Department of Botany, University of Western Australia, Nedlands, Western Australia 6009.
Plant Physiol. 1978 Oct;62(4):486-90. doi: 10.1104/pp.62.4.486.
The effects of CO(2) concentration and illumination on net gas exchange and the pathway of (14)CO(2) fixation in detached seeds from developing fruits of Lupinus albus (L.) have been studied.Increasing the CO(2) concentration in the surrounding atmosphere (from 0.03 to 3.0% [v/v] in air) decreased CO(2) efflux by detached seeds either exposed to the light flux equivalent to that transmitted by the pod wall (500 to 600 micro-Einsteins per square meter per second) in full sunlight or held in darkness. Above 1% CO(2) detached seeds made a net gain of CO(2) in the light (up to 0.4 milligrams of CO(2) fixed per gram fresh weight per hour) but (14)CO(2) injected into the gas space of intact fruits (containing around 1.5% CO(2) naturally) was fixed mainly by the pod and little by the seeds.Throughout development seeds contained ribulose-1,5-bisphosphate carboxylase activity (EC 4.1.1.39), especially in the embryo (up to 99 micromoles of CO(2) fixed per gram fresh weight per hour) and phosphoenolpyruvate carboxylase (EC 4.1.1.31) in both testa (up to 280 micromoles of CO(2) fixed per gram fresh weight per hour) and embryo (up to 355 micromoles of CO(2) fixed per gram fresh weight per hour).In kinetic experiments the most significant early formed product of (14)CO(2) fixation in both light and dark was malate but in the light phosphoglyceric acid and sugar phosphates were also rapidly labeled. (14)CO(2) fixation in the light was linked to the synthesis of sugars and amino acids but in the dark labeled sugars were not formed.
已研究了 CO2 浓度和光照对从发育中的羽扇豆（ Lupinus albus （L.））果实中分离的种子的净气体交换和 14CO2 固定途径的影响。增加周围大气中的 CO2 浓度（空气中从 0.03 到 3.0％[v/v]）降低了暴露于与豆荚壁透射通量相当的光通量（每平方米每秒 500 到 600 微爱因斯坦）的分离种子的 CO2 排放或处于黑暗中。在 1％CO2 以上，分离的种子在光下获得 CO2 的净增益（每克鲜重每小时高达 0.4 毫克 CO2 固定），但注入完整果实气空间的 14CO2（自然含约 1.5％CO2）主要由豆荚固定，而种子固定的则较少。在整个发育过程中，种子都含有核酮糖-1,5-二磷酸羧化酶活性（EC 4.1.1.39），尤其是在胚胎中（每克鲜重每小时高达 99 微摩尔 CO2 固定）和磷酸烯醇丙酮酸羧化酶（EC 4.1.1.31）在种皮（每克鲜重每小时高达 280 微摩尔 CO2 固定）和胚胎（每克鲜重每小时高达 355 微摩尔 CO2 固定）中。在动力学实验中，在光照和黑暗条件下 14CO2 固定的最早形成产物都是苹果酸，但在光照条件下，磷酸甘油酸和糖磷酸也迅速标记。在光照下的 14CO2 固定与糖和氨基酸的合成有关，但在黑暗下未形成标记的糖。
