CO_(2)升高和增温没有稀释椴树叶片氮浓度却降低了叶片的光合能力  

The combination of elevated CO_(2)and warmer temperature reduces photosynthetic capacity without diluting leaf N concentration in Amur linden(Tilia amurensis)

作　　者：Lei Wang Jinping Zheng Gerong Wang Qing-Lai Dang 

机构地区：[1]Department of Landscape Architechture,Jiyang College of Zhejiang A&F University,Zhuji 311800,China [2]Faculty of Natural Resources Management,Lakehead University,Thunder Bay,ON P7B 5E1,Canada [3]Department of Forestry,Forestry College,Beihua University,Jilin 132013,China

出　　处：《Journal of Plant Ecology》2024年第3期39-48,共10页植物生态学报（英文版）

基　　金：the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery grant to Q.-L.Dang(Project No.DDG-2020-00008);Zhejiang A&U University Jiyang College Talent Initiation Project to Lei Wang(RC2023B06).

摘　　要：深入理解CO_(2)升高和全球变暖对植物的影响是预测植物适应性的关键。本研究以温带阔叶耐荫树种椴树(Tilia amurensis)幼苗为试验材料,研究了当前CO_(2)浓度和气温组合处理(CC)与预测的未来气候条件下CO_(2)升高和增温组合处理(FC)对植物光合驯化的影响模式。结果发现,FC处理促进了椴树地上部分的生长,降低了叶片的光合能力(最大羧化速率和最大电子传递速率),也降低了椴树光合作用生化限制中从羧化限制向电子传递限制过渡点的光合速率。FC处理没有改变叶片氮浓度,但是提高了单株叶片的含氮量和光合氮素利用效率。这些结果表明,在椴树适应未来气候条件中发挥重要的作用的可能是叶片的氮素利用效率,而非其光合能力。本研究为理解椴树的光合驯化特征提供了新的见解,研究结果也可以用于预测椴树在未来气候条件下可能的表现。Elevated CO_(2)and warmer temperatures represent the future environmental conditions in the context of global change.A good understanding of plant response to their combined effects is,therefore,critically important for predicting future plant performance.This study investigated the photosynthetic acclimation of Amur linden(Tilia amurensis)seedlings(current year,about 60 cm tall),a shade-tolerant tree species in the temperate broadleaf deciduous forest,to the combination of current CO_(2)concentration and temperature(CC)and the combination of the predicted future CO_(2)concentration and temperature(FC).The results show that FC promoted aboveground growth,but reduced photosynthetic capacity(Vcmax:maximum rate of RuBP carboxylation and J max:maximum photosynthetic electron transport rate).However,the photosynthetic rate measured under the corresponding growth CO_(2)concentration was still higher under FC than under CC.FC depressed the photosynthetic limiting transition point(Ci-t,An-t)from Rubisco carboxylation to RuBP regeneration,i.e.An-t decreased without a change in Ci-t.FC did not change leaf N concentration but increased the total leaf N content per tree and photosynthetic nitrogen utilization effciency.This suggests that N utilization,rather than photosynthetic capacity,may play an important role in the acclimation of the species to future climatic conditions.This study provides new insights into the photosynthetic acclimation of Amur linden and can be used to predict its possible performance under future climatic conditions.

关 键 词：椴树(Tilia amurensis) 光合驯化 CO_(2) 升高和增温 温带阔叶树 氮素浓度 

分 类 号：Q94[生物学—植物学]