[Identification, expression profiling, and natural allelic variation analysis of the platz gene family in sorghum]

Plant AT-rich protein and zinc-dependent protein (Platz) transcription factors are Zn²⁺-binding and A/T-rich sequence-dependent that primarily function as transcriptional, playing crucial roles in stress responses and the regulation of growth and development. To systematically investigate the biological functions of sorghum Platz transcription factors and their roles in stress responses, we employed bioinformatics and molecular biology techniques to analyze their physicochemical properties, protein secondary structures, subcellular localization, gene structures, phylogenetic relationships, cis-acting elements in the promoter regions, expression patterns, protein-protein interactions, and DNA allelic variations of Platz transcription factors in sorghum. A total of 17 platz genes were identified in sorghum, with uneven distribution across six chromosomes (excluding SBI-02, SBI-03, SBI-05, and SBI-09). These genes encoded unstable hydrophilic proteins with favorable structural fluidity. Significant divergence in gene architecture was observed, and promoter regions were enriched with cis-acting elements linked to abscisic acid (ABA) and methyl jasmonate (MeJA). The phylogenetic analysis divided the platz family in sorghum into five subfamilies. RNA expression patterns of these transcription factors varied across different developmental stages, with platz genes exhibiting the highest expression during the seedling stage. During seed development, SbPlatz7 showed the highest expression, followed by SbPlatz5 and SbPlatz3, while SbFl1a, SbFl1b, SbGl6a, and SbGl6b were also expressed. Notably, drought stress induced upregulated expression of SbRHT25/Platz16 in leaves, whereas low nitrogen conditions and Sporisorium reilianum infection triggered upregulated expression of SbPlatz3 and SbPlatz7. Natural allelic variation analysis revealed frequent frameshift mutations and codon insertions in SbPlatz genes. This study gives novel insights into elucidating the functions of platz in sorghum, offers valuable information for further understanding the evolutionary mechanisms and functional characteristics of the platz gene family in this crop, and provides important references and gene resources for enhancing stress resistance in molecular breeding.