Genetic Peculiarities and Plant-Protecting Potential of Two Nocardiopsis Strains

The genetic characteristics and protective potential of the Nocardiopsis tropica strains SCPM-O-B-12605 (RCAM04882) and SCPM-O-B-12606 (RCAM04883), previously identified as N. umidischolae, have been studied. In this study, we aimed to conduct a comparative analysis of the functional genetic pool of N. tropica strains SCPM-O-B-12605 and SCPM-O-B-12606 and evaluate the effectiveness of their culture suspensions in a field experiment on the Azhur F1 tomato variety in terms of phytostimulatory, insectoacaricidal, and antiviral activity. Field trials were conducted in open ground in an arid zone of southern Russia. A high degree of genetic similarity was established among the studied strains: the average nucleotide identity of their genomes was 99.9978%. At the same time, differences in the composition of biosynthetic gene clusters were identified. SCPM-O-B-12605 contains clusters of non‑ribosomal peptide synthesis, type I polyketide synthases, and terpene precursor biosynthesis; SCPM-O-B-12606 contains clusters of class III and IV lantipeptides. The genomes also contain genes associated with resistance to heavy metals, drought, and osmotic stress, including systems for the synthesis and transport of compatible osmolytes. The results indicate the potential of the studied strains for the development of biopreparations aimed at increasing productivity and protecting tomatoes in arid conditions.