杨运良 李建勋 马革农

摘  要：采用Illumina Novaseq 6000測序技术对火龙果果肉3个时期（幼果期、转色期、成熟期）的样品进行转录组测序，对获得的Unigene进行7大数据库注释，共有3617个Unigene成功注释在所有数据库中，进一步筛选与淀粉和蔗糖代谢途径相关的5个酶基因并进行实时荧光定量PCR（qPCR）基因表达验证。结果表明：转录组测序共得到115 193条转录本和47 855条Unigene，N50为2000。GO功能富集分析结果表明，18 582个Unigene在GO功能注释中被分为生物过程、细胞组成及分子功能3大类。KOG功能分类结果表明，6203个Unigene在KOG注释中被分为25个组，其中翻译后修饰、蛋白质周转、伴侣包含的Unigene最多，共854个。KEGG代谢通路注释结果表明，6554个Unigene获得功能注释，共有119条代谢途径，其中碳水化合物代谢所占比例最高。筛选出UGP2、glgC、glgA、Cluster-12747.5831、Cluster-12747.16617等5个参与淀粉和蔗糖代谢合成途径的关键酶基因，qPCR检测表达水平与转录组测序结果一致。

关键词：火龙果;果肉;转录组测序;淀粉;蔗糖

中图分类号：S667.9      文献标识码：A

Differential Expression Analysis of Genes Related to Starch and Sucrose Metabolism Pathway in Different Developmental Stages of Dragon Fruit Pulp Based on Transcriptome

YANG Yunliang， LI Jianxun*， MA Genong

Cotton Research Institute， Shanxi Agricultural University， Yuncheng， Shanxi 044000， China

Abstract： In this study， Illumina Novaseq 6000 sequencing was used to sequence the samples from three stages of dragon fruit pulp （young fruit stage， color conversion stage and mature stage）. The unigenes obtained was annotated in seven databases. A total of 3617 unigenes were successfully annotated in all databases. Five enzyme genes related to starch and sucrose metabolism pathway were further screened and verified by quantitative Real-time PCR （qPCR）. The results showed that 115 193 transcripts and 47 855 transcripts were obtained by transcriptome sequencing and unigene N50 was 2000. The results of GO functional enrichment analysis showed that 18 582 unigenes were divided into three categories： biological process， cell composition and molecular function in GO functional annotation. The results of KOG functional classification showed that 6203 unigenes were divided into 25 group， in KOG annotation， of which post-translational modification， protein turnover and chaperone contained the most unigenes. The results of KEGG metabolic pathway annotation showed that 6554 unigenes got functional annotation， and there were 119 metabolic pathways， among which carbohydrate metabolism accounted for the highest proportion. Five key enzyme genes involved in starch and sucrose metabolism and synthesis pathway， such as UGP2， glgC， glgA， Cluster-12747.5831 and Cluster-12747.16617， were screened. The expression level of qPCR was consistent with that of transcriptome sequencing.

Keywords： dragon fruit; pulp; transcriptome sequencing; starch; sucrose

DOI： 10.3969/j.issn.1000-2561.2021.06.003

火龙果营养丰富，富含糖、有机酸、蛋白质、矿质元素、维生素、膳食纤维等[1-2]，是我国南方重要的果树树种。近年来，随着火龙果产业迅速发展，用于栽培的火龙果良种较少，通过分子生物学手段进行品种遗传改良研究具有必要性。截至目前，火龙果的全基因组测序尚未完成，遗传信息还不清楚，与果实发育相关的基因种类和功能尚不明确，这些均阻碍了火龙果果实品质形成机理等相关基础研究的进行。淀粉和蔗糖是果实内在品质形成的主要因子。目前，对火龙果果实发育过程中淀粉和蔗糖代谢途径研究较少，参与淀粉和蔗糖代谢合成的相关酶及酶基因尚未见报道，淀粉和蔗糖代谢过程是如何进行催化反应还不清楚。……