Plasticidad fenotípica con respecto a la respuesta al estrés salino por Lotus tenuis: el rol de sus simbiontes micorrícico arbuscular y rizobiano

MARIELA ECHEVERRIA, AGUSTINA A. SCAMBATO, ANALÍA I. SANNAZZARO, SANTIAGO MAIALE, OSCAR A. RUIZ, ANA B. MENÉNDEZ.

Chascomús, Argentina

Taller; IV Taller Interdisciplinario de Lotus: Aspectos Genéticos, Moleculares y Ecofisiológicos de Lotus spp. y sus simbiontes; 2008

We have tested the hypothesis that Lotus glaber displays a plastic root phenotypic response to soil salinity that may be influenced  by mycorrhizal and rhizobial microorganisms. Uninoculated plants and plants colonised by Glomus intraradices  or Mesorhizobium loti were exposed to either 150 or 0 mM NaCl. General plant growth and root architectural parameters (morphology and topology) were measured and phenotypic plasticity determined at the end of the salt treatment period. Two genotypes differing in their salt tolerancecapacity were used in this study. We analized root morphology, the root external and internal link lengths and the topological trend (TT). Notwithstanding the absence of a link between TTs and variations in plant growth, it is possible to predict a dissimilar adaptation of plants with different TTs. Root colonisation by either symbiotic microorganism reduced the level of root phenotypic plasticity in the sensitive plant genotype. We conclude that root plasticity could be part of the general mechanism of  L. glaber  salt tolerance only in the case of non-symbiotic plants