A solution culture experiment was conducted to investigate the growth, the accumulation and translocation of Zn, and the metabolic changes of 24 days old plants of corn and wheat with the varied supply of phosphorus (...A solution culture experiment was conducted to investigate the growth, the accumulation and translocation of Zn, and the metabolic changes of 24 days old plants of corn and wheat with the varied supply of phosphorus (0, 0.12, 0.6 and 3.0 mmol L-1 ) and zinc (0.1 and 2.0 μmol L-1 ) under controlled environmental conditions. The results showed the highest dry matter production of both corn and wheat under the moderate combination of phosphorus (0.6 mmol L-1 ) and zinc (2.0 μmol L-1 ) as compared with other imbalance applications of phosphorus and zinc. Excessive P supply significantly inhibited the translocation of Zn from roots of corn to the aboveground part, thus decreasing the content of Zn in the shoots. Application of 3.0 mmol L-1 P could also reduce the water-soluble Zn in plant tissues, leading to an increase in the cell plasma membrane permeability, a decrease in the dehydrogenase activity in roots and the activity of nitrate reductase in leaves, and a decline in the uptake of nitrate by plants. A similar decrease occurred in superoxide dismutase (SOD) and plasma membrane adenosine triphosphatase (ATPase) activity in Zn-deficient plants.But, with increasing P supply, the activity of ATPase in both corn and wheat increased and reached the maximum at the p-supplying level of 3.0 mmol L-1. Similar to the effect of high P supply, no or low P (0.12 mmol L-1 ) supply could be detrimental to dry matter production and physiological functioning of the plants. Corn plants showed a more significant response to the imbalance supply of P and Zn than wheat plants. The possible physiological and biochemical mechanism of phosphorus-zinc antagonistic interaction in corn and wheat might be attributed to decrease in physiological availability and activation of Zn.展开更多
文摘A solution culture experiment was conducted to investigate the growth, the accumulation and translocation of Zn, and the metabolic changes of 24 days old plants of corn and wheat with the varied supply of phosphorus (0, 0.12, 0.6 and 3.0 mmol L-1 ) and zinc (0.1 and 2.0 μmol L-1 ) under controlled environmental conditions. The results showed the highest dry matter production of both corn and wheat under the moderate combination of phosphorus (0.6 mmol L-1 ) and zinc (2.0 μmol L-1 ) as compared with other imbalance applications of phosphorus and zinc. Excessive P supply significantly inhibited the translocation of Zn from roots of corn to the aboveground part, thus decreasing the content of Zn in the shoots. Application of 3.0 mmol L-1 P could also reduce the water-soluble Zn in plant tissues, leading to an increase in the cell plasma membrane permeability, a decrease in the dehydrogenase activity in roots and the activity of nitrate reductase in leaves, and a decline in the uptake of nitrate by plants. A similar decrease occurred in superoxide dismutase (SOD) and plasma membrane adenosine triphosphatase (ATPase) activity in Zn-deficient plants.But, with increasing P supply, the activity of ATPase in both corn and wheat increased and reached the maximum at the p-supplying level of 3.0 mmol L-1. Similar to the effect of high P supply, no or low P (0.12 mmol L-1 ) supply could be detrimental to dry matter production and physiological functioning of the plants. Corn plants showed a more significant response to the imbalance supply of P and Zn than wheat plants. The possible physiological and biochemical mechanism of phosphorus-zinc antagonistic interaction in corn and wheat might be attributed to decrease in physiological availability and activation of Zn.
