水稻条纹病毒与不同抗性水稻互作中的脱落酸调控

The role of abscisic acid in the interaction between host rice ( Oryza sativa) and Rice stripe virus

虫传接毒鉴定表明,水稻品种(系)武育粳3号和KT95-418对条纹叶枯病的抗性差异明显.以这2个水稻品种(系)为材料,研究了脱落酸(ABA)在水稻与水稻条纹病毒(RSV)互作中的作用.采用高效液相色谱技术测定了水稻受RSV侵染后内源ABA含量的动态变化,结果表明,武育粳3号和KT95-418 ABA含量均先迅速升高,分别是未接种的3.7和5.7倍,后下降至与健株一致.实时荧光定量RT-PCR分析表明,外施ABA处理后武育粳3号中CP基因转录水平表达量下调比率为2.8,KT95-418中CP基因表达量与对照相比未发生明显变化;ABA合成抑制剂norflurazon处理未引起武育粳3号和KT95-418中CP基因表达量的变化.武育粳3号外施ABA处理后,水稻显症期推迟,症状减轻,条纹叶枯病的发病率降低.

Resistance identification showed that rice cuhivar Wuyujing No.3 was susceptible to Rice stripe virus （RSV）, while rice cultivar KT95-418 was medium resistance to RSV. These two japonica rice cultivars （line） were used to reveal the role of ABA in the interaction between RSV and host rice. Endogenous ABA level in RSV-infected rice plants was evaluated by HPLC. ABA contents in Wuyujing No.3 and KT95-418 increased by 3.7 and 5.7 times respectively, and then decreased. Real-time qRT-PCR detection showed that the expression of RSV CP gene in Wuyujing No.3 was suppressed with reduction ratio of 2.8 and that of KT95-418 was not affected with ABA treatment; While ABA biosynthetic inhibitor nodlurazon had no effect on CP gene expression in both Wuyujing No.3 and KT95-418. Exogenous application of ABA to Wuyujing No.3 prior to inoculation with RSV resulted in a decline of incidence rates, alleviation of stripes in flee leaves and a delay of the leaf symptoms.