关键词: MYB基因, 转录因子, 基因克隆, 表达模式, 亚细胞定位

Abstract: MYB (MYB transcription factor) is a class of transcription factors that plays an important role in plant growth and stress resistance,including salt stress,drought stress,heavy metal stress,and plant disease resistance,its gene family is one of the largest transcription factor families in plants. Based on the transcriptome data of Poa pratensis ‘Baron’,we obtained a 705 bp CDS sequence and a 1115 bp promoter sequence of PpMYB2 by using homologous cloning and chromosome walking techniques. The qRT-PCR results showed that PpMYB2 had the highest expression level in the roots,followed by the leaves and the lowest expression level in the,it also respond to plant hormones such as GA and ABA treatment,and showed a significantly upregulated expression trend under drought stress (15% PEG6000) and salt stress treatments (150 mmol·L^-1 NaCl). The subcellular localization results indicated that PpMYB2 was located in the nucleus. Promoter analysis showed that the promoter region of PpMYB2 contains plant hormone responsive elements such as auxin and gibberellin,as well as stress responsive elements such as low temperature and drought. These results suggested that PpMYB2 played an important role in plant response to stresses,and further research on it had a guiding significance for exploring its stress resistance mechanism in Poa pratensis.

Key words: MYB gene, Transcription factor, Gene cloning, Expression pattern, Subcellular localization