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Hydrogen peroxide mediates plant root cell response to nutrient deprivation

2004; National Academy of Sciences; Volume: 101; Issue: 23 Linguagem: Inglês

10.1073/pnas.0401707101

1091-6490

Ryoung Shin, Daniel P. Schachtman,

Plant Micronutrient Interactions and Effects

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.