大豆根系响应早期缺铁胁迫的转录组分析

Transcriptome analysis of soybean roots in response to early iron deficiency stress

[目的]本文旨在探明2个大豆品种根系对早期缺铁胁迫的响应差异。[方法]以铁高效品种‘吉育99’和铁低效品种‘吉育93’大豆为材料进行水培试验,将对照(25μmol·L^(-1) Fe)和早期(1和6 h)缺铁胁迫(1μmol·L^(-1) Fe)处理的大豆根系进行转录组测序。[结果]与对照相比,铁高效大豆品种差异基因数随着缺铁胁迫时间的延长而增加,而铁低效品种差异基因数随着胁迫时间的延长而降低。差异表达基因(differential expression gene,DEG)的KEGG通路富集结果表明,缺铁胁迫处理1 h,2个大豆品种在苯丙烷生物合成、倍半萜和三萜生物合成、植物病原体相互作用、植物MAPK信号通路、淀粉和蔗糖代谢等代谢通路中的相关基因表达有显著差异。缺铁胁迫处理6 h,2个大豆品种在苯丙烷生物合成、倍半萜和三萜生物合成、类黄酮生物合成、谷胱甘肽代谢等代谢通路中的相关基因表达有显著差异。差异表达基因转录因子分析结果表明,铁高效大豆品种受早期缺铁胁迫调控的转录因子家族主要有AP2/ERF-ERF、C2H2、MYB、WRKY、bHLH、NAC,铁低效大豆品种中转录因子家族主要有AP2/ERF-ERF、MYB、WRKY、bHLH、NAC。[结论]缺铁胁迫1 h大豆就能对缺铁胁迫作出响应,且不同铁效率大豆品种在苯丙烷生物合成、转录因子调控等相关基因的表达存在显著差异。

[Objectives]The paper aimed to explore the difference of root response to early iron deficiency stress in two soybean varieties.[Methods]In this study,iron efficient soybean variety‘Jiyu 99’and iron inefficient soybean variety‘Jiyu 93’were used as materials for hydroponic experiment,and soybean roots under control(25μmol·L^(-1)Fe)and early(1 and 6 h)iron deficiency stress(1μmol·L^(-1) Fe)were subjected to RNA-Seq.[Results]Compared with control,the number of differential genes in iron efficient soybean variety increased with the extension of iron deficiency stress time,while the number of differential genes in iron inefficient soybean variety decreased with the extension of iron deficiency stress time.KEGG pathway enrichment analysis of differential expression genes showed that there were significant differences in the expression of related genes in phenylpropane biosynthesis,sesquiterpene and triterpene biosynthesis,plant pathogen interaction,plant MAPK signal pathway,starch and sucrose metabolism between the two soybean varieties after 1 h of iron deficiency stress.There were significant differences in the expression of related genes in phenylpropane biosynthesis,sesquiterpene and triterpene biosynthesis,flavonoid biosynthesis and glutathione metabolism between the two soybean varieties after 6 h of iron deficiency stress.Transcription factor analysis of differentially expressed genes showed that AP2/ERF-ERF,C2H2,MYB,WRKY,bHLH,NAC were the transcription factor families regulated by early iron deficiency stress in iron efficient soybean varieties,and AP2/ERF-ERF,MYB,WRKY,bHLH,NAC were the main transcription factor families in iron inefficient soybean varieties.[Conclusions]Soybean could respond to iron deficiency stress for 1 h,and there were significant differences in the expression of phenylpropane biosynthesis,transcription factor regulation and other related genes among soybean varieties with different iron efficiency.