色。在此，我们对水稻苗期耐热性基因(OsHTAS)进行了鉴定，该基因在水稻苗期耐热性中起积极作用。OsHTAS编码一种定位于细胞核和细胞质的泛素连接酶。OsHTAS在所有供试组织中均有表达，且在叶片中表达最强，表达集中在叶肉细胞中。OsHTAS对多种胁迫反应强烈，且受外源ABA强烈诱导。在酵母双杂交试验中，OsHTAS与泛素/26S蛋白酶体系统的组件和水稻抗坏血酸过氧化物酶的一种异构体相互作用。OsHTAS调节地上部过氧化氢的积累，改变水稻叶片的气孔状态，促进ABA的生物合成。这些结果表明，环指泛素E3连接酶OsHTAS在叶片中通过调节过氧化氢诱导的气孔关闭来增强耐热性，并参与了ABA依赖和耐旱性和盐耐性介导的途径。
Heat stress often results in the generation of reactive oxygen species, such as hydrogen peroxide, which plays a vital role as a secondary messenger in the process of abscisic acid (ABA)-mediated stomatal closure. Here, we characterized the rice (Oryza sativa) HEAT TOLERANCE AT SEEDLING STAGE (OsHTAS) gene, which plays a positive role in heat tolerance at the seedling stage. OsHTAS encodes a ubiquitin ligase localized to the nucleus and cytoplasm. OsHTAS expression was detected in all tissues surveyed and peaked in leaf blade, in which the expression was concentrated in mesophyll cells. OsHTAS was responsive to multiple stresses and was strongly induced by exogenous ABA. In yeast two-hybrid assays, OsHTAS interacted with components of the ubiquitin/26S proteasome system and an isoform of rice ascorbate peroxidase. OsHTAS modulated hydrogen peroxide accumulation in shoots, altered the stomatal aperture status of rice leaves, and promoted ABA biosynthesis. The results suggested that the RING finger ubiquitin E3 ligase OsHTAS functions in leaf blade to enhance heat tolerance through modulation of hydrogen peroxide-induced stomatal closure and is involved in both ABA-dependent and DROUGHT AND SALT TOLERANCE-mediated pathways.