In order to reveal the genome characteristics of HNU24, which has excellent antagonistic ability to Ralstonia solanacearum, its complete genome was sequenced by the BGISEQ-500 and ONT PromethION technology, and the genome assembly, gene prediction, function annotation, and protein homology analysis also were conducted. Phylogenetic analysis results demonstrated that HNU24 belonged to Bacillus velezensis. Its completed genomic sequence length was 3 932 768 bp, GC content was 46.48%, and had 3822 genes. A total of 43 carbohydrate active enzyme gene families were identified in the genome, and the cellulase activity experiment further confirmed that the strain HNU24 had the ability to degrade cellulose. Thirteen clusters of secondary metabolite biosynthesis genes were predicted in genome, including eight compounds: surfactin, fengycin, plantazolicin, butirosin A/butirosin B, macrolactin, bacillaene, difficidin, bacillibactin and bacilysin, which have been reported as the antibacterial components. Five unknown components, which were found no homologous genes or were less similar to the known database sequences, may be new compounds that have not been identified and reported. In addition, greenhouse experiment demonstrated that HNU24 had significant growth promoting effect on tomato plants. Thus, HNU24 may antagonize R. solanacearum and promote tomato growth by secreting active compounds, and it is a potential biofertilizer strain. The relevant results would lay a foundation for further research and application of HNU24 in biological control.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |