Screening Of Resveratrol Candidate Genes In Grape And Its Correlation With Temperature Under Protected Environment

Resveratrol is a kind of polyphenol compound which is beneficial to human health and has great potential for the prevention of human diseases.The main source of resveratrol is grape.The key technology of grape planting is the cultivation of two-cropping grape a year.In addition,temperature change has an important effect on resveratrol accumulation.In this experiment,the content of resveratrol in different parts of summer fruit and winter fruit in different growth stages was studied under the two-riping-one year cultivation mode of ‘Summer black’ grape as test material.To explore metabolic pathways related to resveratrol biosynthesis and screen hub genes;To explore the effects of temperature change on resveratrol content and hub gene expression in summer and winter fruits at different developmental stages.The results are as follows:1.The changes of resveratrol content during the growth and development of summer fruit and winter fruit were analyzed.The results showed as follows: with the growth and ripening of grape,the resveratrol content in the skin and flesh of winter fruit did not change significantly in the early stage,but increased significantly after the color turning stage,while the resveratrol content in the skin and flesh of summer fruit showed a decreasing trend from the green fruit stage to the color turning stage,and increased after the color turning stage.The resveratrol content of winter fruit was significantly higher than that of summer fruit at maturity stage(P<0.05).The content of resveratrol in the skin of winter fruit and summer fruit was significantly higher than that in the flesh of summer fruit(P<0.05).The reason for the difference of resveratrol content between winter fruit and summer fruit may be related to the change of temperature in winter and summer cultivation.2.Based on transcriptome data and weighted gene co-expression network(WGCNA),hub genes for resveratrol biosynthesis during grape fruit growth and development were screened.The results showed that a total of 10 specific modules were identified by WGCNA,and it was found that the gene expressions of Magenta,Purple and Cyan modules were significantly positively correlated with the changes of resveratrol content.Twelve hub genes related to resveratrol biosynthesis(STS＿1,STS＿2,STS＿3,STS＿4,CHS,PAL＿1,PAL＿2,F3’5’H＿1,F3’5’H＿2,F3’5’H＿3,F3’5’H＿4,HCT)were selected from 3 modules by Cytoscape software,the expression levels of CHS,STS,F3’5’H and PAL reached the maximum with fruit growth at maturity stage.KEGG pathway enrichment analysis showed that resveratrol biosynthesis was related to flavonoid biosynthesis,phenylalanine metabolism,phenylpropane biosynthesis and stilbene biosynthesis pathways.Six candidate genes(STS＿1,STS＿2,STS＿3,PAL＿1,PAL＿2,F3’5’H＿1)were selected from the hub genes for q RT-PCR verification in different parts of winter fruit and summer fruit.The results showed that the expression level of candidate genes in winter fruit was significantly higher than that in summer fruit,and the expression level of hub genes in skin of winter fruit and summer fruit was significantly higher than that in flesh.The resveratrol content of hub genes reached the maximum at the maturity stage,which provided theoretical basis for the function and regulatory mechanism of subsequent hub genes.3.The correlation between resveratrol content,hub gene expression and air temperature was analyzed by intelligent monitoring of temperature change in greenhouse with temperature sensor.The results showed that resveratrol content in skin was significantly negatively correlated with average daily temperature during the growth and development of winter fruit(P < 0.05).At the same time,the expression levels of F3’5’H＿1 and STS＿1 in skin and STS＿1 and STS＿2 in flesh were significantly negatively correlated with average daily temperature(P <0.05).It is likely that the mass expression of STS was stimulated under the environmental pressure of decreasing average daily temperature during the growth and development of winter fruit,and reached the maximum at maturity stage.In addition,there was a significant positive correlation between the expression of PAL＿1 and the diurnal temperature range(P < 0.05),indicating that the greater the diurnal temperature range,the higher expression of PAL＿1.The expression of PAL＿2 in flesh of summer fruit was positively correlated with average daily temperature and diurnal temperature range.These results indicated that the temperature change affected PAL expression,which may affect the biosynthesis of resveratrol.