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.
- P acquisition
- P solubilization