中间砧‘南通小方柿’嫁接柿转录组测序及分析

Transcriptome Sequencing and Analysis of Grafted Persimmon with 'Nantong-xiaofangshi' as the Interstock

本研究通过Illumina Hiseq^(TM)4000高通量测序对嫁接甜柿(‘山东君迁子’/‘南通小方柿’/‘甘秋’,‘山东君迁子’/‘甘秋’)的5个嫁接部位茎中提取的总RNA进行测序,分别分析以‘南通小方柿’作中间砧致矮过程中,接穗(‘甘秋’)和基砧(‘山东君迁子’)中相关基因表达的变化。测序结果按倍性不同组装后分别获得119 573 (六倍体)和63 245(二倍体)个Unigenes的序列及在不同数据库中的注释信息,并在接穗和基砧中筛选到了9 863和7 805个差异表达基因。综合这些差异基因在接穗和基砧中GO和Pathway的分析结果表明,它们主要注释到包括代谢和植物激素信号转导在内的20条通路,其中二萜生物合成、色氨酸代谢和油菜素内酯生物合成途径中多个酶基因,以及GA、IAA和BR等激素信号转导通路中的一系列受体及作用元件基因,可能在矮化中间砧对树体生长的影响中起着关键作用。研究表明,‘南通小方柿’作中间砧的矮化作用是由于茎生长发育相关代谢通路中基因表达量变化引起的。本研究丰富了柿树的转录组信息,为进一步挖掘‘南通小方柿’中间砧矮化过程中的关键基因及其矮化机理提供重要依据,并为今后研究中间砧在植株生长发育过程中的分子作用机制提供科学依据。

In the present study, the total RNA extracted from the stems of 5 grafted persimmon(’Shandong Diospyros lotus’/’Nantong-xiaofangshi’/’Kanshu’, ’Shandong Diospyros lotus’/’Kanshu’) were sequenced by Illumina HiseqTM4000 high-throughput sequencing to analyze the expression of related genes in scion and rootstock using ’Nantong-xiaofangshi’ as interstock to dwarf, respectively. In total, 119 573(hexaploid) and 63 245(diploid) unigenes and their annotated information in different databases were obtained after the assembly in accordance with different ploidy. 9 863 and 7 805 differential expression genes(DEGs) were screened from scion and rootstock, separately. GO and KEGG analysis of DEGs in scion and rootstock revealed that these DEGs were mainly involved in 20 pathways, including metabolism and plant hormone signal transduction. Multiple enzyme genes in the pathway of diterpenoid biosynthesis, tryptophan metabolism and brassinosteroid biosynthesis, and a series of receptors and acting elements in the pathway of GA, IAA and BR hormone signal transduction were probably the key genes in the effect of dwarfing interstock on the tree growth. The results indicated that dwarfing mechanism of ’Nantong-xi aofangshi’ as an inter stock was caused by the genes expression changes related to metabolic pathways of stem growth and development. This study greatly enriched the genetic information of persimmon, and provided a theoretical basis for further exploring the essential genes and their mechanism in the dwarfing process of ’Nantong-xiaofangshi’ interstock. Also, it could provide scientific evidence for studying the molecular mechanism of interstocks in plant growth and development.