Genome-wide identification, phylogenetic analysis and expression pattern study of trihelix transcription factors in Pisum sativum L.

Trihelix transcription factors have essential functions in plant development, growth, and coping with environmental stresses. Peas (Pisum sativum) are an important economic crop, rich in protein themselves, and their stems and leaves also serve as high-quality green manure and forage. In this study, we conducted a comprehensive analysis of the trihelix gene family in the pea, identifying a total of 56 PsTrihelix genes. These genes exhibited significant diversity in structure and were classified into six subfamilies based on their homology with Arabidopsis thaliana. Additionally, we found that trihelix genes in the pea were most densely distributed on chromosome 6, with segmental duplication events further confirming the importance of chromosome 6. In terms of gene structure, most PsTrihelix genes contained few introns, although two genes contained a higher number of introns, and the relationship between motif number and exon number was complex. Through evolutionary and collinearity analysis with other plants, we found that pea and tomato exhibit the highest number of collinear Trihelix genes, indicating a closer evolutionary relationship between the two species. Regarding functional prediction, trihelix genes were highly expressed in pea leaf and bean tissues and exhibited significant expression changes under specific stresses and hormone treatments, suggesting their important roles in plant growth, development, and adaptation strategies. Particularly, the PsTrihelix55 showed significant upregulation under multiple stress treatments, making it a promising candidate gene for further study. These results offer valuable perspectives on the role and evolutionary history of the trihelix gene family in peas, and lay the groundwork for subsequent studies in this field.