Multi-Locus Genome-Wide Association Studies Reveal Novel Genomic Regions Associated With Fructan Content in Bread...

Fructans function as reserve carbohydrates and osmotic regulators, enabling the plant to withstand stresses like drought, cold, and salinity. In the present study, we explored the genetic determinants of fructan content in 278 wheat accessions over two consecutive years. To identify specific genetic elements associated with fructan content, we performed multi-locus genome-wide association studies (ML-GWAS) using the GAPIT and mrMLM models, analyzing 9,333 single-nucleotide polymorphisms (SNPs) alongside fructan content. Our analysis, employing six ML-GWAS models from mrMLM, identified 41 significant marker-trait associations (MTAs), explaining 0.0%-17.84% of phenotypic variation. Additionally, the Bayesian-information and linkage-disequilibrium iteratively nested keyway (BLINK) model in GAPIT revealed 44 significant MTAs (-log10 (p) ≥ 3.0). We further identified candidate genes (CGs) involved in fructan biosynthesis and drought tolerance, including MYB genes, glycoside hydrolases, sugar transporters, glycosyltransferases, zinc finger RING/FYVE/PHD-type proteins, and F-box-like domain proteins. These results were further validated by the in silico gene expression analysis and KnetMiner network. These findings highlight the complex genetic regulation of fructan content in wheat, contributing to a deeper understanding of the mechanisms controlling fructan accumulation for improving wheat quality.