A 31P nuclear magnetic resonance study of phosphate levels in roots of ectomycorrhizal and nonmycorrhizal plants of Castanea sativa Mill.

TLDR: The level of orthophosphate in mycorrhizal roots was significantly lower than in nonmycorrhIZal ones, which indicates that this system relies upon the fungal polyphosphates as a major source of phosphate.

Abstract: 31P-Nuclear Magnetic Resonance (NMR) was used to assess phosphate distribution in ectomycorrhizal and nonmycorrhizal roots of Castanea sativa Mill. as well as in the mycorrhizal fungus Pisolithus tinctorius in order to gain insight into phosphate trafficking in these systems. The fungus P. tinctorius accumulated high levels of polyphosphates during the rapid phase of growth. Mycorrhizal and nonmycorrhizal roots accumulate orthophosphate. Only mycorrhizal roots presented polyphosphates. The content in polyphosphates increased along the 3 months of mycorrhiza formation. In mycorrhizal roots of plants cultured under axenic conditions, the orthophosphate pool decreased along the culture time. In nonmycorrhizal roots the decrease in the orthophosphate content was less pronounced. The level of orthophosphate in mycorrhizal roots was significantly lower than in nonmycorrhizal ones, which indicates that this system relies upon the fungal polyphosphates as a major source of phosphate.

Figures

Fig. 2 31P-NMR spectra of control (A) and mycorrhizal (B) chestnut roots at different mycorrhization times: (a) 3 weeks after mycorrhizal induction; (b) 1 month after mycorrhizal induction; (c) 3 months after mycorrhizal induction. Pi, intracellular orthophosphate; polyP, polyphosphates&/fig.c:

Fig. 1 31P-NMR spectra of the fungus Pisolithus tinctoriusgrown in axenic conditions with different ages: (a) 7 days, (b) 15 days and (c) 1.5 months. Pi, intracellular orthophosphate; tP, terminal phosphate; UDP-Hexose, uridine diphosphate hexose; PP, penultimate phosphate; polyP, polyphosphates&/fig.c:

Frequently asked questions

Q1. What are the contributions in this paper?

Martins et al. this paper found that mycorrhizal and nonmycizal roots accumulate orthophosphate, which indicates that this system relies upon the fungal polyphosphates as a major source of phosphate.