The Molecular Mechanism Research On The Red Pigment Development Of Zizyphus Jujuba Mill Cv. Dongzao

This research takes jujube of green-ripe stage,white-ripe stage,half-red stage,full-red stage as raw materials.To explore the relationships between pericarp redstain,storage quality,nutrients content antioxidant enzyme activity and gene expression related to anthocyanin synthesis,reveal the changes of jujube quality after harvest,calcium chloride,compound film,abscisic acid were studied to treat the jujube fruit of white ripe stage.The influence of different ripe stages and different treatments on Dongzao was analyzed from physiological and molecular level system.Our results will further the understanding of anthocyanin in regulation the peel color of Dongzao,which will be useful to use a genetic engineering approach to improve the fruit color.It turns out that the contents of titratable acid,soluble solids and carotenoid gradually increase while the contents of vitamin C,total phenolics,total flavonoids and chlorophyll gradually decrease in the process of Dongzao maturing.In the storage process,calcium chloride and composite coating treatments delay the decreasing speed of vitamin C,proanthocyanidins,anthocyanin and chlorophyll,which effectively puts off the red speed of Dongzao pericarp.And the composite coating treatment has the best preservation effect.However,the ABA treatment accelerates the quality deterioration of Dongzao and pericarp erubescence,indicating that ABA significantly promotes the maturity and senescence of Dongzao.It is indicated by research that the changes of pericarp color of Dongzao are the conjunct result of chlorophyll,carotenoid,anthocyanin,flavonoid and polyphenol.The results of enzyme activity demonstrate that the increase of PPO activity is accompanied by the occurrence of browning in the process of normal maturity and postharvest storage and the extent of browning in positively correlated with enzyme activity.The treatments of calcium chloride and composite coating can help to keep a higher level of SOD of Dongzao and remarkably postpone the phenomenon of pericarp erubescence and senescence of Dongzao.POD plays an important role in the removal of excessive peroxide in the earlier stage of the Dongzao storage while in the later stage,it participates in the browning and erubescence of pericarp.PAL activity increases in the normal ripening of Dongzao process to generate more Phenolics so that they can reduce the oxidative damage on Dongzao.The results of gene expression indicate that in the Dongzao`s ripening process,the expression level of PAL gene reaches the maximum value in the half-red period and CHI,DFR,UFGT gene reach the maximum value in the full-red stage.In the storage process,compared with contrast group,the ABA treatment induces the expression of DFR and UFGT gene of Dongzao pericarp.And the expression of DFR and UFGT gene of Dongzao pericarp is inhibited by the treatment of calcium chloride and composite coating;Low-temperature storage down-regulates CHI gene expression;The expression of DFR and UFGT gene is positively correlated with the content of anthocyanin.