The SINA E3 Ligase OsDIS1 Negatively Regulates Drought Response in Rice

• Published in: Plant physiology (Bethesda) Vol. 157; no. 1; pp. 242 - 255
• Main Authors: Ning, Yuese, Jantasuriyarat, Chachawan, Zhao, Qingzhen, Zhang, Huawei, Chen, Songbiao, Liu, Jinling, Liu, Lijing, Tang, Sanyuan, Park, Chan Ho, Wang, Xuejun, Liu, Xionglun, Dai, Liangying, Xie, Qi, Wang, Guo-Liang
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01-09-2011
• Subjects: Amino Acid Sequence; Base Sequence; Biological and medical sciences; DNA Primers; Drought; Drought tolerance; Droughts; ENVIRONMENTAL STRESS AND ADAPTATION TO STRESS; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Genes; Genes, Plant; Molecular Sequence Data; Oryza - enzymology; Oryza - genetics; Oryza - physiology; Plant physiology and development; Plants; Plants, Genetically Modified - enzymology; Plants, Genetically Modified - genetics; Plants, Genetically Modified - physiology; Plasmids; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Rice; RNA; RNA Interference; Sequence Homology, Amino Acid; Transgenic plants; Ubiquitin-Protein Ligases - chemistry; Ubiquitin-Protein Ligases - metabolism; Ubiquitins; Monocotyledones; Oryza; Plant physiology; Enzyme; Gramineae; Ligases; Angiospermae; Herbaceous plant; Spermatophyta; Drought
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.111.180893

Ubiquitin-regulated protein degradation is a critical regulatory mechanism that controls a wide range of biological processes in plants. Here, we report that OsDISl (for Oryza sativa drought-induced SINA protein 1), a C3HC4 RING finger E3 ligase, is involved in drought-stress signal transduction in rice (O.sativa).The expression of OsDISl was up-regulated by drought treatment. In vitro ubiquitination assays showed that OsDISl possessed E3 ubiquitin ligase activity and that the conserved region of the RING finger was required for the activity. Transient expression assays in Nicotiana benthamiana leaves and rice protoplasts indicated that OsDISl was localized predominantly in the nucleus. Overexpression of OsDISl reduced drought tolerance in transgenic rice plants, while RNA interference silencing of OsDISl enhanced drought tolerance. Microarray analysis revealed that a large number of drought-responsive genes were induced or suppressed in the OsDISl overexpression plants under normal and drought conditions. Yeast two-hybrid screening showed that OsDISl interacted with OsNek6 (for O. sativa NIMA-related kinase 6), a tubulin complex-related serine/threonine protein kinase. Coexpression assays in N. benthamiana leaves indicated that OsNek6 was degraded by OsDISl via the 26S proteasome-dependent pathway and that this degradation was abolished by the OsDISl (H71Y) mutation, which is essential for its E3 ligase activity. Together, these results demonstrate that OsDISl plays a negative role in drought stress tolerance through transcriptional regulation of diverse stressrelated genes and possibly through posttranslational regulation of OsNek6 in rice.