Effects Of SA On Polyphenols Accumulation And Flavan-3-ol Synthase Expression In Grape Berries

‘Jizaomi’ grapes were used as materials,and were sprayed with 100 mg/L salicylic acid(SA)for different times at young fruit stage,color changing stage and mature stage in the dissertation.The contents of phenolic compounds,the enzyme activities and genes expression related to flavan-3-ol synthesis in grape berries were analyzed.It’s to explore the effects of exogenous SA on polyphenols accumulation and expression of enzymes related to flavan-3-ol synthesis in grape berries.The main results are as follows:(1)100 mg·L-1 SA increased the contents of free SA and bound SA in grape berries,especially in young fruit stage,followed by color-changing stage and mature stage.(2)100 mg·L-1 SA did not change the accumulation of total phenols,phenolic acids,total flavonoids,flavanols polyphenols,flavan-3-ol monomers in grape berries,but increased their contents.Among them,the effect of young fruit stage is the most obvious,followed by color-changing stage and mature stage.From 3 h to 12 h after spraying in young fruit stage,the content of phenolic compounds increased significantly in young fruit.After spraying at young fruit stage and color-changing stage,the content of phenolic compounds increased obviously during color-changing stage from 3 h to 12 h.After spraying at young fruit stage,color-changing stage and mature stage,the content of phenolic compounds increased obviously in mature fruit from 0 h to 6 h.Furthermore,after spraying at young fruit stage and color-changing stage,the accumulation of phenolic compounds was more obvious in mature fruit from 6 h to 24 h.(3)100 mg·L-1 SA promoted PAL,LAR and ANR enzyme activities in grape berries.From 3 h to 6 h after spraying in young fruit stage,the activities of LAR and ANR increased significantly in young grape berries.After spraying at the young fruit stage and color-changing stage,the PAL activity increased extremely significantly during color-changing stage from 6 h to 24 h,and the LAR and ANR activities increased obviously at 6 h in color-changing stage.After spraying at young fruit stage,color-changing stage and mature stage,the ANR activity of mature fruit increased significantly from 12 h to 24 h.(4)100 mg·L-1 SA could promote the transcription of Vv PAL,Vv LAR1,Vv LAR2 and Vv ANR in grape berries,and the induction effect was the most obvious in young fruit stage,followed by mature stage.From3 h to 6 h after spraying at young fruit stage,the expression of Vv PAL,Vv LAR1,Vv LAR2 and Vv ANR increased obviously in young grape berries.After spraying at young fruit stage and color-changing stage,the expression of Vv LAR1 and Vv LAR2 increased obviously at 6 h in color-changing stage.After spraying at young fruit stage,color-changing stage and mature stage,the expression of Vv PAL,Vv LAR1,Vv LAR2 and Vv ANR increased obviously at 6 h in mature fruit.