Abstract：
Plant resistance (R) genes play a crucial role in the detection of effector proteins secreted by pathogens, either directly or indirectly, as well as in the subsequent activation of downstream defence mechanisms. However, little is known about how R genes regulate the defence responses of conifers, particularly Pinus massoniana, against the destructive pine wood nematode (PWN; Bursaphelenchus xylophilus). Here, we isolated and characterised PmHs1pro-1, a nematode-resistance gene of P. massoniana, using bioinformatics, molecular biology, histochemistry and transgenesis. Tissue-specific expressional pattern and localisation of PmHs1pro-1 suggested that it was a crucial positive regulator in response to PWN attack in resistant P. massoniana. Meanwhile, overexpression of PmHs1pro-1 was found to activate reactive oxygen species (ROS) metabolism-related enzymes and the expressional level of their key genes, including superoxide dismutase, peroxidase and catalase. In addition, we showed that PmHs1pro-1 directly recognised the effector protein BxSCD1of PWN, and induced the ROS burst responding to PWN invasion in resistant P. massoniana. Our findings illustrated the molecular framework of R genes directly recognising the effector protein of pathology in pine, which offered a novel insight into the plant-pathogen arms race.
摘要：
植物抗性（R）基因在检测病原体分泌的效应蛋白中起着至关重要的作用，直接或间接,以及随后激活下游防御机制。然而,对R基因如何调节针叶树的防御反应知之甚少，尤其是马尾松,对抗破坏性的松木线虫（PWN；松材线虫）。这里,我们分离并鉴定了PmHs1pro-1，马尾松的线虫抗性基因，利用生物信息学，分子生物学,组织化学和转基因。PmHs1pro-1的组织特异性表达模式和定位表明，它是抗性马尾藻对PWN攻击的关键正调节因子。同时,发现PmHs1pro-1的过表达激活活性氧（ROS）代谢相关酶及其关键基因的表达水平，包括超氧化物歧化酶,过氧化物酶和过氧化氢酶。此外,我们发现PmHs1pro-1直接识别PWN的效应蛋白BxSCD1，并诱导了抗性马尾藻对PWN入侵的ROS爆发。我们的发现说明了R基因的分子框架直接识别松树病理学的效应蛋白，这为植物-病原体军备竞赛提供了新的见解。
