Soil Cu contamination destroys the photosynthetic systems and hampers the growth of green vegetables

Abstract

Soil metal contamination leads to a decrease in a yield of crops and is a threat to human health. In the present study, the properties (i.e., photosynthetic pigments, gas-exchange parameters, chlorophyll fluorescence, biomass, leaf area, leaf mass per area) of three green vegetables (i.e., Brassica chinensis, Chrysanthemum coronarium, Brassica alboglabra) grown under various Cu treatments [0, 200, 400, and 600 mg(Cu) kg-1] were measured and analysed. The results showed that soil Cu contamination resulted in the damage of photosynthetic pigments, negative effects on gas exchange, and hampered growth of all three vegetables. However, it did not significantly influence PSII functions of the three vegetables. It indicates that soil Cu contamination negatively affected photosynthesis particularly due to stomatal factors, but not due to the damage of photosynthetic apparatus.