Cloning And Expression Analysis Of MYBJ2 From Caragana Intermedia

The growth and development of plants will inevitably suffer from a variety of environment effects, including drought, high salt, low temperature, pest invasion and so on. Caragana belongs to Legumes, mainly distributed in the arid and semi-arid regions of China. Among them, Caragana intermedia, which has a drought, cold, and barren resistance, high reproduction and other characteristics, has important ecological values in soil improvement, soil and water conservation. MYB transcription factors are one of the largest family of transcription factors in plants, involved in the regulation of plant growth and development, and the response to adverse stress conditions. In this study, a R2R3-MYB transcription factor encoding gene, CiMYBJ2 was cloned and analyzed. The main results are as follows:1. A gene named CiMYBJ2 (GenBank Accession:KJ937783) was cloned by RACE technique from C. intermedia. The full-length cDNA of CiMYBJ2 was 1,368 bp with the 5’UTR of 203 bp and the 3’UTR of 196 bp. The ORF of CiMYBJ2 was 969 bp, encoding a protein of 322 amino acids which was hydrophilic. The full-length gDNA was 1,285 bp, including three exons and two introns.2. The expression pattern of CiMYBJ2 analyzed by qRT-PCR showed that it was altered by heat, dehydration, NaCl and drought treatments. These results indicated that CiMYBJ2 might be involved in response of C. intermedia to abiotic stresses.3. The promoter sequence of CiMYBJ2 with 873 bp in length was obtained by genome walking technique and many abiotic stress-related cis-elements were predicted. The construct of CiMYBJ2 promoter driven GUS was transformed into wild-type Arabidopsis thaliana. Histochemical GUS staining analysis showed that GUS expression was detected specificly in trichome, roots and flowers.4. The construct with the coding sequence of CiMYBJ2 driven by CaMV 35S promoter was obtained and transformed into wild-type A. thaliana. CiMYBJ2 expression level varied among different transgenic lines.5. No nuclear localization was observed in the transgenic plants transformed with the construct of GFP fused CiMYBJ2 driven by CaMV 35S promoter. Western blot analysis showed that there was no fusion protein detectable, while the corresponding transcript did exist.