大麦白化颖壳突变体的转录组学分析

Transcriptome Analysis of Albino Lemma Mutant in Barley

为了探究大麦白化颖壳突变体形成机理,以白化颖壳突变体(AL)和野生型植株(WT)为试验材料,对2份材料抽穗期的颖壳进行转录组测序分析,通过Illumina Hi SeqTM2500高通量转录组测序技术分别从WT和AL中获得2.7 Gb和4.1 Gb有效数据,拼接组装后得到64 634条通用基因(unigenes),其中长度大于1 kb的有23 696条。通过对2份材料间差异基因的筛选,共得到672个差异表达基因(DEGs),其中139个上调表达,533个下调表达。GO功能富集分析发现,在分子功能类型中注释的差异基因主要与叶绿体相关;KEGG显著富集分析发现差异基因广泛涉及碳代谢、光合作用等调控途径。对其中6个相关基因进行了RT-qPCR验证,表达趋势与RNA-Seq测序结果一致。表明AL的形成可能是由于叶绿体形成和发育相关基因的表达受到抑制,进一步导致了光合作用的下降,该研究结果对深入探究大麦的白化形成机理具有重要的参考价值。

To study the molecular mechanism of albino lemma mutant in barley, transcriptome analysis was performed with the lemma of wild type （WT） and mutant （AL） in their heading stage using Illumina HiSeqTM 2500 system. Totally 2.7 Gb and 4. 1 Gb clean data were generated from WT and AL, respectively, and 64 634 unigenes were obtained by de novo assembly. Among these unigenes, 23 696 were larger than lkb. Totally 672 differently expressed genes （DEGs） were identified according to their expression profile. Among these DEGs, 139 were up-regulated while 533 DEGs were down-regulated in AL. Gene Ontology analysis revealed that these DEGs were mostly related to chloroplast in molecular function, and KEGG pathway analysis revealed their functional enrichment in carbon metabolism, photosynthesis and so on. Six unigenes related to photosynthesis were confirmed by quantitative realtime PCR, and the results were highly consistent with those of the RNA-Seq. The formation of AL mutant might be attributed to the down-regulation of the genes related to chloroplast development that led to the decrease of photosynthesis. The results would be beneficial for revealing the molecular mechanism of AL mutant.