Characterization of the Maize GASA Gene Family and Their Responses to Low-Phosphorus Stress

Gibberellic Acid-Stimulated Arabidopsis (GASA) proteins are cysteine-rich peptides broadly conserved in plants and implicated in growth regulation, stress adaptation, and hormone signaling. Here, we identified 13 GASA genes in the maize genome, distributed across six chromosomes. Comprehensive analyses of their physicochemical properties, subcellular localization, and structural features classified them into three conserved clades. Promoter cis-element analysis suggested roles in developmental regulation, phytohormone responses, abiotic stress adaptation, and light signaling. Comparative synteny revealed close evolutionary relationships between maize and sugarcane GASA genes, implying divergence from a common ancestor. Transcriptomic and qRT-PCR analyses demonstrated that maize GASA genes exhibit tissue-specific and stress-responsive expression under low-phosphorus condition, with ZmGASA06 showing pronounced responsiveness to low-phosphorus stress. This study provides novel insights into the evolutionary dynamics and potential functional roles of the GASA family in maize, laying a foundation for further functional and molecular breeding studies.