Abstract：
The coordinated interspecific variation in leaf traits and leaf lifespan is known as the leaf economic spectrum (LES). The limitation of CO2 diffusion to chloroplasts within the lamina is significant in C3 photosynthesis, resulting in a shortage of CO2 for Rubisco. Although Rubisco CO2/O2 specificity (SC/O) should be adaptively adjusted in response to the interspecific variation in CO2 concentrations [CO2] associated with Rubisco, SC/O variations across species along the LES remain unknown. We investigated the coordination among leaf traits, including SC/O, CO2 conductance, leaf protein content, and leaf mass area, across 23 woody C3 species coexisting on an oceanic island through phylogenetic correlation analyses. A high SC/O indicates a high CO2 specificity of Rubisco. SC/O was negatively correlated with [CO2] at Rubisco and total CO2 conductance within lamina, while it was positively correlated with leaf protein across species, regardless of phylogenetic constraint. A simulation analysis shows that the optimal SC/O for maximizing photosynthesis depends on both [CO2] at Rubisco sites and leaf protein per unit leaf area. SC/O is a key parameter along the LES axis and is crucial for maximizing photosynthesis across species and the adaptation of woody plants.
摘要：
叶片性状和叶片寿命的协调种间变异被称为叶片经济谱（LES）。在C3光合作用中，CO2扩散到叶片内叶绿体的限制是显着的，导致Rubisco的二氧化碳短缺。尽管RubiscoCO2/O2特异性（SC/O）应自适应地调整以响应与Rubisco相关的CO2浓度[CO2]的种间变化，沿LES的物种之间的SC/O变化仍然未知。我们调查了叶片性状之间的协调，包括SC/O，CO2电导率,叶片蛋白质含量，和叶质量面积，通过系统发育相关分析，跨越23个木质C3物种共存于一个海洋岛屿上。高SC/0表示Rubisco的高CO2特异性。SC/O与Rubisco的[CO2]和叶片内的总CO2电导呈负相关，虽然它与不同物种的叶片蛋白呈正相关，无论系统发育约束如何。模拟分析表明，最大化光合作用的最佳SC/O取决于Rubisco位点的[CO2]和每单位叶面积的叶蛋白。SC/O是沿LES轴的关键参数，对于最大化跨物种的光合作用和木本植物的适应性至关重要。
