Transcriptome Analysis And Effects On Genes Expression Related To Ripening And Softening Of Sweet Cherry ?Prunus Avium L.? Fruit Under GA₃ Treatment

Fruit ripening and softening is a complex process.The degradation of cell wall components and structural changes affect the hardness and texture of fruits,which is the main reason for the decline of fruit storability.In this experiment,10-year-old'Hongdeng'sweet cherries?Prunus avium L.?under different GA₃ concentrations treatment were used as test materials.The transcriptome of sweet cherry fruit under GA₃ treatment were sequenced by Illumina HiSeq high-throughput platform,the cell wall degrading enzyme gene and the regulatory gene MADS-box transcription factor related to fruit ripening were selected by bioinformatics analysis,and these gene expression level under GA₃ treatment were analyzed by real-time fluorescent quantitative PCR.The research results are as follows:?1?A total of 88593 transcripts were obtained by transcriptome sequencing,with an average length of 1088 bp,and predicted a total of 65,727 unigenes with an average length of1368 bp.The unigenes were annotated in 7 databases:Nr,Nt,Pfam,KOG/COG,Swiss-prot,KEGG,and GO,and a total of 45115 unigenes were annotated.The differential genes under different GA₃ concentrations treatment at different periods were analyzed,and 8 cell wall degradation-related enzyme genes of PG,PME,?-L-Af,Cx,?-Gal,XTH and PEL were screened,PG,?-Gal up-regulated expression,PME,?-L-Af,Cx,,XTH,PEL down-regulated expression.?2?PG,PME,?-L-Af and Cx genes expression levels increased with the ripening and softening process of sweet cherry fruits,which was closely related to the ripening and softening of sweet cherry fruits.?-Gal genes were also involved in fruit ripening and softening;while the XTH and PEL genes were highly expressed in the fruit hard core stage,which was associated with initiation phase of fruit ripening and softening.?3?High GA₃ concentration treatment increased the expression level of PG gene,and the peak of PME gene expression was advanced,which increased the activity of PG and PME enzymes,promoted the degradation of fruit cell wall,and also promoted?-L-Af,Cx,?-Gal,PEL and XTH genes expression,accelerates fruit ripening and softening.?4?MADS-box2,MADS-box3,MADS-box4,MADS-box6 and MADS-box7 mainly regulate fruit ripening in the hard core stage and early stage of rapid growth of II in sweet cherry fruit,MADS-box1,MADS-box5 and MADS-box8 regulated fruit ripening after sweet cherry turns color.GA₃ increased MADS-box1?MADS-box2?MADS-box3?MADS-box4?MADS-box5?MADS-box8 gene expression levels,but delayed MADS-box1?MADS-box2?MADS-box3?MADS-box4?MADS-box6?MADS-box8 gene expression peaks,inhibited MADS-box7 gene expression level,GA3 treatment regulates fruit ripening by affecting gene expression of these transcription factors.