Study On Starch Metabolism And Expression Analysis Of Aroma Gene During Grape Berry Development

Grape is the type fruit with sugar accumulation, while it is also belonging to a non-climacteric fruit. Although the sucrose metabolism is the main carbohydrate metabolism during grape berry development, there is little known about the role of starch metabolism in grape development stages. In this study, the grape berries in different development stages were used as the material,4 kinds of genes correlated with starch metabolism were cloned successfully to get the preliminary understanding the function of each gene. Then, the mechanism of starch metabolism and sucrose metabolism were studied in grape fruit pericarp and flesh tissues on the morphology level, enzymology level and gene expression, respectively. The role of starch during grape development was illuminated preliminary. To explore the carbohydrate metabolism in young fruits in circadian rhythm, the leaves were set as the contrast material and the change of trace amounts of starch content in young fruits were researched during the daily cycle. To explore the regulation mechanism of terpenoid, the expression of (E)-β-caryophyllene synthase gene during grape development was studied. The main results of the study are as follows:1. In this study, bioinformatics methods to predict 4 genes encoding the starch metabolism key enzymes in grape like VvAPS, VvAPL, VvGBSSl and VvAMY, specific primers were designed, the leaf and fruit mixed cDNA as a template for PCR cloning. The use of the evolutionary tree for homology analysis showed that four genetic clones obtained with other species have high homology.2. Starch granul changes were observed in the developmental pericarp and flesh tissues of grape by transmission electron microscope (TEM). The changes of starch and soluble sugar content in pericarp and flesh tissues of developmental stages was determined, the enzymes activity and gene expression analysis related to starch and sucrose metabolism were examined, we found that starch present in the chloroplasts, starch was as the temporary stored substance to involve in the supersession of young fruit itself. During the young fruit development, not only AGPase genes VvAPS and VvAPL regulating the starch metabolism, but SPS and VvSPS also involved in the regulation. Starch accumulation in pericarp in veraison fruit as an energy’supply station’. In fruit maturity, BMY and AMY activity is greater than the degradation of starch to starch synthesis AGPase, VvBMY for BMY has played an important role in the regulation; Since enzymes and VvcwINV and CWI section of fruit development stages II and III by apoplastic pathway to flesh unload a lot of sugar, so that the accumulation of sugar in the flesh earlier than peel. Other sucrose metabolism enzymes SuS, AI, NI and related genes VvSuS, VvGIN1, VvGIN2, VvNIN also accumulate sugar fruit development stage and played an important role, which shows the accumulation of sugar in the grapes not just by a single enzyme works, but the result of a variety of enzymes and co-regulated genes, so consider the combined effect of several metabolic enzymes of sucrose accumulation mechanism of sugar should be in research.3. Comparison with leaves, young fruit grapes can contain chloroplasts for photosynthesis to produce starch and sucrose, and as a young fruit at the same time has a certain capacity to absorb carbon assimilation library assimilates to mobilize young fruit in transit. VvAPS, VvBMY and VvSPS gene expression has some circadian rhythms, which regulate AGPase, BMY and SPS enzyme activity also showed some circadian rhythm, circadian rhythm leaves more obvious than the young fruit in leaves weak circadian rhythms may and young fruit photosynthesis and sucrose metabolism in the regulation of sugar and starch sugar allocation among more about bias, resulting in starch metabolism in young fruit circadian obvious.4. (E)-β-caryophyllene synthase is the formation of a fruit aroma terpene synthases, the process for determining the regulation of fruit development in the gene encoding the enzyme, this study ’Deyin 84-1’grapes as test material, the use of fluorescence quantitative RT-PCR analysis of the preliminary Vv-ECar relative expression levels in different developmental stages of grape fruit. The results showed that, Vv-ECar expression levels in young fruit strongest expression of other times weak.