| Autor: |
Sampedro I; Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain.; Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100 Armilla, Granada, Spain., Pérez-Mendoza D; Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain.; Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Profesor Albareda 1, 18008 Granada, Spain., Toral L; Xtrem Biotech S.L., European Business Innovation Center, Avenida de la Innovación, 1, 18016 Armilla, Granada, Spain., Palacios E; Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain.; Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100 Armilla, Granada, Spain., Arriagada C; Department of Forestry Science, Bioremediation Laboratory, Faculty of Agricultural and Forestry Science, University of La Frontera, 01145 Temuco, Chile., Llamas I; Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain.; Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100 Armilla, Granada, Spain. |
| Abstrakt: |
Increase in soil salinity poses an enormous problem for agriculture and highlights the need for sustainable crop production solutions. Plant growth-promoting bacteria can be used to boost the growth of halophytes in saline soils. Salicornia is considered to be a promising salt-accumulating halophyte for capturing large amounts of carbon from the atmosphere. In addition, colonization and chemotaxis could play an important role in Salicornia -microbe interactions. In this study, the role of chemotaxis in the colonization of the halophilic siredophore-producing bacteria, Halomonas anticariensis FP35 T , on Salicornia hispanica plants was investigated. The chemotactic response of FP35 T to Salicornia root exudates showed optimum dependence at a salt concentration of 5 % NaCl (w/v). Oleanolic acid, the predominant compound in the exudates detected by HPLC and identified by UPLC-HRMS Q-TOF, acts as a chemoattractant. In vitro experiments demonstrated the enhanced positive effects of wild-type H. anticariensis strain FP35 T on root length, shoot length, germination and the vigour index of S. hispanica. Furthermore, these positive effects partially depend on an active chemotaxis system, as the chemotaxis mutant H. anticariensis FP35 ΔcheA showed reduced plant growth promotion for all the parameters tested. Overall, our results suggest that chemotaxis responses to root exudates play an important role in interactions between Salicornia and halophilic bacteria, enhance their colonization and boost plant growth promotion. Preliminary results also indicate that root exudates have a positive impact on H. anticariensis FP35 T biofilm formation under saline conditions, an effect which totally depends on the presence of the cheA gene. |
