Carbon dioxide metabolism in leaf epidermal tissue.
Carbon dioxide metabolism in leaf epidermal tissue.
复制标题
叶表皮组织中的二氧化碳代谢。
作者：
C. Willmer;J. Pallas;Clanton C. Black
为了获得大量的纯叶表皮组织，对许多植物进行了调查。鸭跖草和郁金香Tulipa gesnariana L.（郁金香）被选为进一步的工作。叶绿素a/B比值为2.41和2.45。communis和郁金香。用表皮组织和除去表皮的叶组织测定磷酸烯醇式丙酮酸羧化酶、1，5-二磷酸核酮糖羧化酶、苹果酸酶、NAD（+）和NADP（+）苹果酸脱氢酶。在这两个物种中，有较少的核酮糖1，5-二磷酸比磷酸烯醇式丙酮酸羧化酶活性在表皮组织中表达的蛋白质或叶绿素的基础上，而相反的是真实的叶组织减去表皮组织。在这两个物种中，苹果酸酶的活性较高，在表皮组织比在其余的叶组织时，表达的蛋白质或叶绿素的基础上。在这两个物种中，NAD（+）和NADP（+）苹果酸脱氢酶活性较高的表皮组织时，表达的叶绿素的基础上，然而，在蛋白质的基础上，匡威亦然。C.显微放射自显影表皮和酮酸组织化学试验表明，CO（2）固定主要发生在保卫细胞。的意义和可能的位置的酶进行了讨论，在保卫细胞代谢。
A number of plant species were surveyed to obtain pure leaf epidermal tissue in quantity. Commelina communis L. and Tulipa gesnariana L. (tulip) were chosen for further work. Chlorophyll a/b ratios of epidermal tissues were 2.41 and 2.45 for C. communis and tulip, respectively. Phosphoenolpyruvate carboxylase, ribulose-1,5-diphosphate carboxylase, malic enzyme, and NAD(+) and NADP(+) malate dehydrogenases were assayed with epidermal tissue and leaf tissue minus epidermal tissue. In both species, there was less ribulose 1,5-diphosphate than phosphoenolpyruvate carboxylase activity in epidermal tissue whether expressed on a protein or chlorophyll basis whereas the reverse was true for leaf tissue minus epidermal tissue. In both species, malic enzyme activities were higher in epidermal tissue than in the remaining leaf tissue when expressed on a protein or chlorophyll basis. In both species, NAD(+) and NADP(+) malate dehydrogenase activities were higher in the epidermal tissue when expressed on a chlorophyll basis; however, on a protein basis, the converse was true. Microautoradiography of C. communis epidermis and histochemical tests for keto acids suggested that CO(2) fixation occurred predominantly in the guard cells. The significance and possible location of the enzymes are discussed in relation to guard cell metabolism.