This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Hanson, A. D. Articles by Jacobsen, J. V. Search for Related Content PubMed PubMed Citation Articles by Hanson, A. D. Articles by Jacobsen, J. V. Agricola Articles by Hanson, A. D. Articles by Jacobsen, J. V.

Articles

Control of Lactate Dehydrogenase, Lactate Glycolysis, and -Amylase by O₂ Deficit in Barley Aleurone Layers ¹

Commonwealth Scientific and Industrial Research Organization, Division of Plant Industry, Canberra, A.C.T. 2601, Australia

After 4 days in an atmosphere of N₂, aleurone layers of barley (Hordeum vulgare L. cv Himalaya) remained viable as judged by their ability to produce near normal amounts of -amylases when incubated with gibberellic acid (GA₃) in air. However, layers did not produce -amylase when GA₃ was supplied under N₂, apparently because -amylase mRNA failed to accumulate.

When an 8-hour pulse of [U-¹⁴C]glucose was supplied under N₂ to freshly prepared aleurone layers, both [¹⁴C]lactate and [¹⁴C]ethanol accumulated; the [¹⁴C]lactate/[¹⁴C]ethanol ratio was about 0.3. Prior incubation of layers for 1 day under N₂ changed this ratio to about 0.8, indicating an increase in the relative importance of the lactate branch of glycolysis.

L(+)Lactate dehydrogenase (LDH) activity was low in freshly prepared aleurone layers and increased 10-fold during 2 days under N₂, whereas alcohol dehydrogenase activity (ADH) was high initially and rose by 60%. The responses of LDH and ADH activities to O₂ tension were dissimilar; when layers were incubated in various O₂/N₂ mixtures, LDH activity peaked at 2 to 5% O₂ whereas ADH activity was highest at 0% O₂. The LDH activity was resolved into several enzymically active bands by native polyacrylamide gel electrophoresis.

We conclude that barley aleurone layers are highly adapted to O₂ deficiency, that they possess an inducible LDH system as well as an ADH system, and we infer that the LDH and ADH systems are independently regulated.

¹ Supported in part by a Guggenheim Fellowship to A. D. H.

This article has been cited by other articles:

				J. Kreuzwieser, J. Hauberg, K. A. Howell, A. Carroll, H. Rennenberg, A. H. Millar, and J. Whelan Differential Response of Gray Poplar Leaves and Roots Underpins Stress Adaptation during Hypoxia Plant Physiology, January 1, 2009; 149(1): 461 - 473. [Abstract] [Full Text] [PDF]

				A. U. Igamberdiev and R. D. Hill Nitrate, NO and haemoglobin in plant adaptation to hypoxia: an alternative to classic fermentation pathways J. Exp. Bot., December 1, 2004; 55(408): 2473 - 2482. [Abstract] [Full Text] [PDF]

				J. M. Frantz and B. Bugbee Anaerobic conditions improve germination of a gibberellic acid deficient rice Crop Sci., March 1, 2002; 42(2): 651 - 654. [Abstract] [Full Text] [PDF]

				A. W. Sowa, S. M. G. Duff, P. A. Guy, and R. D. Hill Altering hemoglobin levels changes energy status in maize cells under hypoxia PNAS, August 18, 1998; 95(17): 10317 - 10321. [Abstract] [Full Text] [PDF]