水稻与稻瘟病菌非亲和性互作中重要防御酶活性变化规律研究

 选以CO39为背景的水稻抗稻瘟病近等基因系,与稻瘟菌生理小种ZC₁₃(菌株97-151a)组成的3类典型非亲和性互作,以亲和性互作为对照,对各互作中过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、几丁质酶及β-1,3-葡聚糖酶的活性变化规律进行了系统研究。完全非亲和性互作C101A51/97-151a、高度非亲和性互作C101L AC/97-151a及中度非亲和性互作C104 PKT/97-151a,POD比活性接种后即开始明显升高,48h前达到高峰,升高趋势一直持续到7d完全显症时,幅度基本与各互作非亲和程度呈正相关;亲和性互作CO39/97-151a接种后40 h POD比活性才开始升高,4~6 d达到高峰,峰值也较大。3类非亲和性互作PAL比活性在接种后0 h或16 h开始较明显升高,整个互作中形成3~4个较明显的峰;亲和性互作中PAL比活性一直明显下降。3类非亲和性互作外切几丁质酶比活性接种后即开始升高,基本一直保持升高趋势,在40 h前幅度较大,并形成1~3个较高的峰;亲和性互作外切几丁质酶比活性接种后即开始大幅度升高直至完全显症,48h后幅度远高于非亲和性互作。3类非亲和性互作β-1,3-葡聚糖酶比活性在24 h内开始较明显升高,在48h前形成2~3个较明显的峰;亲和性互作在接种后β-1,3-葡聚糖酶比活性即开始升高,在48h后显著高于非亲和性互作。讨论了POD、PAL、几丁质酶及β-1,3-葡聚糖酶参与水稻抗稻瘟病的可能性。

DYNAMICS OF IMPORTANT DEFENSE ENZYME ACTIVITY OF INCOMPATIBLE INTERACTIONS BETWEEN RICE AND Magnaporthe grisea

Dynamic changes in the activities of peroxidase (POD), phenylalanine ammonia lyase (PAL), Exo-chitinase and β-1,3-glucanase of three typical types of incompatible interactions, contrasted with those of compatible interaction, between near isogenic rice lines with CO39 background and rice blast fungus (Magnaporthe grisea) race ZC₁₃ (strain 97-151a) were studied. POD activities of completely incompatible interaction C101A51/97-151a, highly incompatible interaction C101LAC/97-151a and moderately incompatible interaction C104PKT/97-151a started to increase remarkably right at the time of inoculation, and peaked before 48 hours post inoculation (h p.i.). The levels of increase were positively correlated with their incompatible degrees. POD activities of compatible interaction CO39/97-151a began to increase at 40 h p.i., and reached a peak at 4-6 days post inoculation (d p.i.). PAL activities of the three types of incompatible interactions began to increase apparently at 0 or 16 h p.i., and formed three or four peaks during the interactions. PAL activities of the compatible interaction declined significantly after inoculation. Exo-chitinase activities of the three types of incompatible interactions started to increase after inoculation, and the trend was basically kept until 7 d p.i. The increase was greater and formed one to three peaks before 40 h p.i. Exo-chitinase activities of the compatible interaction increased greatly after inoculation and were much higher than those of the three incompatible interactions after 48 h p.i. β-1,3-glucanase activities of the three types of incompatible interactions increased before 24 h p.i., and formed two to three peaks before 48 h p.i. β-1,3-glucanase activities of the compatible interaction increased significantly after inoculation, being much higher than those of the incompatible interactions after 48 h p.i. The possibilities of POD, PAL, chitinase and β-1,3-glucanase being involved in the resistance of rice to M. grisea were discussed.