Le Yu, Xiong Xingchen, Xu Zhiyong, Chen Meilin, Li Yuanxue, Fu Chao, You Chunyuan, Lin Zhongxu
National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Cotton Research Institute, Shihezi Academy of Agriculture Science, Shihezi 832011, China.
Biology (Basel). 2025 Aug 2;14(8):983. doi: 10.3390/biology14080983.
Cotton fiber initiation determines the fiber yield, yet the genetic basis underlying lint and fuzz initiation has still not been fully uncovered. Here, map-based cloning was carried out to identify the fiberless mutant genes derived from a cross between acc. WT and a natural fiberless mutant, . The 12:3:1 segregation ratio in F populations (including 1848 and 3100 individuals that were developed in 2016 and 2018, respectively) revealed dominant epistasis, with the fuzz gene exerting dominance over the lint gene. Genetic linkage analysis revealed that controls fuzz fiber initiation, while both and regulate lint fiber development. Sequencing analyses showed that the mutant exhibited a K104M mutation in the R2R3 domain of and a transposable element insertion in , leading to fiberless seeds. Knockout of produced fuzzless seeds, knockout of led to no obvious change in seeds, and knockout of both (&) resulted in fiberless seeds. The 12:3:1 ratio reappeared in the F population developed from the & mutated plants as female and Jin668 as the male, which further confirmed the genetic interaction observed in . RNA-seq analysis revealed that regulates cotton fiber initiation through multiple pathways, especially fatty acid metabolism. This study elucidates the key genes and their genetic interaction mechanisms governing cotton fiber initiation, providing a theoretical foundation for genetic improvement of cotton fiber traits.
棉纤维起始决定纤维产量，然而皮棉和棉短绒起始的遗传基础仍未完全揭示。在此，进行了基于图谱的克隆，以鉴定源自陆地棉野生型（acc. WT）与天然无纤维突变体杂交的无纤维突变基因。F群体（分别包括2016年和2018年培育的1848株和3100株个体）中12:3:1的分离比例显示出显性上位性，其中棉短绒基因对皮棉基因具有显性作用。遗传连锁分析表明， 控制棉短绒纤维起始，而 和 均调控皮棉纤维发育。测序分析表明， 突变体在 的R2R3结构域中表现出K104M突变，且在 中有一个转座元件插入，导致种子无纤维。敲除 产生无棉短绒种子，敲除 导致种子无明显变化，同时敲除两者（&）导致种子无纤维。以&突变体植株为母本、晋668为父本培育的F群体中再次出现12:3:1的比例，这进一步证实了在 中观察到的遗传互作。RNA测序分析表明， 通过多种途径调控棉纤维起始，尤其是脂肪酸代谢。本研究阐明了控制棉纤维起始的关键基因及其遗传互作机制，为棉花纤维性状的遗传改良提供了理论基础。
