Molecular mechanisms of high tiller development based on transcriptome and proteome correlation analysis in Poa...

Poa pratensis, a high-quality forage and turfgrass, plays a significant role in grassland construction, biodiversity maintenance, and ecological restoration, and has considerable ecological value. Exploring the molecular mechanisms of high tillering occurrence in Kentucky bluegrass is an effective approach for understanding nutrient dense germplasm materials. Additionally, it provides a theoretical foundation for enhancements in plant yield and competitive survival. In this study, statistical analyses of tiller number and tiller node diameter in two wild Kentucky bluegrass germplasms from Gansu Province were conducted. Transcriptome and proteomic analyses were performed on the tillering nodes of these grasses at various tillering stages, aiming to identify the genes, proteins, and pathways that regulate tillering formation. The 'SN' variety was found to possess stronger tillering abilities and greater tillering potential. Through RNA sequencing (RNA-Seq) and DIA quantitative proteomics, a total of 331,749 Unigenes and 21,140 proteins were identified. Among these, 29,932 Unigenes exhibited differential expression and 6974 proteins demonstrated differential accumulation between the tillering nodes of the two varieties of Kentucky bluegrass. KEGG analysis indicated that differentially expressed genes and proteins were significantly enriched in pathways such as phenylpropanoid biosynthesis, plant hormone signal transduction, glutathione metabolism, starch and sucrose metabolism, as well as secondary metabolite biosynthesis. Joint transcriptome and proteome analysis identified 784, 733, and 483 genes/proteins that were coordinately expressed between the 'SN' and 'QS' varieties at the prophase, peak, and anaphase stages of tillering, respectively. KEGG analysis was conducted on these genes and proteins, revealing that pathways such as phenylpropanoid biosynthesis, glutathione metabolism, and photosynthesis were likely involved in regulating the growth and development of tillers. This study elucidated the biological and metabolic characteristics of Kentucky bluegrass at different tillering stages, aiding in the identification of genes and proteins associated with tillering formation. This work establishes a theoretical foundation for exploring the mechanisms of tillering formation in Kentucky bluegrass.