Cardoso-Vilhena J, Barnes J
Air Pollution Laboratory, Department of Agricultural and Environmental Science, Ridley Building, The University of Newcastle, Newcastle Upon Tyne NE1 7RU, UK.
J Exp Bot. 2001 Sep;52(362):1901-11. doi: 10.1093/jexbot/52.362.1901.
Spring wheat (Triticum aestivum cv. Hanno) was grown at ambient (350 micromol mol(-1)) or elevated CO(2) (700 micromol mol(-1)) in charcoal/Purafil-filtered air (CFA <5 nmol mol(-1)) or ozone (CFA +75 nmol mol(-1) 7 h d(-1)) at three levels of N supply (1.5, 4 and 14 mM NO(-3)), to test the hypothesis that the combined impacts of elevated CO(2) and O(3) on plant growth and photosynthetic capacity are affected by nitrogen availability. Shifts in foliar N content reflected the level of N supplied, and the growth stimulation induced by elevated CO(2) was dependent on the level of N supply. At 60 d after transfer (DAT), elevated CO(2) was found to increase total biomass by 44%, 29%, 12% in plants supplied with 14, 4 and 1.5 mM NO(-3), respectively, and there was no evidence of photosynthetic acclimation to elevated CO(2) across N treatments; the maximum in vivo rate of Rubisco carboxylation (V(cmax)) was similar in plants raised at elevated and ambient CO(2). At 60 DAT, ozone exposure was found to suppress plant relative growth rate (RGR) and net photosynthesis (A) in plants supplied with 14 and 4 mM NO(-3). However, O(3) had no effect on the RGR of plants supplied with 1.5 mM NO(-3) and this effect was accompanied by a reduced impact of the pollutant on A. Elevated CO(2) counteracted the detrimental effects of O(3) (i.e. the same ozone concentration that depressed RGR and A at ambient CO(2) resulted in no significant effects when plants were raised at elevated CO(2)) at all levels of N supply and the effect was associated with a decline in O(3) uptake at the leaf level.
在三种氮供应水平（1.5、4和14 mM NO₃⁻）下，将春小麦（普通小麦品种汉诺）种植在环境二氧化碳浓度（350 μmol mol⁻¹）或升高的二氧化碳浓度（700 μmol mol⁻¹）、经木炭/ Purafil过滤的空气（CFA＜5 nmol mol⁻¹）或臭氧（CFA +75 nmol mol⁻¹，每天7小时）环境中，以检验升高的二氧化碳和臭氧对植物生长及光合能力的综合影响是否受氮有效性影响这一假设。叶片氮含量的变化反映了所供应的氮水平，且升高的二氧化碳诱导的生长刺激取决于氮供应水平。转移后60天（DAT），发现升高的二氧化碳使分别供应14、4和1.5 mM NO₃⁻的植株总生物量分别增加44%、29%、12%，并且在各氮处理中均未发现光合作用对升高的二氧化碳有适应性；在升高和环境二氧化碳浓度下生长的植株中，核酮糖-1,5-二磷酸羧化酶羧化的最大体内速率（Vcmax）相似。在60 DAT时，发现臭氧暴露抑制了供应14和4 mM NO₃⁻的植株的相对生长速率（RGR）和净光合作用（A）。然而，臭氧对供应1.5 mM NO₃⁻的植株的RGR没有影响，且这种影响伴随着污染物对A的影响降低。在所有氮供应水平下，升高的二氧化碳抵消了臭氧的有害影响（即在环境二氧化碳浓度下降低RGR和A的相同臭氧浓度，当植株在升高的二氧化碳浓度下生长时没有显著影响），且这种影响与叶片水平上臭氧吸收的下降有关。
