| Grape(Vitis L.)is one of the most important fruit trees,and its disease resistance and aroma components are widely concerned.Hormone signal substances such as methyl jasmonate and salicylic acid play a role in plant disease resistance and induce the expression of disease resistance genes.Therefore,the application of exogenous hormones to induce the gene expression of the corresponding signal pathway can mine the disease resistance-related genes in the signal pathway.In this research,on the resistance of grapes to white rot,the increase of methyl jasmonate content was closely related to the disease resistance of grapes.Treatment with exogenous hormones,explore the types and numbers of differentially expressed genes induced by methyl jasmonate,so as to identify important candidate genes for white rot resistance.By applying Me JA at a concentration of 100μM to the leaves of Zaotianmeiguixiang grapes,total RNA was extracted after 0,12,24 and 48 hours of treatment for transcriptome sequencing,and a total of 1,242 genes were identified through analysis of differentially expressed genes.Out of Differentially expressed genes(DEGs),850 genes were up-regulated and 392 genes were down-regulated.GO and KEGG analysis of DEGs showed that genes related to mitogen-activated protein kinase(MAPK),plant hormone signal transduction,jasmonic acid-mediated defense genes,and flavonoid biosynthetic pathways were up-regulated.Up-regulation of these pathway genes in grape leaves helps to regulate reactive oxygen species(ROS),disease resistance elements,and enhances the hormone signal transduction related to disease resistance.The expression of some DEGs was verified by real-time quantitative PCR(q RT-PCR),and the results were consistent with the RNA-seq data.The four key genes WRKY22,LOX,PR1,and PR4 of the jasmonic acid signaling pathway were included in DEGs.Previous studies found that PR1 expression in disease-resistant grapes was higher than that in susceptible grapes,and PR1-induced changes in resistant grapes were higher than in susceptible ones.On this basis,research has been carried out around the PR1 promoter.Construct vectors of different length promoters(β-glucuronidase(GUS)fusion vector),and test their GUS activity after transient expression in tobacco leaves.A series of 5’Vd PR1 promoter fragments [-1837,-1443,-1119,-864,-558,-436,-192,and(-1837 to-20)] bp vectors were constructed and tested The response activity of GUS gene to salicylic acid(SA),abscisic acid(ABA),and methyl jasmonate(Me JA).The results showed that the region from-1837 bp to-558 bp of the PR1 promoter is the key region in response to hormone induction.The fruits of wild grapes in China have different aromas from cultivated species.The purpose of testing the aroma components is to clarify the differences between the different components and their relationship with aroma types.In this study,high-efficiency gas phase GC-MS was used to detect volatile organic compounds(VOC)in 10 grape varieties belonging to 9 different grape varieties.Its fruit aroma types include rose,strawberry,musk and so on.A total of 45 volatile compounds were detected in the study,of which a variety of unique volatile organic compounds were detected in wild grapes in China,including valeric acid,cyclobutyl ester,maltol,(+)-neoisomenthol and 8-methyl Octahydrocoumarin,which is not found in grape berries from other sources.Abundant esters are found in the musk-type American grapes,while the rose-type is dominated by terpenoids.Principal component analysis showed that Chinese wild grapes,V.yeshanensis,V.ficifolia,V.davidii,V.betulifolia V.heyneana,and V.adenoclada have a strong correlation with wine grape variety Cabernet Sauvignon.Studies have shown that there were aroma components in wild grapes different from cultivated species in China,and this result can provide a theoretical basis for the utilization of wild germplasm... |
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