PeCHYR1, a ubiquitin E3 ligase from Populus euphratica, enhances drought tolerance via ABA-induced stomatal closure by ROS production in Populus 

First author: Fang He; Affiliations: Beijing Forestry University (北京林业大学): Beijing, China

Corresponding author: Xinli Xia (夏新莉)

Drought, a primary abiotic stress, seriously affects plant growth and productivity. Stomata play a vital role in regulating gas exchange and drought adaptation. However, limited knowledge exists of the molecular mechanisms underlying stomatal movement in trees. Here, PeCHYR1, a ubiquitin E3 ligase (E3泛素连接酶), was isolated from Populus euphratica (胡杨), a model of stress adaptation in forest trees. PeCHYR1 was preferentially expressed in young leaves and was significantly induced by ABA (abscisic acid) and dehydration (干燥) treatments. To study the potential biological functions of PeCHYR1, transgenic poplar 84K (Populus alba × Populus glandulosa) plants overexpressing PeCHYR1 were generated. PeCHYR1 overexpression significantly enhanced H2O2 production and reduced stomatal aperture (气孔孔径). Transgenic lines exhibited increased sensitivity to exogenous ABA and greater drought tolerance than that of WT (wild-type) controls. Moreover, up-regulation of PeCHYR1 promoted stomatal closure and decreased transpiration (蒸腾), resulting in strongly elevated WUE (water use efficiency). When exposed to drought stress, transgenic poplar maintained higher photosynthetic activity (光合活性) and biomass accumulation. Taken together, these results suggest that PeCHYR1 plays a crucial role in enhancing drought tolerance via ABA-induced stomatal closure caused by hydrogen peroxide (H2O2) production in transgenic poplar plants.

干旱是一类主要的非生物胁迫，严重影响了植物的生长和产量。气孔在调控气体交换和干旱适应中扮演重要作用。然而，对于林木中气孔运动的分子机制还了解得不多。本文从胁迫适应的模式林木胡杨中克隆到了一个E3泛素连接酶PeCHYR1基因。PeCHYR1基因优先在幼嫩的叶子的表达，并且被ABA和脱水显著诱导。为了研究PeCHYR1基因潜在的生物学功能，作者对转基因杨树84K进行了过表达PeCHYR1基因。过表达PeCHYR1基因会显著增强H2O2的产量，并减少气孔的孔径。转基因植株对外源的ABA处理更加敏感，同时抗旱性较野生型更强。此外，上调PeCHYR1基因的表达促进气孔的闭合，减少蒸腾，进而极大提升了水分利用效率。干旱胁迫下，转基因杨树会维持更高的光合活性和生物量积累。综上，在转基因植株中，PeCHYR1基因通过ABA诱导的气孔闭合增强干旱抗性。

通讯：夏新莉 (http://biology.bjfu.edu.cn/szdw/zrjs/jiaoshou/99077.html)

个人简历：1988-1992，华中师范大学，生物系学士；1994-1999，北京林业大学，硕士、博士；2002-2003年，韩国汉城国立大学，生物系博士后。

研究方向：植物逆境生理学、植物逆境分子生物学。

doi: 10.1111/pbi.12893

Journal: Plant Biotechnology Journal

First Published date: 08 March, 2018

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