Affiliation:
1. Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences Southwest University Chongqing 400715 China
2. Key Laboratory of Eco‐environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences Southwest University Chongqing 400715 China
3. Plant Genetic Engineering Center of Heibei Province, Institute of Biotechnology and Food Science, Hebei Academy of Agriculture and Forestry Sciences Shijiazhuang 050051 China
Abstract
SUMMARYDrought 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 GA2‐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 GA3 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.
Funder
National Natural Science Foundation of China
Subject
Cell Biology,Plant Science,Genetics
Cited by
2 articles.
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