摘要
镁原卟啉Ⅸ甲酯环化酶被认为是与叶绿素生物合成相关的重要酶之一。为了探究其编码基因(MPEC)在杂交兰叶色变异中的功能,该研究基于杂交兰叶片转录组测序数据,采用RT-PCR技术,以杂交兰‘紫妍氏’K21及其叶艺品系K21-3叶片为材料,克隆得到杂交兰MPEC基因的2个ORF序列,并对其生物信息及表达情况进行分析。杂交兰ChMPEC1和ChMPEC2基因的ORF序列长度均为1 221 bp,共编码406个氨基酸,两者存在2个差异氨基酸。生物信息学分析表明,ChMPEC1和ChMPEC2编码的蛋白质可能是一种稳定的亲水性蛋白质,属于Ferritin-like家族。进化树分析发现,杂交兰ChMPEC1和ChMPEC2与同属于兰科植物的墨兰、桃红蝴蝶兰和铁皮石斛亲缘关系较近。qPCR结果显示,在不同组织比较中,ChMPEC基因的表达情况为叶>茎>根;在不同发育时期比较中,ChMPEC基因的相对表达量从高到低依次为中苗期、小苗期和试管苗期;不同品系比较中,ChMPEC基因的相对表达量在K21中显著高于K21-3。通过叶绿素含量测定及其与ChMPEC基因相对表达量相关性分析,发现ChMPEC基因相对表达量与叶绿素a、叶绿素b及总叶绿素存在显著或极显著正相关,推测该基因参与杂交兰叶绿素的合成途径,且在K21-3叶艺形成中起一定作用。上述研究结果可为杂交兰叶艺形成机理研究提供参考依据。
Magnesium-protoporphyrin Ⅸ monomethyl ester cyclase has been considered to be an important enzyme which related to chlorophyll biosynthesis.In order to explore the function of MPEC (Mg-protoporphyrin Ⅸ rnonomethyl ester cyclase) gene in leaf color variation,the cDNA of MPEC gene was successfully cloned from the leaves of Cymbidium hybrid ‘Purple Element’ (K21) and its new strain K21-3 by RT-PCR on the basis of transcriptome sequencing results in this study.Meanwhile,the biological information and expression of gene were analyzed.The ORF sequence lengths of ChMPEC1 and ChMPEC2 were both 1 221 bp,and they encoded 406 amino acids.There were two different amino acids in ChMPEC1 and ChMPEC2.Bioinformatics analysis showed that ChMPEC1 and ChMPEC2 might be stable hydrophilic proteins,and they belonged to the Ferritin-like family.The phylogenetic tree analysis showed that ChMPEC1 and ChMPEC2 of Cymbidium hybrid were closely related to that of Cymbidium sinense,Phalaenopsis equestris and Dendrobium catenatum from Orchidaceae.qPCR results indicated that the relative expression of ChMPEC in different tissues was as follows:leaves>stems>roots.The expression level of ChMPEC in descending order was at middle seedling stage,seedling stage and test-tube plantlets stage in the comparison of different development stages.Among the different strains,the expression level of ChMPEC in K21 was significantly higher than that of K21-3.Correlation analysis results showed that there were close correlations among ChMPEC gene expression,chlorophyll a,chlorophyll b and total chlorophyll.It was speculated that this gene was involved in the synthetic pathway of chlorophyll in Cymbidium hybrid and played a role in the formation of K21-3 leaf color variation.The above research results can provide a reference for the study on the formation mechanism of leaf color variation in Cymbidium hybrid.
作者
林榕燕
陈艺荃
吴建设
林兵
叶秀仙
钟淮钦
LIN Rongyan;CHEN Yiquan;WU Jianshe;LIN Bing;YE Xiuxian;ZHONG Huaiqin(Crops Research Institute,Fujian Academy of Agricultural Sciences/Fujian Engineering Research Center for Characteristic Floriculture,Fuzhou 350013,China;Agricultural Engineering and Technology Research Institute,Fujian Academy of Agricultural Sciences,Fuzhou 350003,China)
出处
《中国细胞生物学学报》
CAS
CSCD
2020年第10期1738-1747,共10页
Chinese Journal of Cell Biology
基金
福建省自然科学基金(批准号:2019J01113)
福建省农业科学院英才项目(批准号:YC2019001)、福建省农业科学院对外合作项目(批准号:DEC201821212)和福建省农业科学院科技创新团队(批准号:STIT2017-2-9)资助的课题。
