Heterotrimeric G-proteins are fundamental signal transducers highly conserved in plant species, which play crucial roles in regulating plant growth, development, and responses to abiotic stresses. Identification of G-protein members and their expression patterns in plants are essential for improving crop resilience against environmental stresses. Here, we identified eight heterotrimeric G-protein genes localized on four chromosomes within the barley genome by using comprehensive genome-wide analysis. Phylogenetic analysis classified these genes into four distinct subgroups with obvious evolutionary relationships. Further analysis on gene structure, protein motif, and structure indicated that G-proteins within each evolutionary branch exhibited similar exon-intron organization, conserved motif patterns, and structural features. Collinearity analysis showed no significant collinear relationships among those G-protein genes, indicating a unique evolutionary trajectory within barley. Moreover, cis-regulatory elements detected in the upstream sequences of these genes were involved in response to plant hormones and signaling molecules. Expression analyses revealed tissue-specific expression patterns and differential regulation in response to abiotic stresses. The expression patterns of G-protein genes were further validated using a quantitative real-time PCR (qRT-PCR) technique, indicating the reliability of transcriptomic data, as well as special responses to salt, drought, and waterlogging stresses. These findings may provide underlying mechanisms by which G-protein genes participate in salt tolerance of barley, and also highlight candidate genes for potential genetic engineering applications in improving crop resilience to salinity stress.

Cadmium (Cd) contamination in agricultural soils poses a significant risk to crop production and food safety. This study explored the role and mechanisms of manganese (Mn) in mitigating Cd toxicity using two rice genotypes: ZS97B (Cd-tolerant) and MY46 (Cd-sensitive). A hydroponic experiment was conducted under two Mn levels (0 and 100 µM) and three Cd levels (0, 5, 10 µM). Exposure to 10 µM Cd significantly inhibited plant growth and induced physiological disorders, with more severe effects observed in MY46 than in ZS97B. The addition of Mn markedly alleviated Cd toxicity, as reflected by increased antioxidant enzyme activities and reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents in both roots and shoots. Gene expression analysis showed that Mn addition up-regulated genes related to antioxidant enzymes and down-regulated key Cd uptake and transport genes, including OsNramp1, OsYSL2, OsMTP9, and OsHMA3. These changes contributed to enhanced antioxidant capacity and reduced Cd accumulation in rice plants under Cd stress. Our findings demonstrate that appropriate Mn application can effectively reduce Cd accumulation and alleviate toxicity in rice grown in Cd-contaminated environments.