Bioinformatics and Tissue Expression Analyses of NtHSP70-2 Gene in Tobacco under Temperature Stress

Cui Shuai; Duan Lili; Wang Yu; Tang Qin; Li Changyuan; Long Benshan; Liu Renxiang

doi:10.14083/j.issn.1001-4942.2025.02.003

Abstract：HSP70 is an important member of the heat shock protein family,which is widely present in plants and plays an important role in plant abiotic stress response.In order to study the structure and function of NtHSP70-2 gene in tobacco,the promoter sequence,protein physicochemical properties and structure were analyzed in this study,and its response to temperature stress was analyzed.The results showed that the NtH-SP70-2 gene encoded a complete open reading frame of 1 947 bp,and encoded 649 amino acids.The NtH-SP70-2 protein was predicted to be a hydrophilic protein with the theoretical isoelectric point as 5.13,the in-stability coefficient as 35.03,and the molecular weight as 71.10 kDa.The NtHSP70-2 had high similarity with the homologous sequences of capsicum,tomato,potato and eggplant.Its secondary structure was mainly com-posed of α-helix,and its tertiary structure was similar to that of CaHSP70 of capsicum.NtHSP70-2 mainly contained P-box,CGTCA-motif,ABRE,STER,MYB,DRE core and other cis-acting elements,and all them could respond to temperature stress.qRT-PCR analysis showed that the relative expression level of NtHSP70-2 gene increased in the former 12 hours after high and low temperature stresses,and then decreased gradually with the extension of stress time.NtHSP70-2 gene was expressed in roots,stems and leaves of tobacco,and the expression level was higher in leaves than that in stems and roots;the relative expression level under high temperature stress was higher than that under low temperature stress in the same part of tobacco.In summary,the NtHSP70-2 gene could respond to temperature stress and improve the tolerance of tobacco to temperature.