Characterization of Rice NADPH Oxidase Genes and Their Expression under Various Environmental Conditions

Abstract

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.

Genome-Wide Analysis of Respiratory Burst Oxidase Homologs in Grape (Vitis vinifera L.)

“…Six groups of orthologs were identified (Figure 2), which is in agreement with previous evolutionary analyses of plant Rbohs [34]. The VvRboh sequences were distributed amongst all groups (Figure 2): VvRbohA, VvRbohB, VvRbohC1, VvRbohE and VvRbohH belong to group V, III, II, IV and VI, respectively, while VvRbohC2 and VvRbohD belong to group I.…”

Suppression of auxin signalling promotes rice susceptibility to Rice black streaked dwarf virus infection

“…In plants, NADPH oxidases (respiratory burst oxidase homologs, Rboh ) play key roles in generating ROS by catalysing the conversion of O 2 to superoxide (O 2 ‐ ) (Suzuki et al , ). The rice genome encodes nine Rboh proteins (A–I) (Wang et al , ) of which OsRbohA , OsRbohB and OsRbohE are reported to be involved in ROS production during pathogen invasion (Wong et al , ; Yoshie et al , ). To verify the impact of auxin signalling on OsRboh ‐mediated ROS levels, the expression of OsRboh transcripts was monitored in auxin signalling mutants.…”

Structural complexity and functional diversity of plant NADPH oxidases

“…However, the role of only monocot Rboh (Potamogeton crispus PcRboh1) present in this cluster has not been identified yet. In the case of cluster 6, out of six proteins in sub-cluster 6A, only two (OsRbohB and OsRbohH) were reported to be drought-induced (Wang et al 2013; Kaur and Pati 2016). We hypothesize that other monocot Rbohs (ZmRbohF, ZmRbohl, HvRbohBl and HvRbohB2) may function in abiotic stress.…”