油莎豆块茎转录组测序分析与油脂合成相关基因的挖掘

Transcriptome Analysis and Mining of Genes Related to Oil Synthesis of Cyperus esculentus Tubers

油莎豆(Cyperus esculentus)是一种开发潜力大、综合利用价值高的新兴经济作物,其块茎油分含量最高可达38.70%。为了获取其块茎中油脂合成遗传信息,试验采集4个不同发育时期的油莎豆块茎样品,采用第三代PacBio测序平台对样品进行全长转录组测序,原始数据经聚类、纠错和去冗余,最终获得的高质量序列87061条,预测分析84394个ORF,11224条lncRNA,31995条转录因子以及9165个SSR位点。将筛选预测为有功能的23408条高质量转录本在blastx、NR、KOG、GO、KEGG、Pfam等数据库进行功能注释分析,获得19287条(82.39%)序列功能注释信息。NR数据库比对结果显示,油莎豆与油棕(Elaeis guineensis)的相似度最高(21.69%);GO功能分析将获得GO注释的unigenes划分为生物过程、分子功能和细胞成分3大类55子类;KOG数据库分析获得25个功能簇;KEGG注释将转录组中涉及的基因注释到6大类共188条代谢通路中。根据注释到的油脂合成功能基因序列构建出油莎豆脂肪酸合成代谢通路,并发掘到了FATA、GPAT、PDAT和DGAT等油脂合成关键基因。本研究在无参考基因组的情况下,根据油莎豆块茎三代转录组数据,获得基因信息,同时构建了脂肪酸合成代谢通路并得到部分功能基因的全长序列,为后续油莎豆油分合成代谢的分子机制研究提供数据支持。

Cyperus esculentus is an emerging economic crop with great development potential and high comprehensive utilization value.The oil content of tuber can reach up to 38.7%.In order to obtain genetic information on the oil synthesis in its tubers,the experiment collected four samples of Cyperus esculentus tubers at different developmental stages,and used the third-generation PacBio sequencing platform to sequence the full-length transcriptome of the samples.87061 high-quality sequences was finally obtained through clustering,error correction and de-redundancy of the original data.And 84394 ORFs,11224 LnRNAs,31995 transcription factors and 9165 SSRs sites were predicted and analyzed by software.Among them,23408 high-quality transcripts predicted to be gene sequences were screened for functional annotation analysis in BLASTX,NR,KOG,eggNOG,GO,KEGG,Pfam and other databases.A total of 19287(82.39%)sequences were functionally annotated.NR database comparison results show that it has the most similar sequences with Elaeis guineensis(21.69%);GO function analysis divides the unigenes into 55 branches in three categories:biological processes,molecular functions and cellular components;KOG database analysis results are divided into 25 functional clusters;the KEGG annotation results annotate the genes involved in the transcriptome into 6 categories,a total of 188 metabolic pathways.And the lipid metabolism pathway of Cyperus esculentus tubers was constructed according to the annotated functional gene sequences.And key genes for lipid synthesis such as FATA,GPAT,PDAT and DGAT were discovered.In this study,genetic information was obtained according to the third-generation transcriptome data of Cyperus esculentus tuber.At the same time,the fatty acid anabolism pathway was constructed and the full-length sequence of some functional genes were obtained,providing data support for subsequent studies on the molecular mechanism of lipid metabolism of Cyperus esculentus.