为初步探究OsAGO家族在水稻抗病毒通路中的功能,对水稻OsAGO蛋白的基因组结构、系统发育关系、氨基酸序列及水稻瘤矮病毒(rice gall dwarf virus,RGDV)和南方水稻黑条矮缩病毒(southern rice black streaked dwarf virus,SRBSDV)侵染后的转录组数据进行分析,同时采用实时荧光定量PCR(quantitative real-time PCR,qPCR)技术对这2种病毒侵染后OsAGO基因的相对表达量变化进行验证.结果表明,19个水稻OsAGO蛋白的外显子数量、内含子数量及编码区长度存在较大差异,且这19个OsAGO蛋白均匀分布在3个分支中;OsAGO蛋白PAZ结构域中与小RNA结合相关的YF(酪氨酸-苯丙氨酸)基序在OsAGO2、OsAGO3和OsAGO5中变成了YY(酪氨酸-酪氨酸),OsAGO蛋白PIWI结构域中与OsAGO蛋白切割活性相关的DDX(X代表H或D,即天冬氨酸-天冬氨酸-组氨酸/天冬氨酸)基序在OsAGO13中替换为LDH(亮氨酸-天冬氨酸-组氨酸)基序,而在OsAGO17中不包含YF基序且DDX基序替换为HDR(组氨酸-天冬氨酸-精氨酸)基序.RGDV侵染后OsAGO5和OsAGO12基因的转录组分析结果与qPCR结果一致,其中OsAGO5上调表达,OsAGO12下调表达;SRBSDV侵染后OsAGO1a、OsAGO1b、OsAGO1c、OsAGO1d和OsAGO4b基因的转录组分析结果与qPCR结果一致,均上调表达.表明大多数OsAGO均能响应RGDV和SRBSDV的侵染.
Characteristics of argonaute protein family members and their responses to rice gall dwarf virus and southern rice black-streaked dwarf virus infections in rice
To explore the function of the rice argonaute protein (AGO) family in the rice antiviral path-way,we analyzed the genomic structure,phylogenetic relationships,amino acid sequences of OsAGO proteins,as well as transcriptome data after infection with rice gall dwarf virus (RGDV) and southern rice black streaked dwarf virus (SRBSDV). Quantitative real-time PCR (qPCR) was used to verify the changes in relative expression levels after infection with RGDV and SRBSDV. The results showed that there were significant differences in the number of exons,introns,and coding regions among the 19 OsAGO transcripts,and these protein-coding sequences were evenly distributed among three branches. The tyrosine-phenylalanine (YF) motif related to small RNA binding in the PAZ domain of OsAGO pro-teins was changed to tyrosine-tyrosine (YY) motif in OsAGO2,OsAGO3,and OsAGO5. The aspartic acid-aspartic acid-histidine/aspartic acid (DDX) motif related to the cleavage activity of OsAGO pro-teins in the PIWI domain was replaced with LDH (leucine-aspartic acid-histidine) motif in OsAGO13,while in OsAGO17 which did not contain YF motif and the DDX motif was replaced with histidine-aspartic acid-arginine (HDR) motif. The transcriptome analysis results of OsAGO5 and OsAGO12 genes after RGDV infection were consistent with the qPCR results,with upregulated expression of OsAGO5 and downregulated expression of OsAGO12. After SRBSDV infection,the transcriptome analysis results of OsAGO1a,OsAGO1b,OsAGO1c,OsAGO1d,and OsAGO4b genes were consistent with those of qPCR results,all showing upregulated expression. These results indicate that most OsAGO genes can respond to the infection of RGDV and SRBSDV.
riceRNA silencingAGO proteinrice gall dwarf virussouthern rice black streaked dwarf virus
万方数据
维普
