水稻OsERF96应答病原菌的表达及启动子的功能分析

Expression of OsERF96 Response to Pathogen and Functional Analysis of Its Promoter

前人研究发现水稻Os ERF96(ethylene responsive factor 96)可应答白叶枯病病原菌的侵染,但其功能及表达调控机制仍不清楚,本研究进一步分析了该基因在水稻应答稻瘟病病原菌侵染及外源激素(SA和Me JA)处理下的转录情况,并分析了其启动子的诱导表达活性。结果表明:相对于对照组,Os ERF96在接种稻瘟病后1~4 d表达量显著上调,以第1天最高,此后逐渐下降,外源SA处理后Os ERF96表达量持续上调;利用Os ERF96启动子驱动GUS的转基因株系分析了Os ERF96启动子的诱导活性,结果表明GUS在根、茎和叶均有不同程度组成型表达,稻瘟病菌接种后4~7 d GUS活性持续升高。GUS活性定量表明,稻瘟病菌和SA处理条件下均出现了升高。综上所述,Os ERF96可应答白叶枯病或稻瘟病病原菌的浸染,其启动子是一个对病原菌侵染产生应答的诱导性启动子。

OsERF96 in rice was previously found to upregulated by Xanthomonas Campestris attack, but its role in rice immunity and its expressional regulation remains elusive. In the present study, the transcripts of OsERF96 were analyzed in response to inoculation of Magnaporthe oryzae （ M. oryzae） as well as exogenous application of sali- cylic acid （SA） and Methyl Jasmonate （MeJA）. The results showed that the transcripts of OsERF96 were increased at 1-4 day post inoculation （dpi）of M. oryzae compared to that in mock-treated control plants, with the maximum at the 1 dpi. Additionally, the transcripts of OsERF96 were up-regulated steadily in response to exogenous application of SA. The GUS expression driven by OsERF96 promoter was consistently upregulated with inoculation of M. oryzae in transgenie lines. GUS activities were increased with treatment of M. oryzae or exogenous SA. The data collectively showed that OsERF96 could respond not only to Xanthomonas Campestris attack, but also to M. oryzae inoculation and its promoter was pathogen-inductive.