Salicornia strobilacea (Synonym of Halocnemum strobilaceum) Grown under Different Tidal Regimes Selects Rhizosphere Bacteria Capable of Promoting Plant Growth.
Halophytes classified under the common name of salicornia colonize salty and coastal environments across tidal inundation gradients. To unravel the role of tide-related regimes on the structure and functionality of root associated bacteria, the rhizospheric soil of Salicornia strobilacea (synonym of Halocnemum strobilaceum) plants was studied in a tidal zone of the coastline of Southern Tunisia. Although total counts of cultivable bacteria did not change in the rhizosphere of plants grown along a tidal gradient, significant differences were observed in the diversity of both the cultivable and uncultivable bacterial communities. This observation indicates that the tidal regime is contributing to the bacterial species selection in the rhizosphere. Despite the observed diversity in the bacterial community structure, the plant growth promoting (PGP) potential of cultivable rhizospheric bacteria, assessed through in vitro and in vivo tests, was equally distributed along the tidal gradient. Root colonization tests with selected strains proved that halophyte rhizospheric bacteria (i) stably colonize S. strobilacea rhizoplane and the plant shoot suggesting that they move from the root to the shoot and (ii) are capable of improving plant growth. The versatility in the root colonization, the overall PGP traits and the in vivo plant growth promotion under saline condition suggest that such beneficial activities likely take place naturally under a range of tidal regimes.
Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal Saudi Arabia.
Ramona
R
Marasco
Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan Italy.
Francesca
F
Mapelli
Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan Italy.
Eleonora
E
Rolli
Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal Saudi Arabia.
Maria J
MJ
Mosqueira
Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal Saudi Arabia.
Marco
M
Fusi
Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan Italy.
Paola
P
Bariselli
Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, ThuwalSaudi Arabia; Greenhouse Laboratory, King Abdullah University of Science and Technology, ThuwalSaudi Arabia.
Muppala
M
Reddy
Institut Supérieur de Biotechnologie Sidi Thabet, BVBGR-LR11ES31, Manouba University, Ariana Tunisia.
Ameur
A
Cherif
Department of Environmental and Natural Resources Management, University of Patras, Panepistimioupoli Patron Greece.
George
G
Tsiamis
Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan Italy.
Sara
S
Borin
Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, ThuwalSaudi Arabia; Department of Food, Environmental and Nutritional Sciences, University of Milan, MilanItaly.
Daniele
D
Daffonchio
bacterial diversity; coastal environments; halophyte; plant growth promoting bacteria; salicornia; salt systems; tidal regime