Record ID No. |
4253 |
Author(s) |
Nazeri, N.K. , Lambers, H., Tibbett, M., Ryan, M.H. , 2014 |
Affiliation |
School of Plant Biology and Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia, Email: nazern01@student.uwa.edu.au |
Title |
Moderating mycorrhizas: Arbuscular mycorrhizas modify rhizosphere chemistry and maintain plant phosphorus status within narrow boundaries |
Source. Vol.(no):Page |
Plant, Cell and Environment 37(4): 911-921p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry |
Sub-subjects |
Phosphorus metabolism |
Host |
Kennedia prostrata, Cullen australasicum, Bituminaria bituminosa, Medicago sativa and Trifolium subterraneum |
Organism |
Arbuscular Mycorrhiza (AM) |
Country |
Australia |
Abstracts |
Pastures often experience a pulse of phosphorus (P) when fertilized. We examined the role of arbuscular mycorrhizal fungi (AMF) in the uptake of P from a pulse. Five legumes (Kennedia prostrata, Cullen australasicum, Bituminaria bituminosa, Medicago sativa and Trifolium subterraneum) were grown in a moderate P, sterilized field soil, either with (+AMF) or without (-AMF) addition of unsterilized field soil. After 9-10 weeks, half the pots received 15mg P kg-1 of soil. One week later, we measured: shoot and root dry weights; percentage of root length colonized by AMF; plant P, nitrogen and manganese (Mn) concentrations; and rhizosphere carboxylates, pH and plant-available P. The P pulse raised root P concentration by a similar amount in uncolonized and colonized plants, but shoot P concentration increased by 143% in uncolonized plants and 53% in colonized plants. Inoculation with AMF decreased the amount of rhizosphere carboxylates by 52%, raised rhizosphere pH by ~0.2-0.7 pH units and lowered shoot Mn concentration by 38%. We conclude that AMF are not simply a means for plants to enhance P uptake when P is limiting, but also act to maintain shoot P within narrow boundaries and can affect nutrient uptake through their influence on rhizosphere chemistry. |