Pseudomonas putida KT2440 AS A PLANT GROWTH PROMOTING RHIZOBACTERIA (PGPR) UNDER SALINITY CONDITIONS

CARAM DI SANTO, CAROLINA M; ESPINOSA-URGEL, MANUEL; COSTA GUTIERREZ, STEFANIE BERNARDETTE; VINCENT, PAULA ANDREA; ZENOFF, ANA M; DE CRITÓBAL, RICARDO EZEQUIEL

Buenos Aires

Congreso; LIII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN BIOQUÍMICA Y BIOLOGÍA MOLECULAR (SAIB); 2017

AbstractThe role of Pseudomonas putida KT2440 as PGPR under salinity conditions was evaluated; at the same time, a mutant (Mut11) which was previously studied in our laboratory as a low salinity tolerance strain due to a mutation in the LPS synthesis was also evaluated. So in this way, it could help us to shed light in some mechanisms of action of P. putida KT2440 in salinity. To achieve this, the bacteria`s plant growth promoting properties (The plant growth promoting properties of bacteria), such as indol acetic acid (IAA), phosphate solubilization and siderophore synthesis of the wild type and the mutant strain were evaluated, under saline (0.5 M NaCl) and non saline conditions. Additionally, in vitro seed germination and growth promotion of soybean and corn under saline soils were assayed.The strain P. putida KT2440 and the Mut11 mutant exhibited plant growth promoting properties. The wild type and the Mut11 mutant showed similar activities in phosphate solubilization and IAA production for both conditions, seeming not to be affected in presence of saline conditions. Nevertheless, the siderophore synthesis was significantly affected under saline conditions; and no synthesis was detected in the mutant, contrary for the wild type strain which exhibited a small halo.The plant growth promoting effect under salinity conditions of the P. putida KT2440 strain was highlighted and the negative effect of the mutant Mut11, especially under saline conditions, evidence the effect of the mutation, which apparently is not only important for salinity tolerance of the bacterium, but also is involved in the PGPR effect under salinity conditions for soybean and corn crops.This study showed that P. putida KT2440 strain is a useful PGPR bacterium for salinity conditions and also suggest that LPS are relevant to reduce salinity stress, these data provides new information on the KT2440 strain adaptation in response to those kinds of environment.