Cell Wall Reorganization in Low-Pectin Flax Fiber: Implications for Mechanical Properties and Binding Capacity

Despite its numerous applications, flax fiber utilization is limited by time-consuming extraction largely determined by pectin content. To address this, transgenic flax plants with reduced pectin levels were generated to facilitate fiber release. We evaluated how pectin reduction affects plant growth, fiber composition, and properties. Field cultivation showed that low-pectin lines exhibited a phenotype comparable to the control. Fibers from these plants contained significantly less pectin and hemicellulose and accumulated more cellulose. These changes were accompanied by conformational and spatial reorganization of the cell wall structure. As a result, fibers with reduced pectin demonstrated improved tensile strength (by 45,6% and by 61,5% for PGI11 and RHA7 fibers, respectively) and enhanced binding capacity for therapeutic substances. Our results support the hypothesis of a compensatory mechanism between pectin and cellulose, where a decrease in one component is offset by an increase in the other. Furthermore, we show that structural reorganization induced by pectin reduction improves the mechanical properties and functional potential of flax fibers. This study highlights that targeted modification of pectin content can enhance fiber quality and functionality without adverse effects on plant growth, offering a promising strategy for optimizing flax for industrial and biomedical applications.