秋茄低温胁迫转录组分析及脱落酸信号途径基因挖掘

Transcriptome Analysis and Gene Discovery of Abscisic Acid Signaling Pathway in Kandelia obovata under Low Temperature Stress

[目的]深入了解秋茄响应低温胁迫的分子机制以及培育秋茄的抗寒新品种。[方法 ]以耐寒红树植物‘龙港’秋茄1年生容器苗为实验材料,15℃处理12 h为对照组(CK),-5℃处理12 h为低温组(LT),采用Illumina HiSeq测序平台进行转录组测序,挖掘脱落酸信号途径相关基因。[结果 ]转录组测序共鉴定到148个转录因子,分属于25个转录因子家族,其中,ERF、NAC、WRKY、bHLH、MYB、bZIP、HB-other和MYB-related等家族所包含的基因数量较多,分别为17、14、12、12、10、9、6和6;差异组共筛选到1 330个差异表达基因(Differentially Expressed Genes, DEGs),其中,698(52.48%)个上调表达,632(47.52%)个下调表达;KEGG通路富集分析发现,DEGs显著富集在植物激素信号转导、苯丙素生物合成、半乳糖代谢、光合作用-天线蛋白和α-亚麻酸代谢等通路中;脱落酸信号途径相关基因KoPYL1、KoABF1和KoABF2上调表达,KoPP2C1和KoABF3下调表达,且这些基因表达情况与qRT-PCR验证结果一致。[结论 ]ERF、NAC、WRKY、b HLH、MYB、bZIP、HB-other和MYB-related等家族转录因子对秋茄响应低温胁迫起重要调控作用。植物激素信号转导、苯丙素生物合成、半乳糖代谢、光合作用-天线蛋白和α-亚麻酸代谢等是秋茄响应低温胁迫的重要KEGG通路。脱落酸信号途径中的KoPYL1、 KoPP2C1、KoABF1、KoABF2和KoABF3基因可作为后期研究秋茄响应低温胁迫的重要候选基因。

[Objective]To understand the molecular mechanism of Kandelia obovata in response to low temperature stress and cultivate new varieties of cold resistance.[Method]Based on the annual container seedlings of'Longgang'K.obovata,a cold-tolerant mangrove cultiva,the control group(CK)was treated at 15 oC for 12 h and the low temperature group(LT)was treated at−5 oC for 12 h.Illumina HiSeq sequencing platform was used for transcriptome sequencing,and the genes related to abscisic acid signaling pathway were discovered.[Result]The results showed that a total of 148 transcription factors were identified by transcriptome sequencing,which belonged to 25 transcription factor families.Among them,ERF,NAC,WRKY,bHLH,MYB,bZIP,HB-other and MYB-related families contained more genes,which were 17,14,12,12,10,9,6 and 6,respectively.A total of 1330 differentially expressed genes(DEGs)were screened in the differential group,of which 698(52.48%)were up-regulated and 632(47.52%)were down-regulated.KEGG pathway enrichment analysis showed that DEGs were significantly enriched in plant hormone signal transduction,phenylpropanoid biosynthesis,galactose metabolism,photosynthesis-antenna protein,and alpha-Linolenic acid metabolism.Among the abscisic acid signaling pathways,Ko-PYL1,KoABF1,and KoABF2 were up-regulated and KoPP2C1 and KoABF3 were down-regulated,and the expression of these genes was consistent with the qRT-PCR validation results.[Conclusion]ERF,NAC,WRKY,bHLH,MYB,bZIP,HB-other and MYB-related play an important role in regulating the response of K.obovata to low temperature stress.Phytohormone signal transduction,phenylpropanoid biosynthesis,galactose metabolism,photosynthesis-antenna protein and alpha-Linolenic acid metabolism are important KEGG pathways in K.obovata in response to low temperature stress.KoPYL1,KoPP2C1,Ko-ABF1,KoABF2 and KoABF3 genes in abscisic acid signaling pathway can be used as important candidate genes for future studies on the response of K.obovata to cold stress.