| Autor: |
Miftakhov AK; Laboratory of Molecular Genetics and Microbiology Methods, Kazan Scientific Center of Russian Academy of Sciences, 420111 Kazan, Russia., Diabankana RGC; Laboratory of Molecular Genetics and Microbiology Methods, Kazan Scientific Center of Russian Academy of Sciences, 420111 Kazan, Russia.; Centre of Agroecological Research, Kazan State Agrarian University, 420015 Kazan, Russia., Frolov M; Laboratory of Molecular Genetics and Microbiology Methods, Kazan Scientific Center of Russian Academy of Sciences, 420111 Kazan, Russia., Yusupov MM; Laboratory of Molecular Genetics and Microbiology Methods, Kazan Scientific Center of Russian Academy of Sciences, 420111 Kazan, Russia., Validov SZ; Laboratory of Molecular Genetics and Microbiology Methods, Kazan Scientific Center of Russian Academy of Sciences, 420111 Kazan, Russia., Afordoanyi DM; Laboratory of Molecular Genetics and Microbiology Methods, Kazan Scientific Center of Russian Academy of Sciences, 420111 Kazan, Russia.; FRC Kazan Scientific Center, Tatar Scientific Research Institute of Agricultural Chemistry and Soil Science, Russian Academy of Sciences, 420111 Kazan, Russia. |
| Abstrakt: |
Competition for nutrients and niches (CNN) is known to be one of the mechanisms for biocontrol mostly exhibited by Pseudomonas strains. Phenotypic and full genome analysis revealed Pseudomonas putida PCL1760 controlling tomato foot and root rot (TFRR) solely through CNN mechanism. Although the availability of nutrients and motility are the known conditions for CNN, persistence of bacteria through dormancy by ribosomal hibernation is a key phenomenon to evade both biotic and abiotic stress. To confirm this hypothesis, rsf S gene knockout mutant of PCL1760 (SB9) was first obtained through genetic constructions and compared with the wild type PCL1760. Primarily, relative expression of rsf S in PCL1760 was conducted on tomato seedlings which showed a higher expression at the apical part (1.02 ± 0.18) of the plant roots than the basal (0.41 ± 0.13). The growth curve and persistence in ceftriaxone after the induction of starvation with rifampicin were performed on both strains. Colonization on the tomato root by CFU and qPCR, including biocontrol ability against Fusarium, was also tested. The growth dynamics of both PCL1760 and SB9 in basal and rich medium statistically did not differ ( p ≤ 0.05). There was a significant difference observed in persistence showing PCL1760 to be more persistent than its mutant SB9, while SB9 (pJeM2: rsf S) was 221.07 folds more than PCL1760. In colonization and biocontrol ability tests, PCL1760 was dominant over SB9 colonizing and controlling TFRR (in total, 3.044 × 10 4 to 6.95 × 10 3 fg/µL and 55.28% to 30.24%, respectively). The deletion of the rsf S gene in PCL1760 reduced the persistence and effectiveness of the strain, suggesting persistence as one important characteristic of the CNN. |
