Pseudomonas stutzeri MJL19, a rhizosphere-colonizing bacterium that promotes plant growth under saline stress

MARÍA J LAMI; ADLER CONRADO; CARAM DI SANTO MC; ANA M ZENOFF; RICARDO E DE CRISTOBAL; MANUEL ESPINOSA URGEL; PAULA A VINCENT

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020

1364-5072

Aims: The aim of this study was to find and use rhizobacteria able to conferplants advantages to deal with saline conditions.Methods and Results: We isolated 24 different bacterial species from therhizosphere of halophyte plants growing in Santiago del Estero, Argentina saltflat. Four strains were selected upon their ability to grow in salinity and theirbiochemical traits associated with plant growth promotion. Next, we tested theadhesion on soybean seeds surface and root colonization with the four selectedisolates. Isolate 19 stood out from the rest and was selected for furtherexperiments. This strain showed positive chemotaxis towards soybean rootexudates and a remarkable ability to form biofilm both in vitro conditions andon soybean roots. Interestingly, this trait was enhanced in high salineconditions, indicating the extremely adapted nature of the bacterium to highsalinity. In addition, this strain positively impacted on seed germination, plantgrowth and general plant health status also under saline stress.Conclusions: A bacterium isolate with outstanding ability to promote seedgermination and plant growth under saline conditions was found.Significance and Impact of the Study: The experimental approach allowed usto find a suitable bacterial candidate for a biofertilizer intended to alleviatesaline stress on crops. This would allow the use of soil now consideredinadequate for agriculture and thus prevent further advancement of agriculturefrontiers into areas of environmental value.