Abstract:

The molecular chaperone heat shock protein HSP40 binds to HSP70 through the J domain to assist in protein folding and participates in various stress responses in plants.However,the mechanism and function of NtHSP40 gene family in response to UV-B radiation remain unknown.Through bioinformatics methods,the members of the NtHSP40 gene family were identified at the whole-genome level,and phylogenetic analysis,collinearity analysis,cis-acting elements of the promoter,chromosomal localization,gene structure analysis and physical and chemical property analysis were carried out to clarify the basic characteristics of the NtHSP40 gene family.In tobacco seedlings treated with UV-B radiation,RNA-sequencing analysis was performed to investigate the eight differentially regulated genes according to the transcriptome data.The expression levels of candidate genes belonging to NtHSP40 gene family were investigated by Quantitative Real-time PCR(qRT-PCR)experiments and the total polyphenol content of metabolites was quantified by spectrometry.The results showed that there were 48 NtHSP40 genes in the genome of tobacco K326.These genes were distributed on 20 chromosomes and all encoded J domain proteins which can be further divided into three subfamilies.The variable gene structure and protein sequence characteristics indicated the diversification of the functions of the NtHSP40 gene family members.Among them,eight NtHSP40 genes responded to UV-B radiation,and was correlated with the total polyphenol content in tobacco.The research findings establish a foundation for further elucidating the functions of the NtHSP40 gene family in plant stress responses and secondary metabolism in tobacco,and for enhancing the quality of tobacco leaves.

Key words: Nicotiana tabacum, Heat shock proteins HSP40 family, Bioinformatics, Ultraviolet-B, Polyphenol content

CLC Number: 

• S572

• Q943.2植物基因工程