Gene expression of lactate dehydrogenase and alcohol dehydrogenase under anaerobic conditions

厌氧条件下乳酸脱氢酶和乙醇脱氢酶基因表达

• 批准号: 07456004
• 负责人: TAKANO Tetsuo
• 金额: $ 4.35万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07456004/
• 关键词: lactate dehydrogenase; alcohol dehydrotenases; anaerobic stress; submergence tolerance; LDH; ADH; glycolysis; gene expression; 嫌気条件; 冠水耐性; 発酵

Under anaerobic condition, the tricarboxylic pathway is blocked and pyruvate is metabolized via lactate and ethanol fermentation. We have analyzed the gene expression of alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH) which are the key enzumes of these two fermentation pathway.1.ADH(1) In a mutant with reduced ADH activity (rad) , fructose 1,6 bis phosphate was accumulated due to reduced amount of NAD.(2) ADH activity was localized in root and only the isozume band for ADH2 mono-dimer was observed in the mutant. (3) mRNA of ADH1 was normally produced although no isozyme band for ADH1 was obserbed. (4) The submergence tolerance of the mutant was inferior to wild type suggesting that ADH is important for submergence tolerance of the rice seedlings.2.LDH(1)A gene for LDH was cloned and sequenced. The transcription start point was determined to be -129 from ATG by 5'-RACE method. Result of genomic southern hybridization suggested that the LDH gene is single copy in the rice genome, which differ from the LDH gene of animal and barley. (2) The level of LDH mRNA increased continuously for six hours then declined gradually under anaerobic condition. LDH mRNA in rice is induced more transiently in response to anaerobic than ADH and LDH in barley and maize.(3) The rice LDH gene was mapped on chromosome 6 by RFLP analysis.

在厌氧条件下，三羧酸途径被阻断，丙酮酸通过乳酸和乙醇发酵代谢。我们分析了这两个发酵途径的关键酶乙醇脱氢酶（ADH）和乳酸脱氢酶（LDH）的基因表达。1.ADH（1）在ADH活性（rad）降低的突变体中，由于NAD量减少，果糖1,6二磷酸积累。（2）ADH活性集中在根部，仅存在ADH2的等量带。 在突变体中观察到单二聚体。 (3)虽然没有观察到ADH1的同工酶条带，但ADH1的mRNA正常产生。 (4)突变体的耐淹性较野生型差,表明ADH对于水稻幼苗的耐淹性具有重要作用。2.LDH(1)克隆并测序了LDH基因。通过5'-RACE方法确定ATG的转录起始点为-129。基因组Southern杂交结果表明，LDH基因在水稻基因组中为单拷贝，与动物和大麦的LDH基因不同。 (2)厌氧条件下LDH mRNA水平持续升高6小时后逐渐下降。与大麦和玉米中的ADH和LDH相比，水稻中LDH mRNA对厌氧的诱导更短暂。(3)通过RFLP分析将水稻LDH基因定位在6号染色体上。

项目成果

Matsumura, H.et.al.: "Adh1 is transcriptionally active in a rice mutant with reduced ADH activity (rad).Theor.Appl.Genet.in press" Theor.Appl.Genet. (in press). (1998)

Matsumura, H.et.al.：“Adh1 在 ADH 活性降低 (rad) 的水稻突变体中具有转录活性。Theor.Appl.Genet.in press”Theor.Appl.Genet。

Matsumura,H.et.al: "Adh 1 is transcriptionally active in a rice mutant with reduced ADH activity (rad)." Theor.Appl.Genet. (印刷中).

Matsumura, H.et.al：“Adh 1 在 ADH 活性降低 (rad) 的水稻突变体中具有转录活性。”Theor.Appl.Genet。