Abstract

BBX transcription factors are key regulators of plant growth, development, and stress responses, yet their functions in jujube (Ziziphus jujuba Mill.), an economically important fruit tree, remain largely unexplored. Here, we systematically identified 26 ZjBBX genes and comprehensively analyzed their phylogenetic relationships, structural features, and expression dynamics. Our integrative approach revealed three major findings. First, nine ZjBBX genes exhibited distinct expression patterns during fruit coloration, with ZjBBX9 and ZjBBX25 emerging as persistent up-regulated candidates. Second, under salt stress, ZjBBX members displayed three contrasting response modes, sustained down-regulation, rapid induction, or sharp repression, suggesting functional diversification in salinity adaptation. Third, under jujube witches’ broom, ZjBBX8, ZjBBX11, and ZjBBX13 showed differential expression between healthy and infected materials, implicating them in biotic stress defense. Collectively, this study provides the first multidimensional expression atlas of the ZjBBX family linked to fruit quality, salt tolerance, and pathogen resistance in jujube. Our findings open new avenues for marker-assisted breeding and genetic improvement of stress-resilient jujube cultivars.

IPC Classification

Keywords