NAC transcription factor GbNTL9 modifies the accumulation and organization of cellulose microfibrils to enhance cotton fiber strength

作者：Mi Wu, Zhiyong Xu, Chao Fu, Wang Nian, Ruiting Zhang, Le Yu, Meilin Chen, Ningyu Yang, Yuanxue Li, Xianlong Zhang, Ximei Li, Zhongxu Lin · 发表于：Journal of Advanced Research · 年份：2025 · DOI：10.1016/j.jare.2025.02.022 · 被引用次数：10 · 研究领域：Research in Cotton Cultivation、Textile materials and evaluations、Lipid metabolism and biosynthesis

• The NAC transcription factor GbNTL9 is a candidate gene for fiber strength. • Both NTL9 E22 and NTL9 BS41 positively regulate fiber strength. • NTL9 enhances fiber strength by promoting dense accumulation and organized arrangement of cellulose microfibrils. • The molecular marker NTL9-24 effectively distinguishes haplotypes between Gb and Gh , advancing fiber quality breeding. Fiber strength is a critical determinant of fiber quality, with stronger fibers being highly preferred in the cotton textile industry. However, the genetic basis and the specific regulatory mechanism underlying the formation of cotton fiber strength remain largely unknown. To explore fiber strength-related genes, QTL mapping, map-based cloning, and gene function verification were conducted in a backcross inbred line BS41 derived from interspecific hybridization between upland cotton and sea-island cotton. Upland cotton Emian22 (E22) and an interspecific backcross inbred line (BIL) BS41 were used as parents to construct secondary segregation populations for BSA and QTL mapping of fiber strength. The candidate gene GbNTL9 was identified through map-based cloning and expression analysis. The function of NTL9 was determined through transgenic experiments and cytological observations. The regulatory mechanisms of NTL9 were explored using RNA-seq, RT-qPCR, yeast two-hybrid, bimolecular fluorescence complementation, and yeast one-hybrid. A major QTL for fiber strength, qFS-A11-1 , was mapped to a 14.6-kb gen...