【摘要】 本文研究了小麦（Triticum aestivum L.）和大豆（Glycine max L.）的不同光合器官中的PEP羧化酶及其相关的酶类。在这些器官中均含有PEP羧化酶,其中以大豆的荚壳和种皮及小麦的内稃中PEP羧化酶活性最高。不同绿色器官在光下或暗中均能固定CO₂,但是在黑暗条件下,小麦的内稃和大豆的荚壳及种皮所固定的CO₂远高于叶片。此外,参与暗固定的NAD-苹果酸酶和NAD-苹果酸脱氢酶的活性,在这些器官中也最高,说明这些器官中PEP羧化酶的CO₂ β-羧化作用主要在于固定呼吸作用所释放的CO₂,只有少量的CO₂是通过C₄光合途径被固定。更多还原

【Abstract】 PEPC and relevant enzymes in different photosynthetic organs of wheat and soybean were studied.Almost all green organs examined have been found to contain PEPC.PEPC activity in pod hull and seed coat of soybean as well as in paleae of wheat is higher than that in leaves.¹⁴CO₂ can be fixed in different green organs either in light or in dark, however in dark,¹⁴CO₂ fixation in pol hull and seed coat of soybean as well as in paleae of wheat is higher than in leaves.Similarly,NAD-malic enzyme and NAD-malate dehydrogenase are also higher in those organs than in leaves.It was shown that active β-carboxylation of PEPC took place in the fruit organs.The above results indicate that PEPC is important not only for CO₂ fixation during photosynthesis but also for recapturing CO₂ released from respiration.更多还原