화학공학소재연구정보센터
Biochemical and Biophysical Research Communications, Vol.319, No.4, 1190-1196, 2004
Direct involvement of hydrogen peroxide in curvature of wheat coleoptile in blue-light-treated and dark-grown coleoptiles
Blue-light-induced photomorphogenesis is the sum total of a sequence of phenomena involving absorption of light by specific receptors, generation of a signal, processing transmembrane transport of signal, and the activation of a cascade of reactions in the cell interior. Though four blue-light receptors cryptochrome1, cryptochrome2, phototropin1, and phototropin2 have been identified, the signal transduction events associated with blue-light receptor activation are not understood. In this report, we demonstrate the generation and spatiotemporal distribution of H2O2 in wheat coleoptile in response to blue light. Interception of the free-radical generation pathways dithiothreitol and propyl gallate rendered wheat coleoptile tips phototropically non-responsive. Unilateral application of H2O2 onto the sub-apical region of a growing coleoptile brought about curvature in dark. Blue light also caused lipid peroxidation and augmented membrane rigidity of coleoptile cell membranes. We conclude that H2O2 can act as a translocating second messenger that could bring about coleoptile curvature, and the signaling events may trigger Ca2+ signaling cascades, changes in gene expression, and protein modifications. (C) 2004 Elsevier Inc. All rights reserved.