Identification and Functional Exploration of BraGASA Genes Reveal Their Potential Roles in Drought Stress Tolerance and Sexual Reproduction in Brassica rapa L. ssp. pekinensis

Gibberellic acid-stimulated Arabidopsis sequences (<i>GASAs</i>) are a subset of the gibberellin (GA)-regulated gene family and play crucial roles in various physiological processes. However, the <i>GASA</i> genes in <i>Brassica rapa</i> have not yet been documented. In this study, we identified and characterized 16 <i>GASA</i> genes in Chinese cabbage (<i>Brassica rapa</i> L. ssp. <i>pekinensis</i>). Analysis of the conserved motifs revealed significant conservation within the activation segment of <i>BraGASA</i> genes. This gene family contains numerous promoter elements associated with abiotic stress tolerance, including those for abscisic acid (ABA) and methyl jasmonate (MeJA). Expression profiling revealed the presence of these genes in various tissues, including roots, stems, leaves, flowers, siliques, and callus tissues. When plants were exposed to drought stress, the expression of <i>BraGASA3</i> decreased notably in drought-sensitive genotypes compared to their wild-type counterparts, highlighting the potentially crucial role of <i>BraGASA3</i> in drought stress. Additionally, <i>BraGASAs</i> exhibited various functions in sexual reproduction dynamics. The findings contribute to the understanding of the function of <i>BraGASAs</i> and provide valuable insights for further exploration of the <i>GASA</i> gene function of the <i>BraGASA</i> gene in Chinese cabbage.