Characterization of Rice NADPH oxidase genes and their expression under various environmental conditions

• Published in: International journal of molecular sciences 2013-04, Vol.14 (5), p.9440-9458
• Main Authors: Wang, Gang-Feng, Li, Wen-Qiang, Li, Wen-Yan, Wu, Guo-Li, Zhou, Cong-Yi, Chen, Kun-Ming
• Format: Article
• Language: English
• Subjects: Amino acids; Calcium Chloride - pharmacology; Droughts; Egtazic Acid - pharmacology; Environment; environmental stress; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Enzymologic - drug effects; Gene Expression Regulation, Plant - drug effects; Genes, Plant; Genomes; High temperature; NADPH oxidase (Nox); NADPH Oxidases - chemistry; NADPH Oxidases - genetics; NADPH Oxidases - metabolism; Organ Specificity - drug effects; Organ Specificity - genetics; Oryza - enzymology; Oryza - genetics; Oryza sativa; phylogenetic analysis; Phylogenetics; Phylogeny; Protein Structure, Tertiary; Proteins; Rice; rice (Oryza sativa); Signal transduction; Sodium Chloride - pharmacology; Stress, Physiological - drug effects; Stress, Physiological - genetics; Temperature
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms14059440

Plasma membrane NADPH oxidases (Noxs) are key producers of reactive oxygen species under both normal and stress conditions in plants. We demonstrate that at least eleven genes in the genome of rice (Oryza sativa L.) were predicted to encode Nox proteins, including nine genes (OsNox1-9) that encode typical Noxs and two that encode ancient Nox forms (ferric reduction oxidase 1 and 7, OsFRO1 and OsFRO7). Phylogenetic analysis divided the Noxs from nine plant species into six subfamilies, with rice Nox genes distributed among subfamilies I to V. Gene expression analysis using semi-quantitative RT-PCR and real-time qRT-PCR indicated that the expression of rice Nox genes depends on organs and environmental conditions. Exogenous calcium strongly stimulated the expression of OsNox3, OsNox5, OsNox7, and OsNox8, but depressed the expression of OsFRO1. Drought stress substantially upregulated the expression of OsNox1-3, OsNox5, OsNox9, and OsFRO1, but downregulated OsNox6. High temperature upregulated OsNox5-9, but significantly downregulated OsNox1-3 and OsFRO1. NaCl treatment increased the expression of OsNox2, OsNox8, OsFRO1, and OsFRO7, but decreased that of OsNox1, OsNox3, OsNox5, and OsNox6. These results suggest that the expression profiles of rice Nox genes have unique stress-response characteristics, reflecting their related but distinct functions in response to different environmental stresses.