Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/1998
Publication Date: N/A
Citation: N/A Interpretive Summary: 1) Rationale: The goal here was to determine if enolase (an enzyme involved in glucose metabolism) is encoded by more than one gene in maize, and if so, does the expression differ among the members of the gene family. 2) Accomplishments: It was determined that enolase is encoded by at least two genes. One gene's expression is turned on in response to flooding, the other gene is on all the time (including during non-flooding conditions). 3) Significance: The understanding of the role of enolase in a plant's response to low oxygen-stress conditions will allow for a greater understanding of how a plant can cope under flooding conditions, and may allow for effective methods to produce crop plants that are tolerant to flooding.
Technical Abstract: Previously it was reported that enolase enzyme activity and ENO1 transcript levels are induced by anaerobic stress in maize. Here we show that not all isoforms of maize enolase are anaerobically induced. We cloned and sequenced a second enolase cDNA (pENO2) clone from maize. Sequence analysis shows that pENO2 shares 75.6% nucleotide and 89.5% deduced amino acid sequence identity with pENO1 and is encoded by a distinct gene. Expression of ENO2 is constitutive under aerobic conditions, whereas ENO1 levels are induced 10-fold in maize roots after 24 h of anaerobic treatment. Western blotting experiments and N-terminal sequencing of ANP45A and ANP45B (two previously described major anaerobic proteins; Sachs et al., 1980. Cell 20: 761-767) show that these ANPs correspond to two enolase isozymes. The expression of enolase in maize roots under anaerobic stress is described.