title: Iron nanoparticle-induced activation of plasma membrane H(+)-ATPase promotes stomatal opening in Arabidopsis thaliana.
abstract: Engineered nanomaterials (ENMs) enable the control and exploration of intermolecular interactions inside microscopic systems, but the potential environmental impacts of their inevitable release remain largely unknown. Plants exposed to ENMs display effects, such as increase in biomass and chlorophyll, distinct from those induced by exposure to their bulk counterparts, but few studies have addressed the mechanisms underlying such physiological results. The current investigation found that exposure of Arabidopsis thaliana to nano zerovalent iron (nZVI) triggered high plasma membrane H(+)-ATPase activity. The increase in activity caused a decrease in apoplastic pH, an increase in leaf area, and also wider stomatal aperture. Analysis of gene expression indicated that the levels of the H(+)-ATPase isoform responsible for stomatal opening, AHA2, were 5-fold higher in plants exposed to nZVI than in unexposed control plants. This is the first study to show that nZVI enhances stomatal opening by inducing the activation of plasma membrane H(+)-ATPase, leading to the possibility of increased CO2 uptake.
authors.affiliation: School of Environmental Science and Engineering, and ‡Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH) , Pohang 790-784, Republic of Korea.
authors.forename: Jae-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Youngjun
authors.initials: Y
authors.lastname: Oh
authors.forename: Hakwon
authors.initials: H
authors.lastname: Yoon
authors.forename: Inhwan
authors.initials: I
authors.lastname: Hwang
authors.forename: Yoon-Seok
authors.initials: YS
authors.lastname: Chang
mesh_terms: D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018533:Biomass; D002245:Carbon Dioxide / Q000737:chemistry; D002462:Cell Membrane / Q000201:enzymology*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry; D018515:Plant Leaves / Q000201:enzymology; D054046:Plant Stomata / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012987:Soil; D014961:X-Ray Diffraction
chemical_list: D029681:Arabidopsis Proteins; D012987:Soil; D002245:Carbon Dioxide; D007501:Iron; D006180:Proton-Translocating ATPases