Effects of bisphenol A on growth, photosynthesis and chlorophyll fluorescence in above-ground organs of soybean seedlings.

Bisphenol A (BPA) is a representatively endocrine disruptor, which shows a highly toxic effect on life system. Its potential toxicity on plants that are the primary producers in earth's ecosystem is not well documented. Here, the effects of BPA on the growth, photosynthesis, content of chlorophyll (Chl), initial fluorescence (F(0)), maximal photochemical efficiency (F(v)/F(m)), effective quantum yield of photosystem II (Φ(PSII)) and photosynthetic electron transport rate (ETR) in soybean seedlings were investigated by using gas exchange measurement system and chlorophyll fluorometer to understand the toxic effect of BPA on plants. It was found that when soybean seedlings were treated with BPA at the low concentration (1.5 mg L(-1)), the growth indices (the plant height, fresh and dry weights of stems, fresh and dry weights of leaves, leaf area) were increased obviously compared with those of the control, which was not related with the photosynthesis, the content of Chl and the chlorophyll fluorescence. When soybean seedlings were treated with BPA at the high concentrations (7.0, 12.0, 17.2 and 50.0 mg L(-1)), the growth indices, net photosynthetic rate, the content of chlorophyll, F(v)/F(m), Φ(PSII), ETR were decreased, while F(0) was increased, compared with those of the control. Obviously, BPA at the high concentrations showed the toxic effect on soybean seedlings. The results from correlation analysis indicated that the inhibition in the growth of soybean seedlings treated with BPA was related to the decrease in photosynthesis because of the decrease in the content of chlorophyll and the change in chlorophyll fluorescence.