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Changes in soluble sugar, starch, and alcohol dehydrogenase in Arabidopsis thaliana exposed to N2 diluted atmospheresProper exchange of atmospheric gases is important for normal root and shoot metabolism in plants. This study was conducted to determine how restricted air supply affects foliar carbohydrates, while using the marker enzyme alcohol dehydrogenase (ADH) to report on the oxygenation status of the rootzone. Fourteen-day-old Arabidopsis thaliana (L.) Heynh. plants grown singly in 7-ml tubes containing agarified nutrient medium were placed in coupled Magenta vessels and exposed for six days to either ambient air or one of six different air/nitrogen dilutions. Redox potential of the agar medium was measured immediately after harvesting and freezing leaf tissue, and then root systems were quickly extracted from the agar and frozen for subsequent analyses. Redox potential measurements indicated that this series of gas mixtures produced a transition from hypoxia to anoxia in the root zones. Root ADH activity increased at higher rates as the redox potential neared anoxic levels. In contrast, ADH mRNA expression quickly neared its maximum as the medium became hypoxic and showed little further increase as it became anoxic. Foliar carbohydrate levels increased 1.5- to 2-fold with decreased availability of metabolic gases, with starch increasing at higher concentrations of air than soluble carbohydrate. The results serve as a model for plant performance under microgravity conditions, where absence of convective air movement prevents replenishment of metabolic gases.
Document ID
20040172749
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Porterfield, D. M.
(Louisiana State University Agricultural Center Baton Rouge 70803, United States)
Crispi, M. L.
Musgrave, M. E.
Date Acquired
August 22, 2013
Publication Date
December 1, 1997
Publication Information
Publication: Plant & cell physiology
Volume: 38
Issue: 12
ISSN: 0032-0781
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Plant Biology
Non-NASA Center

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