Effects of Environmental and Non-Environmental Factors on Dynamic Photosynthetic Carbon Assimilation in Leaves under Changing Light

Abstract

Major research on photosynthesis has been carried out under steady light. However, in the natural environment, steady light is rare, and light intensity is always changing. Changing light affects (usually reduces) photosynthetic carbon assimilation and causes decreases in biomass and yield. Ecologists first observed the importance of changing light for plant growth in the understory; other researchers noticed that changing light in the crop canopy also seriously affects yield. Here, we review the effects of environmental and non-environmental factors on dynamic photosynthetic carbon assimilation under changing light in higher plants. In general, dynamic photosynthesis is more sensitive to environmental and non-environmental factors than steady photosynthesis, and dynamic photosynthesis is more diverse than steady photosynthesis. Finally, we discuss the challenges of photosynthetic research under changing light.

Keywords: changing light; fluctuating light; higher plant; photosynthetic carbon assimilation.

Figure 1

Light intensity and dynamic net photosynthetic carbon assimilation rate (Pn) in leaves of C3 species Triticum aestivum. The A area indicates post-irradiance carbon assimilation; the B area indicates the post-irradiance carbon burst; the C area indicates the loss in photosynthetic carbon assimilation in the photosynthetic induction stage.

Figure 2

The dynamic net photosynthetic carbon assimilation rate (Pn) in leaves of the C3 species Triticum aestivum and the C4 species Zea mays. The relative Pn curve was obtained from the standardization between the Pn under constant high light (100%) and the minimum Pn under constant low light (0%).