Comparative analysis of the reactive oxygen species‐producing enzymatic activity of Arabidopsis NADPH oxidases. (14th February 2019)

• Record Type: Journal Article
• Authors: Kaya, Hidetaka; Takeda, Seiji; Kobayashi, Masaki J.; Kimura, Sachie; Iizuka, Ayako; Imai, Aya; Hishinuma, Haruka; Kawarazaki, Tomoko; Mori, Kyoichiro; Yamamoto, Yuta; Murakami, Yuki; Nakauchi, Ayuko; Abe, Mitsutomo; Kuchitsu, Kazuyuki
• Is Part Of: Plant journal. Volume 98:Number 2(2019)
• Page Start: 291
• Page End: 300
• Publication Date: 2019-02-14
• Subjects: respiratory burst oxidase homolog (Rboh) -- reactive oxygen species (ROS) -- Ca2+ -- phosphorylation -- Arabidopsis thaliana; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.14212
• Languages: English
• ISSNs: 0960-7412

Abstract

Summary: Reactive oxygen species (ROS) produced by NADPH oxidases, called respiratory burst oxidase homologs (Rbohs), play crucial roles in development as well as biotic and abiotic stress responses in plants. Arabidopsis has 10 Rboh genes, AtRbohA to AtRbohJ . Five AtRboh s ( AtRbohC, ‐ D, ‐ F, ‐ H and ‐ J ) are synergistically activated by Ca 2+ ‐binding and protein phosphorylation to produce ROS that play various roles in planta, although the activities of the other Rbohs remain unknown. With a heterologous expression system, we found a range of ROS‐producing activity among the AtRbohs with differences up to 100 times, indicating that the required amounts of ROS are different in each situation where AtRbohs act. To specify the functions of AtRbohs involved in cell growth, we focused on AtRbohC, ‐H and ‐J, which are involved in tip growth of root hairs or pollen tubes. Ectopic expression of the root hair factor AtRbohC / ROOT HAIR DEFECTIVE 2 ( RHD2 ) in pollen tubes restored the atrbohH atrbohJ defects in tip growth of pollen tubes. However, expression of AtRbohH or ‐ J in root hairs did not complement the tip growth defect in the atrbohC/rhd2 mutant. Our data indicate that Rbohs possess different ranges of enzymatic activity, and that some Rbohs have evolved to carry specific functions in cell growth. Significance statement: All 10 Rboh proteins in Arabidopsis thaliana carry the reactive oxygen species‐producing activity that is stimulated by Ca 2+ binding and protein phosphorylation, but their activity differs 100‐fold between the most and least active. Complementation tests and phylogenetic analyses suggest that AtRbohs involved in tip growth have evolved to carry out distinct developmental functions while maintaining a similar activation mechanism by Ca 2+ binding and phosphorylation.