白背飞虱取食后水稻幼苗内源激素变化研究

Changes in Endogenous Hormones in Rice Seedlings Infested by White-backed Planthoppers

【目的】研究白背飞虱取食后苗期水稻内源激素含量变化规律及其合成途经相关基因的差异表达,为进一步解析内源激素调控水稻白背飞虱抗性机理提供参考。【方法】利用UPLC-MS方法测定了白背飞虱敏感材料9311与抗性近等基因系(NIL)在白背飞虱取食0、24和48 h后植株水杨酸(SA)、脱落酸(ABA)、茉莉酸(JA)和生长素(IAA)4种激素含量的变化;qRT-PCR分析5个与激素合成途径相关基因在抗、感植株中表达水平的差异。【结果】激素含量测定结果表明,白背飞虱取食的48 h内,NIL中SA含量先升后降,而在9311中先降后升;ABA的含量在NIL中波动较小,而在9311中先升后降;IAA和JA在抗、感植株中均持续上升。激素合成途径相关基因OsPAL06、OsZEP、OsLOX和OsYUCCA1在接虫后24 h的表达量差异在抗、感植株中均达到显著或极显著水平,而在0 h和48 h差异不显著。OsICS1则在接虫后48 h的表达量差异在抗、感植株达到显著水平,而接虫0和24 h后差异不显著。【结论】在接虫或者对照处理中,JA和ABA含量在抗性植株中均高于感虫植株,可能与抗性基因有较大关系;而SA含量和OsPAL06、OsICS1基因表达水平均表明抗性植株对白背飞虱的取食响应更迅速,在抗虫过程中能够起到明显的调控作用。

【Objective】It is of great importance to study the changes of endogenous hormone concentration and relative expression level of associated genes in rice seedling after infestation by white-backed planthoppers(WBPH),which would provide reference for insight into WBPH resistance mechanism regulated by endogenous hormones.【Method】Salicylic acid(SA),abscisic acid(ABA),jasmonic acid(JA),and auxin(IAA)in susceptible line 9311 and near isogenic line(NIL)of resistance were quantified using UPLC-MS at 0,24,and 48 h after infestation by WBPH;and the relative expression levels of five associated genes between resistant and susceptible lines were detected by qRT-PCR.【Result】SA concentration in NIL increased at 24 h after WBPH infestation and decreased at 48 h after WBPH infestation as compared to the untreated line;while it was on the contrary in 9311.ABA concentration was relatively stable in NIL after WBPH infestation,but increased at 24 h and then decreased at 48 h after WBPH infestation in 9311.Both IAA and JA concentration continuously increased in resistant and susceptible lines after infestation treatment.The result of qRT-PCR indicated that the relative expression levels of hormone pathway-related genes OsPAL06,OsZEP,OsLOX,and OsYUCCA1 were significantly different at 24 h after WBPH infestation between resistant and susceptible lines,but no significant difference was observed at 0 and 48 h after WBPH infestation.However,the relative expression level of OsICS1 showed significant difference at 48 h after WBPH infestation between the resistant and susceptible lines;whereas no significant difference was detected at 0 or 24 h after WBPH infestation【.Conclusion】JA and ABA concentration in the resistant plants were higher than those in the susceptible ones,which was possibly associated with the resistant genes.SA concentration and the relative expression level of its associated genes OsPAL06 and OsICS1 indicated that the resistant line responded more quickly to WBPH infestation,which suggested that it might play an important role during insect infestation.