Effects of peanut rhizobia on the growth and symbiotic performance ofArachis hypogaea under abiotic stress

Abstract

The effects of saline and osmotic stress on four peanut rhizobia, plant growth and symbiotic Nz-fixation in Arachis hypogaea were studied. Abiotic stress was applied by adding either 100 mM NaCI or 20 mM PEG6000. At the rhizobial level, Bradyrhizobium ATCClO317 and TALlOOO showed stronger tolerance to stress than TALl371 and SEM1A6144. The effect of salinity on the bacterium-plant association was studied by using the variety Blanco Manfredi M68. In the absence of stresses, all the strains induced a significantly higher number of nodules on the roots, although TAL1371 and SEMIA6144 were more effective. Both stresses affected the interactionprocess, while TAL1371 was the best partner.

Phosphatidylcholine levels of peanut-nodulatingBradyrhizobiumsp. SEMIA 6144 affect cell size and motility

“…Seeds of A. hypogaea L. cv. Blanco Manfredi M68, obtained from INTA Manfredi (Córdoba, Argentina), were surface‐sterilized, grown in sand and inoculated according to Dardanelli et al (2009). Uninoculated plants did not develop nodules.…”

Crescimento e acúmulo de cátions em plantas de moringa mantidas em solos salinos

“…A produtividade agrícola em várias partes do globo é afetada pela alta concentração de sais no solo, prejudiciais ao crescimento das plantas (Dardanelli et al, 2009). A grande concentração de sais no ambiente desencadeia vários tipos de estresses físicos e químicos nas plantas, promovendo respostas complexas que envolvem mudanças na morfologia, fisiologia e no metabolismo (Hasegawa et al, 2000;Musyimi et al, 2007).…”

Stress Physiology in Azospirillum and Other PGPRs

“…ATCC 10317 increased while in TAL169 diminished, indicating a strain dependent response. However, the growth of these peanut rhizobia under osmotic did not induce changes in their trehalose content (Dardanelli et al 2009 ). An explanation for this response can be the genetic variability of peanut symbionts or the use of other compatible solutes to modulate their response to stress.…”

“…In peanut rhizobia, alterations in membrane lipid composition in response to salinity and variation in the trehalose content have been detected in response to osmotic stress (Dardanelli et al 2000(Dardanelli et al , 2008(Dardanelli et al , 2009Medeot et al 2007 ). At 400 mM NaCl, the synthesis and accumulation of this compatible solute in the salt-tolerant strain Bradyrhizobium sp.…”