Durum wheat straw represents an abundant and renewable source of lignocellulosic biomass with great potential for sustainable bioenergy production. However, its conversion into fermentable sugars is limited by the complex structure of the plant cell wall and the interaction of multiple genetic and environmental factors. In this study, we combined phenotypic, biochemical, mineral profiling, and genomic approaches to investigate the determinants of saccharification efficiency in a panel of 166 durum wheat genotypes. Saccharification potential showed marked variation between contrasting seasons and a strong genotype × season interaction (F = 3.37, p < 0.001), with glucose release ranging from 35.78 to 59.25 nmol/mg in 1h in the 2021-2022 season and from 14.10 to 38.92 nmol/mg in 1h in the 2022-2023 season. Climate fluctuations alter the balance of cellulose and hemicellulose components and the efficiency of enzymatic hydrolysis. Higher saccharification efficiency was associated with increased xylose and cellulose content, with positive correlations between saccharification potential and xylose (r = 0.54-0.73) and cellulose (r = 0.61-0.50). Furthermore, we show that mineral nutrients were associated with contrasting effects on cell wall degradability. Mineral content explained 48.8% of the total variability in saccharification potential, highlighting the importance of mineral homeostasis and of key element for biomass quality. In particular, chlorine showed a positive correlation (r = 0.56, p < 0.001), with saccharification potential and silicon exhibiting a strong negative correlation (r = -0.75, p < 0.001). Genome-wide association analysis identified several loci associated with saccharification potential on different chromosomes, along with loci associated with mineral accumulation, revealing the putative role of understudied cell wall factors. Overall, these results provide an integrated framework linking genotype-by-season variation, cell wall composition, mineral balance, and the genetic loci controlling the saccharification potential of durum wheat straw. They offer valuable insights for breeding strategies to enhance biomass digestibility.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)