蚕豆自噬基因鉴定及响应干旱胁迫分析

Identification and Expression Pattern Analysis of Vica faba L. Autophagy Gene Family

【目的】根据转录组测序结果鉴定蚕豆自噬(Augophagy, ATG)基因,分析其对干旱胁迫的响应,为深入研究该类基因在干旱胁迫下的作用机制提供理论参考。【方法】利用蚕豆干旱胁迫转录组测序(RNA-seq)数据,根据swiss-port、NCBI、Ensemble等数据库的注释,筛选和鉴定蚕豆ATG基因;通过Smart、MEGA-X、MEME等软件进行保守结构域、亚细胞定位预测、系统发育树和motif等进行生物信息学分析。基于转录组数据,分析ATG基因在蚕豆CDAS105(耐旱)和鄂蚕1号(敏感)品种中干旱胁迫下的表达差异。【结果】筛选注释得到12个蚕豆ATG基因,均含有Autophagy结构域。根据C端结构域的不同将其分成5个亚族:ATG3、ATG6、ATG8、ATG18和ATG26。蚕豆ATG基因与拟南芥、玉米、水稻、酵母共同构建的进化树,发现同一C端结构域的基因聚集在一起。亚细胞定位预测结果显示:11个蚕豆ATG基因定位于细胞外,1个ATG蛋白定位于细胞质中。基因结构分析表明,蚕豆ATG家族基因的DNA序列中均无内含子,且均由UTR区和CDS区组成。保守基序分析鉴定出这些蛋白含有20个mortif。基于干旱胁迫转录组数据的ATG基因表达模式分析结果显示,ATG18b、ATG18c和ATG8a在干旱处理16或64 h后在抗旱品种中较敏感品种表达上调,且ATG8a在抗旱品种中随着干旱处理时间的增加表达进一步增强。【结论】从蚕豆中鉴定得到了12个ATG基因,分布于5个亚家族,ATG8a、ATG18b和ATG18c响应干旱胁迫,可以作为潜在的基因资源改良蚕豆种子萌发耐旱能力。

【Objective】The present paper aimed to identify the augophagy(ATG)gene of Vicia faba L.based on the results of transcriptional sequencing,and analyze its response to drought stress,which provides theoretical reference for further study on the mechanism of these genes under drought stress.【Method】According to the annotation of Swiss port,NCBI,ensemble and other databases,the ATG gene of V.faba L.was screened and identified based on RNA sewuencing data.The conserved domain,subcellular localization prediction,phylogenetic tree and motif were analyzed by SMART,MEGA-X and MEME software.Based on transcriptome data,the expression differences of ATG gene in V.faba L.varieties CDAS105(drought tolerant)and ECAN No.1(sensitive)were analyzed under drought stress.【Result】Twelve ATG genes from V.faba L.were screened and annotated,all of which contained autophagy domain.According to the different C-terminal domains,they were divided into five subfamilies:ATG3,ATG6,ATG8,ATG18 and ATG26.In the phylogenetic tree constructed by faba bean ATG gene and Arabidopsis,maize,rice and yeast,it was found that genes with the same C-terminal domain were clustered together.Prediction of subcellular localization indicated the elevent genes and one ATG gene were located in extracellular and cytoplasm,respectively.Gene structure analysis showed that there were no introns in the DNA sequences of ATG family genes in V.faba L.,and they were composed of UTR and CDs regions.Conserved motif analysis identified that these proteins contained 20 mortifs.Analysis of ATG expression showed that ATG18 b,ATG18 c and ATG8 a were up-regulated in drought resistant varieties after 16 hours or 64 hours drought treatment,and the expression of ATG8 a in drought resistant varieties was further enhanced with the increase of drought treatment time.【Conclusion】Twelve ATG genes were identified and distributed in five subfamilies.ATG8 a,ATG18 b and ATG18 c responded to drought stress,which could be used as potential gene resources to improve the drought tolerance during seed germinating in faba bean.