关键词: 芝麻, 低氮胁迫, ERF转录因子, 基因表达

Abstract: The AP2/ERF is one of the largest families of transcription factors in plants，which is involved in plant metabolic biosynthesis，organ development，stress response and hormone signal transduction.To explore the expression characteristics of ERF genes under low nitrogen stress in sesame，24 differentially expressed SiERF genes were identified from the former transcriptome result of sesame roots under low nitrogen stress，and their expression characteristics，co‐expression network and the expression profiles of the key gene SiERF08 under different treatments were analyzed.The results showed that the open reading frame length of 24 differentially expressed SiERF genes was 564—1 254 bp，protein molecular weight ranged from 20.92—44.97 ku，and isoelectric point ranged from 4. 39 to 10. 92. And 24 differentially expressed SiERF genes were unevenly distributed on 13 chromosomes.The promoter sequences contained a number of plant hormone response elements（ABRE，AuxRE and so on），stress response elements（such as ARE，DRE core and LTR），growth and development elements（O2‐site，Gap‐box and CAT‐box）and light response cis‐acting elements（G‐box，MRE，I‐box and so on）.The results of gene expression and Venn diagram showed that 24 and 14 differentially expressed SiERF genes were detected in Burmese prolific and Zhengzhi HL05，respectively.Among them，3 differentially expressed genes such as SiERF06 were identified in two varieties at 3，9 days after low nitrogen stress.Five key candidate genes in response to low nitrogen stress，such as SiERF08 were screened by co‐expression network analysis.The expression characteristics of key candidate gene SiERF08 under different stresses were analyzed.The results showed that，SiERF08 gene was induced under low nitrogen，drought，high salinity，GA and SA stresses，and under different treatments SiERF08 gene exhibited different expression patterns.The expression of SiERF08 gene was the highest in drought，high salt，SA，high temperature and low temperature treatment for 6 h，and reached the peak at 12 h under low nitrogen treatment.Under GA treatment，the expression of SiERF08 gene was only induced at 6 h and 72 h，and the difference was significant.Overall，24 differentially expressed SiERF genes under low nitrogen stress were analyzed by bioinformatics，and 5 key candidate genes such as SiERF08 were screened，among which SiERF08 gene was induced to express under low nitrogen，drought，high salinity and SA stress.This research will provide theoretical basis and genetic resources for further exploring SiERF genes function and revealing the molecular mechanism of low nitrogen tolerance in sesame.

Key words: Sesame, Low nitrogen stress, ERF transcription factor, Gene expression