Cold stress tolerance genes of the wild cotton species Gossypium thurberi

Low temperatures at the start of the growing season can impair the productivity of crop species. Chilling (0 – 20°C) and freezing (< 0°C) both negatively affect plant growth and development. Cotton is an important crop and the primary source of natural fiber for the textile industries. Cotton production has been hit hard by various abiotic stresses, including cold stress, prompted by narrow genetic diversity and intensive selection. Utilization of the wild cotton germplasm in breeding efforts has the potential to unravel the problem of abiotic stress and increase the genetic diversity of the cultivated cotton. However, due to the limited amount of genomic information available for wild cotton species, few studies have been able to provide a comprehensive interpretation of the transcriptomic changes in cotton in response to cold stress acclimation.

In a recent study published in AoBP, Cai et al. compared transcription changes in leaves of Gossypium thurberi under cold stress using high-throughput transcriptome sequencing. G. thurberi is a wild cotton species that has adapted to a wide range of temperatures and is more tolerant to chilling stress. Transcriptome analysis and RNAi technique revealed the integral role played by two novel genes, CBF4 and ICE2 in enhancing cold stress tolerance in this wild cotton species. These findings reveal a new regulatory network of cold stress response in G. thurberi and broaden our understanding of the cold tolerance mechanism in cotton. The authors state that this work will help to accelerate future functional genomics studies and genetic improvement for cold stress tolerance in cultivated cotton.