摘要
为了探究花青苷和叶绿素相关结构基因与'妃子笑'荔枝果皮着色的关系,本研究首先基于基因组数据鉴定了花青苷和叶绿素相关结构基因,然后分析了其在外源CPPU抑制'妃子笑'荔枝着色过程的表达及对应酶活性.结果显示,花青苷合成关键酶UFGT,叶绿素降解途径NYC/NOL、MDcase以及PAO酶活性明显受到抑制,叶绿素合成途径CS和CAO及Chlase酶活性明显增加.转录组测序和RT-qPCR结果表明,外源CPPU 显著抑制了花青苷合成途径结构基因 LcPAL1、LcPAL3、LcC4H1、Lc4CL2、Lc4CL3、Lc4CL4、LcCHS2、Lc-CHS5、LcCHI、LcF3H/LcF3'H、LcDFR2、LcANS1、LcUFGT2、LcUFGT3,和叶绿素降解途径结构基因 LcSGR2、LcPPH和LcPAO的表达;促进叶绿素合成相关途径基因LcHEMA、LcHEMD、LcCHLH1、LcCHLH2和LcCAO的表达,同时抑制转录因子基因LcMYB3、LcMYB4和LcWRKY3的表达.因此,推测外源CPPU可能通过抑制花青苷合成和叶绿素降解相关基因表达及酶活性,促进叶绿素合成相关基因的表达及酶活性,使'妃子笑'荔枝果皮中花青苷与叶绿素比值在最佳可食期偏低而不能完全着色.研究结果为解决'妃子笑'荔枝"滞绿"问题提供理论依据,也可为植物色泽问题的研究提供参考.
Abstract
In order to explore the relationship between the anthocyanin and chlorophyll related structural genes with the coloration of'Feizixiao'litchi,identification of the above gene based on genome data was conducted firstly,and then analyzed their expression and corresponding enzyme activities during the coloration inhibition of'Feizixiao'litchi induced by exogenous CPPU in this study.The results showed that the key enzyme UFGT in anthocyanin biosynthesis,as well as the enzymes NYC/NOL,MDcase,and PAO involved in the chlorophyll degradation path way,were significantly inhibited,while the activities of CS and CAO in the chlorophyll synthesis pathway,along with Chlase,were notably increased.Transcriptome sequencing and RT-qPCR results indicated that exogenous CPPU significantly inhibited the expression of structural genes involved in the anthocyanin biosynthesis pathway,includ-ing LcPAL1,LcPAL3,LcC4H1,Lc4CL2,Lc4CL3,Lc4CL4,LcCHS2,LcCHS5,LcCHI,LcF3H/LcF3'H,LcDFR2,LcANS1,LcUFGT2,LcUFGT3,and those involved in the chlorophyll degradation pathway,including LcSGR2,LcPPH,and LcPA O.At the same time,it promoted the expression of genes related to chlorophyll synthesis,such as LcHEMA,LcHEMD,Lc CHLH1,Lc CHLH2 and LcCAO,while inhibiting the expression of transcription factor genes LcMYB3,LcMYB4 and LcWRKY3.Therefore,it is speculated the expression and enzyme activity of genes related to anthocyanin synthesis and chlorophyll degradation may be inhibited,the expression and enzyme activity of genes related to chlorophyll synthesis may be promoted by exogenous CPPU to make the ratio of anthocyanin to chloro-phyll in the pericarp of'Feizixiao'litchi fruit lower in the best edible period and unable to complete coloration.The results provide a theoretical basis for solving the problem of"stay green"in'Feizixiao'litchi,and also provide a ref-erence for the study of plant color.
基金项目
海南省基础与应用基础研究计划(自然科学领域)青年项目(320QN191)
海南省重大科技计划项目(ZD-KJ2021006)
国家自然科学基金项目(32260750)
海南大学引进高层次人才启动基金项目(KYQD2R1970)
海南省研究生创新科研课题项目(Qhys2021-249)
万方数据