Characterization of cell wall structure, stress resistance, and biomass saccharification in space-mutated Arundo donax L.

Giant reed ( Arundo donax L.) is a promising biomass feedstock due to its exceptional biomass accumulation and stress resistance. Space mutagenesis further enhances these traits through cell wall modifications, boosting enzymatic hydrolysis and bioenergy conversion efficiency. Compared to the wild type (WT), the space-mutated Arundo donax L. (MUT) exhibited a 10 % increase in vascular bundle density, improving water and nutrient transport. Additionally, the MUT exhibited a 5.6 % increase in porosity and a 16.3 % reduction in cellulose crystallinity, both promoting enzyme accessibility. The 10.6 % increase in the Ara/Xyl ratio in hemicellulose was associated with enhanced flexibility and hydration of the cell wall. A lower lignin S/G ratio decreased inhibition of polysaccharide degradation, while increased G-lignin may contribute to cell wall strength. These changes collectively improved stress resistance and enzymatic digestibility. The optimized balance between cell wall architecture, stress resistance, and biomass saccharification in MUT significantly strengthens its potential for bioenergy development. • Space mutagenesis optimizes cell wall structure in Arundo donax L. • Modified cell walls balance stress resistance and biomass saccharification. • Reduced S/G ratio and cellulose crystallinity improve biomass pretreatment. • Enhanced porosity and Ara/Xyl ratio facilitate enzymatic hydrolysis.