Arabidopsis phenotyping reveals the importance of alcohol dehydrogenase and pyruvate decarboxylase for aerobic plant growth
SCIENTIFIC REPORTS
Authors: Ventura, Irene; Brunello, Luca; Iacopino, Sergio; Valeri, Maria Cristina; Novi, Giacomo; Dornbusch, Tino; Perata, Pierdomenico; Loreti, Elena
Abstract
Alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) are key to the establishment of the fermentative metabolism in plants during oxygen shortage. Most of the evidence that both ADH and PDC are required for plant tolerance to hypoxia comes from experiments performed by limiting oxygen in the environment, such as by exposing plants to gaseous hypoxia or to waterlogging or submergence. However, recent experiments have shown that hypoxic niches might exist in plants grown in aerobic conditions. Here, we investigated the importance of ADH and PDC for plant growth and development under aerobic conditions, long-term waterlogging and short-term submergence. Data were collected after optimizing the software associated with a commercially-available phenotyping instrument, to circumvent problems in separation of plants and background pixels based on colour features, which is not applicable for low-oxygen stressed plants due to the low colour contrast of leaves with the brownish soil. The results showed that the growth penalty associated with the lack of functional ADH1 or both PDC1 and PDC2 is greater under aerobic conditions than in hypoxia, highlighting the importance of fermentative metabolism in plants grown under normal, aerobic conditions.
A distinct type of alcohol dehydrogenase, adh4(+), complements ethanol fermentation in an adh1-deficient strain of Schizosaccharomyces pombe
FEMS YEAST RESEARCH
Authors: Sakurai, M; Tohda, H; Kumagai, H; Giga-Hama, Y
Abstract
In the fission yeast Schizosaccharomyces pombe, only one alcohol dehydrogenase gene, adh1(+), has been identified. To elucidate the influence of adh1(+) on ethanol fermentation, we constructed the adh1 null strain (Deltaadh1). The Deltaadh1 cells still produced ethanol and grew fermentatively as the wild-type cells. Both DNA microarray and RT-PCR analysis demonstrated that this ethanol production is caused by the enhanced expression of a Saccharomyces cerevisiae ADH4-like gene product (SPAC5H10.06C named adh4(+)). Since the strain lacking both adh1 and adh4 genes (Deltaadh1 Deltaadh4) showed non-fermentative retarded growth, only these two ADHs produce ethanol for fermentative growth. This is the first observation that a S. cerevisiae ADH4-like alcohol dehydrogenase functions in yeast ethanol fermentation. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.