Dong Huixia, Zhang Wei, Li Yongxia, Feng Yuqian, Wang Xuan, Liu Zhenkai, Li Dongzhen, Wen Xiaojian, Ma Shuai, Zhang Xingyao
Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China.
College of Life Science, Henan Normal University, Xinxiang, China.
Front Plant Sci. 2022 Oct 31;13:973305. doi: 10.3389/fpls.2022.973305. eCollection 2022.
Salicylic acid (SA) is generally considered to be a critical signal transduction factor in plant defenses against pathogens. It could be converted to methyl salicylate (MeSA) for remote signals by salicylic acid methyltransferase (SAMT) and converted back to SA by SA-binding protein 2 (SABP2). In order to verify the function of SAMT in poplar plants, we isolated the full-length cDNA sequence of from 84K poplar and cultivated overexpression lines (OE-2 isolate) to test its role in SA-mediated defenses against the virulent fungal pathogen . Our results showed that after inoculation with , OE-2 significantly increased MeSA content and reduced SA content which is associated with increased expression of in both infected and uninfected leaves, when compared against the wild type (WT). Additionally, overexpression plant lines (OE-2) exhibited higher expression of pathogenesis-related genes and -5, but were still susceptible to suggesting that in poplar SA might be responsible for resistance against this pathogen. This study expands the current understanding of joint regulation of SAMT and SABP2 and the balance between SA and MeSA in poplar responses to pathogen invasion.
水杨酸（SA）通常被认为是植物抵御病原体过程中的关键信号转导因子。它可被水杨酸甲基转移酶（SAMT）转化为水杨酸甲酯（MeSA）用于远距离信号传递，并被水杨酸结合蛋白2（SABP2）再转化回SA。为了验证SAMT在杨树中的功能，我们从84K杨中分离出其全长cDNA序列，并培育了过表达系（OE - 2分离株）以测试其在SA介导的对强毒性真菌病原体防御中的作用。我们的结果表明，与野生型（WT）相比，接种后，OE - 2显著增加了MeSA含量并降低了SA含量，这与感染和未感染叶片中相关基因的表达增加有关。此外，SAMT过表达植株系（OE - 2）表现出病程相关基因PR - 1和PR - 5的更高表达，但仍对敏感，这表明在杨树中SA可能负责对这种病原体的抗性。本研究扩展了目前对杨树中SAMT和SABP2联合调控以及SA和MeSA在杨树对病原体入侵反应中的平衡的理解。
