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Interdependency of efficient nodulation and arbuscular mycorrhization in Piptadenia gonoacantha, a Brazilian legume tree
Author(s) -
Bournaud Caroline,
James Euan K.,
Faria Sergio M.,
Lebrun Michel,
Melkonian Rémy,
Duponnois Robin,
Tisseyre Pierre,
Moulin Lionel,
Prin Yves
Publication year - 2018
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.13095
Subject(s) - biology , rhizobia , symbiosis , caesalpinioideae , root nodule , botany , legume , arbuscular mycorrhizal fungi , frankia , fabaceae , inoculation , horticulture , bacteria , genetics
Tripartite interactions between legumes and their root symbionts (rhizobia and arbuscular mycorrhizal fungi, AMF) are poorly understood, although it is well established that only specific combinations of symbionts lead to optimal plant growth. A classic example in which to investigate such interactions is the Brazilian legume tree Piptadenia gonoacantha (Caesalpinioideae), for which efficient nodulation has been described as dependent on the presence of AMF symbiosis. In this study, we compared the nodulation behaviour of several rhizobial strains with or without AMF inoculation, and performed analyses on nodulation, nodule cytology, N‐fixing efficiency, and plant growth response. Nodulation of P. gonoacantha does not rely on the presence of AMF, but mycorrhization was rhizobial strain‐dependent, and nodule effectiveness and plant growth were dependent on the presence of specific combinations of rhizobial strains and AMF. The co‐occurrence of both symbionts within efficient nodules and the differentiation of bacteroids within nodule cells were also demonstrated. Novel close interactions and interdependency for the establishment and/or functioning of these symbioses were also revealed in Piptadenia , thanks to immunocytochemical analyses. These data are discussed in terms of the evolutionary position of the newly circumscribed mimosoid clade within the Caesalpinioid subfamily and its relative proximity to non‐nodulated (but AMF‐associated) basal subfamilies.