title: Hydrogen peroxide mediates plant root cell response to nutrient deprivation.
abstract: Potassium (K(+)) is an essential nutrient required by plants in large quantities, but changes in soil concentrations may limit K(+) acquisition by roots. It is not known how plant root cells sense or signal the changes that occur after the onset of K(+) deficiency. Changes in the kinetics of Rb(+) uptake in Arabidopsis roots occur within 6 h after K(+) deprivation. Reactive oxygen species (ROS) and ethylene increased when the plants were deprived of K(+). ROS accumulated in a discrete region of roots that has been shown to be active in K(+) uptake and translocation. Suppression of an NADPH oxidase in Arabidopsis (rhd2), which is involved in ROS production, prevented the up-regulation of genes that are normally induced by K(+) deficiency, but the induction of high-affinity K(+) transport activity was unchanged. Application of H(2)O(2) restored the expression of genes induced by K(+) deficiency in rhd2 and was also sufficient to induce high-affinity K(+) transport activity in roots grown under K(+)-sufficient conditions. ROS production is an early root response to K(+) deficiency that modulates gene expression and physiological changes in the kinetics of K(+) uptake.
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, MO 63132, USA.
authors.forename: Ryoung
authors.initials: R
authors.lastname: Shin
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Schachtman
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism; D015870:Gene Expression; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism*; D017136:Ion Transport; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012413:Rubidium / Q000378:metabolism
chemical_list: D005030:Ethylenes; D017382:Reactive Oxygen Species; C036216:ethylene; D006861:Hydrogen Peroxide; D012413:Rubidium; D011188:Potassium