Plant Physiology 69:1128-1131 (1982)
© 1982 American Society of Plant Biologists
Articles
Effect of Ethylene on the Release of -Amylase through Cell Walls of Barley Aleurone Layers 1
Tuan-Hua David Ho,
James Abroms and
Joseph E. Varner
Department of Botany, University of Illinois, Urbana, Illinois 61801,
Department of Biology, Washington University, St. Louis, Missouri 63130
A large portion of the gibberellic acid (GA3)-induced -amylase in isolated aleurone layers is transported into the incubation medium. In the presence of GA3 and ethylene, an even larger portion of the enzyme is found in the medium. Employing an acid washing technique developed by Varner and Mense (Plant Physiol 1972 49:187-189), it was observed that ethylene significantly reduces the amount of -amylase trapped by the thick cell walls of aleurone layers. However, the amount of enzyme remaining in the cell (within the boundary of plasma membrane) is not affected by ethylene. Ethylene has no observable effect on membrane formation as measured by the incorporation of [32P]orthophosphate into phospholipids. Because of these observations it is suggested that ethylene enhances the release of -amylase, i.e. transport of -amylase across cell walls, but not the secretion of -amylase, i.e. transport of -amylase past the barrier of plasma membrane. The possible mechanism of this ethylene effect is discussed.
1 Supported by National Science Foundation grants PCM-7816143 and PCM 8021632 to T. H. D. H. and GB-39944 to J.E.V.
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