两个水稻抗稻瘟病单基因系防卫反应相关酶的活性变化

Changes in Enzymes Activities Related to Defense Responses in Two Rice Blast Resistance Monogenic Lines

本研究利用抗谱差异较大的两个水稻抗稻瘟病基因Pik-h和Pik-s的单基因系为材料,以不含抗性基因的普感亲本丽江新团黑谷(LTH)作对照,分别接种非亲和菌株G85和亲和菌株G64-1,研究接种后不同时点水稻叶片几丁质酶、β-1,3-葡聚糖酶、过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶等5种防御酶的活性变化,以探究水稻抗稻瘟病基因的抗性水平差异与防御酶活性的关系。结果表明,接种后水稻叶片中5种防御酶活性水平均明显升高,但不同材料接种不同菌株后防御酶活性的升幅有差异。在接种G85后的大多数时点,广抗谱的Pik-h单基因系与窄抗谱的Pik-s单基因系相比,前者表达的几丁质酶、β-1,3-葡聚糖酶和苯丙氨酸解氨酶的活性水平升高或显著升高,过氧化物酶和多酚氧化酶的活性水平降低或显著降低。除了过氧化物酶外,其余4种酶的最高酶活性均以Pik-h单基因系最高。在接种G64-1后的各个时点或绝大多数时点,广抗谱的Pik-h单基因系与窄抗谱的Pik-s单基因系相比,前者表达的几丁质酶、过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶的活性水平和最高酶活性升高或显著升高,只有β-1,3-葡聚糖酶活性水平显著降低或无明显差异。在接种后的大多数时点,LTH表达的防御酶活性显著低于单基因系或与单基因系无显著差异。本研究结果体现了抗性基因的抗性水平与防御酶活性水平基本呈正相关关系。

In order to understand the relationship between activities of defense enzymes and resistant abilities of blast resistance genes, the changes in the activities of chitinase, β-1,3-glucanase, peroxidase, polyphenol oxidase and phenylalanine ammonia-lyase in the leaves of two rice monogenic lines （harbored Pik-h gene with broad-spec- trum resistance and Pik-s gene with narrow-spectrum resistance respectively） and the susceptible parent Lijiang- xintuanheigu （LTH, CK） were analyzed by inoculation of the incompatible blast isolate G85 and compatible blast isolate G64-1. The results indicated that the activities of five defense enzymes in rice leaves were obviously enhanced after innoculation, but the increases of enzymes activities were different depending on rice material and blast isolates. In comparision with Pik-s monogenic line at most points of time after inoculating G85, Pik-h monogenic line was higher or significantly higher in the activities of chitinase, β-1,3-glucanase and phenylalanine ammonia-lyase, lower or significantly lower in the activities of peroxidase and polyphenol oxidase. Among two monogenie lines and LTH, Pik-h monogenic line was highest in the peak activities of chitinase, β-1,3-glucanase, polyphenol oxidase and phenylalanine ammonia-lyase except peroxidase. At all points or most points of time after inoculating G64-1, the activities and peak activities of chitinase, peroxidase, polyphenol oxidase and pheny- lalanine ammonia-lyase in P/k-h monogenic line were higher or significantly higher than those in Pik-s monogenic line, but the activities and peak activities of β-l,3-glucanase in Pik-h monogenic line were significantly lower than or no obviously different from those in Pik-s monogenic line.Contrast to the enzymes activities of two monogenic lines, those of LTH were significantly lower or no obviously different at most points of time after innoculation. This study was basically showed that the activities of defense enzymes were positively correlated to the resistant abilities of blast resistane genes.