Anaerobic response

R. J. Ferl (1990) ARF-B2 a protein complex that specifically binds to part of anaerobic response element of maize adhl. Plant Physiol., 93 1094-1101... 

M. R. Olive, W. J. Peacock, E. S. Dennis (1991) The anaerobic responsive element contains two GC-rich sequences essential for binding a nuclear protein and hypoxic activation of the maize adhl promoter. Nucl. Acids Res., 19 7053-7960... 

LeGall J, Xavier AV. 1996. Anaerobes response to oxygen the sulfate-reducing bacteria. Anaerobe 2 1-9. 

The Anaerobic Response Element (ARE) regulates anaerobic induction of the maize Adh gene... 

This deletion and mutation analysis of the promoter resulted in the identification of a region located between —140 and —100, relative to the transcription start, the Anaerobic Responsive Element (ARE), which was critical for anaerobic gene expression. Two subregions exist within this promoter, both of which are necessary for activity, and each of these two subregions contained a core sequence T/CGGTTT. 

Thus, in the anaerobic response the plant haemoglobin protein present in the roots could assume different conformations depending upon the oxygen concentration. This conformational change could activate another molecule which in turn could alter transcription factor binding and induce the anaerobic response (Fig. 6). 

This remains a most fascinating question in the anaerobic response how does the plant sense that it is experiencing anaerobic conditions and mount a gene response ... 

Fig. 6. Root haemoglobin as an oxygen sensor. Model for root haemoglobin sensing oxygen levels and inducing the anaerobic response. There could be many more steps in this pathway than shown in the figure.

We have been studying the anaerobic response in cotton, a crop which experiences a reduction in growth rate during irrigation or waterlogging. Cotton shows a level of anaerobically inducible ADH activity comparable with that of maize, a plant which is relatively resistant to anoxia (A. Millar, unpublished data T.L. Setter, unpublished data). However, in cotton the level of the enzyme catalysing the preceding step in the fermentation pathway, PDC, is relatively low and this may lead to low rates of ethanol synthesis and hence low tolerance to anoxia. 

Bailey-Serres, J., Kloeckner-Gruissem, B. Freeling, M. (1988). Genetic and molecular approaches to the study of the anaerobic response and tissue specific gene expression in maize. Plant, Cell and Environment 11, 351-7. 

Olive, M.R., Walker, J.C., Singh, K., Dennis, E.S. Peacock, W.J. (1990). Functional properties of the anaerobic responsive element of the maize Adhl gene. Plant Molecular Biology 15, 593-604. 

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