Effect Of Temperature And Soil Moisture On The Flavonoid Synthesis Of Ginkgo Leaf

The pot soil culture expriment in the artificial climate chamber was conducted to study theinfluence of moisture and temperature on flavonoid content, flavonoid biosynthesis key geneexpression and their relationship in the2-year-old ginkgo leaf. Temperature and moisture setthree levels of a total of nine treatments. Samples were collected at10d,20d,30d,40d and50dafter the initiation of treatment, and the treatmnt time of50days. The main results were asfollows:1,Along with the treatment time prolonging, there was an increasing trend in the Ginkgoleaves of W1T1, W2T1and W3T1treatments, while a trend of increasing firstly and thendecreasing was observed for the Ginkgo leaves of W1T2, W2T2,W3T2,W1T3,W2T3and W3T3.The highest contents of total flavone of Ginkgo leaves were observd in the treatment of W2T1and W3T1with the low temperature of15℃and the soil water content30％～35％or40％～45％of water holding capacity conditions which were more suitable for the synthesis offlavonoids in Ginkgo leaves. The contents of Ginkgo leaves for treatment W2T3was found to belowest, which showed that35℃and the soil water content40％～45％of water holdingcapacity conditions were not suitable for the synthesis of flavonoids in Ginkgo leaves. It wasshowed that the accumulation of flavonoids from Ginkgo leaves was closely related to thetemperature and soil moisture, as evidenced by the feasibly lower temperature(15℃) andmoderate drought(30％～35％or40％～45％of water holding capacity).2,Along with the treatment time prolonging, different gene expressions for PAL, C4H, CHS,F3H, FLS, ANS and ANR were observed in the nine treatments. The results of gene expressionsfor PAL, FLS, ANS, and ANR presented a ascending tendency, while C4H and CHS geneexpressions showed a descending tendency. F3H expression presented a descending tendency forW1T1, W1T2, W3T2and W2T1treatment, while an oppsite gene expression tendency wasfound in the other treatments.Above all, our results of the expressions of seven key genes corresponded with that of thechanges of flavonoid content. The sampling time with the highest genes expressions coincidedwith that of the highest contents of flavonoids accumulation in the Ginkgo leaves. It was showedthat a certain emperature(15℃) and moisture(30％～35％or40％～45％of water holdingcapacity) conditions for the Ginkgo biloba flavonoids biosynthesis cuold promoted key geneexpression, improve the activity of flavonoids biosynthesis key enzymes, and subsequentlypromotes the biosynthesis and accumulation of flavonoids.