Abstract:

Objective To identify the members of the auxin response factor (ARF) gene family in cabbage, analyze the expression patterns of BoARF genes under various abiotic stresses in cabbage, and lay a foundation for clarifying the functions of the ARF gene family in cabbage. Method Bioinformatics approaches were used to identify 36 ARF gene family members in the cabbage genome. Comprehensive analyses were conducted, including phylogenetic tree construction, gene structure analysis, conserved motif identification, chromosomal localization, cis-acting element prediction, and collinearity relationship analysis. Additionally, real-time quantitative polymerase chain reaction (RT-qPCR) technology was applied to detect the expression patterns of selected BoARF genes in response to various abiotic stresses (low temperature, high temperature, drought, and salt stress). Result Phylogenetic analysis revealed that the 36 BoARF genes can be classified into four main clades, and these genes are distributed across the nine chromosomes of Brassica oleracea. All 36 BoARF genes contain the conserved Auxin_resp domain characteristic of the ARF family. With the exception of BoARF31, the remaining 35 members possess a B3-type DNA-binding domain. In terms of gene structure, most members contain 12-15 exons. Intraspecies collinearity analysis identified 17 pairs of collinear genes within the cabbage genome. Interspecies collinearity analysis revealed that the cabbage ARF gene family shares 27 collinear relationships with Arabidopsisthaliana and 30 collinear gene pairs with Brassica rapa. Promoter region analysis uncovered a variety of cis-acting elements related to light response, hormone response and abiotic stress response. The analysis of the expression patterns of BoARF genes under abiotic stresses found that BoARF genes responded to different degrees to treatments of low temperature, high temperature, salt, and drought stresses, indicating that the ARF gene family may be involved in the adaptive regulation of cabbage to abiotic stresses. Conclusion A total of 36 BoARF genes are identified in cabbage, which are localized on 9 chromosomes. The promoters of ARF genes contain cis-acting elements associated with abiotic stress. BoARF genes demonstrate distinct expression patterns under abiotic stress.

Key words: cabbage, auxin response factor (ARF), gene family, abiotic stress, chromosomal localization, phylogenetic analysis, cis-acting elements, expression analysis