ENERGETICS OF PLANT-GROWTH UNDER ANOXIA - METABOLIC ADAPTATIONS OF ORYZA-SATIVA AND ECHINOCHLOA PHYLLOPOGON
ENERGETICS OF PLANT-GROWTH UNDER ANOXIA - METABOLIC ADAPTATIONS OF ORYZA-SATIVA AND ECHINOCHLOA PHYLLOPOGON
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DOI：
10.1006/anbo.1994.1140
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发表时间：
1994-11-01
期刊：
影响因子：
4.2
通讯作者：
RUMPHO, ME
中科院分区：
文献类型：
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作者：
FOX, TC;KENNEDY, RA;RUMPHO, ME
与大多数植物物种不同，水稻（Oryza sativa L.）CV. S-201和稗草Echinochloa phyllopogon（Stev.）Koss在厌氧条件下发芽和生长。在这两个物种中，胚根或芽出现的第3天，当种子在空气或N-2中发芽。在任一条件下，地上部和/或根干重（d. wt）从第3天到第7天线性增加，种子d相应减少。重量在厌氧培养的O.萨蒂亚湾wt积累量降低到空气中的7%，而d.从晶种损失的重量减少到仅37%。在厌氧萌发和芽萌发过程中，根不生长。wt积累量占d.种子中损失的重量。在大肠叶芒湾缺氧时WT积累量为空气中的25%，而D.从种子的重量是好氧速率的44%。在空气中，48%的d。从种子损失的重量转化为芽或根D。重量像O。sativa、E.在N-2处理下，叶芒草不生根，但地上部生长量占d.从种子中流失。因此，无论是在空气中还是在N-2中，E. plyllopogon比O.燕麦。根据代谢物库的变化，O. sativa似乎在厌氧生长期间专门转向发酵。在大肠然而，在没有O-2的情况下，单独的发酵不能满足叶芒草生长的能量需求。相反，发酵，加上有限的三羧酸（TCA）循环操作可以提供足够的ATP生长在厌氧条件下。讨论了活性氧化戊糖磷酸途径和脂质合成作为将NADH转化为NAD的重要机制，NAD是发酵和TCA循环活性的必要辅因子。
Unlike most plant species, Oryza sativa L. cv. S-201 and Echinochloa phyllopogon (Stev.) Koss germinate and grow under anaerobic conditions. In both species, the radicle or shoot emerged by day 3 when the seeds were germinated in air or N-2. Under either condition, shoot and/or root dry weight (d. wt) increased linearly from day 3 to day 7, with a corresponding decrease in seed d. wt. In anaerobically grown O. sativa, d. wt accumulation was reduced to 7% of that in air whereas d. wt lost from the seed was reduced to only 37%. No root growth occurred during anaerobic germination and shoot d. wt accumulation accounted for 10% of the d. wt lost from the seed. In E. phyllopogon, d. wt accumulation during anoxia was 25% of that in air, but loss of d. wt from the seed was 44% of the aerobic rate. In air, 48% of the d. wt lost from the seed was converted to shoot or root d. wt. Like O. sativa, E. phyllopogon does not produce a root under N-2, but shoot growth accounted for 27% of the d. wt lost from the seed. Thus, either in air or N-2, E. plyllopogon was more efficient at converting seed reserves to shoot/root structural dry matter than O. sativa. Based on changes in metabolite pools, O. sativa appeared to shift exclusively to fermentation during anaerobic growth. In E. phyllopogon, however, fermentation alone cannot satisfy the energy requirement for growth without O-2. Rather, fermentation, coupled with limited tricarboxylic acid (TCA) cycle operation could supply sufficient ATP for growth under anaerobic conditions. An active oxidative pentose phosphate pathway and lipid synthesis were discussed as important mechanisms for converting NADH to NAD, a necessary cofactor for fermentation and TCA cycle activity.