Overexpression of MpCYS4, A Phytocystatin Gene from Malus prunifolia (Willd.) Borkh., Enhances Stomatal Closure to Confer Drought Tolerance in Transgenic Arabidopsis and Apple.
Overexpression of MpCYS4, A Phytocystatin Gene from Malus prunifolia (Willd.) Borkh., Enhances Stomatal Closure to Confer Drought Tolerance in Transgenic Arabidopsis and Apple.
复制标题
MpCYS4（一种来自海棠的植物胱抑素基因）的过表达可增强转基因拟南芥和苹果的气孔闭合，从而赋予其耐旱性
DOI：
10.3389/fpls.2017.00033
复制
发表时间：
2017
影响因子：
5.6
通讯作者：
Ma F
中科院分区：
文献类型：
--
作者：
Tan Y;Li M;Yang Y;Sun X;Wang N;Liang B;Ma F
植物半胱氨酸抑制素（PhyCys）包括一组植物半胱氨酸蛋白酶抑制剂。它们在调节内源过程和保护植物免受各种环境胁迫方面发挥着广泛的重要作用，但其潜在机制仍不清楚。本文详细研究了从苹果中分离到的胱抑素基因成员MpCYS4的生物学功能。该基因在缺水、高温（40°C）、外源脱落酸（ABA）或甲基紫素（MV）下被激活（Tan et al., 2014a）。在细胞水平上，MpCYS4蛋白定位于洋葱表皮细胞的细胞核、细胞质和质膜。纯化了在大肠杆菌中表达的重组MpCYS4胱抑素，其具有抑制半胱氨酸蛋白酶的活性。转基因MpCYS4在拟南芥（Arabidopsis thaliana）和苹果（Malus domestica）中的过表达导致ABA过敏和ABA相关的一系列表型，如ABA诱导的气孔关闭增强，许多ABA/胁迫响应基因的表达改变，以及抗旱性增强。综上所述，我们的研究结果表明，MpCYS4参与ABA介导的胁迫信号转导，并至少部分通过增强气孔关闭和上调ABA和干旱相关基因的转录水平来赋予耐旱性。这些发现为植物胱抑素影响植物生长、发育和耐受性的分子机制提供了新的见解。
Phytocystatins (PhyCys) comprise a group of inhibitors for cysteine proteinases in plants. They play a wide range of important roles in regulating endogenous processes and protecting plants against various environmental stresses, but the underlying mechanisms remain largely unknown. Here, we detailed the biological functions of MpCYS4, a member of cystatin genes isolated from Malus prunifolia. This gene was activated under water deficit, heat (40°C), exogenous abscisic acid (ABA), or methyl viologen (MV) (Tan et al., 2014a). At cellular level, MpCYS4 protein was found to be localized in the nucleus, cytoplasm, and plasma membrane of onion epidermal cells. Recombinant MpCYS4 cystatin expressed in Escherichia coli was purified and it exhibited cysteine protease inhibitor activity. Transgenic overexpression of MpCYS4 in Arabidopsis (Arabidopsis thaliana) and apple (Malus domestica) led to ABA hypersensitivity and series of ABA-associated phenotypes, such as enhanced ABA-induced stomatal closing, altered expression of many ABA/stress-responsive genes, and enhanced drought tolerance. Taken together, our results demonstrate that MpCYS4 is involved in ABA-mediated stress signal transduction and confers drought tolerance at least in part by enhancing stomatal closure and up-regulating the transcriptional levels of ABA- and drought-related genes. These findings provide new insights into the molecular mechanisms by which phytocystatins influence plant growth, development, and tolerance to stress.