Ma Yuzhao, Liu Yiqi, Jia Fenglin, Zhu Wanying, Wang Guoyue, Yang Xiaojin, Guo Qing, Zhang Hongbo
Heilongjiang University of Science and Technology, Harbin, China.
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
PLoS One. 2025 Sep 12;20(9):e0332076. doi: 10.1371/journal.pone.0332076. eCollection 2025.
WRKY is a crucial transcription factor family in plants, participating in a variety of physiological processes and stress responses. In this study, we identified 102 WRKY genes from the poplar genome, randomly distributed on 18 chromosomes and one scaffold, and classified them into three subgroups based on phylogenetic analysis. Members of the same subgroup form similar structures due to their shared relatively conservative domains. All poplar WRKY proteins are hydrophilic, located in the cell nucleus, and form target relationships with a large number of miRNAs, with their promoter containing a large number of stress defense elements. The expansion of the poplar WRKY family mainly occurs through segmental duplication, and they also have abundant cross-species collinearity. Based on RNA-Seq, we identified 83 WRKYs significantly respond to cadmium (Cd) stress. Subsequently, we conducted a study on WRKY95, which was significantly up-regulated in the roots, stems, and leaves under Cd stress. Under cadmium toxicity, the plant height of PsnWRKY95-overexpressing plants increased by 16%-26% compared with the wild type (WT), the root length increased by 12%-27% compared with WT, the peroxidase (POD) activity was 28%-51% higher than that of WT, the chlorophyll content increased by 15%-29% compared with WT, the malondialdehyde (MDA) content decreased by 13%-32% compared with WT, and the electrical conductivity decreased by 9%-20% compared with WT, with the expression levels of POD and HMA1 in the overexpressing plants also being higher than those in WT. Results from yeast experiments demonstrated that PsnWRKY95 can improve Cd tolerance by specifically binding to cadmium (Cd) resistance element G-box, activating the reactive oxygen clearance ability and downstream target gene. This study comprehensively analyzes the basic data of WRKYs, identifying their response to Cd stress and specifically analyzes the stress-resistant function of PsnWRKY95, providing clues for understanding the molecular mechanism of WRKYs resistance to Cd.
WRKY是植物中一个关键的转录因子家族，参与多种生理过程和应激反应。在本研究中，我们从杨树基因组中鉴定出102个WRKY基因，它们随机分布在18条染色体和一个支架上，并根据系统发育分析将它们分为三个亚组。同一亚组的成员由于共享相对保守的结构域而形成相似的结构。所有杨树WRKY蛋白都是亲水性的，位于细胞核中，并与大量miRNA形成靶标关系，其启动子含有大量应激防御元件。杨树WRKY家族的扩张主要通过片段重复发生，并且它们还具有丰富的跨物种共线性。基于RNA测序，我们鉴定出83个WRKY基因对镉（Cd）胁迫有显著响应。随后，我们对WRKY95进行了研究，它在Cd胁迫下在根、茎和叶中显著上调。在镉毒性下，过表达PsnWRKY95的植株株高比野生型（WT）增加了16%-26%，根长比WT增加了12%-27%，过氧化物酶（POD）活性比WT高28%-51%，叶绿素含量比WT增加了15%-29%，丙二醛（MDA）含量比WT降低了13%-32%，电导率比WT降低了9%-20%，过表达植株中POD和HMA1的表达水平也高于WT。酵母实验结果表明，PsnWRKY95可以通过特异性结合镉（Cd）抗性元件G-box来提高对Cd的耐受性，激活活性氧清除能力和下游靶基因。本研究全面分析了WRKY基因的基础数据，确定了它们对Cd胁迫的响应，并具体分析了PsnWRKY95的抗逆功能，为理解WRKY基因抗Cd的分子机制提供了线索。
