植物激活蛋白对水稻抗性相关基因转录水平的影响

Effect of Plant Activator Protein on the Transcription of Defense-Related Genes in Rice Seedlings

在cDNA芯片分析结果的基础上,对从交链孢真菌(Alternariaspp.)中提取的新型植物激活蛋白对水稻抗病相关基因转录水平的影响进行了研究,同时检测了抗病防御相关酶活性和稻瘟菌抗性的变化。结果表明,水稻幼苗经2μg·ml-1激活蛋白喷雾处理后,NPR1基因从第天时转录水平开始提高,第3天和5天时转录活性继续增强;EIN2基因的转录在第1天、3天时转录水平显著提高,第5天时又有所回复,但仍高于对照;CTR1的转录在第1天时虽无影响,但第3天和第5天转录水平明显降低,而PR4的转录在各检测时段均未表现明显变化。5d后叶片的稻瘟菌病情指数和平均每叶病斑数开始显著降低,14d时对稻瘟菌的诱抗效果最为明显。叶片苯丙氨酸解氨酶(PAL)活性在处理后1d迅速增加,7d和9d时活性增加达到高峰期;β-1,3-葡聚糖酶活性在处理后3d开始增加,5d时增幅最大,随后增幅降低,14d时略低于对照水平;几丁质酶活性在处理后前3d低于对照,5d后活性平稳增加,14d时降至略低于对照的水平。

Rice seedlings sprayed with plant activator protein, a novel proteinaceous elicitor originated from Alternaria spp., developed increased resistance to rice blast after 5 days. Enzymatic activities of phenyalanine ammonialyase (PAL), 1,3-β-glucanases and chitnases in rice leaves were enhanced in a similar manner, reached a peak on the 7th, 5th and 9th day, respectively. The protein also led to the transcription activation of defense gene NPR1 and EIN2 since the 1st day, transcription repression of CTR1 after 3 days, but had no effect on transcription level of defense gene PR4, which seemed to indicate that salicylic acid ( SA) and ethylene (Et) signal pathway may mediate the resistance plant activator protein induced.