Genome-wide identification and characterization of HSP70 gene family in four species of cotton

Authors: REHMAN, ABDUL - Bahauddin Zakariya University; ATIF, RANA MUHAMMAD - University Of Faisalabad; QAYYUM, ABDUL - Bahauddin Zakariya University; DU, XIONGMING - Chinese Academy Of Agricultural Sciences; Hinze, Lori; AZHAR, MUHAMMAD TEHSEE - University Of Faisalabad

Submitted to: Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2020
Publication Date: 7/31/2020
Citation: Rehman, A., Atif, R., Qayyum, A., Du, X., Hinze, L.L., Azhar, M. 2020. Genome-wide identification and characterization of HSP70 gene family in four species of cotton. Genomics. 112(6):4442-4453. https://doi.org/10.1016/j.ygeno.2020.07.039.
DOI: https://doi.org/10.1016/j.ygeno.2020.07.039

Interpretive Summary: Cotton is an important dual purpose crop that provides lint for textiles and seed and oil for animal and human consumption. The vegetative and reproductive growth stages of cotton are adversely affected by abiotic stresses including high temperature, increased salinity, and reduced water availability as well as biotic stresses including insects and diseases. Heat shock proteins protect cells from damage when plants are exposed to these stresses. The objective of this study was to better understand these proteins and their development in cotton. Across four cotton species, 113 genes responsible for these proteins were identified. Many of these genes were duplicated across species, and some were found in the cellular cytoplasm as well as the nucleus. Genes were clustered into subfamilies based on duplications that occurred during the evolution of these species. These findings are valuable to understand the complex role of heat shock proteins in response to stress during cotton growth and development. This study provides a foundation for research scientists to understand the genomic organization and evolution of the heat shock protein gene family. It will be immediately useful in characterization of the function and interaction of this gene family with other genes and proteins in cotton.

Technical Abstract: Heat shock proteins (HSPs) are important elements of the cellular group of molecular chaperones. Specifically, HSP70 proteins protect cells from being damaged when plants are exposed to environmental stresses. These proteins are catalysts that manage the correct folding of other proteins, and they play a key role in the development of tolerance against biotic and abiotic stresses. In the present study, 113 HSP70 genes were retrieved from the available genome assemblies of four cotton species, including Gossypium hirsutum, G. barbadense, G. arboreum, and G. raimondii. The HSP70 genes were clustered into 11 subfamilies based on phylogeny. One hundred and nine (109) gene duplications were found across these four species. Localization of genes revealed that several HSP70 genes reside in the cytoplasm. Synonymous and non-synonymous substitution rates revealed that functional segregation of HSP70 genes in cotton is due to rapid evolutionary processes, i.e. duplications. Furthermore, HSP70 genes in cotton are expressed constitutively during developmental stages. These findings are valuable to understand the complex mechanism of HSP70 gene regulation that occurs in signaling pathways in response to plant stress.