OsRboh基因家族在水稻免疫应答中的表达及功能分析

Expression and functional analysis of OsRboh gene family in rice immune response

摘要:

为了阐明Rboh基因家族在水稻免疫应答中的功能，首先利用生物信息学方法从水稻基因组数据库中检索到7个水稻Rboh基因，并对其进行系统发育学和组织特异性表达分析，发现OsRbohD只在穗和愈伤组织中表达，且OsRbohE和OsRbohF仅在愈伤组织中特异表达，而其他基因为组成型表达。利用Real-time PCR对分别在水杨酸SA、茉莉酸甲酯MeJA和水稻黄单胞菌PXO99致病菌株处理下的OsRboh基因家族的表达水平进行了分析，同时对处理后的叶片H2O2含量进行测定。结果表明，SA可以提高OsRbohA、OsRbohB、OsRbohC和OsRbohD的表达水平，MeJA可以提高OsRbohA、OsRbohB、OsRbohC和OsRbohG的表达水平，接种水稻黄单胞菌致病菌株PXO99可以提高OsRbohA和OsRbohB的表达水平。然而三者在诱导OsRboh基因家族成员的表达时序性和表达程度存在着差异。此外，3种不同处理都能导致不同程度的H2O2积累。结果显示，OsRboh基因家族各基因在水稻免疫应答中可能扮演不同角色，发挥不同作用。

Abstract:

The preliminary role of respiratory burst oxidase homolog (Rboh) in plant immune response is defined, but the exact function of OsRboh gene in rice immune response and its expression pattern is yet unclear. In order to clarify the role of OsRboh in rice immune response, we screened seven OsRboh genes from the latest rice genome annotation database. The result of tissue specific expression analysis demonstrated that OsRbohD was expressed only in spike and calli, and OsRbohE and OsRbohF were only expressed in calli. The rest of OsRboh genes were constitutively expressed in rice. In addition, the expression level of OsRboh gene family was analyzed in the rice leaves respectively treated with salicylic acid (SA), methyl jasmonic acid (MeJA) and Xanthomonas oryzae PV. oryzae (Xoo) PXO99 strain by Real-time PCR, and H2O2 content was also quantified by spectrophotometry after the three treatments. The result shows that the expression of OsRbohA, B, C and D was increased under the treatments of SA, the expression of OsRbohA, B, C and G was increased under the treatments of MeJA, and the expression of OsRbohA and OsRbohB was induced by Xoo PXO99 strain. However, the levels of expression and responsive times of these genes were different. Moreover, all three treatments led to H2O2 accumulation. These OsRboh genes have functional roles in rice native immune response.