Cell expansion is a central process in plant morphogenesis, and the elongation of roots and root hairs is essential for uptake of minerals and water from the soil. Ca2+ influx from the extracellular store is required for (and sets the rates of) cell elongation in roots1. Arabidopsis thaliana rhd2 mutants are defective in Ca2+ uptake and consequently cell expansion is compromised—rhd2 mutants have short root hairs2,3 and stunted roots. To determine the regulation of Ca2+ acquisition in growing root cells we show here that RHD2 is an NADPH oxidase, a protein that transfers electrons from NADPH to an electron acceptor leading to the formation of reactive oxygen species (ROS). We show that ROS accumulate in growing wild-type (WT) root hairs but their levels are markedly decreased in rhd2 mutants. Blocking the activity of the NADPH oxidase with diphenylene iodonium (DPI) inhibits ROS formation and phenocopies Rhd2-. Treatment of rhd2 roots with ROS partly suppresses the mutant phenotype and stimulates the activity of plasma membrane hyperpolarization-activated Ca2+ channels, the predominant root Ca2+ acquisition system. This indicates that NADPH oxidases control development by making ROS that regulate plant cell expansion through the activation of Ca2+ channels.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Cramer, G. R. & Jones, R. L. Osmotic stress and abscisic acid reduce cytosolic calcium activities in roots of Arabidopsis thaliana. Plant Cell Environ. 19, 1291–1298 (1996)
Wymer, C. L., Bibikova, T. N. & Gilroy, S. Cytoplasmic free calcium distributions during the development of root hairs of Arabidopsis thaliana. Plant J. 12, 427–439 (1997)
Schiefelbein, J. W. & Somerville, C. Genetic control of root hair development in Arabidopsis thaliana. Plant Cell 2, 235–243 (1990)
Carroll, A. D. et al. Ca2+, annexins, and GTP modulate exocytosis from maize root cap protoplasts. Plant Cell 10, 1267–1276 (1998)
Demidchik, V. et al. Arabidopsis thaliana root nonselective cation channels mediate calcium uptake and are involved in growth. Plant J. 32, 799–808 (2002)
Kiegle, E., Gilliham, M., Haseloff, J. & Tester, M. Hyperpolarisation-activated calcium channels found only in cells from the elongation zone of Arabidopsis thaliana roots. Plant J. 21, 225–229 (2000)
Véry, A.-A. & Davies, J. M. Hyperpolarization-activated calcium channels at the tip of Arabidopsis root hairs. Proc. Natl Acad. Sci. USA 97, 9801–9806 (2000)
Miedema, H., Bothwell, J. H. F., Brownlee, C. & Davies, J. M. Calcium uptake by plant cells—channels and pumps acting in concert. Trends Plant Sci. 11, 514–519 (2001)
Dolan, L. et al. Clonal relationships and cell patterning in the root epidermis of Arabidopsis. Development 120, 2465–2474 (1994)
Keller, T. et al. A plant homolog of the neutrophil NADPH oxidase gp91phox subunit gene encodes a plasma membrane protein with Ca2+ binding motifs. Plant Cell 10, 255–266 (1998)
Torres, M. A. et al. Six Arabidopsis thaliana homologues of the human respiratory burst oxidase (gp91phox). Plant J. 14, 365–370 (1998)
Segal, A. W. & Abo, A. The biochemical basis of the NADPH oxidase of phagocytes. Trends Biochem. Sci. 18, 43–47 (1993)
Torres, M. A., Dangl, J. L. & Jones, J. D. Arabidopsis gp91phox homologues AtrbohD and AtrbohF are required for accumulation of reactive oxygen intermediates in the plant defence response. Proc. Natl Acad. Sci. USA 99, 517–522 (2002)
Williams, A. J. & Cole, P. J. Investigation of alveolar macrophage function using lucigenin-dependent chemiluminescence. Thorax 36, 866–869 (1981)
Bolwell, G. P. & Wojtaszek, P. Mechanisms for the generation of reactive oxygen species in plant defence—a broad perspective. Physiol. Mol. Plant Pathol. 51, 347–366 (1997)
Pei, Z. M. et al. Calcium channels activated by hydrogen peroxide mediate abscisic acid signalling in guard cells. Nature 406, 731–734 (2000)
Fry, S. C. Oxidative scission of plant cell wall polysaccharides by ascorbate-induced hydroxyl radicals. Biochem. J. 332, 507–515 (1998)
Halliwell, B. & Gutteridge, J. M. C. Free Radicals in Biology and Medicine (Oxford Univ. Press, Oxford, 1999)
Hirsch, R. E., Lewis, B. D., Spalding, E. P. & Sussman, M. R. A role for the AKT1 potassium channel in plant nutrition. Science 280, 918–921 (1998)
Kiss, T. & Osipenko, O. N. Toxic effects of heavy metals on ionic channels. Pharmacol. Rev. 46, 245–267 (1994)
Felle, H. & Hepler, P. K. The cytosolic Ca2+ concentration gradient of Sinapsis alba root hairs as revealed by Ca2+-selective microelectrode tests and fura-dextran ratio imaging. Plant Physiol. 114, 39–45 (1997)
Molendijk, A. J. et al. Arabidopsis thaliana Rop GTPases are localized to tips of root hairs and control polar growth. EMBO J. 20, 2779–2788 (2001)
Jones, M. A. et al. The Arabidopsis Rop2 GTPase is a positive regulator of both root hair initiation and tip growth. Plant Cell 14, 763–776 (2002)
Tissier, A. F. et al. Multiple independent defective Suppressor-mutator transposon insertions in Arabidopsis: A tool for functional genomics. Plant Cell 11, 1841–1852 (1999)
Coen, E. S. et al. floricaula: a homeotic gene required for flower development in Antirrhinum majus. Cell 63, 1311–1322 (1990)
Altschul, S. F. et al. Gapped BLAST and PSI-BLAST: A new generation of protein database search programs. Nucleic Acids Res. 25, 3389–3402 (1997)
Thompson, J. D., Higgins, D. G. & Gibson, T. J. CLUSTAL W: Improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice. Nucleic Acids Res. 22, 4673–4680 (1994)
Page, R. D. M. TREEVIEW: An application to display phylogenetic trees on personal computers. Computer Applic. Biosci. 12, 357–358 (1996)
Zhang, W. H., Rengel, Z. & Kuo, J. Determination of intracellular Ca2+ in cells of intact wheat roots: loading of acetoxymethyl ester of Fluo-3 under low temperature. Plant J. 15, 147–151 (1998)
We thank D. Graham and A. Dark for help with screening and cultivation, respectively; E. Ryan, P. Shaw and K. Roberts for comments on the manuscript; and P. Doerner for support. This work was funded by the BBSRC, the Gatsby Foundation, the Leverhulme Trust and the European Union.
The authors declare that they have no competing financial interests.
About this article
Cite this article
Foreman, J., Demidchik, V., Bothwell, J. et al. Reactive oxygen species produced by NADPH oxidase regulate plant cell growth. Nature 422, 442–446 (2003). https://doi.org/10.1038/nature01485
Sensitivity of plants to high frequency electromagnetic radiation: cellular mechanisms and morphological changes
Reviews in Environmental Science and Bio/Technology (2021)
Proteomic investigation of Zn-challenged rice roots reveals adverse effects and root physiological adaptation
Plant and Soil (2021)
Plant Molecular Biology (2021)
Journal of Soil Science and Plant Nutrition (2021)
Plant Cell, Tissue and Organ Culture (PCTOC) (2021)