Planta (2006) 225:103–114
DOI 10.1007/s00425-006-0333-x
123
ORIGINAL ARTICLE
Organ-speciWc analysis of the anaerobic primary metabolism
in rice and wheat seedlings. I: Dark ethanol production
is dominated by the shoots
Angelika Mustroph · Elena I. Boamfa ·
Lucas J. J. Laarhoven · Frans J. M. Harren ·
Gerd Albrecht · Bernhard Grimm
Received: 12 December 2005 / Accepted: 25 May 2006
/ Published online: 15 July 2006
© Springer-Verlag 2006
Abstract During anaerobiosis in darkness the main
route for ATP production in plants is through glycol-
ysis in combination with fermentation. We compared
the organ-speciWc anaerobic fermentation of Xood-
ing-tolerant rice (Oryza sativa) and sensitive wheat
(Triticum aestivum) seedlings. A sensitive laser-
based photoacoustic trace gas detection system was
used to monitor emission of ethanol and acetalde-
hyde by roots and shoots of intact seedlings. Dark-
incubated rice seedlings released 3 times more acet-
aldehyde and 14 times more ethanol than wheat
seedlings during anaerobiosis. Ninety percent of
acetaldehyde originated from shoots of both species.
In comparison to wheat shoots, the high ethanol pro-
duction of rice shoots correlated with larger amounts
of soluble carbohydrates, and higher activities of fer-
mentative enzymes. After 24 h of anaerobiosis in
darkness rice shoots still contained 30% of aerated
ATP level, which enabled seedlings to survive this
period. In contrast, ATP content declined almost to
zero in wheat shoots and roots, which were irrevers-
ibly damaged after a 24-h anaerobic period. When
plants were anaerobically and dark incubated for 4 h
and subsequently transferred back to aeration,
shoots showed a transient peak of acetaldehyde
release indicating prompt re-oxidation of ethanol.
Post-anoxic acetaldehyde production was lower in
rice seedlings than in wheat. This observation
accounts for a more eVective acetaldehyde detoxiW-
cation system in rice. Compared to wheat the greater
tolerance of rice seedlings to transient anaerobic
periods is explained by a faster fermentation rate of
their shoots allowing a suYcient ATP production and
an eYcient suppression of toxic acetaldehyde forma-
tion in the early re-aeration period.
Keywords Acetaldehyde · Anaerobiosis · Ethanolic
fermentation · Oryza · Triticum
Abbreviations
ADH Alcohol dehydrogenase
AEC Adenylate energy charge
PDC Pyruvate decarboxylase
PQ Pasteur quotient
Introduction
Plants use diVerent adaptation strategies against
Xooding stress causing oxygen deWciency: Morpholog-
ical changes, such as the formation of aerenchyma,
adventitious roots and lenticels, as well as enhanced
shoot growth (Jackson 1985) can suYciently provide
Angelika Mustroph and Elena I. Boamfa contributed equally to
the paper.
E. I. Boamfa · L. J. J. Laarhoven · F. J. M. Harren
Life Science Trace Gas Exchange Facility,
Molecular and Laser Physics, Radboud University,
Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
G. Albrecht
Institute of Biology, AG Botany,
Humboldt-University Berlin, Spaethstrasse 80/81,
12437 Berlin, Germany
A. Mustroph (&) · B. Grimm
Department of Plant Physiology, Humboldt-University
Berlin, Philippstrasse 13/Haus 12, 10115 Berlin, Germany
e-mail: angelika.mustroph@web.de