Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, State Key Laboratory of Hydraulics and Mountain River Engineering, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, State Key Laboratory of Hydraulics and Mountain River Engineering, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
Biochem Biophys Res Commun. 2020 Jul 23;528(2):292-298. doi: 10.1016/j.bbrc.2020.05.067. Epub 2020 Jun 1.
Abscisic acid (ABA) is an important plant hormone that mediates abiotic stresses in plant growth and development. A number of E3 ligases have been reported to be involved in ABA signaling pathway. In this study, we identified a C3H2C3 RING-type E3 ligase, Arabidopsis thaliana Tόxicos en Levadura 61 (ATL61), which regulated drought stress in planta. Enzyme assay in vitro demonstrated that ATL61 had E3 ubiquitin ligase activity, while point mutation of ATL61 (mATL61) abolished its E3 ubiquitin ligase activity. ATL61 overexpression plants exhibited ABA hypersensitivity and were more tolerant to drought, while the atl61 mutant plants were insensitive to ABA. Moreover, mATL61 overexpression lines exhibited similar ABA-related phenotypes with wild type (WT) plants. The transcript abundances of ABA-mediated drought stress-related genes RD20 and RD22 were higher in ATL61 overexpression plants than those in WT, atl61, and mATL61 plants. Our results indicated that ATL61 acted as a positive regulator in the ABA-mediated drought stress response.
脱落酸（ABA）是一种重要的植物激素，介导植物生长发育中的非生物胁迫。已经报道了许多 E3 连接酶参与 ABA 信号通路。在这项研究中，我们鉴定了一个 C3H2C3 RING 型 E3 连接酶，拟南芥 Tόxicos en Levadura 61（ATL61），它调节植物中的干旱胁迫。体外酶活性测定表明 ATL61 具有 E3 泛素连接酶活性，而 ATL61 的点突变（mATL61）使其 E3 泛素连接酶活性丧失。ATL61 过表达植物表现出 ABA 超敏性，对干旱更耐受，而 atl61 突变体植物对 ABA 不敏感。此外，mATL61 过表达系表现出与野生型（WT）植物相似的 ABA 相关表型。在 ATL61 过表达植物中，ABA 介导的干旱胁迫相关基因 RD20 和 RD22 的转录丰度高于 WT、atl61 和 mATL61 植物。我们的结果表明，ATL61 作为 ABA 介导的干旱胁迫反应的正调节剂发挥作用。
