Record ID No. |
4308 |
Author(s) |
Facelli E., Duan T., Smith, S.E., Christophersen H.M., Facelli, J.M., Smith F.A. , 2014 |
Affiliation |
School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA, 5005, Australia, Email: evelina.facelli@adelaide.edu.au |
Title |
Opening the black box: Outcomes of interactions between arbuscular mycorrhizal (AM) and non-host genotypes of Medicago depend on fungal identity, interplay between P uptake pathways and external P supply |
Source. Vol.(no):Page |
Plant, Cell and Environment 37(6): 1382-1392p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Physiology |
Host |
Medicago truncatula |
Organism |
Rhizophagus irregularis or (Glomus intraradices) or Gigaspora margarita |
Country |
Australia |
Abstracts |
We investigated the physiology that underlies the influence of arbuscular mycorrhizal (AM) colonization on outcomes of interactions between plants. We grew Medicago truncatula A17 and its AM-defective mutant dmi1 in intragenotypic (two plants per pot of the same genotype, x2) or intergenotypic (one plant of each genotype, 1 + 1) combinations, inoculated or not with Rhizophagus irregularis (formerly Glomus intraradices) or Gigaspora margarita. We measured plant growth, colonization, contributions of AM and direct P uptake pathways using 32P, and expression of plant Pi transporter genes at two levels of P supply. A17 (x2) responded positively to inoculation only at low P. The response was enhanced with 1 + 1 even at high P where colonization in A17 was reduced. With R. irregularis P uptake by the AM pathway was unaffected by P supply, whereas with G. margarita, the AM pathway was lower at high P, and direct uptake higher. Gene expression varied and was unrelated to P uptake through the two pathways. There was no evidence of plant control of P uptake via R. irregularis at high P but there was via G. margarita. Importantly, growth responses of plant genotypes grown alone did not predict outcomes of intergenotypic interactions. |