Zhao Zhengping, Lei Jieyun, Zhang Min, Li Jiale, Pi Chungeng, Yu Jinxiu, Yan Xuewu, Luo Kun, Xia Yonggang
Hunan Academy of Forestry, Changsha 410004, China.
College of Plant Protection, Hunan Agricultural University, Changsha 410125, China.
Plants (Basel). 2025 Aug 3;14(15):2399. doi: 10.3390/plants14152399.
Lamb. is an economically important conifer native to China. However, it is highly susceptible to the pine wood nematode (, PWN), the causal agent of pine wilt disease (PWD), resulting in substantial ecological and economic losses. To elucidate potential molecular defense mechanisms, 50 NAC (NAM, ATAF1/2, and CUC2) transcription factors (PmNACs) were identified in the genome. Phylogenetic analysis divided these PmNACs into seven subfamilies, and motif analysis identified ten conserved motifs associated with stress responses. Twenty-three genes were selected for expression analysis in various tissues and under exogenous salicylic acid (SA), methyl jasmonate (MeJA), and PWN infection. Six genes (, , , , , and ) were significantly up-regulated by both hormonal treatment and PWN infection, implying their involvement in JA/SA-mediated immune pathways. Functional characterization showed is a nuclear-localized transcription factor with autoactivation activity. Furthermore, transient overexpression of in induced reactive oxygen species (ROS) accumulation and necrotic lesions. Collectively, these results elucidate NAC-mediated defense responses to PWN infection in and identify candidate genes for developing PWD-resistant pine varieties.
冷杉是一种原产于中国的具有重要经济价值的针叶树。然而，它对松材线虫（PWN）高度敏感，松材线虫是松材线虫病（PWD）的致病因子，会导致巨大的生态和经济损失。为了阐明潜在的分子防御机制，在其基因组中鉴定出了50个NAC（NAM、ATAF1/2和CUC2）转录因子（PmNACs）。系统发育分析将这些PmNACs分为七个亚家族，并进行基序分析确定了十个与应激反应相关的保守基序。选择了23个基因在不同组织以及外源水杨酸（SA）、茉莉酸甲酯（MeJA）和PWN感染条件下进行表达分析。六个基因（、、、、、和）在激素处理和PWN感染下均显著上调，这表明它们参与了茉莉酸/水杨酸介导的免疫途径。功能表征显示是一种具有自激活活性的核定位转录因子。此外，在中瞬时过表达会诱导活性氧（ROS）积累和坏死病变。总的来说，这些结果阐明了NAC介导的对PWN感染的防御反应，并鉴定出了用于培育抗PWD松树品种的候选基因。
