Balaguer Luis, Valladares Fernando, Ascaso Carmen, Barnes Jeremy D, DE Los Rios Asuncion, Manrique Esteban, Smith Elizabeth C
Departamento de Biologia Vegetal I, Facultad de Biologia, Universidad Complutense, E-28040, Madrid, Spain.
Centro de Ciencias Medioambientales (CSIC), Serrano 115 dup. E-28006, Madrid, Spain.
New Phytol. 1996 Apr;132(4):641-652. doi: 10.1111/j.1469-8137.1996.tb01882.x.
Pormelia sulcata Taylor was used as a model to examine the effects of elevated CO and/or O on green algal lichens. Thalli were exposed for 30 d in duplicate controlled-environment chambers to two atmospheric concentrations of CO ('ambient' [350μmol mol ] and 'elevated' [700μmol mol ] 24 h d ) and two O regimes ('non-polluted' air [CF, < 5 nmol mol ] and 'polluted' air [15 nmol mol overnight rising to a midday maximum of 75 nmol mol ]), in a factorial design. Elevated CO , or elevated O depressed the light saturated rate of CO , assimilation A ) measured at ambient CO , by 30% and 18%, respectively. However, despite this effect ultrastructure) studies revealed increased lipid storage in cells of the photobiont in response to CO -enrichment. Simultaneous exposure to elevated O reduced CO -induced lipid accumulation and reduced A in an additive manner. Gold-antibody labelling revealed that the decline in photosynthetic capacity induced by elevated CO and/or O was accompanied by a parallel decrease in the concentration of Rubiscoa in the algal pyrenoid (r= 0.93). Interestingly, differences in the amount of Rubisco protein were not correlated with changes in pyrenoid volume. Measurements of in vivo chlorophyll-fluorescence induction kinetics showed that the decline in A induced by elevated CO , and/or O , was not associated with significant changes in the photochemical efficiency of photosystem (PS) II. Although the experimental conditions inevitably imposed some stress on the thalli, revealed as a significant decline in the efficiency of PS II photochemistry, and enhanced starch accumulation in the photobiont over the fornication period, the study shows that the green-algal lichen symbiosis might be influenced by future changes in atmospheric composition. Photosynthetic capacity, measured at ambient CO , was found to be reduced after a controlled 30 d exposure to elevated CO , and/or O and this effect was associated with a parallel decline in the amount of Rubisco in the pyrenoid of algal chloroplasts.
沟状梅衣（Pormelia sulcata Taylor）被用作模型，以研究二氧化碳（CO）浓度升高和/或臭氧（O）对绿藻地衣的影响。藻体在重复的可控环境培养箱中暴露30天，采用析因设计，设置两种大气CO浓度（“环境浓度”[350μmol/mol]和“升高浓度”[700μmol/mol]，每天24小时）以及两种O处理方式（“无污染”空气[CF，<5 nmol/mol]和“污染”空气[夜间15 nmol/mol，中午最高升至75 nmol/mol]）。CO浓度升高或O浓度升高分别使在环境CO浓度下测得的CO同化光饱和速率（A）降低了30%和18%。然而，尽管有这种影响，超微结构研究表明，响应于CO富集，共生藻细胞中的脂质储存增加。同时暴露于升高的O会以累加方式减少CO诱导的脂质积累并降低A。金抗体标记显示，CO浓度升高和/或O浓度升高引起的光合能力下降伴随着藻类蛋白核中核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）浓度的平行下降（r = 0.93）。有趣的是，Rubisco蛋白量的差异与蛋白核体积的变化无关。体内叶绿素荧光诱导动力学测量表明，CO浓度升高和/或O浓度升高引起的A下降与光系统（PS）II的光化学效率的显著变化无关。尽管实验条件不可避免地对藻体施加了一些压力，表现为PS II光化学效率的显著下降以及在暴露期间共生藻中淀粉积累增加，但该研究表明，绿藻地衣共生可能会受到未来大气成分变化的影响。发现在可控的30天暴露于升高的CO和/或O后，在环境CO浓度下测得的光合能力降低，并且这种影响与藻类叶绿体蛋白核中Rubisco量的平行下降有关。
