Abstract
Sugar beet is one of the important sugar crops in China, and drought has become the main constraint on the high-quality development of the sugar beet industry due to the regional factors such as lower precipitation, uneven seasonal distribution and limited water resources and so on. Heat shock protein 70 (HSP70) plays an important role in plant growth, development and abiotic stress response. However, there is still very limited information about the identification of HSP70s and drought resistance in sugar beet. In this study, bioinformatics was used to explore the HSP70s in sugar beet, and their gene structure, phylogenetic relationship, chromosome mapping, cis element distribution and expression under drought stress were analyzed. The results showed that a total of 28 BvHSP70 genes were identified, with sequence length ranges from 1551 bp to 3240 bp, which were distributed on 9 chromosomes of sugar beet. The number of amino acids encoding proteins are 516 ~ 1079, and the theoretical isoelectric point is between 4.98 and 9.33, most of which are acidic hydrophobic proteins, which are mainly located in the endoplasmic reticulum and cytoplasm. Collinearity analysis showed higher homology with rice and maize, and analysis of gene structure and protein conserved motif showed that it had different degrees of differentiation during the evolution of sugar beet. Analysis of cis-elements in the promoters revealed their association with growth and development, hormone response, and abiotic stress. RNA-seq and proteomics analysis showed that 20 genes of BvHSP70s responded to drought stress, and qRT-PCR validation confirmed that 10 of these genes were upregulated, and they were specifically expressed in roots, petioles and leaves of sugar beet, and more genes were expressed in roots. The results of this study lay a foundation for the subsequent in-depth analysis of the gene function of the BvHSP70 family in sugar beet, and also provided a theoretical basis for further exploring the response mechanism of beet under drought stress. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12864-025-12261-x.