Xue Renfeng, Wu Xingbo, Wang Yingjie, Zhuang Yan, Chen Jian, Wu Jing, Ge Weide, Wang Lanfen, Wang Shumin, Blair Matthew W
Crop Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, Liaoning 110161, China.
Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, TN 37209, USA.
Plant Sci. 2017 Jul;260:1-7. doi: 10.1016/j.plantsci.2017.03.011. Epub 2017 Mar 29.
Plant peroxidases (POXs) are one of the most important redox enzymes in the defense responses. However, the large number of different plant POX genes makes it necessary to carefully confirm the function of each paralogous POX gene in specific tissues and disease interactions. Fusarium wilt is a devastating disease of common bean caused by Fusarium oxysporum f. sp. phaseoli. In this study, we evaluated a peroxidase gene, PvPOX1, from a resistant common bean genotype, CAAS260205 and provided direct evidence for PvPOX1's role in resistance by transforming the resistant allele into a susceptible common bean genotype, BRB130, via hairy root transformation using Agrobacterium rhizogenes. Analysis of PvPOX1 gene over-expressing hairy roots showed it increased resistance to Fusarium wilt both in the roots and the rest of transgenic plants. Meanwhile, the PvPOX1 expressive level, the peroxidase activity and hydrogen peroxide (HO) accumulation were also enhanced in the interaction. The result showed that the PvPOX1 gene played an essential role in Fusarium wilt resistance through the occurrence of reactive oxygen species (ROS) induced hypersensitive response. Therefore, PvPOX1 expression was proven to be a valuable gene for further analysis which can strengthen host defense response against Fusarium wilt through a ROS activated resistance mechanism.
植物过氧化物酶（POXs）是防御反应中最重要的氧化还原酶之一。然而，大量不同的植物POX基因使得有必要仔细确认每个旁系同源POX基因在特定组织和病害互作中的功能。枯萎病是由尖孢镰刀菌菜豆专化型引起的菜豆毁灭性病害。在本研究中，我们从抗性菜豆基因型CAAS260205中鉴定了一个过氧化物酶基因PvPOX1，并通过发根农杆菌介导的发根转化，将抗性等位基因导入感病菜豆基因型BRB130中，为PvPOX1在抗性中的作用提供了直接证据。对过表达PvPOX1基因的发根分析表明，它增强了根系和转基因植株其他部位对枯萎病的抗性。同时，在互作中PvPOX1的表达水平、过氧化物酶活性和过氧化氢（H₂O₂）积累也有所增强。结果表明，PvPOX1基因通过活性氧（ROS）诱导的过敏反应在枯萎病抗性中发挥重要作用。因此，PvPOX1的表达被证明是一个有价值的基因，可通过ROS激活的抗性机制加强宿主对枯萎病的防御反应，用于进一步分析。
