Genome-wide identification and expression analysis of the SHAGGY-like kinase gene family in foxtail millet (

Introduction: Glycogen Synthase Kinase 3 (GSK3) is a family of highly conserved serine/threonine protein kinases originally identified in animals. Subsequently, homologous proteins with analogous functions were discovered in plants and designated as GSK3-like kinases or SHAGGY-like kinases (SKs). These kinases play pivotal roles in plants, including participation in growth and development, abiotic stress responses, and hormone signaling. However, the bioinformatics characteristics and protein functions of this gene family in foxtail millet remain poorly characterized. Methods: This study identified 9 SHAGGY-like kinase gene family members in the foxtail millet, which were classified into four subfamilies based on phylogenetic analysis. The functions of the gene family members were dissected by integrating bioinformatics analysis with quantitative real-time PCR (qRT-PCR). Results: Chromosomal localization analysis revealed uneven distribution of family members across chromosomes, prompting renaming based on their chromosomal order. Analysis of conserved domains, motifs, and gene structures demonstrated high conservation among subfamily members. Transcriptome analysis indicated active expression offoxtail millet SHAGGY-like kinase family members in stems and leaves. Stress treatment experiments showed that most foxtail millet SHAGGY-like kinase genes are responsive to abiotic stresses (drought, cold, NaCl) and exogenous hormones (ABA and MeJA). Conclusion: In summary, the phylogenetic and functional analysis of the foxtail millet SHAGGY-like kinase gene family provides insights into its role in stress responses and lays the foundation for future research aimed at enhancing the stress tolerance of foxtail millet.