‘台农1号’杧果转录组测序分析

Transcriptome Sequencing Analysis of'Tainong No.1'Mango

杧果(Mangifera indica L.)是一种味道甜美、营养丰富的热带水果。为了进一步了解杧果果实中独特风味形成的原因,本研究通过GC-MS检测了‘台农1号’果实后熟过程中的挥发性有机化合物,测得杧果在成熟时会产生大量的萜类化合物。使用高通量测序技术平台Illumina HiSeq对转色期杧果(0 d)和成熟期杧果(4 d)进行转录组测序,共发现9832个存在表达差异的基因,与转色期相比,完熟期上调表达的差异基因4138个,下调表达的差异基因5694个。本研究重点分析了杧果果实中6条与萜类生物合成相关途径的108个unigenes,分别是萜类骨架生物合成途径、泛醌和其他萜类醌的生物合成途径、二萜生物合成途径、单萜生物合成途径、柠檬烯和蒎烯降解途径以及倍半萜和三萜生物合成途径。在萜类骨架生物合成途径中发现36个差异表达基因,差异表达发现,采后的杧果果实主要是通过MVA途径合成IPP和DMAPP等类异戊二烯前体物质。研究结果丰富了杧果的转录组资源,这些基因为深入挖掘杧果功能基因的克隆及功能分析、研究杧果萜类化合物的生物合成提供依据,也为杧果香味品质育种工作提供参考。

Mango(Mangifera indica L.)is a sweet and nutritious tropical fruit.In order to further understand the reasons for the formation of unique flavor in mango fruit,the volatile organic compounds in the ripening process of'Tainong No.1'fruit were detected by GC-MS.It was found that a large number of terpenoids were produced during mango ripening.High-throughput sequencing technology platform Illumina HiSeq was used to sequence the transcriptome of color turning stage mango(0 d)and ripe stage mango(4 d).A total of 9832 differentially expressed genes were found.Compared with the color-changing period,4138 differentially expressed genes were up-regulated and 5694 differentially expressed genes were down-regulated in the mature period.This study focused on the analysis of 108 unigenes in 6 pathways related to terpenoid biosynthesis in mango fruits,including terpenoid skeleton biosynthesis,ubiquinone and other terpenoid quinone biosynthesis,diterpene biosynthesis,monoterpene biosynthesis,limonene and pinene degradation,sesquiterpene and triterpenoid biosynthesis.Thirty-six differentially expressed genes were found in the terpenoid skeleton biosynthesis pathway.The differential expression showed that the postharvest mango fruit mainly synthesized isoprenoid precursors such as IPP and DMAPP through the MVA pathway.The results enrich the transcriptome resources of mango.These genes provide a basis for further exploration of the cloning and functional analysis of mango functional genes and the biosynthesis of mango terpenoids,and also provide a reference for mango flavor quality breeding.