大白菜MBF1家族基因鉴定及高温或低温胁迫下的表达分析OA

Multiprotein bridging factor 1(MBF1),as a class of transcriptional coactivators,plays an important role in plant responses to high-and low-temperature stress.In this study,the MBF1 family genes were systematically identified from the whole genome of Chinese cabbage,and their molecular characteristics were analyzed.Using bioinformatics tools,the gene structures,chromosomal locations,cis-acting elements,intraspecific and interspecific collinearity of these family genes,as well as the physicochemical properties,subcellular localization,and protein structures of the encoded proteins,were comprehensively analyzed.Fur-thermore,based on transcriptome sequencing(RNA-seq)data combined with quantitative real-time reverse tran-scription PCR(qRT-PCR),their expression patterns un-der high-and low-temperature stress were analyzed.The results showed that the Chinese cabbage MBF1 family genes contained six members(designated BrMBF1-01 to BrMBF1-06,respectively),which were distributed on five chromosomes.The encoded proteins ranged from 127 aa to 458 aa in amino acid length,with relative molecular masses from 14 098.37 to 50 794.78,and their isoelectric points ranged from 9.25 to 10.16.The promoters of these family genes were found to contain three major categories of cis-acting elements:hormone-responsive,stress-responsive,and circadian rhythm regulatory elements.The secondary structures of the proteins encoded by the Chinese cabbage MB F1 family genes all contained α-helices,β-turns,extended strands,and random coils.The secondary structure composition was highly conserved,while the tertiary structure conformations exhibited significant diversity.Three pairs of MBF1 genes in Chinese cabbage exhibited segmental duplications,and there was interspecific collinearity between Chinese cabbage MBF1 genes and Arabidopsis thaliana MBF1 genes.Under low-temperature stress,the relative expression levels of BrMBF1-02 and BrMBF1-03 genes in Chinese cabbage were downregulated,while the remaining four MBF1 genes first decreased and then increased in their relative expression levels.Under high-temperature stress,except for the BrMBF1-06 and BrMBF1-02 genes,the other four MB F1 genes responded rapidly and showed significantly upregulated relative expression levels.In summary,the results of this study lay a foundation for functional studies of MBF1 genes in Chinese cabbage and also provide genetic resources for molecular breeding for resistance to high-temperature and low-temperature stresses.