Transcriptome analysis of differences in resistant starch content in different rice cultivars
[Objective]Resistant starch is one of the hot quality traits in functional rice research.By investigating the differentially-expressed genes and possible regulatory pathways among rice varieties with different resistant starch content during grain filling,this study aims to explore the rules and molecular mechanisms of resistant starch synthesis in rice.[Method]A high starch japonica rice variety JTD and a low resistance starch japonica rice variety Ningjing 28(NJ28)were used for transcriptome sequencing and analysis at two time points(10 d and 16 d)in the middle and late grain filling period,with three replicates per sample at each time point.A total of 12 samples were sequenced and analyzed.[Result]There were 1 326 differentially expressed genes(DEGs)in NJ28 and JTD at 10 days of filling,including 986 up-regulated DEGs and 340 down-regulated DEGs.At 16 days,there were 1 158 DEGs,including 384 up-regulated DEGs and 786 down-regulated DEGs.A total of 689 DEGs were co-changed on day 10 and day 16,including 435 up-regulated DEGs and 254 down-regulated DEGs.GO function and KEGG enrichment analysis showed that DEGs were mainly involved in starch metabolism and fatty acid metabolism,such as α-amylase,β-amylase,α-glucosidase,β-glucosidase,isoamylase,fatty acid elongation and degradation related enzymes.qRT-PCR was used to verify the three genes,and it was found that their mRNA expression trends were consistent with the expression trends in transcriptome analysis.Using GC-MS,36 fatty acids were quantified and seven fatty acids,including oleic acid,were found to be higher in the highly resistant starch varieties.[Conclusion]Candidate genes and important fatty acids that may be involved in the synthesis of resistant starch are screened,which provides research directions and molecular basis for further understanding RS synthesis in rice grain and its relationship with non-starch fatty acids.This study provides theoretical basis for the preparation of starch foods with enzyme resistance structure and low glycemic index.
万方数据
维普
