Exposure of cucumber plants to low light (25 degrees C/18 degrees C, 100 micromol m(-2) s(-1)) and low temperature (12 degrees C/12 degrees C, 100 micromol m(-2) s(-1); 7 degrees C/7 degrees C, 100 micromol m(-2) s(-1)) resulted in a retardation or complete inhibition of plant growth, decreases in chlorophyll content, net photosynthetic rate, stomatal conductance and photosynthetic electron transport rate, but an increase in intracellular CO(2) concentration. Significant reversible reduction in Fv/Fm was found in plants after chilling at 7, but not in those after chilling at 12 degrees C. Chilling and low light treatment resulted in a decrease in chlorophyll content, followed by a decreased allocation of photons absorbed by PSII antenna to the photosynthetic electron transport and an increased allocation of thermal dissipation and excessive energy. Plant chilled at 12 degrees C showed higher recovery capacity than those chilled at 7 degrees C upon returning to normal conditions.