基于转录组测序的青蟹寿锦化相关基因分析

Preliminary Study on Molecular Mechanism of Variegated Haworthia magnifica Formation

【目的】以青蟹寿及其全锦突变体qj为材料,研究多肉植物锦化变异分子机理。【方法】利用分光光度计法、转录组测序(RNA-seq),分别测量其叶绿素、类胡萝卜素含量及其相关基因的表达水平,并筛选差异显著的相关代谢途径。【结果】结果表明,qj的叶绿素a、叶绿素b、类胡萝卜素的含量显著下降;对青蟹寿及qj叶片转录组测序分别获得44 988 938和37 271 576条Reads,经过滤拼接组装得到45 226条Unigene;所得Unigene的Nr注释分类中有26 999条,Swissport注释有20 279条,KOG注释有16 943条,KEGG注释有10 775条;筛选获得表达差异显著基因共20 305条,涉及130个途径,其中21个途径差异显著。筛选得到的叶绿素合成途径(ko00860)、天线蛋白(ko00196)和光合作用途径(ko00195)的基因表达对比分析,结果表明这3个途径的基因普遍显著下调表达。【结论】初步探索了多肉植物锦化变异的转录组信息,筛选到表达差异显著的基因及途径,为进一步研究多肉植物锦化变异机制提供了基础。

【Objective】Molecular mechanism responsible for the formation of variegated succulent plants,Haworthia magnifica,was investigated using the mutant qj for the comparison.【Method】Contents of chlorophylls and carotenoids in the plants were determined by spectrophotometry,and gene expression by transcriptome sequencing(RNA-seq).【Result】The contents of chlorophyll a,chlorophyll b and carotenoids in the variegated qj were significantly lower than those of wild-type H.magnifica.Using RNA-seq,44 988 938 Reads were obtained for H.magnifica and 37 271 576 for qj which were assembled into 45 226 Unigenes.There were 26 999 Unigenes assigned to Nr annotations,20 279 to Swissport,16 943 to KOG categories,and 10 775 to KEGG pathway.A total of 20 305 genes exhibited significantly different expressions that involved 130 pathways,of which 21 significantly differed from the others.The gene expression analysis showed that the genes associated with the chlorophyll synthesis(ko00860),antenna protein(ko00196)and photosynthesis(ko00195)pathways were generally significantly down-regulated.【Conclusion】The significant variations on the transcriptome sequences,genes and pathways of H.magnifica and its variegated counterpart obtained from this study provided the fundamental information for further study to unveil the underlaying mechanism.