摘要
Color fading caused by a decrease in anthocyanin accumulation during the post-flowering stage significantly affects postharvest quality of chrysanthemum.However,the underlying mechanism by which anthocyanin accumulation decreases during the post-flowering stage still unclear,which greatly restricts design of molecular breeding in chrysanthemum.Here,a chrysanthemum SG7 R2R3 MYB transcription factor(TF),CmMYB3-like,was identified to have a function in regulating anthocyanin biosynthesis during the post-flowering stage.Quantitative real time PCR(qRT-PCR)assays showed that the expression of CmMYB3-like was gradually downregulated when anthocyanin content increased during the flowering stage and was significantly upregulated during the post-flowering stage.Genetic transformation of chrysanthemum and dual-luciferase assays in N.benthamiana leaves showed that CmMYB3-like suppressed anthocyanin accumulation by inhibiting the transcription of CmCHS and CmANS directly and that of CmF3H indirectly.However,overexpression or suppression of CmMYB3-like did not affect the biosynthesis of flavones or flavonols.Genetic transformation of chrysanthemum revealed that the overexpression of CmMYB3-like inhibited anthocyanin accumulation,but its suppression prevented the decrease in anthocyanin accumulation during the post-flowering stage.Our results revealed a crucial role of CmMYB3-like in regulating the color of petals during the post-flowering stage and provided a target gene for molecular design breeding to improve the postharvest quality of chrysanthemum.
基金
financially supported grants from National Natural Science Foundation of China(Grant Nos.31902053,31870279,31730081)
China Postdoctoral Science Foundation(Grant No.2018M642273)
Jiangsu Planned Projects or Postdoctoral Reaearch Funds(Grant No.2019K169)
the Fundamental Research Funds for the Central Uniersities(Grant No.KYQN202031)
the National Key Research and Development Program of China(Grant Nos.2019YFD1001500,2020YFD1000400)
the earmarked fund for Jiangsu Agricultural Industry Technology System,and a project funded by the Priority academic Program Development of Jiangsu Higher Education Institutions。
