متابولیت های بازدارنده جدایه‌ی آنتاگونیست Streptomyces fimicarius- ghR در برابر بیمارگر Streptomyces sp.-FG1 سیب زمینی

Beneficial species of Streptomyces act as biological control agents with competitive abilities for colonizing the rhizosphere and suppressing disease through the production of enzymes, antibiotics, and other secondary metabolites. They also enhance plant growth and improve crop productivity by facilitating nutrient uptake and producing hormonal compounds. Effective management of common scab has been achieved through methods such as crop rotation, the use of organic soil amendments, chemical treatments, and biological agents. However, none of these management strategies alone are considered efficient for controlling this disease. Therefore, the simultaneous application of multiple approaches is necessary for disease management. In previous studies, the strain S. fimicarius-ghR was identified as an effective agent in reducing the growth of the pathogen Streptomyces sp.-FG1 under laboratory conditions and in decreasing potato common scab disease in pot trials. Herein, the metabolites of the antagonistic isolate S. fimicarius-ghR were extracted using ethyl acetate solvent. Various chromatographic methods, including open column and reverse phase chromatography, were employed for the separation and purification of the metabolites. The metabolite profile of the crude extract and the obtained fractions was investigated and identified using the LC-ESI-QToF-MS/MS technique. The purified compounds were elucidated by NMR and HR-MS. Based on the results, fractions F1, F2, F16, and F17 demonstrated inhibitory halos against the pathogen responsible for common scab in potatoes. LC-MS analyses revealed that alkaloids are the major components in the active fractions. Considering the proven role of alkaloid compounds in controlling plant pathogens, this research demonstrates their efficacy in controlling common potato scab.