Biotechnological improvement of cotton fibre maturity

This mini-review focuses on the prospects and tools for controlling cotton fibre secondary wall thickness. Cotton fibre secondary walls are composed of almost 100% cellulose, and are responsible for fibre maturity and a large component of fibre yield. Improved fibre yield and maturity would result from the ability to control secondary wall cellulose deposition quantitatively, including making the process less sensitive to environmental stress. Both genetic engineering and marker-assisted breeding are possible avenues for effecting such improvements, but first key genes that participate in the regulation and control of secondary wall cellulose biogenesis must be identified. Recent advances towards understanding and manipulating cotton fibre secondary wall deposition that are discussed here include: (i) experimental approaches to identify metabolic participants in cellulose biogenesis; (ii) isolation and characterization of promoters to drive foreign gene expression preferentially during secondary wall deposition; and (iii) a novel set of cDNA sequences representing genes that are differentially expressed during cotton fibre secondary wall deposition compared with primary wall deposition.