Chin J Plant Ecol ›› 2016, Vol. 40 ›› Issue (11): 1208-1217.DOI: 10.17521/cjpe.2015.0470

• Research Articles • Previous Articles    

Comparison on light-response models of actual photochemical efficiency in photosystem II

Zi-Piao YE1,*(), Wen-Hai HU2, Xiao-Hong YAN2,3   

  1. 1Maths & Physics College, Jinggangshan University, Ji’an, Jiangxi 343009, China;

    2School of Life Sciences, Jinggangshan University, Ji’an, Jiangxi 343009, China;
    3College of Forest Resources and Environment, Nanjing Forestry University, Nanjing 210037, China
  • Received:2015-12-22 Accepted:2016-07-19 Online:2016-11-10 Published:2016-11-25
  • Contact: Zi-Piao YE


Aims The objective of this study was to compare the merits and demerits of three models (i.e., a mechanistic model, a negative exponential model and an exponential model) to simulate the light-response curves of actual photochemical efficiency (ΦPSII-I). Moreover, it was to reveal the mechanism that ΦPSII decreased with light intensity increasing.
Methods The electron transport rate (ETR) and the ΦPSII of Coreopsis lanceolata, Vitex negundo and Bidens frondosa were measured by LI-6400-40B under controlled CO2 concentrations and temperatures, then light-response curves of ETR-I and ΦPSII-I were simulated by a mechanistic model, a negative exponential model and an exponential model, respectively.
Important findings The fitted results showed that ETR-I and ΦPSII-I data of the three plants fit well to the three models. However, the saturation light intensity (PARsat) and maximum efficiency of photosystem II (Fv/Fm) estimated by exponential model for ETR-I and ΦPSII-I were greatly different from the measured data. Moreover, the mechanistic model revealed that the ΦPSII for the three species decreased with increasing I as the effective light energy absorption cross-section of light-harvesting pigments decreased. At the same time, it showed that ΦPSII depended not only on I, but also on eigen-absorption cross-section of light-harvesting pigment, efficiency of exciton, photochemical constant, heat dissipation constant and average lifetime of light-harvesting pigment-protein complex in the lowest state.

Key words: photosystem II, actual photochemical efficiency, electron transport rate, a mechanistic model, light- harvesting pigment-protein complex