Modifications Of Grape Berry Quality As Affected By The Rootstocks And Preliminary Exploration On The Underlying Mechanism

Grape berry quality was evaluated from 15 different combinations among 6 rootstocks and 3 scions,and thereby the optimal rootstock was obtained for each cultivar.In order to unravel the mechanisms underlying the effects of rootstocks on berry quality,the gene and protein expression profiling induced by the rootstocks of 3309 C and 101-14 M in the ?Gold finger? berries were performed.Additionaly,the impacts of rootstocks on carbon and nitrogen nutrition as well as growth of seedling is analysised.The main results as follows:1.The fruit characters of ?Gold finger? grape were the best on 101-14 M,i.e.,keeping content of sugar,acid,aroma and amino acids and enhancing cluster weight and content of resveratrol in the skin.The Beta rootstock improved fruit size,color and aroma of ?Summer Black? berries,and generated similar sugar and amino acid content to control?Self-rooted vine?.All of the rootstocks imparted negative impacts on sugar content and coloration of ?Fujiminori? berries;in contrast,101-14 M enhanced cluster and berry weight,decreased the soluble sugar content slightly,and did not produced adverse effect on aroma.In conclusion,the 101-14 M rootstock is suitable for ?Gold finger? and ?Fujiminori?,and the Beta rootstock for ?Summer black?.2.The SO₄ rootstock impaired berry quality on sugar,aroma and animo acids in all of three scions,and the decrements of TSS/TA reached 23.5%,26.7% and 55.4% in ?Gold finger?,?Summer black? and ?Fujiminori?,respectively.In contrast,SO₄ is in favor of cluster and berry weight.5BB decreased the content of animo acids of ?Gold finger? and decreased the content of soluble sugar,ester aroma and resveratrol of ?Summer Black? berries;110R decreased soluble sugar content and produced more aroma components.In conclusion,SO₄,5BB and 3309 C generally impaired fruit quality.3.Using RNA-seq and bioinformatics analysis,we identified 259 differentially expressed genes in ?Gold finger? mature berries induced by the rootstocks of 3309 C and 101-14 M,and 152 of them were induced by two rootstocks simultaneously.GO enrichment analysis showed that functions of the DGE genes are primarily related to stimulus,multi-organism process,immune system process and transcription regulator activity.KEGG analysis showed that the genes mainly involved in carbohydrate metabolism,amino acid metabolism,aroma metabolism and so on.4.By label-free proteomics analysis,a total of 3197 proteins were identified in ?Gold finger? berries at veraison,929 proteins were induced by two rootstocks of 3309 C and 101-14 M,745 proteins were regulated only by 3309 C,and 494 proteins regulated only by 101-14 M.GO enrichment analysis showed that the proteins induced by two rootstocks are related to cellular process,metabolic process and establishment of localization,while hexose metabolic process,glucose metabolic process and monosaccharide metabolic process have high degree of enrichment in metabolic process.Additionally,a large number of proteins matched to carbohydrate metabolism and amino acid metabolism via KEGG analysis.5.A wide range of changes were induced by the rootstocks of 3309 C and 101-14 M in transcriptome?berries in mature?and proteomics?berries at veraison?and additionally,most of the genes or proteins were negatively regulated by the two rootstocks.Additionally,the similar changing patterns of DGE genes were found between the two rootstocks.6.The rootstocks of 3309 C and 101-14 M affected the characteristics of carbon and nitrogen nutrition of ?Gold finger? vines,increased nitrogen absorption ability of roots and carbon fixation ability of leaves,and increased the proportion of C:N and content of dry matter in the whole plant.Carbon and nitrogen tracer experiments showed that grafting promoted the polar transport of carbon and nitrogen nutrients in plants.