The Mining And Analysis Of Low Temperature Stress MiRNAs And Targets In Solanum Aculeatissimum

Eggplant is a thermophilic vegetable of Solanaceae,which is sensitive to low temperature.Temperature is one of the main limiting factors for the growth and development of eggplant.The growth of eggplant is inhibited when the temperature is lower than 15?,the stem and leaf are chilled when the temperature is lower than 5 ?,and the eggplant is frozen ever died when the temperature is lower than 0?.Cold damage will affect its yeild and quality.Solanum aculeatissimum Jacq.is a close wild species of eggplant,which has strong cold tolerance and is an important eggplant material for study on cold resistance.MicroRNA?miRNA?is an important regulator of plant growth and development.MiRNA regulate gene expression at post-transcriptional level in different biological and metabolic processes.Plant miRNAs are involved in the regulation of abiotic stresses such as temperature,drought,salinity and nutritional stress.In this study,Solanum aculeatissimum Jacq.was used as experimental material,high-throughput sequencing and bioinformatics analysis were used to mine miRNAs and their target genes in response to low-temperature stress,and the expression patterns and functions of cold-tolerant candidate miRNAs in response to low-temperature stress were studied in depth.The main results are as follows:1.High-throughput sequencing was carried out on leaves of Solanum aculeatissimum Jacq.treated at 1? for 2 h,6 h,12 h,24 h?CA?and 0 h?CK?.A total of 61657 differentially expressed genes were screened from transcriptome database.A total of 306 conservative miRNAs were screened by miRNAs sequencing,and 239 differentially expressed miRNAs were detected.In combination with transcription group and miRNAs analysis,190 differentially expressed miRNAs were able to predict a total of 1134 mRNAs.In addition,each miRNA has multiple target genes,and each target gene may be regulated by multiple miRNAs.2.A total of 84 cold-tolerant candidate miRNAs were screened out,56 down-regulated miRNAs and 28 up-regulated miRNAs corresponded to 220 up-regulated mRNAs and 94 down-regulated mRNAs,respectively.In addition,52 new cold-tolerant related miRNAs were predicted.The target genes of differentially expressed miRNAs in Solanum aculeatissimum Jacq.under low temperature stress mainly involve GO functional items such as catalytic activity and binding in molecular functions,cell and cell parts in cell components,single biological processes and biological regulation in biological processes,and KEGG pathways such as RNA transport,RNA degradation and ribosome biogenesis.The results of high throughput sequencing and qRT-PCR showed that there was a negative regulation between miRNAs and target genes.3.Pre-miR5813 and target gene Ser/Thr protein kinase?STPK?were selected for sequence analysis.Pre-miR5813 was compared with>Sme2.5₀3005.1 in eggplant genome by BLAST,and 55 bp of precursor sequence was cloned.The full length of target gene STPK is 2791 bp,and the ORF is 2466 bp,encoding 821 amino acids.