Guglielminetti Lorenzo, Busilacchi Héctor Abel, Perata Pierdomenico, Alpi Amedeo
Dipartimento di Biologia delle Piante Agrarie, Sezione Fisiologia Vegetale, Via Mariscoglio 34, I-56124 Pisa, Italy.
Present address: Facultad de Ciencias Agrarias, University of Rosario, CC 14 CP (2123) Zavalla, Pcia de Santa Fe, Argentina.
New Phytol. 2001 Sep;151(3):607-612. doi: 10.1046/j.0028-646x.2001.00218.x.
• Cereal grains differ greatly in their reponses to anaerobiosis. Here, the in vivo conversion of carbohydrates to ethanol and CO under anoxia is reported for three cereal grains. • The conversion of glucose, fructose or sucrose to ethanol under anaerobic conditions was investigated in rice (Oryza sativa), barley (Hordeum vulgare) and wheat (Triticum aestivum) grains; alcohol dehydrogenase (EC 1.1.1.1) and pyruvate decarboxylase (EC 4.1.1.1) activities were also analysed under aerobic and anaerobic incubation. • Our data suggest that rice grains are able to produce ethanol under anoxia for the whole period of anoxic treatment, whereas barley and wheat grains can produce this terminal product of fermentation only during the first days of anaerobiosis. The level of enzymes involved in the fermentation pathway increases strongly under anoxic conditions in all three cereals. • Conversion of hexose to CO is nearly unaffected by anoxia in wheat, barley and rice, whereas only rice grains are able to degrade and utilize sucrose efficiently under anoxia. By contrast, wheat and barley do not utilize sucrose efficiently under anaerobic conditions.
• 谷物对缺氧的反应差异很大。本文报道了三种谷物在缺氧条件下碳水化合物在体内转化为乙醇和二氧化碳的情况。
• 研究了水稻（Oryza sativa）、大麦（Hordeum vulgare）和小麦（Triticum aestivum）籽粒在厌氧条件下葡萄糖、果糖或蔗糖向乙醇的转化；还分析了需氧和厌氧培养条件下乙醇脱氢酶（EC 1.1.1.1）和丙酮酸脱羧酶（EC 4.1.1.1）的活性。
• 我们的数据表明，水稻籽粒在整个缺氧处理期间都能够在缺氧条件下产生乙醇，而大麦和小麦籽粒仅在厌氧处理的最初几天能够产生这种发酵终产物。在所有三种谷物中，参与发酵途径的酶水平在缺氧条件下均大幅增加。
• 小麦、大麦和水稻中己糖向二氧化碳的转化几乎不受缺氧影响，而只有水稻籽粒能够在缺氧条件下有效降解和利用蔗糖。相比之下，小麦和大麦在厌氧条件下不能有效利用蔗糖。
