不同生育期高温胁迫下水稻OsRboh家族基因的表达模式

Expression Pattern of the OsRboh Family Genes in Rice under Heat Stress of Different Growth Stages

为了探究高温胁迫诱导水稻活性氧(ROS)产生的基因表达调控机制,在幼苗期、抽穗期和灌浆期设置高温胁迫,分析水稻ROS积累的动态变化,并采用实时荧光定量PCR技术分析不同生育期高温胁迫下水稻中9个NADPH氧化酶(Rboh)编码基因成员(OsRboh1~OsRboh9)的基因表达模式。结果表明:随着高温胁迫时间的延长,水稻叶片和籽粒内ROS积累呈显著增加趋势。幼苗期高温胁迫7 d后水稻叶片ROS含量增加缓慢;抽穗期间和灌浆初期(1~10 d)高温胁迫导致水稻籽粒ROS含量持续增加。幼苗期和抽穗期高温胁迫下,9个Rboh家族基因的表达量随高温胁迫的持续逐渐升高,基因表达量较高的是OsRboh7和OsRboh5。灌浆期高温胁迫下,OsRboh1、OsRboh5和OsRboh9的基因表达量持续增加,其他基因呈先增加后下降的变化趋势。水稻OsRboh基因家族成员中以OsRboh7和OsRboh5在幼苗期、抽穗期和灌浆初期高温胁迫下的表达量较高。此外,OsRboh7和OsRboh5在水稻幼苗叶片、剑叶、小花、外稃、内稃、雄蕊、雌蕊和籽粒等组织器官中具有较高的表达量。高温胁迫对幼苗叶片、小花、雄蕊、雌蕊和籽粒中OsRboh7和OsRboh5的基因表达量诱导幅度较大。综上所述,水稻OsRboh基因家族成员以OsRboh7和OsRboh5对不同生育期高温胁迫的响应最为明显,在高温胁迫诱导水稻ROS生成的代谢通路中发挥关键作用。

In order to explore the gene expression regulation mechanism in the formation of reactive oxygen species(ROS)induced by heat stress,heat stress treatments were set at seedling,heading and filling stage to investigate the dynamic change of ROS accumulation in rice,respectively.And the Quantitative Real-time PCR(qRT-PCR)was used to analyze the expression pattern of nine respiratory burst oxidase homologue(Rboh)encoding genes(OsRboh1-OsRboh9)in rice under different growth stages.Results showed that the ROS accumulation in rice leaves and grains significantly increased with the extension of heat stress.The ROS content increased slowly after 7 days of heat stress at seedling stage,while increased continuously after heat stress during the heading stage and early filling stage(1-10 d)in rice grains.Expression levels of the nine OsRboh family genes continuously increased with the extension of heat stress at seedling and heading stages,and OsRboh7 and OsRboh5 showed higher expression levels under heat stress.The expression levels of OsRboh1,OsRboh5 and OsRboh9 were continuously increased,while other genes showed a change tendency of increasing initially and then decreasing under heat stress at filling stage.The expression levels of OsRboh7 and OsRboh5 were all reached to a high level at seedling,heading and filling stage under heat stress.Furthermore,higher expression levels of OsRboh7 and OsRboh5 were showed in various tissues and organs of rice such as seedling leaves,flag leaf,floret,lemma,palea,stamen,pistil and grain.The higher induced range of gene expression levels in OsRboh7 and OsRboh5 by heat stress was shown in seedling leaves,floret,stamen,pistil and grain.Taken together,OsRboh7 and OsRboh5 were mostly remarkably responsive to heat stress at different growth stages among the OsRboh family genes in rice,which indicated that OsRboh7 and OsRboh5 played a vital role in the regulation of ROS formation pathway in rice under heat stress condition.