Effects Of Exogenous Salicylic Acid On Sugar Metabolism In Cabernet Sauvignon Grape Fruits Infected With Virus

In order to improve the fruit quality of wine grapes,the effects of exogenous salicylic acid on sugar metabolism of Cabernet Sauvignon grapes infected with virus at the eastern foot of Helan Mountain were studied.In this experiment,with ’Cabernet Sauvignon’ as the test material,the effects of different concentrations of exogenous salicylic acid sprayed on the leaf surface of ’Cabernet Sauvignon’ grape fruits and leaves on the expression levels of sugar metabolization-related enzymes and fruit quality were studied.The results showed that:1.Detected the infection of 9 viruses in the fruits and leaves of Cabernet Sauvignon grapes,and a total of 7 viruses were detected.Among them,GLRaV-3,GFKV,and GVB were detected in the fruits;Seven types of GLRaV-2,GLRaV-3,GLRaV-4,GLRaV-5,GFKV,GVB,and GPGVCP were detected in the leaves.2.Exogenous salicylic acid treatment can increase the content of tannin,total phenol and soluble solids in Cabernet Sauvignon grape fruit,increase the weight of 100 seeds,increase the particle size,significantly reduce titratable acid,and increase the content of soluble total sugar,sucrose and reducing sugar in the fruit.100 mg/L exogenous salicylic acid treatment significantly increased the content of soluble total sugar,reducing sugar,starch and tannin of virus infected ’Cabernet Sauvignon’grapes,and the content of titratable acid significantly decreased;300 mg/L exogenous salicylic acid treatment significantly increased fruit grain size,soluble total sugar and starch content,and significantly reduced titratable acid content;500 mg/L exogenous salicylic acid treatment significantly reduced the content of titratable acid in fruit.100 mg/L,300 mg/L,and 500 mg/L exogenous salicylic acid treatments can all increase fruit weight,sucrose,and total phenolic content,but there is no significant effect.3.Spraying exogenous salicylic acid can effectively increase the relative expression levels of sugar metabolism related genes VvSSS,VvNIN1,and VvCWINV in the fruits and leaves of Cabernet Sauvignon grapes during harvest.However,the relative expression levels of VvSUC genes in Cabernet Sauvignon fruits decrease,and VvSUC in leaves first promotes and then suppresses.The treatment with 100mg/L exogenous salicylic acid significantly increased the relative expression levels of VvSPS,VvSSS,VvNIN1,and VvCWINV genes at various stages of leaf growth and development in Cabernet Sauvignon.The treatment with 300 mg/L exogenous salicylic acid significantly increased the expression of VvNIN1 genes in the fruit;500 mg/L exogenous salicylic acid treatment significantly inhibited the expression of VvSUC and VvCWINV genes in fruits and leaves;The treatment with 100mg/L exogenous salicylic acid significantly increased the relative expression levels of VvSPS,VvSSS,and VvNIN1 genes in fruits and leaves.In summary,100mg/L exogenous salicylic acid treatment has the best comprehensive effect.