<b>Plant Cell Wall Engineering: Redefining Industrial Biomass through Molecular Innovation</b>

Biomass, particularly lignocellulosic biomass, a promising renewable energy source in the production of biofuel and bio-based products, but its effective use is limited due to the cell wall recalcitrance. The intricate structure of the plant cell wall limits the enzymatic accessibility, which leads to the low conversion efficiency of less than 10% into fermentable sugars. Recent developments in molecular and genetic engineering, especially the CRISPR-Cas based genome editing and pathway manipulation, have enabled the targeted modifications of the cell wall components. Experimental results show that modifications of lignin biosynthesis and composition have the potential to increase saccharification efficiency without causing growth penalties. Cellulose crystallinity and hemicellulose structure modifications can enhance the digestibility of biomass. This review critically discusses the molecular basis of cell wall recalcitrance, recent experimental approaches to reduce the recalcitrance, and evaluates their industrial relevance in enhancing biomass conversion efficiency.