“糖心”苹果香气物质生物合成的转录代谢联合分析  

Combined Transcriptional and Metabolic Analysis of Aroma Substances in Watercore Apples

作　　者：蒙小玉 冯建文[1] 黄欣艳 王林 吴亚维[1] MENG Xiaoyu;FENG Jianwen;HUANG Xinyan;WANG Lin;WU Yawei(Guizhou Institute of Pomology,Guiyang,Guizhou 550006)

机构地区：[1]贵州省果树科学研究所,贵州贵阳550006

出　　处：《核农学报》2025年第4期696-706,共11页Journal of Nuclear Agricultural Sciences

基　　金：贵州省科技支撑计划项目(黔科合支撑[2020]1Y025)。

摘　　要：为探究黔选3号苹果“糖心”与正常组织代谢化合物的差异,解析特征差异香气物质形成的分子机制,本研究采用气相色谱-串联质谱技术(GC-MS/MS)和Illumina高通量测序技术获得黔选3号苹果果肉“糖心”与正常组织的代谢组学和转录组学数据。转录组学分析显示,共产生1795个差异表达基因(DEGs),其中671个下调基因、1124个上调基因,与脂肪酸合成途径(fatty acid synthesis pathway)相关的基因有7个,与乙醇脱氢酶(ADH)相关的基因有8个。代谢组学共检测到353个香气物质,分析表明有20种差异香气物质,包含上调物质8个、下调物质12个,其中己酸乙酯和正壬醛显著上调。转录组-代谢组学联合分析结果表明,脂肪酸合成途径与乙醇脱氢酶家族中11个DEGs与己酸乙酯、正壬醛呈正相关关系,2个DEGs与己酸乙酯呈负相关关系,且MdFAD6、MdADH2、MdADH3和MdADH4在“糖心”组织特异性表达,实时荧光定量PCR(qRT-PCR)结果表明上述基因在“糖心”组织中的相对表达量显著高于正常组织,推测这些基因在苹果“糖心”组织差异香气物质合成途径中发挥了关键作用。研究结果初步揭示了“糖心”苹果香味变化的生物学基础,可为“糖心”苹果品质改良提供参考依据。To explore the difference of volatile compounds between the watercore and normal tissue of Qianxuan No.3 apple,and to elucidate the molecular mechanism underlying the formation of characteristic aroma substances in apple watercore,gas chromatography-tandem mass spectrometry(GC-MS/MS)and Illumina HiSeqTM highthroughput sequencing techniques were conducted to obtain the metabolome and transcriptome data of the watercore and normal tissue of Qianxuan No.3.Transcriptomics analysis revealed 1795 differentially expressed genes(DEGs),including 671 down-regulated genes and 1124 up-regulated genes.Additionally,7 genes related to fatty acid synthesis pathway and 8 genes related to alcohol dehydrogenase were explored.In this study,353 metabolites were detected through widely targeted metabolomics,identifying 20 differential accumulated metabolites,including 8 up-regulated metabolites and 12 down-regulated metabolites.Notably,the relative contents of ethyl hexanoate and nonanal in the apple watercore tissue were significantly higher than those in the normal tissue.The transcriptome-metabolomics association analysis illustrated that 11 DEGs were positively correlated with ethyl hexanoate and nonanal,while 2 DEGs were negatively correlated with ethyl hexanoate within fatty acid synthesis pathway and the alcohol dehydrogenase family.MdFAD6,MdADH2,MdADH3,and MdADH4 were found to be expressed exclusively in watercore tissues.Quantitative real-time PCR(qRT-PCR)results showed that the relative expression levels of these genes in watercore tissues were significantly up-regulated compared to those in normal tissues,suggesting that these genes may play a crucial role in the synthesis pathway of volatile compounds in watercore apples.The differential metabolites and genes identified in this study will not only provide preliminary insights into the biological basis of flavor changes in watercore tissues,but also provide reference information for the quality improvement of watercore apples.

关 键 词：“糖心”苹果 代谢组学 转录组学 代谢物质 

分 类 号：S661.1[农业科学—果树学]