Bioinformatics and expression pattern analysis of BpNOS gene in Betula platyphylla / 中草药

ABSTRACT

Objective: Nitric oxide synthase (NOS) is a kind of important NOS in organisms. The gene cloning and expression pattern analysis of NOS in plant laid the foundation for study on the biological functions of nitric oxide in plants. Methods: NOS gene in B. platyphylla was cloned by RACE technology, named BpNOS. Bioinformatics and molecular evolution analysis, abiotic stress, and signal induced of the gene were preliminarily carried out. Results: This full-length gene was 1 806 bp with the complete ORF, encoding 601 amino acids (Genebank ID KJ197336). BpNOS was an unstable hydrophobic protein. This protein may exist signal peptide with transmembrane ability. The alpha helix, extension chain, random coil distributed throughout the protein. Molecular evolution analysis results showed that the genetic distance of BpNOS gene was closer to the gene genetic distance of grape species NOS, which indicates the relatively close relationship between them; While the genetic distance of BpNOS gene was farther from soybean and alfalfa, which explains that the relationship of them is far. The expression of BpNOS has rhythm, reached the maximum at 15 00, 12 times as at 0 00. The expression of BpNOS gene could be inhibited by salt, low temperature, and heavy metal cadmium stress, but in a different response pattern. The expression of BpNOS gene could be promoted by salicylic acid and exogenous NO. Conclusion: Abiotic stress could inhibit the activity of NOS. The salicylic acid and exogenous NO could be synthesized by NOS pathway to regulate endogenous NO. This paper lays a solid foundation for the further research on the metabolic regulation of NO in B. platyphylla.