剧毒裂皮鹅膏转录组测序与毒肽相关基因家族分析

De novo Transcriptome Sequencing of Highly Toxic Amanita rimosa Transcriptome and Analyses of Poison-peptide-related Gene Family

裂皮鹅膏(Amanita rimosa)是中国特有的剧毒蘑菇资源,其子实体含有多种鹅膏肽类毒素,常引起严重的中毒死亡事件。剧毒鹅膏菌的毒肽基因家族可编码多种毒环肽及丰富的未知功能肽类,目前裂皮鹅膏的毒肽基因家族尚未开展系统的研究。本研究以裂皮鹅膏新鲜子实体为材料提取RNA,构建cDNA文库。利用Illumina HiSeq 2000测序平台进行转录组测序,采用Trinity软件组装拼接,首次获得了裂皮鹅膏的转录组数据,转录组测序共获得19 598条Unigenes,通过Nr、KEGG、SwissPort及KOG数据库比对获得Unigene的功能注释。基于转录组序列和PCR验证获取了裂皮鹅膏的毒肽及相关肽类不同编码基因24条,分别编码α-amanitin、β-amanitin和Phallacidin等3种毒肽,以及编码21种未知功能肽类,其中16种为首次预测的新肽类。并对裂皮鹅膏毒肽基因家族编码的前体肽进行了系统聚类分析,明确了其系统发育位置。研究结果表明裂皮鹅膏具有丰富的毒肽及相关肽类的编码基因,为鹅膏肽类毒素的基因表达和新肽类资源的开发利用提供了数据。

Amanita rim osa is a unique poisonous mushrooms resource in China,which contains rich peptide toxins and often responsible for fatal poisonings.Toxic peptide gene family of lethal Amanita encodes various toxic cyclopeptides and related peptides.At present,the toxic peptides gene family of A.rimosa has not been studied systematically.In this research,we extracted RNA from fresh fruiting bodies of A.rimosa and constructed cDNA library.We used Illumina HiSeq2000 sequencing platform for transcription sequencing and assembled and spliced it with Trinity software.The transcriptome data of Amanita rimosa were obtained for the frist time.A total of 19 598 unigenes were identified in A.rimosa transcriptome,and unigene annotations were obtained by the alignment with Nr、KEGG、SwissProt and KOG databases.Based on the transcriptome data and PCR,we got toxic peptides of A.rimosa and 24 differ ent coding gene of related peptides,which encoded 3 toxic peptides(α-amanitin,β-amanitin and phallacidin)and 21 unknown peptides.16 of these unknown peptides were firstly reported.A systematic clustering analysis of precursor peptides of A.rimosa poison peptide gene family coding were carried out,and the position of its systematic development was determined.The results showed that A.rimosa had abundant toxic peptides and related peptides coding genes,which provided data for the toxic peptide gene expression and exploitation of new cyclopeptide resources.