RBSDV侵染对水稻ABA代谢相关基因表达的影响

Effect of RBSDV Infection on Transcriptional Expression of Abscisic Acid Metabolism Related Genes in Rice

为明确水稻黑条矮缩病毒(Rice black streaked dwarf virus,RBSDV)侵染对水稻脱落酸(abscisic acid,ABA)含量的影响,通过灰飞虱在水稻日本晴和淮稻5号两个品种上人工接种RBSDV,待接种的水稻表现明显矮缩症状时,采用ELISA方法测定ABA含量。结果显示,在接种RBSDV的日本晴和淮稻5号中,ABA含量均明显增加。接种病毒的日本晴植株中ABA含量为111.04ng/g,而对照中仅为60.86ng/g;淮稻5号对照植物ABA含量为70.61ng/g,而病株中ABA的含量为102.60ng/g。为进一步明确病毒侵染如何调控ABA的含量,采用荧光定量PCR方法分析了日本晴接种RBSDV 8d,12d,16d和60d时ABA合成关键基因(OsZEP、OsNCED1、OsNCED2、OsNCED3、OsNCED4和OsNCED5)及分解关键基因(OsABA8ox1、OsABA8ox2和OsABA8ox3)mRNA相对表达量的变化。结果显示,病毒侵染8d,ABA合成和分解代谢基因的表达量均高于对照,其中OsNCED4和OsNCED5的表达量随病毒侵染时间的延长而增加,至60d时OsNCED3、OsNCED4和OsNCED5的表达量为对照的3.97、7.66和2.99倍,而OsZEP,OsABA8ox1和OsABA8ox2的表达量则随侵染时间的延长而降低。RBSDV侵染后可能既影响了ABA合成也影响了其分解,两者共同作用导致了ABA含量增加。

To investigate the effect of virus infection on abscisic acid （ABA）content in rice,two rice varieties, Nipponbare and Huaidao 5 ,were inoculated with rice black streaked dwarf virus （RBSDV）artificially via small brown planthoppers,and the ABA content was measured by ELISA method when the plants showed the obvious viral disease symptoms.The results showed that the ABA content was increased in virus infected rice.The ABA content in virus infected Nipponbare was 1 1 1 .04 ng/g compared to 60.86 ng/g in the control.In Huaidao 5 ,it was 102.60 ng/g in the virus infected plants and 70.6 1 ng/g in the control.To reveal how the virus regulates the ABA content,the relative expression levels of genes involved in ABA biosynthesis （OsZEP ,OsNCED1 ,OsNCED2 ,OsNCED3 ,OsNCED4 and OsNCED5 ）and catabolism （OsABA8ox1 ,OsABA8ox2 and OsABA8ox3 ）were analyzed in Nipponbare at 8 d,12 d, 1 6 d and 60 d after virus infection.The qRT-PCR results showed that the expression levels of the genes involved in ABA biosynthesis and catabolism in the plants than at 8 days after virus infection were higher than those in the control. The expression levels of OsNCED4 and OsNCED5 increased continuously with infection duration.At 60 d,the expression levels of OsNCED3 ,OsNCED4 and OsNCED5 in RBSDV infected plants were 3.97-,7.66-and 2.99-fold higher than those in the control,and the expression levels of OsZEP ,OsABA8ox1 and OsABA8ox2 were decreased with time extension.The data suggested that RBSDV infection affected the ABA biosynthesis and catabolism metabolism pathway,resulting in the increase of ABA content.