Effects of rare-earth elements on physiological and biochemical responses of wheat under acid rain stress

The effects of rare-earth elements on physiological and biochemical respons es of wheat under acid rain stress were studied by pot experiments. The res ults showed that the stress of acid rain resulted in the decrease of chloro phyll content and the change of chlorophyll a/b values. Chlorophyll a and c hlorophyll content were positively correlated with the pH value of acid rai n and the peroxidase activity increased gradually with decreasing pH value. The effects led to the increased decomposition of chlorophyll and decrease d content and a/b values of chlorophyll, which reulted in a speed-up blade decay and the defect of absorption and transformation of light energy and m etabolism of carbohydrates. Under lower acidic conditions, the rare-earth e lements can protect wheat from being damaged by acid rain and affect chloro phyll metabolism and peroxidase activity of wheat.