摘要
电子传递速率光响应模型是研究植物光合生理和生态学的重要工具,可为量化原初反应光能的吸收和传递对光的响应提供理论依据。该文综述了目前常用的电子传递速率光响应模型的数学特征,分析了不同模型的优势及其在实际应用中的潜在问题,并在此基础上对这些模型可能的发展趋势进行了展望。原初反应包括光能的吸收、光合色素分子的激发和退激发(包括光化学反应、荧光发射和热耗散)、激子共振传递以及光系统Ⅱ(PSⅡ)反应中心发生电荷分离产生电子传递速率等一系列复杂的物理和生化反应过程。电子传递速率光响应经验模型和半机理模型因不涉及或只涉及部分原初反应过程而难以解释藻类和高等植物的PSⅡ动力学下调、光适应和光保护等现象。电子传递速率光响应机理模型综合考虑了光合色素分子的物理参数(如本征光能吸收截面(σ_(ik))、分子处于最低激发态的平均寿命(τ_(min))、分子的能级简并度和处于激发态的光合色素分子数(Nk))在整个原初反应过程中的重要作用,不仅可以获得藻类和高等植物叶片的最大电子传递速率以及对应的饱和光强等光合参数,还可以获得σ_(ik)和τ_(min)等重要的物理参数,以及有效光能吸收截面(σ′_(ik))和N_(k)对光的响应规律等。将环境因子(如温度、CO_(2)浓度等)耦合到已有的电子传递速率光响应机理模型中,并明确其与植物的σ′_(ik)和N_(k)等参数间的关系,可能是今后光合电子传递速率光响应机理模型的发展方向。
The light response curve of electron transport rate is an important tool to investigate plant physiology and ecology.It can provide a theoretical basis for quantifying the absorption and transmission of light energy in primary reaction.In this paper,the mathematical characteristics,the advantages,and the potential weaknesses in practical application and research trends of the light response models of electron transport rate are reviewed and discussed.The primary reaction,which includes absorption of light energy,excitation and de-excitation of photosynthetic pigment molecules(including photochemical reaction,fluorescence emission and heat dissipation),and electron transport rate stemming from charge separation in the photosystem Ⅱ(PSⅡ)reaction center caused by exciton resonance,is consisted by a series of complex physical and biochemical reactions.The classical and semi-mechanistic models of light response curve of electron transport rate are difficult to explain the dynamic down-regulation of PSII,light adaptation and light protection of algae and higher plant,because they did not involve or only partly involved the primary reaction process.However,the mechanism model takes into account the important role of the physical parameters of the photosynthetic pigment molecule(e.g.,the eign-absorption cross-section of light energy(σ_(ik)),the average life-time of the molecule in the lowest excited state(τ_(min)),the energy level degeneracy of the molecule and the number of photosynthetic pigment molecules in the excited state(N_(k)))in the whole primary reaction process.This model can not only obtain the maximum electron transfer rate and its corresponding saturation light intensity of algae and higher plant,but also get some important physical parameters such asσik andτmin.Meanwhile,it also can obtain the laws about light-response of the effective light energy absorption cross-section(σ′_(ik))and of Nk.It may be the developmental direction of the mechanism model of electron transport rate response to light
作者
王复标
叶子飘
WANG Fu-Biao;YE Zi-Piao(The Institute of Biophysics,College of Math and Physics,Jinggangshan University,Ji’an,Jiangxi 343009,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2024年第3期287-305,共19页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(31960054和32260063)。
关键词
电子传递速率
原初反应
经验模型
半机理模型
机理模型
electron transport rate
primary reaction
classical model
semi-mechanistic model
mechanistic model
