Differential induction of mRNAs for the glycolytic and ethanolic fermentative pathways by hypoxia and anoxia in maize seedlings.
AUTOR(ES)
Andrews, D L
RESUMO
Fructose-1,6-biphosphate aldolase (ALD) and enolase (ENO) from the glycolytic pathway and pyruvate decarboxylase (PDC) and alcohol dehydrogenase 2 (ADH2) from the ethanolic fermentative pathway, are enzymes previously identified as among those synthesized selectively in O2-deficient roots of maize (Zea mays L.). The present study measured levels of transcripts representing these two pathways in 5-mm root tips, root axes (the remainder of the primary seminal root), and shoots of maize seedlings to determine how closely both pathways were co-induced and how they were modulated by changes in O2 concentration. In hypoxic seedlings with the roots in solution sparged with 5% (v/v) O2 (balance N2) and the shoots in the same gaseous atmosphere, mRNAs for Pdc1 and Adh2 in root tips both increased about 15-fold during the first 12 h, followed by a decline toward initial levels by 18 to 24h. Message levels for Ald1 and Eno1 showed only small changes during hypoxia. When expression was examined under anoxia, the extent to which all four mRNAs increased in different tissues depended on whether the seedlings had been previously acclimated to hypoxia or were anoxically shocked. The results show that although all the genes examined increased expression during hypoxia and/or anoxia, they differed in the rapidity and magnitude of the response and in the time to reach maximal message levels: there was no common pattern of change of message levels for the glycolytic or for the fermantative enzymes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=159700Documentos Relacionados
- Differential expression of two hemA mRNAs encoding glutamyl-tRNA reductase proteins in greening cucumber seedlings.
- Yeast glycolytic mRNAs are differentially regulated.
- Induction of the transcription factor IRF-1 and interferon-beta mRNAs by cytokines and activators of second-messenger pathways.
- A nuclear mutation in maize blocks the processing and translation of several chloroplast mRNAs and provides evidence for the differential translation of alternative mRNA forms.
- Differential induction of pyruvate decarboxylase subunits and transcripts in anoxic rice seedlings.