珍珠芦荟失绿突变体‘MT-1’的农艺性状、解剖结构、光合特性和代谢组特征分析

Analysis of Agronomic Traits, Anatomical Structure, Photosynthetic Characters and Metabolomic Characteristics of Leaf Chlorosis Mutant ‘MT-1’ in Aristaloe aristata

摘要:

为阐明珍珠芦荟叶色突变的变异机制, 以珍珠芦荟(Aristaloe aristata)叶色失绿突变体‘MT-1’及其叶色正常种质‘WT-18’为试材，对其表型特征、叶片超微结构、光合色素含量、叶绿素荧光参数、差异代谢产物等方面进行了对比研究。结果表明, 与‘WT-18’相比，突变体‘MT-1’从幼叶开始呈现出黄化条斑现象，且株型变小、生长缓慢；气孔数量少且小，形状由长方形变成正方形；叶绿体数量及内部片层数量变少、体积也明显变小；光合色素(叶绿素a、叶绿素b和类胡萝卜素)含量和叶绿素荧光动力参数(F_o、F_m、F_v/F_m、ФPSⅡ、qP、qN和ETR)均显著降低。‘MT-1’和‘WT-18’的代谢产物差异明显，KEGG代谢通路分析表明，大多数差异代谢物富集到氨基酸代谢、糖代谢、脂类代谢、核酸代谢、次级代谢产物生物合成等途径。因此，叶绿体相关基因的改变可能是发生叶色失绿突变的重要原因。

Abstract:

In order to elucidate the mutation mechanism of leaf color mutation ofAristaloe aristata, the phenotypic characteristics, leaf ultrastructure, photosynthetic pigment content, chlorophyll fluorescence parameters and metabolomics between leaf color mutant ‘MT-1’ and normal leaf color germplasm ‘WT-18’ were compared. The results showed that compared with ‘WT-18’, the mutant ‘MT-1’ exhibited yellow strips from young leaves, and the plant type became smaller and the growth was slower. The number of stomata became less and small, and the shape changed from rectangle to square. The number of chloroplasts and internal lamella decreased, and the volume decreased obviously. The contents of photosynthetic pigments, including chlorophyll a, chlorophyll b and carotenoids, and chlorophyll fluorescence dynamic parameters (F_o, F_m, F_v/F_m, Ф_PSⅡ, qP, qN and ETR) decreased significantly. The metabolites of ‘MT-1’ and ‘WT-18’ were significantly different. The KEGG metabolic pathway analysis showed that most of the different metabolites were enriched in amino acid metabolism, glucose metabolism, lipid metabolism, nucleic acid metabolism, secondary metabolite biosynthesis, and other pathways. Therefore, the changes in chloroplast related genes might be an important cause of leaf chlorosis mutation.