Liu Jianping, Zhang Cuicui, Wei Chuchu, Liu Xin, Wang Mugui, Yu Feifei, Xie Qi, Tu Jumin
Institute of Crop Science, Zhejiang University, Hangzhou 310058, China (J.L., C.Z., C.W., X.L., M.W., J.T.); andState Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China (F.Y., Q.X.).
Institute of Crop Science, Zhejiang University, Hangzhou 310058, China (J.L., C.Z., C.W., X.L., M.W., J.T.); andState Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China (F.Y., Q.X.)
Plant Physiol. 2016 Jan;170(1):429-43. doi: 10.1104/pp.15.00879. Epub 2015 Nov 12.
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.
热胁迫常常导致活性氧的产生，比如过氧化氢，它在脱落酸（ABA）介导的气孔关闭过程中作为第二信使发挥着至关重要的作用。在此，我们对水稻（Oryza sativa）幼苗期耐热性（OsHTAS）基因进行了表征，该基因在幼苗期耐热性方面发挥着积极作用。OsHTAS编码一种定位于细胞核和细胞质的泛素连接酶。在所有被检测的组织中均检测到了OsHTAS的表达，且在叶片中表达量达到峰值，其表达集中在叶肉细胞中。OsHTAS对多种胁迫有响应，并且受到外源ABA的强烈诱导。在酵母双杂交试验中，OsHTAS与泛素/26S蛋白酶体系统的组分以及水稻抗坏血酸过氧化物酶的一种同工型相互作用。OsHTAS调节地上部过氧化氢的积累，改变水稻叶片的气孔孔径状态，并促进ABA的生物合成。结果表明，环状泛素E3连接酶OsHTAS在叶片中发挥作用，通过调节过氧化氢诱导的气孔关闭来增强耐热性，并且参与ABA依赖和耐旱耐盐介导的途径。
