Cloning And Expression Analysis Of ASR2Gene In Dongxiang Wild Rice

Abiotic stresses, such as low temperature, affect growth, development and yield ofrice. It is well known that Dongxiang wild rice has a strong chilling and freezing tolerance.However, the mechanism of cold resistance of Dongxiang wild rice still remains unclear.In this work, the ASR2gene with an ORF of318bp was cloned and identified fromcDNA library of the Dongxiang wild rice. The ASR2gene of Dongxiang wild rice wascompletely homologous with that of Oryza Sativa. The gene was screened from the cDNAlibrary of root in winter, however could not from that of root in summer, indicating that theASR2may be involved in cold tolerance. Bioinformatic analysis of ASR2protein showedthat ASR2protein containing an ABA-WDS conservative structure domain and has astrong hydrophilic.ASR2gene expression of dongxiang wild rice under cold stress was detected byRq-PCR technique. The result showed that ASR2gene expression increased in thebeginning and reached a maximum expression after12h treatment. The detection of ASR2gene expressions in different growth stage of Dongxiang wild rice revealed that ASR2showed the highest expression in leaves in winter and the lowest in roots in the headingperiod.By constructing ASR2: GFP fusion protein plant expression vector and transforminginto onion epidermal cell, the ASR2protein was found locating in the nucleus. ThepET28a (+)-ASR2prokaryotic expression vector was constructed, and, the ASR2fusionprotein was expressed induced by IPTG and purified by Ni-IDA-SefinoseTMResinchromatography. The protein thermo-stable test showed the ASR2protein detection hashigh thermal stability.This study provided basis for further study in the function of ASR2gene. It was alsoof significance in revealing the mechanism of cold resistance of Dongxiang wild rice.