Lal S K, Lee C, Sachs M M
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Plant Physiol. 1998 Dec;118(4):1285-93. doi: 10.1104/pp.118.4.1285.
It was reported previously that enolase enzyme activity and ENO1 transcript levels are induced by anaerobic stress in maize (Zea mays). Here we show that not all isoforms of maize enolase are anaerobically induced. We cloned and sequenced a second enolase cDNA clone (pENO2) from maize. Sequence analysis showed 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-blot analysis and N-terminal sequencing of in vivo-labeled maize roots identified two major proteins selectively synthesized upon anaerobic stress as isozymes of enolase. We describe the expression of enolase in maize roots under anaerobic stress.
先前有报道称，玉米（Zea mays）中的烯醇化酶活性和ENO1转录水平受厌氧胁迫诱导。在此我们表明，并非玉米烯醇化酶的所有同工型都受厌氧诱导。我们从玉米中克隆并测序了第二个烯醇化酶cDNA克隆（pENO2）。序列分析表明，pENO2与pENO1的核苷酸序列一致性为75.6%，推导的氨基酸序列一致性为89.5%，且由一个不同的基因编码。ENO2的表达在需氧条件下是组成型的，而厌氧处理24小时后，玉米根中ENO1的水平被诱导升高10倍。对体内标记的玉米根进行的蛋白质免疫印迹分析和N端测序确定，厌氧胁迫时选择性合成的两种主要蛋白质为烯醇化酶的同工酶。我们描述了厌氧胁迫下玉米根中烯醇化酶的表达情况。
