稻瘟菌激发子CSB I专化性及相关性质研究

 以一套水稻抗稻瘟病近等基因系为材料,接种稻瘟菌(Magnaporthe grisea)细胞壁来源的糖蛋白激发子CSB I,其诱导植保素的积累在高度非亲和性互作水稻远高于亲和性互作水稻;研究同时表明,CSB I可专化性诱导完全非亲和性互作和高度非亲和性互作水稻的过敏性坏死反应;表明该激发子具有小种-品种专化性。经热、胰蛋白酶和过碘酸钠处理后的生物活性检测结果表明,CSB I的活性位点为糖基部分。经pH稳定性检测,CSB I在酸性及相对弱碱性条件下较稳定;而在强碱性条件下,激发子活性下降较多,甚至完全丧失。对CSB I诱导活性的有效浓度测定表明,激发子诱导水稻叶片酶活性升高的最低有效浓度为0.07~0.70 nmol/L。

Specificity and partial characterization of an elicitor (CSB Ⅰ) from Magnaporthe grisea

With four near-isogenic resistant lines (NIL) of rice, specificity and partial characterization of a glycoprotein elicitor CSB I from Magnaporthe grisea were studied. The results showed that, after treatment with CSB I, the phytoalexin production in highly incompatible rice C101LAC was higher than that in compatible rice CO39. The elicitor CSB I could also induce hypersensitive reaction in leaves of completely and highly incompatible rice, but not in the other two NIL rice (moderate incompatible rice and compatible rice). These results suggested that CSB I was cultivar-specific. Digestion with trypsin and boiling at 100℃ for 10 min did not abolish the elicitor activity, whereas the complete loss of elicitor activity was observed after periodate treatment, which suggested that the carbohydrate moiety contained the active site of the elicitor. The elicitor CSB I could maintain its activity of inducing POD and PAL activity in rice leaves after acid and weak alkali treatment. The elicitor was sensitive to strong alkali. Elicitor CSB I could induce POD and PAL activity in rice leaves at different doses ranging from 0.70 nmol/L to 7.00 nmol/L but not at 0.07 nmol/L, indicating that the minimal efficient dosage of CSB I was between 0.07-0.70 nmol/L.