Transcriptional regulatory networks in cotton fiber development and fiber quality improvement

Cotton fiber is an important natural textile raw material, and its yield and quality are directly influenced by the developmental stages. Specifically, the number of fiber initiations at the initiation stage determines the yield of mature fiber. The duration of the rapid elongation stage is one of the key factors determining fiber length. The transition stage, which mediates the shift from fiber elongation to secondary cell wall (SCW) synthesis, exerts an influence on fiber length, strength, and fineness. The thickness of the SCW during the SCW synthesis stage affects fiber strength and fineness. At different stages of fiber development, specific key transcription factors play pivotal roles: GhMYB25-like determines the initiation of fiber cells, GhHOX3 governs the early elongation of fibers, GhMYB4 coordinates the transition from fiber elongation to SCW synthesis, and NAC-MYB transcription factors regulate cellulose synthesis. This article reviews the molecular mechanisms of the regulatory networks controlled by key transcription factors at each stage of fiber development and their impacts on fiber quality, and it also provides prospects for future strategies aimed at improving fiber quality.