国家重点基础研究发展计划(2010CB951303); 中国科学院战略性先导科技专项(XDA05050408); 国家自然科学基金(90711001, 40971123)资助
State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Chinese Academy of Meteorological Sciences
Leaf maximum carboxylation rate represents plant photosynthetic capacity and is a key parameter of photosynthetic model, thus plays a key role in accurately evaluating terrestrial ecosystem productivity and carbon budget. This paper is intended to review the researches on the measurement methods, environmental controls and models of leaf maximum carboxylation rate. The present studies indicated that leaf maximum carboxylation rate depends on both abiotic and biotic factors. The stomatal conductance (gs) of plant varies with light intensities, and light intensity can regulate the content of related enzymes, such as Rubisco, Rubisco activase, etc. Temperature controls the activity of carboxylation enzymes, therefore leaf maximum carboxylation rate increases with temperature. The change of water status would affect stomatal conductance, mesophyll conductance (gm) and the synthesis of Rubisco, as a result, leaf maximum carboxylation rate would decline immediately once suffered water stress. Atmospheric CO2 content directly limits the substrate concentration of carboxylation reaction, and it is crucial in determining leaf maximum carboxylation rate. Soil nutrient availability would influence leaf maximum carboxylation rate by altering leaf area, the synthesis of related enzymes, photosynthetic quantum efficiency, etc. Other environmental factors, such as UV-B, O3 and human activities, can also influence leaf maximum carboxylation rate by regulating stomatal movement, leaf nitrogen distribution, or the root to shoot ratio. Furthermore, biotic factors including leaf age, leaf position, and internal structure of leaves, would also affect leaf maximum carboxylation rate. Usually, fully expanded leaves have the highest photosynthetic capacity, and then leaf maximum carboxylation rate declines with leaf age. The thicker and larger the leaf is, the higher the leaf maximum carboxylation rate is. Leaves grown at different position of a branch have different maximum carboxylation rate because of different leaf age, like green leaves have higher maximum carboxylation rate than red leaves. Based on present study, we conclude that the research on the relationship between plant maximum carboxylation rate and environmental factors still focused on the effect of single environmental factor, the relationship between leaf maximum carboxylation rate and single environmental factor is not enough to describe the variation of leaf maximum carboxylation rate with environmental change. Thus, in order to simulate terrestrial ecosystem productivity accurately, it is urgent to develop the relationship between leaf maximum carboxylation rate and interactive biological and mutiple environmental factors. To reveal the relationship between leaf maximum carboxylation rate and its controls, the following three tasks should be emphasized in the future: (1) Biological and environmental control mechanisms of leaf maximum carboxylation rate; (2) Quantifying the effects of interactive biological and environmental factors on plant maximum carboxylation rate and scaling up; (3) Study on environmental factor threshold of leaf maximum carboxylation rate.