From developmental overlap to molecular coordination: regulation of cotton fiber elongation and secondary wall thickening

Abstract

Abstract Elongation and secondary wall thickening determine the length, strength, and fineness of cotton fibers, with inherent trade-offs between these traits. Cotton fiber development involves a partially overlapping transition from rapid elongation to secondary wall cellulose deposition, and the duration and coordination of this transition directly affect fiber length, strength, and fineness. Although this overlap has long been recognized, the molecular mechanisms that coordinate elongation and wall-thickening programs during this transition remain poorly understood. Recent work by Zhu et al. on the GhCEWT1–GhCEWT2 module provides novel insight into how fiber elongation rate and secondary wall deposition may be jointly regulated during the elongation-to-thickening transition. This emerging framework advances our understanding of fiber developmental coordination and offers new opportunities to overcome long-standing trade-offs and improve fiber quality.