炭疽病病原菌侵染对茶树叶片生理特性的影响

摘要

本试验筛选出一株强致病力茶树刺盘孢菌株ZRG,并测定其侵染后对茶树叶片相对电导率,丙二醛( MDA)含量,超氧化物歧化酶( SOD)、过氧化物酶( POD)、过氧化氢酶( CAT)等抗氧化酶活性及其基因表达量的影响,探究茶树刺盘孢对茶树叶片生理特性的影响.结果表明：ZRG侵染48 h内,茶树叶片相对电导率明显增高；MDA先是快速积累,含量上升,随后下降；POD、SOD和CAT活性都出现不同程度的上升,随后下降.qRT-PCR验证结果显示,POD、SOD和CAT相关基因的表达先上调后下降,三者相互协调配合,起到清除过剩自由基的作用.%To investigate pathogenicity of Colletotrichum sp.on tea leaves, a virulent strain ZRG of Colletotrichum kahawaewas isola-ted to infect 7 types of tea leaves that were commonly grown in Fujian. Physiological parameters, including relative conductivity, ma-londialdehyde(MDA)concentration and three types of antioxidase, i.e. superoxide dismutase(SOD), peroxidase(POD) and cata-lase( CAT) , were monitored at 0, 24, 48, 72 hours after infection. Subsequently, qRT-PCR was applied to express genes that were relevant to SOD, POD and CAT. Results showed that relative conductivities of infected leaves were significantly enhanced within 48h after infection. Concentrations of MDA, SOD, POD and CAT all demonstrated similar pattern, which peaked around 24th or 48th hour after inoculation and decreased afterwards. Correspondingly, qRT-PCR on SOD, POD and CAT genes detected upregulated ex-pressions of three antioxidases in infected leaves.