Ding Xiaodong;Fu Li;Liu Chenjia;Chen Fanjun;Hoffland Ellis;Shen Jianbo;Zhang Fusuo;Feng Gu
期刊论文
10.1007/s11104-011-0783-1
SCI
Plant and Soil
9
349#1-2
2011//
13#24
13#24
To test the hypothesis that rhizosphere acidification would enhance the hydrolyzation of organic phosphates by increasing phosphatase activity. A Petri dish experiment with sterile agar and a pot experiment with a low P soil were used. In the Petri dish experiment, roots of each plant were cultured in two compartments, each of which contained agar with one of three nitrogen combinations: NH (4) (+) /N0 (N0 = nitrogen free), NH (4) (+) /NO (3) (-) , and NO (3) (-) /N0. Phytin was supplied as the sole phosphorus (P) source to all compartments. In the pot experiment, the soil in each pot was treated with N0, KNO(3), or (NH(4))(2)SO(4)) together with 0 or 75 mg kg(-1) phytin-P. Dry weight, P concentration, and P content of roots were highest in the NH (4) (+) compartments in the Petri dish experiment. In the pot experiment, dry weight, P concentration, and P content of both shoots and roots were higher with NH (4) (+) than with NO (3) (-) . NH (4) (+) treatments reduced rhizosphere pH, promoted the hydrolization of phytin, enhanced acid phosphatase activity in the rhizosphere, and increased phytin-P utilization relative to N0 and NO (3) (-) treatments. Phosphatase activity was negatively correlated with rhizosphere pH but was positively correlated with plant P content in both experiments. Rhizosphere acidification optimized the activity of acid phosphatase excreted by maize roots and promoted phytin mineralization. NH (4) (+) -induced acidification in the maize rhizosphere improved the growth of maize roots by improving P uptake from phytin; the improved growth, in turn, increased NH (4) (+) uptake and acidification.
Acidification; Rhizosphere; Organic phosphate; Acid phosphatases; Zea mays L.
作物高效利用养分资源的根际调控机理