文献类型： 外文期刊

作者： Song, Qin ¹ ; Kong, Lingfei ¹ ; Yang, Jiarui ¹ ; Lin, Minghui ¹ ; Zhang, Yuqian ¹ ; Yang, Xuerui ¹ ; Wang, Xiaojing ¹ ; Zhao, Zhengjie ¹ ; Zhang, Meng ¹ ; Pan, Jiarui ¹ ; Zhu, Shunqin ¹ ; Jiao, Bo ¹ ; Xu, Changzheng ¹ ; Luo, Keming ¹ ;

作者机构： 1.Southwest Univ, Integrat Sci Ctr Germplasm Creat Western China Cho, Sch Life Sci, Chongqing Key Lab Plant Resource Conservat & Germp, Chongqing 400715, Peoples R China

2.Southwest Univ, Sch Life Sci, Key Lab Ecoenvironm Three Gorges Reservoir Reg, Minist Educ, Chongqing 400715, Peoples R China

3.Hebei Acad Agr & Forestry Sci, Inst Biotechnol & Food Sci, Plant Genet Engn Ctr Heibei Prov, Shijiazhuang 050051, Peoples R China

关键词： Populus tomentosa; drought stress; gibberellin; PtoMYB142; PtoGA2ox4

期刊名称：PLANT JOURNAL （ 影响因子：7.2； 五年影响因子：7.9 ）

ISSN： 0960-7412

年卷期： 2024 年 118 卷 1 期

页码：

收录情况： SCI

摘要： Drought stress caused by global warming has resulted in significant tree mortality, driving the evolution of water conservation strategies in trees. Although phytohormones have been implicated in morphological adaptations to water deficits, the molecular mechanisms underlying these processes in woody plants remain unclear. Here, we report that overexpression of PtoMYB142 in Populus tomentosa results in a dwarfism phenotype with reduced leaf cell size, vessel lumen area, and vessel density in the stem xylem, leading to significantly enhanced drought resistance. We found that PtoMYB142 modulates gibberellin catabolism in response to drought stress by binding directly to the promoter of PtoGA2ox4, a GA(2)-oxidase gene induced under drought stress. Conversely, knockout of PtoMYB142 by the CRISPR/Cas9 system reduced drought resistance. Our results show that the reduced leaf size and vessel area, as well as the increased vessel density, improve leaf relative water content and stem water potential under drought stress. Furthermore, exogenous GA(3) application rescued GA-deficient phenotypes in PtoMYB142-overexpressing plants and reversed their drought resistance. By suppressing the expression of PtoGA2ox4, the manifestation of GA-deficient characteristics, as well as the conferred resistance to drought in PtoMYB142-overexpressing poplars, was impeded. Our study provides insights into the molecular mechanisms underlying tree drought resistance, potentially offering novel transgenic strategies to enhance tree resistance to drought.