Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266000, People's Republic of China; Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, People's Republic of China.
Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266000, People's Republic of China.
Plant Sci. 2019 Mar;280:1-11. doi: 10.1016/j.plantsci.2018.11.004. Epub 2018 Nov 13.
Abscisic acid (ABA) and jasmonates (JAs) are the primary plant hormones involved in mediating salt tolerance. In addition, these two plant hormones exert a synergistic effect to inhibit seed germination. However, the molecular mechanism of the interaction between ABA signalling and JA signalling is still not well documented. Here, a moss jasmonate ZIM-domain gene (PnJAZ1), which encodes a nucleus-localized protein with conserved ZIM and Jas domains, was cloned from Pohlia nutans. PnJAZ1 expression was rapidly induced by various abiotic stresses. The PnJAZ1 protein physically interacted with MYC2 and was degraded by exogenous 12-oxo-phytodienoic acid (OPDA) treatment, implying that the JAZ protein-mediated signalling pathway is conserved in plants. Transgenic Arabidopsis and Physcomitrella plants overexpressing PnJAZ1 showed increased tolerance to salt stress and decreased ABA sensitivity during seed germination and early development. The overexpression of PnJAZ1 inhibited the expression of ABA pathway genes related to seed germination and seedling growth. Moreover, the transgenic Arabidopsis lines exhibited enhanced tolerance to auxin (IAA) and glucose, mimicking the phenotypes of abi4 or abi5 mutants. These results suggest that PnJAZ1 acts as a repressor, mediates JA-ABA synergistic crosstalk and enhances plant growth under salt stress.
脱落酸（ABA）和茉莉酸（JAs）是参与介导盐胁迫耐受性的主要植物激素。此外，这两种植物激素发挥协同作用抑制种子萌发。然而，ABA 信号和 JA 信号之间相互作用的分子机制仍未得到很好的阐述。在这里，从 Pohlia nutans 中克隆了一种苔藓茉莉酸 ZIM 结构域基因（PnJAZ1），该基因编码一种具有保守 ZIM 和 Jas 结构域的核定位蛋白。PnJAZ1 的表达被各种非生物胁迫迅速诱导。PnJAZ1 蛋白与 MYC2 发生物理相互作用，并被外源 12-氧-植物二烯酸（OPDA）处理降解，这表明 JAZ 蛋白介导的信号通路在植物中是保守的。过表达 PnJAZ1 的转基因拟南芥和Physcomitrella 植物对盐胁迫的耐受性增加，在种子萌发和早期发育过程中 ABA 敏感性降低。PnJAZ1 的过表达抑制了与种子萌发和幼苗生长相关的 ABA 途径基因的表达。此外，转基因拟南芥系表现出对生长素（IAA）和葡萄糖的耐受性增强，模拟 abi4 或 abi5 突变体的表型。这些结果表明，PnJAZ1 作为一种抑制剂，介导 JA-ABA 协同互作，并增强植物在盐胁迫下的生长。
