Genome-Wide Identification of Members of the Soybean CBL Gene Family and Characterization of the Functional Role of GmCBL1 in Responses to Saline and Alkaline Stress

Abstract

Calcium ions function as key messengers in the context of intracellular signal transduction. The ability of plants to respond to biotic and abiotic stressors is highly dependent on the calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) signaling network. Here, a comprehensive effort was made to identify all members of the soybean CBL gene family, leading to the identification of 15 total genes distributed randomly across nine chromosomes, including 13 segmental duplicates. All the GmCBL gene subfamilies presented with similar gene structures and conserved motifs. Analyses of the expression of these genes in different tissues revealed that the majority of these GmCBLs were predominantly expressed in the roots. Significant GmCBL expression and activity increases were also observed in response to a range of stress-related treatments, including salt stress, alkaline stress, osmotic stress, or exposure to salicylic acid, brassinosteroids, or abscisic acid. Striking increases in GmCBL1 expression were observed in response to alkaline and salt stress. Subsequent analyses revealed that GmCBL1 was capable of enhancing soybean salt and alkali tolerance through the regulation of redox reactions. These results offer new insight into the complex mechanisms through which the soybean CBL gene family regulates the responses of these plants to environmental stressors, highlighting promising targets for efforts aimed at enhancing soybean stress tolerance.