GRUSP, an Universal Stress Protein, Is Involved in Gibberellin-dependent Induction of Flowering in Arabidopsis thaliana

Genome-wide identification and expression analysis of the universal stress protein (USP) gene family in Arabidopsis thaliana, Zea mays, and Oryza sativa

The Universal Stress Protein (USP) primarily participates in cellular responses to biotic and abiotic stressors, playing a pivotal role in plant growth, development, and Stress responses to adverse environmental conditions. Totals of 23, 26 and 26 USP genes were recognized in Arabidopsis thaliana, Zea mays, and Oryza sativa, respectively. According to USP genes physicochemical properties, proteins from USP I class were identified as hydrophilic proteins with high stability. Based on phylogenetic analysis, USP genes family were classified into nine groups, USP II were rich in motifs. Additionally, members of the same subgroup exhibited similar numbers of introns/exons, and shared conserved domains, indicating close evolutionary relationships. Motif analysis results demonstrated a high degree of conservation among USP genes. Chromosomal distribution suggested that USP genes might have undergone gene expansion through segmental duplication in Arabidopsis thaliana, Zea mays, and Oryza sativa. Most Ka/Ks ratios were found to be less than 1, suggesting that USP genes in Arabidopsis thaliana, Zea mays, and Oryza sativa have experienced purifying selection. Expression profile analysis revealed that USP genes primarily respond to drought stress in Oryza sativa, temperature, and drought stress in Zea mays, and cold stress in Arabidopsis thaliana. Gene collinearity analysis can reveal correlations between genes, aiding subsequent in-depth investigations. This study sheds new light on the evolution of USP genes in monocots and dicots and lays the foundation for a better understanding of the biological functions of the USP genes family.

Universal Stress Proteins: From Gene to Function

Universal stress proteins (USPs) exist across a wide range of species and are vital for survival under stressful conditions. Due to the increasingly harsh global environmental conditions, it is increasingly important to study the role of USPs in achieving stress tolerance. This review discusses the role of USPs in organisms from three aspects: (1) organisms generally have multiple USP genes that play specific roles at different developmental periods of the organism, and, due to their ubiquity, USPs can be used as an important indicator to study species evolution; (2) a comparison of the structures of USPs reveals that they generally bind ATP or its analogs at similar sequence positions, which may underlie the regulatory role of USPs; and (3) the functions of USPs in species are diverse, and are generally directly related to the stress tolerance. In microorganisms, USPs are associated with cell membrane formation, whereas in plants they may act as protein chaperones or RNA chaperones to help plants withstand stress at the molecular level and may also interact with other proteins to regulate normal plant activities. This review will provide directions for future research, focusing on USPs to provide clues for the development of stress-tolerant crop varieties and for the generation of novel green pesticide formulations in agriculture, and to better understand the evolution of drug resistance in pathogenic microorganisms in medicine.