Cotton promoters for controlled gene expression

Cotton (Gossypium hirsutum) is one of the most important crops and is the main source of fiber for the textile industry, but its productivity is still hampered by several challenges, such as pests, diseases and abiotic stresses. This scenario has increased interest in achieving cotton events with greater productivity and sustainability through biotechnological approaches. An essential component of these strategies is the controlled expression of the gene of interest, suggesting that promoters are a key element. These promoters are generally divided into three types: constitutive, spatiotemporal, and inducible. However, to date, this diversity of promoter activity has not been as widely explored in cotton improvement. In this review, we provide an overview of cotton promoters that can be used to achieve fine-tuning of expression, facilitating decision-making and improving the ability to develop desirable traits in cotton plants. In addition, we present new approaches to identify promoters that may be useful for the development of new tools for cotton improvement.