红蓝光调控茉莉开花的转录组分析

Transcriptome analysis of flowering regulated by red and blue light in Jasminum sambac

摘要:

茉莉花是多年生常绿灌木植物，因其香气芬芳怡人，常被作为天然香料的原材料。本研究通过红光和蓝光分别处理茉莉植株，以白光模拟日光作为对照，观察茉莉植株开花早晚情况，结果表明，红光处理可促使茉莉花提前开花且增加花蕾数量，而蓝光延迟茉莉开花但花蕾数量减少，且各组之间花蕾数量差异显著。采用Illumina Hiseq/Miseq 2000高通量测序技术对红光组、蓝光组及白光组的顶芽部分进行转录组测序，共得到2 452 457条单基因簇 (Unigene)，其中1 760 723个Unigenes注释到GO、COG、KEGG、KOG、NR、Pfam、Swiss-Prot、NOG 数据库。差异表达基因分析显示，对照组vs红光组共获得894个DEGs，对照组vs蓝光组共获得2 690个DEGs，红光组vs蓝光组共获得3 828个DEGs，共有的DEGs有72个。KEGG富集分析显示对照组vs红光组与对照组vs蓝光组共有的显著富集通路包括次生代谢物生物合成、苯丙素生物合成、吲哚生物碱生物合成、光合作用、植物激素信号传导和植物-病原体相互作用等，并从中筛选出24条差异表达基因，采用荧光定量PCR技术检测其表达水平，进行相关性分析，结果表明与转录组数据显著相关。通过对转录组数据进一步分析，发掘出大量调控开花相关的激素 (IAA、ETH、GA、CTK、ABA、SA、JA) 信号转导基因、开花途径相关调控基因 (PHY、CRY1、FPA、AGL和SOC1) 以及转录因子 (bHLH、MYB、WKRY) 家族基因，有助于阐明不同光质调控茉莉开花的差异表达机理。

Abstract:

Jasminum sambac is a perennial evergreen shrub plant. With fragrant and aroma, and often used as a raw material for natural spices. In this study, we used white light as the control group, red-light and blue-light as the treatment to study effects of different light on jasmine flowering. Red- light promoted jasmine flowering in advance and increased the number of flower buds, whereas blue-light delayed jasmine flowering and decreased the number of flower buds. There was significant difference on the number of flower buds among the three groups. The top buds’ transcriptomes of different light were sequenced by the Illumina Hiseq/Miseq 2000 high-throughput sequencing technology. In total 2 452 457 Unigenes were generated by transcriptome sequencing, of which 1 760 723 Unigenes were annotated into GO, COG, KEGG, KOG, NR, Pfam, Swiss-Prot, NOG databases. There were 894 DEGs in the control group vs red-light group, 2 690 DEGs in the control group vs blue-light group, and 3 828 DEGs in the red-light group vs blue-light group. KEGG Enrichment analysis reveals that the significant enrichment pathways had 6 pathways, including secondary metabolite biosynthesis, phenylpropanoid biosynthesis, indole alkaloid biosynthesis, photosynthesis, plant hormone signaling, and plants-pathogen interactions, and 24 related DEGs were detected by RT-qPCR, the result of which was significantly correlated with the transcriptome data. Through further analysis of transcriptome data, a large number of flowering-related hormones (IAA, ETH, GA, CTK, ABA, SA, JA) signal transduction genes and flowering pathway-related regulatory genes (PHY, CRY1, FPA, AGL and SOC1) and transcription factor (bHLH, MYB, WKRY) family genes were found. The study will help elucidate the differential expression mechanism of different light regulation of jasmine flowering.