TY - JOUR

T1 - Influx and efflux of organic acids across the soil-root interface of Zea mays L. and its implications in rhizosphere C flow

AU - Jones, Davey L.

AU - Darrah, P.R.

PY - 1995/6

Y1 - 1995/6

N2 - The influx and efflux of organic acids across the root-soil interface were investigated in intact, sterile maize (Zea mays L.) roots under a variety of experimental conditions. Under nutrient-sufficient conditions the efflux of organic acids was shown to constitute < 1% of the total C lost across the root-soil interface. Under severe nutrient stress, however, the rates of malate and citrate efflux from the root increased 33 and 12 fold respectively. Influx experiments indicated that roots could not directly reabsorb citrate-Fe3+ or other metal complexes from solution. Influx of citrate was observed only at high external citrate concentration (≥ 1 mM) or from solutions with low ionic strengths. It was postulated that citrate influx is of little importance in a soil environment.

AB - The influx and efflux of organic acids across the root-soil interface were investigated in intact, sterile maize (Zea mays L.) roots under a variety of experimental conditions. Under nutrient-sufficient conditions the efflux of organic acids was shown to constitute < 1% of the total C lost across the root-soil interface. Under severe nutrient stress, however, the rates of malate and citrate efflux from the root increased 33 and 12 fold respectively. Influx experiments indicated that roots could not directly reabsorb citrate-Fe3+ or other metal complexes from solution. Influx of citrate was observed only at high external citrate concentration (≥ 1 mM) or from solutions with low ionic strengths. It was postulated that citrate influx is of little importance in a soil environment.

KW - MAIZE

KW - ORGANIC ACIDS

KW - RHIZOSPHERE

KW - ROOT

U2 - 10.1007/BF00155523

DO - 10.1007/BF00155523

M3 - Article

VL - 173

SP - 103

EP - 109

JO - Plant and Soil

JF - Plant and Soil

SN - 0032-079X

IS - 1

ER -