A rice really interesting new gene H2‐type E3 ligase, OsSIRH2‐14, enhances salinity tolerance via ubiquitin/26S proteasome‐mediated degradation of salt‐related proteins

• Published in: Plant, cell and environment Vol. 42; no. 11; pp. 3061 - 3076
• Main Authors: Park, Yong Chan, Lim, Sung Don, Moon, Jun‐Cheol, Jang, Cheol Seong
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-11-2019
• Subjects: Abiotic factors; Arabidopsis - genetics; Arabidopsis - metabolism; Cation Transport Proteins - genetics; Cation Transport Proteins - metabolism; Complementation; Cytoplasm; Fluorescence; Fusion protein; Gene Expression; Gene Expression Regulation, Plant - drug effects; Gene Expression Regulation, Plant - genetics; Golgi apparatus; Na+ transporter; Oryza - drug effects; Oryza - enzymology; Oryza - genetics; Plant breeding; Plant growth; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - metabolism; Plant tissues; Plants, Genetically Modified - metabolism; Proteasome 26S; Proteasome Endopeptidase Complex - metabolism; Protein Stability; Proteins; Protoplasts; Rice; RING E3 ligase; Salinity; Salinity effects; salinity stress; Salinity tolerance; Salt Stress - genetics; Salt Stress - physiology; Salt Tolerance - genetics; Salt Tolerance - physiology; Salts; Sodium - metabolism; Sodium chloride; Sodium Chloride - pharmacology; Ubiquitin; Ubiquitin - metabolism; Ubiquitin-protein ligase; Ubiquitin-Protein Ligases - genetics; Ubiquitin-Protein Ligases - metabolism; Ubiquitination - drug effects; Ubiquitination - genetics; Up-Regulation; Na+ transporter; salinity stress; RING E3 ligase
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.13619

Salinity is a deleterious abiotic stress factor that affects growth, productivity, and physiology of crop plants. Strategies for improving salinity tolerance in plants are critical for crop breeding programmes. Here, we characterized the rice (Oryza sativa) really interesting new gene (RING) H2‐type E3 ligase, OsSIRH2‐14 (previously named OsRFPH2‐14), which plays a positive role in salinity tolerance by regulating salt‐related proteins including an HKT‐type Na+ transporter (OsHKT2;1). OsSIRH2‐14 expression was induced in root and shoot tissues treated with NaCl. The OsSIRH2‐14‐EYFP fusion protein was predominately expressed in the cytoplasm, Golgi, and plasma membrane of rice protoplasts. In vitro pull‐down assays and bimolecular fluorescence complementation assays revealed that OsSIRH2‐14 interacts with salt‐related proteins, including OsHKT2;1. OsSIRH2‐14 E3 ligase regulates OsHKT2;1 via the 26S proteasome system under high NaCl concentrations but not under normal conditions. Compared with wild type plants, OsSIRH2‐14‐overexpressing rice plants showed significantly enhanced salinity tolerance and reduced Na+ accumulation in the aerial shoot and root tissues. These results suggest that the OsSIRH2‐14 RING E3 ligase positively regulates the salinity stress response by modulating the stability of salt‐related proteins.
Rice OsSIRH2‐14 gene is highly expressed under salinity stress and exhibits E3 ligase activity.
The OsSIRH2‐14‐EYFP fusion protein was predominately expressed in the cytoplasm, Golgi, and plasma membrane of rice protoplasts.
Rice OsSIRH2‐14 gene plays a positive role in salinity tolerance by regulating salt‐related proteins including an HKT‐type Na+ transporter (OsHKT2;1).
Compared with wild type plants, OsSIRH2‐14‐overexpressing rice plants showed significantly enhanced salinity tolerance and reduced Na+ accumulation in the aerial shoot and root tissues.