【摘要】 目的:分析水稻病程相关基因OsPR1b的表达特性,以进一步了解其表达和调控机制。方法:利用PCR技术从水稻日本晴基因组中扩增OsPR1b基因的启动子片段,命名为OsPR1bp,并构建相应的OsPR1bp::GUS融合表达载体,采用农杆菌介导的转基因技术获得转基因植株,进行GUS组织化学分析;利用Real-time PCR对OsPR1b基因在植物激素、非生物因子和水稻白叶枯菌(Xoo)毒性菌株P10(PXO124)处理下的表达水平进行分析。结果:GUS组织染色结果表明OsPR1b在水稻叶片中的表达量较高,而在茎、根、愈伤和花器中的表达量较低;植物激素水杨酸(SA)、茉莉酸甲酯(MeJA)、激动素(KT)、脱落酸(ABA)及NaCl、PEG均可不同程度地提高OsPR1b在叶片中的表达水平,Me-JA、KT和NaCl的处理能提高其在根部的表达水平,但这些激素在诱导OsPR1b在叶片和根部的表达程度上存在明显差异;单独接种Xoo毒性菌株P10 24 h对OsPR1b表达的影响不大,而MeJA与其共同处理后则可显著增强其在叶片中的表达。结论:作为一种防卫基因,OsPR1b在健康植株中的表达水平较低,容易受盐/干旱胁迫及Xoo病原菌的诱导,多种植物激素如JA、KT和ABA很可能作为信号分子参与激活和介导了这种系统性的反应。更多还原

【Abstract】 Objective: In order to gain further insight into the expression/regulation of marker gene OsPR1 b inrice immune response, expression analysis of OsPR1 b in rice was carried out. Methods: OsPR1 b gene promoterfragment was amplified using the technology of PCR from rice Nipponbare genome and named OsPR1 bp. The plas-mid of OsPR1bp::GUS was introduced into japonica rice via Agrobacterium-mediated transformation for further histo-chemical GUS analysis. In addition, the expression level of OsPR1 b gene in rice leaves and roots was analyzed af-ter treated with plant hormones, abiotic factors and Xanthomonas oryzae pv. oryzae(Xoo) P10(PXO124) strain re-spectively. Results: The expression level of OsPR1 b gene was much higher in leaf than that in stem, root, callusand flower. The expression of OsPR1 b in leaves was differentially increased under the treatments of salicylic acid(SA), methyl jasmonate(MeJA), kinetin(KT), abscisic acid(ABA) as well as NaCl and PEG. The expression of OsPR1 b in roots was increased under the treatments of MeJA, KT and NaCl. However, the increased fold of ex-pression were different between leaves and roots. Inoculation with P10 alone for 24 h had no effect on OsPR1 b ex-pression, while co-treated with MeJA can significantly enhanced the expression level of OsPR1 b in leaves. Conclusion: OsPR1 b is described as a defense gene and the promoter we isolated directed a very low GUS gene expres-sion under normal conditions but responded to salt/drought stress and Xoo, and plants hormones such as JA, KTand ABA probably act as signals to trigger and mediate the systematic response.更多还原