代谢组学-转录组学联合分析不同品种柿叶矿物质含量差异

Integrated metabolomic-transcriptomic analysis of mineral contents from persimmon leaves of different varieties

柿叶含有丰富的钙、铁、锰、锌等人体必需的矿质元素,不同柿树品种,其柿叶中矿质元素的组成和含量有着明显差异。本研究以‘君迁子’(Diospyros Lotus Linn,DL)为对照,采用代谢组学-转录组学联合分析,研究了‘黑柿’(Diospyros kaki.HeiShi,HS)、‘西村早生’(Diospyros kaki Thunb.Nishimurawase,NM)、‘泰富’(Diospyros kaki Thunb.TaiFu,TF)鲜嫩柿叶中矿质元素的含量差异。代谢组学分析显示,从DL vs.HS、DL vs.NM和DL vs.TF中分别获得了382、391和368个差异代谢产物(differentially accumulated metabolites,DAMs),其中229个为共同DAMs。经RNA测序,获得了182008个单基因(unigenes),平均长度为652 bp,从DL vs.HS、DL vs.NM和DL vs.TF中分别获得了2598、3503和3333个差异表达基因(differentially expressed genes,DEGs)。经基因本体论(gene ontology,GO)和京都基因和基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)富集分析,分别从DL vs.HS、DL vs.NM和DL vs.TF中获得了9、12和12个与矿物质吸收相关的DEGs,其中6个为共同DEGs,每百万碱基测序的转录本序列每千碱基序列片段数(fragments per kilobase of transcript sequence per millions base pairs sequenced,FPKM)值差异倍数为1.34–6.15,经实时荧光定量PCR(quantitative real-time polymerase chain reaction,qRT-PCR)验证,其表达趋势均与RNA测序结果一致,相对表达水平差异倍数为0.26–10.21。转录组学数据分析和qRT-PCR验证结果表明,‘黑柿’鲜嫩柿叶中含有较高含量的矿物质,‘西村早生’和‘泰富’次之。联合分析显示,6个DEGs与其代谢产物呈正相关。本研究结果说明,3个柿树品种中,‘黑柿’的鲜嫩柿叶可推荐用于富含矿质元素柿叶茶的制作。

Persimmon leaves are rich in mineral elements(such as Ca,Fe,Mn,Zn)which are essential for human body.However,the composition and content of mineral elements are different in different persimmon varieties/cultivars.In this research,an integrated metabolomics-transcriptomic analysis was carried out to investigate the difference in mineral contents from the tender leaves of‘Diospyros kaki.HeiShi’(HS),‘Diospyros kaki Thunb.Nishimurawase’(NM)and‘Diospyros kaki Thunb.TaiFu’(TF),using rootstock‘Diospyros Lotus Linn’(DL)as the control.The metabolomic analysis showed that 382,391 and 368 differentially accumulated metabolites(DAMs)were obtained from DL vs.HS,DL vs.NM and DL vs.TF,respectively,and 229 common DAMs were obtained by comparative analysis.By RNA sequencing,182008 unigenes with 652 bp of mean length were annotated,and 2598,3503 and 3333 DEGs were detected from DL vs.HS,DL vs.NM and DL vs.TF,respectively.After gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment,9,12 and 12 DEGs involved in mineral absorption were obtained from DL vs.HS,DL vs.NM and DL vs.TF,respectively,among which 6 common DEGs with|log2(fold change)|of 1.34–6.15 were selected for qRT-PCR validation.A consistent trend of relative expression level of each DEG with RNA-Seq data was observed,with|log2(fold change)|of 0.26–10.21.Base on the transcriptomic analysis and qRT-PCR validation,it was observed that the tender leaves of HS had greater level in mineral absorption,followed by NM and TF.In addition,the positive correlations between the 6 DEGs and their metabolites were observed via the conjoint analysis.Thus,the tender leaves of HS could be recommended for the production of persimmon leaf tea rich in minerals.