甘蓝型油菜转录因子MYB4的克隆、亚细胞定位及表达分析OA

This study aims to investigate the role of the MYB4 transcription factor in cadmium(Cd)stress response in rapeseed(Brassica napus).Using the high-Cd-accumulating cultivar'Nanyou 868'(2n=4x=38,AACC)as experimental material,a MYB4 gene was cloned and named BnaMYB4.Bioinformatics analysis,subcellular localization,and qRT-PCR were comprehensively employed to investigate its sequence characteristics,protein properties,and expression patterns under Cd stress.The results were as follows:(1)The open reading frame of BnaMYB4 was 885 bp in length,encoding 294 amino acids;bioinformatics analysis indicated that the encoded protein contained a typical R2R3-MYB domain,belonging to the R2R3-MYB subfamily,and was predicted to localize in the nucleus.(2)Multiple sequence alignment revealed that BnaMYB4 shared high similarity(87.41％-98.97％)with MYB4 homologous proteins from species such as Brassica napus and Arabidopsis thaliana;promoter sequence analysis identified multiple stress-responsive cis-acting elements.(3)Subcellular localization experiments confirmed that BnaMYB4 localized in the nucleus.(4)Tissue expression analysis showed that BnaMYB4 was expressed in root,stem,and leaf,with the highest expression in root;under Cd stress,its expression in leaves slightly increased with increasing Cd concentrations,but decreased slightly in root.In conclusion,BnaMYB4 may be involved in the transcriptional regulatory response of rapeseed to Cd stress.This study provides a theoretical foundation for further elucidating the functional mechanism of MYB4 in heavy metal stress and for stress-resistance breeding in rapeseed.