RESUMEN
Plant-associated bacteria exhibit diverse chemical means to protect plants from the pathogens. The present study has been conducted to evaluate the volatile-mediated antifungal activity of Serratia sp. NhPB1 isolated from the pitcher plant against the notorious pathogen Pythium aphanidermatum. The study has also evaluated the protective effect of NhPB1 on Solanum lycopersicum and Capsicum annuum leaves and fruits against P. aphanidermatum. From the results, NhPB1 was found to have remarkable activity against the tested pathogen. The isolate was also found to impart disease protection in selected plants as evidenced by the morphological changes. Here, the leaves and fruits of S. lycopersicum and C. annuum control which were treated with the uninoculated LB and distilled water were found to have the presence of P. aphanidermatum growth with lesions and decaying of tissues. However, the NhPB1-treated plants did not show any symptoms of fungal infection. This could further be confirmed by the microscopical examination of tissues by propidium iodide staining. Here, the normal architecture of leaf and fruit tissues could be observed in the NhPB1-treated group, but the tissue invasion by P. aphanidermatum was observed in the control group which further confirms the promises of selected bacteria for biocontrol applications.
Asunto(s)
Pythium , Serratia , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología , Antifúngicos/farmacología , FrutasRESUMEN
In the study, the bacterial isolate NhPB54 purified from the pitcher of Nepenthes plant was observed to have activity against Pythium aphanidermatum by dual culture and well diffusion. Hence, it was subjected to 16S rDNA sequencing and BLAST analysis, where the NhPB54 was found to have 100% identity to Pantoea dispersa. Upon screening for the plant beneficial properties, Pantoea dispersa NhPB54 was found to be positive for phosphate, potassium and zinc solubilization, nitrogen fixation, indole-3-acetic acid, ammonia, 1-aminocyclopropane-1-carboxylate deaminase, biofilm and biosurfactant production. Further to this, Solanum lycopersicum seedlings primed with P. dispersa NhPB54 were studied for the improved plant growth and disease protection. Here, the seedlings pre-treated with the NhPB54 culture supernatant were found to have enhanced plant growth and protection from damping off and fruit rot caused by P. aphanidermatum. From the LC-QTOF-MS/MS and GC MS analysis, P. dispersa NhPB54 was found to produce a blend of chemicals including 1-hydroxyphenazine, surfactin, and other bioactive metabolites with the likely basis of its observed antifungal and plant growth-promoting properties. From the results of the study, plants with unique adaptations can expect to harbor microbial candidates with beneficial applications.