Abstract:

The aims are to clarify the role of ASR (ABA-stress-ripening) gene from Ginkgo biloba in response to abiotic stress, and provide materials for studying ASR gene function and environment stress. In this study, Ginkgo biloba was used as material, GbASR gene was cloned and the fusion expression vector pCAMBIA1300-ASR-GFP was constructed by molecular biology techniques, then the subcellular localization of GbASR protein was analyzed. Protein domains and phyletic evolution were analyzed by sequence alignment method. Tissue-specific expression and expression level of GbASR gene under abiotic stress were analyzed by qRT-PCR method. The results showed that the total length of GbASR coding region was 546 bp, encoding a 182 amino acid protein. The theoretical isoelectric point was 5.33 and the molecular weight of GbASR protein was 20111.24 Da, which was a stable hydrophilic protein. Sequence alignment and phylogenetic analysis showed that GbASR protein contained a highly conserved ABA/WDS domain and had high homology with PtASR protein. The subcellular localization analysis showed that GbASR protein was a nucleoprotein. In addition, GbASR gene was widely expressed in different tissues such as root, steam and leaf from Ginkgo biloba, and the GbASR gene was induced under salt, drought and heat stresses, and there were significant different expressions at 0 h, 6 h, 24 h and 48 h under salt, drought, and heat stresses. These results suggest that GbASR might participate in response to abiotic stresses such as salt, drought and heat stresses, and this study could provide a basis for plant breeding and explaining ASR gene function.

Key words: Ginkgo biloba, GbASR gene, bioinformatics analysis, subcellular localization, abiotic stress