Identifies Chilling Responsive MiRNAs And Their Targets In Sweetpotato(Ipomoea Batatas Lam.) During Storage

Sweetpotato(Impomoea batatas Lam.)is a globally important economic food crop with origins in the tropics.In our study,we sequenced the transcriptome,sRNAome,and degradome to systematically investigate sweetpotato miRNA response to chilling stress in storage.In this study,part of nutritional and physiological changes of sweetpotato at low and appropriate temperatures were investigated during process of storage.To clarify the molecular mechanism of chilling responsiveness and to identify and functional analyze chilling responsive of miRNAs,nine independent transcriptome and small RNA libraries from tuberous roots of sweetpotato for 28 days storage were constructed and sequenced using high-throughput Illumina sequencing.Darkening of internal tissues were observed in low temperature storage(LTS)tubers at 4 weeks.Compared with the appropriate temperature storage(ATS),the change range of water content and total protein content were smaller,while the change range of starch content and carbohydrate were bigger.After 4 weeks,SOD activity,POD activity and MDA content between LTS and ATS were significantly differents.A total of 195 known miRNAs and 191 novel miRNAs were identified,and 428 transcripts were targeted by 184 miRNAs identified via high-throughput degradome sequencing.More importantly,we identified 11 miRNAs differentially expressed between chilling stress and control conditions.To validate our sequencing results,the expression of the miRNAs and the differential expression of their target genes were corroborated with qRT-PCR.Our work explores the changes of nutrition and physiology in sweetpotato,combines with multi omics analysis,provides comprehensive molecular evidence supporting the involvement of miRNAs in chilling-stress and clarifies miRNA-mediated gene regulation in storage.