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Growth and Survival of Mesorhizobium loti Inside Acanthamoeba Enhanced Its Ability to Develop More Nodules on Lotus corniculatus.

Karaś MA, Turska-Szewczuk A, Trapska D, Urbanik-Sypniewska T - Microb. Ecol. (2015)

Bottom Line: Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased.The internalization of mesorhizobia was mediated by the mannose-dependent receptor.M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland, magdalena.karas@poczta.umcs.lublin.pl.

ABSTRACT
The importance of protozoa as environmental reservoirs of pathogens is well recognized, while their impact on survival and symbiotic properties of rhizobia has not been explored. The possible survival of free-living rhizobia inside amoebae could influence bacterial abundance in the rhizosphere of legume plants and the nodulation competitiveness of microsymbionts. Two well-characterized strains of Mesorhizobium: Mesorhizobium loti NZP2213 and Mesorhizobium huakuii symbiovar loti MAFF303099 were assayed for their growth ability within the Neff strain of Acanthamoeba castellanii. Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased. The latter strain was also able to survive prolonged co-incubation within amoebae and to self-release from the amoeba cell. The temperature 28 °C and PBS were established as optimal for the uptake of Mesorhizobium by amoebae. The internalization of mesorhizobia was mediated by the mannose-dependent receptor. M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

No MeSH data available.


Related in: MedlinePlus

Nodule formation kinetics of the M. loti NZP2213 wild strain and NZP2213 released from A. castellanii (NZP2213Ac) determined as the number of nodules per plant. Each point represents the mean ± standard error of determinations in three independent sets of 20 plants
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Fig5: Nodule formation kinetics of the M. loti NZP2213 wild strain and NZP2213 released from A. castellanii (NZP2213Ac) determined as the number of nodules per plant. Each point represents the mean ± standard error of determinations in three independent sets of 20 plants

Mentions: Acanthamoeba spp. can be isolated from the rhizosphere of many plants including the Leguminosae family [36]. A great number of molecular mechanisms mediating the communication of partners in symbiosis and pathogenesis are quite similar [37]. The growth of bacteria inside amoebae could change their physiological properties [15–18]. The influence of facultative survival of symbiotic bacteria from the genus Mesorhizobium inside amoebae on their symbiotic properties was examined. In the studies, the ARB-type strain M. loti NZP2213 was used, which forms functional nitrogen-fixing nodules (Nod+Fix+) on L. corniculatus [38]. The ability of strain NZP2213 and NZP2213 released from A. castellanii (described hereafter as NZP2213Ac) to form nodules on Lotus plants was compared. The results obtained indicated that the fresh mass of L. corniculatus shoots inoculated either with the NZP2213 or NZP2213Ac bacteria was quite similar (35 and 27 mg/plant, respectively) and two times higher than that of uninoculated plants (15 mg/plant). The fresh mass of roots infected with NZP2213 and NZP2213Ac was also similar, 30 and 27 mg per plant, respectively, and three times higher than that of root mass of noninfected plants (11 mg/plant). The examination of the nodulation ability showed that the number of nodules induced by the native bacteria after approximately a month was two per plant, while the number of nodules induced by bacteria released from amoebae was three per plant (Fig. 5). The ratio of the fresh mass of shoots and roots of plants inoculated with NZP221 and NZP2213Ac was 1.16:1 and 1:1, respectively, indicating that Mesorhizobium released from A. castellanii exhibited slightly diminished nitrogen fixation efficiency, while the nodule-forming capacity was increased.Fig. 5


Growth and Survival of Mesorhizobium loti Inside Acanthamoeba Enhanced Its Ability to Develop More Nodules on Lotus corniculatus.

Karaś MA, Turska-Szewczuk A, Trapska D, Urbanik-Sypniewska T - Microb. Ecol. (2015)

Nodule formation kinetics of the M. loti NZP2213 wild strain and NZP2213 released from A. castellanii (NZP2213Ac) determined as the number of nodules per plant. Each point represents the mean ± standard error of determinations in three independent sets of 20 plants
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig5: Nodule formation kinetics of the M. loti NZP2213 wild strain and NZP2213 released from A. castellanii (NZP2213Ac) determined as the number of nodules per plant. Each point represents the mean ± standard error of determinations in three independent sets of 20 plants
Mentions: Acanthamoeba spp. can be isolated from the rhizosphere of many plants including the Leguminosae family [36]. A great number of molecular mechanisms mediating the communication of partners in symbiosis and pathogenesis are quite similar [37]. The growth of bacteria inside amoebae could change their physiological properties [15–18]. The influence of facultative survival of symbiotic bacteria from the genus Mesorhizobium inside amoebae on their symbiotic properties was examined. In the studies, the ARB-type strain M. loti NZP2213 was used, which forms functional nitrogen-fixing nodules (Nod+Fix+) on L. corniculatus [38]. The ability of strain NZP2213 and NZP2213 released from A. castellanii (described hereafter as NZP2213Ac) to form nodules on Lotus plants was compared. The results obtained indicated that the fresh mass of L. corniculatus shoots inoculated either with the NZP2213 or NZP2213Ac bacteria was quite similar (35 and 27 mg/plant, respectively) and two times higher than that of uninoculated plants (15 mg/plant). The fresh mass of roots infected with NZP2213 and NZP2213Ac was also similar, 30 and 27 mg per plant, respectively, and three times higher than that of root mass of noninfected plants (11 mg/plant). The examination of the nodulation ability showed that the number of nodules induced by the native bacteria after approximately a month was two per plant, while the number of nodules induced by bacteria released from amoebae was three per plant (Fig. 5). The ratio of the fresh mass of shoots and roots of plants inoculated with NZP221 and NZP2213Ac was 1.16:1 and 1:1, respectively, indicating that Mesorhizobium released from A. castellanii exhibited slightly diminished nitrogen fixation efficiency, while the nodule-forming capacity was increased.Fig. 5

Bottom Line: Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased.The internalization of mesorhizobia was mediated by the mannose-dependent receptor.M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland, magdalena.karas@poczta.umcs.lublin.pl.

ABSTRACT
The importance of protozoa as environmental reservoirs of pathogens is well recognized, while their impact on survival and symbiotic properties of rhizobia has not been explored. The possible survival of free-living rhizobia inside amoebae could influence bacterial abundance in the rhizosphere of legume plants and the nodulation competitiveness of microsymbionts. Two well-characterized strains of Mesorhizobium: Mesorhizobium loti NZP2213 and Mesorhizobium huakuii symbiovar loti MAFF303099 were assayed for their growth ability within the Neff strain of Acanthamoeba castellanii. Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased. The latter strain was also able to survive prolonged co-incubation within amoebae and to self-release from the amoeba cell. The temperature 28 °C and PBS were established as optimal for the uptake of Mesorhizobium by amoebae. The internalization of mesorhizobia was mediated by the mannose-dependent receptor. M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

No MeSH data available.


Related in: MedlinePlus