• light-harvesting complex of photosystem II (LHCII);
  • low-temperature (77 K) chlorophyll fluorescence;
  • net photosynthetic rate;
  • photosystem II (PSII);
  • PSII electron transport;
  • reversible dissociation


  • • 
    Plants often regulate the amount and size of light-harvesting antenna (LHCII) to maximize photosynthesis at low light and avoid photodamage at high light.
  • • 
    Gas exchange, 77 K chlorophyll fluorescence, photosystem II (PSII) electron transport as well as LHCII protein were measured in leaves irradiated at different light intensities.
  • • 
    After irradiance transition from saturating to limiting one leaf photosynthetic rate in some species such as soybean and rice declined first to a low level, then increased slowly to a stable value (V pattern), while in other species such as wheat and pumpkin it dropped immediately to a stable value (L pattern). Saturating pre-irradiation led to significant declines of both 77 K fluorescence parameter F685/F735 and light-limited PSII electron transport rate in soybean but not in wheat leaves, indicating that some LHCIIs dissociate from PSII in soybean but not in wheat leaves.
  • • 
    The L pattern of LHCII-decreased rice mutant and the V pattern of its wild type demonstrate that the V pattern is linked to dissociation/reassociation of some LHCIIs from/to PSII.