Role of cell wall of groundnut roots in solubilizing sparingly soluble phosphorus in soil

Groundnut showed a superior ability to take up P from a soil with low P fertility compared with sorghum and soybean. This ability was not related to its better root development or production of root exudates capable of solubilizing iron-and aluminum-bound P. In efforts to determine the role of roots per se, we found that root cell walls from groundnut showed a higher P-solubilizing activity than those from soybean or sorghum. This finding corresponds well with observations in field and pot experiments using a soil with low P availability. The reaction site of P-solubilizing activity is stable against heating and enzyme digestion by cellulase and pectinase. This is probably the first evidence to demonstrate that cell walls of plant roots are involved in P-solubilizing activity. ei]Section editor: H Marschner (deceased 21 September 1996)