Journal article Open Access

A mechanistic molecular test of the plant-sanction hypothesis in legume–rhizobia mutualism

Marco, Diana E.; Pérez-Arnedo, Rebeca; Hidalgo-Perea, Ángeles; Olivares, José; Ruiz-Sainz, José E.; Sanjuán, Juan

The origin and persistence of mutualism is difficult to explain because of the widespread occurrence of exploitative, 'cheating' partners. As a policing strategy stabilising intraspecific cooperation, host sanctions against non-N2 fixing, cheating symbionts have been proposed to stabilise mutualism in legumerhizobium symbiosis. Mechanism of penalisations would include decreased nodular rhizobial viability and/or early nodule senescence. We tested these potential mechanisms of penalisations in split-root experiments using two soybean varieties and two rhizobial strains, a cooperative, normal N2-fixing strain and an isogenic non-fixing derivative. We found no differences in the number of viable rhizobia recovered from nodules and no differential expression of a nodular senescence molecular marker. Thus, our results do not support the hypothesis of plant sanctions acting against cheating rhizobia in our experimental conditions.

Files (402.0 kB)
Name Size
402.0 kB Download
Views 221
Downloads 60
Data volume 24.1 MB
Unique views 218
Unique downloads 60


Cite as