Pao Yi-Chen, Chen Tsu-Wei, Moualeu-Ngangue Dany Pascal, Stützel Hartmut
Institute of Horticultural Production Systems, Leibniz Universität Hannover, Hannover, Germany.
Bio Protoc. 2020 Mar 20;10(6):e3556. doi: 10.21769/BioProtoc.3556.
Acclimation of leaf traits to fluctuating environments is a key mechanism to maximize fitness. One of the most important strategies in acclimation to changing light is to maintain efficient utilization of nitrogen in the photosynthetic apparatus by continuous modifications of between-leaf distribution along the canopy depth and within-leaf partitioning between photosynthetic functions according to local light availability. Between-leaf nitrogen distribution has been intensively studied over the last three decades, where proportional coordination between nitrogen concentration and light gradient was considered optimal in terms of maximizing canopy photosynthesis, without taking other canopy structural and physiological factors into account. We proposed a mechanistic model of protein turnover dynamics in different photosynthetic functions, which can be parameterized using leaves grown under different levels of constant light. By integrating this dynamic model into a multi-layer canopy model, constructed using data collected from a greenhouse experiment, it allowed us to test the degree of optimality in photosynthetic nitrogen use for maximizing canopy carbon assimilation under given light environments.
叶片性状对波动环境的适应性是使适合度最大化的关键机制。适应光照变化的最重要策略之一是通过沿冠层深度持续调整叶片间分布以及根据局部光照可利用性在叶片内光合功能间进行分配，来维持光合器官中氮的高效利用。在过去三十年中，对叶片间氮分布进行了深入研究，其中在不考虑其他冠层结构和生理因素的情况下，氮浓度与光照梯度之间的比例协调被认为在使冠层光合作用最大化方面是最优的。我们提出了一个不同光合功能中蛋白质周转动态的机理模型，该模型可以使用在不同恒定光照水平下生长的叶片进行参数化。通过将这个动态模型整合到一个多层冠层模型中（该多层冠层模型是使用从温室实验收集的数据构建的），这使我们能够测试在给定光照环境下使冠层碳同化最大化的光合氮利用的最优程度。
