Differential Expression of Gossypium hirsutum USP-Related Genes, GhUSP1 and GhUSP2, During Development and upon Salt Stress

• Published in: Plant molecular biology reporter 2013-12, Vol.31 (6), p.1539-1547
• Main Authors: Merkouropoulos, Georgios, Tsaftaris, Athanasios S.
• Format: Article
• Language: English
• Subjects: Amino acids; Bioinformatics; Biomedical and Life Sciences; Cotton; Life Sciences; Metabolomics; Original Paper; Plant biology; Plant Breeding/Biotechnology; Plant Sciences; Proteins; Proteomics
• ISSN: 0735-9640; 1572-9818
• DOI: 10.1007/s11105-013-0630-z

The universal stress proteins (USPs) comprise a large family of proteins that has been found and characterized in a variety of organisms including plants. Intrinsic domains of these proteins are considered as one of the most ancient domains in all life forms. The first member of the USP family was isolated and extensively characterized in bacteria during the 1990s, demonstrating that the USP-containing proteins are phosphoproteins responsive to a variety of abiotic stress stimuli. Since then, many other members of the family have been characterized. Here, we present the isolation and characterization of two USP genes from Gossypium hirsutum , the most widely cultivated cotton species that has a serious impact in world’s economy. The two cotton USP genes, each in the form of two alleles, possess the same structural organization with their Arabidopsis homologues, possessing one intron sequence separating the coding sequence into two unequal parts, a large 5′-end part and a small 3′-end tail. In silico amino acid sequence analysis and three-dimensional modeling show the high levels of conservation in the USP domain, an indication that the cotton GhUSPs may function in a variety of developmental and stress-induced pathways. Moreover, expression analysis showed that while both are expressed in stems and meristems, although at different levels, only one of them is expressed in flowers. Upon salt treatment, both GhUSPs are transcriptionally activated, with the GhUSP1 reaching a peak within 30 min after the application of the stress stimuli, whereas activation of the GhUSP2 lasts longer.