Effect of soil water content on anthocyanin level and DFR gene expression in roselle
[Objective]The effect of soil water content(SWC)on the anthocyanin content and expression level of dihydroflavonol 4-reductase(DFR)related genes in the calyxes of Hibiscus sabdariffa L.(roselle)were analyzed to provide basis for the water man-agement during roselle cultivation and further clarification of the function of DFR in anthocyanin synthesis.[Method]The seedlings of'Guangdong early-maturity'were treated with 3 levels of SWC,namely 33% (severe drought),55% (moderate drought)and 80% (flood),respectively,and the anthocyanin content as well as the expression levels of 5 DFR genes in the calyxes were meas-ured at 10(early flowering stage),20(middle flowering stage)and 30(late flowering stage)days since flowering.Moreover,the correlation between anthocyanin content and the expression level of DFR genes were analyzed.[Result](1)Under each treatment,the anthocyanin content of roselle calyxes showed decreasing trends with the course of flowering,and varied significantly between the early and late flowering stage,with the sharpest decline occurring at 80% SWC.During early and middle flowering stage,the antho-cyanin contents in the calyxes of roselle were significantly lower at 33% SWC than those of 55% and 80%;while at late flowering stage,the difference in anthocyanin content among the 3 treatments was insignificant.(2)The expressions of DFR genes followed various trends with flowering in response to different SWC treatments.At 33% SWC,the expression levels of the 5 DFR genes were higher than the other 2 treatments,significantly up-regulated,and peaked at 30 d after flowering,among which the expression level of DFR4 ranked the top while that of the DFR5 was at the bottom.Moreover,the expression levels of all the 5 DFR genes were rela-tively low at 55% and 80% SWC.(3)At 55% SWC,the expression levels of DFR4 and DFR5 were significantly correlated with the anthocyanin contents in roselle calyxes,indicating their key roles in regulating anthocyanin synthesis in roselle.[Conclusion]Severe drought and flood impede the synthesis of anthocyanins in roselle calyxes;the expression levels of DFR were promoted by drought stress,while inhibited under waterlogging conditions.In addition,DFR4 and DFR5 genes were the key genes regulating anthocyanin synthesis in roselle calyxes.
rosellesoil water contentanthocyanindihydroflavonol-4-reductasegene expression
万方数据
维普
