Abstract：
Food production must undergo systems change to meet the sustainable development goals (SDGs). For example, organic farming can be empowered by soil microorganisms with plant growth promotion (PGP) and biocontrol features. In this context, there have been limited studies on pomegranate. We investigated microbial diversity in rhizosphere of the pomegranate \"Bhagwa\" variety and its potential role in PGP and biocontrol. Both bulk and rhizosphere soil samples were analyzed for their physicochemical properties. Whole metagenome sequencing was conducted using the Illumina NovaSeq6000 platform. Surprisingly, we found that bulk and rhizosphere soil samples had comparable microbial diversity. Metagenome sequencing revealed the abundance of Streptomyces indicus, Bradyrhizobium kalamazoonesis, and Pseudomonas cellulosum in the rhizosphere that are reported here for the first time in agricultural literature. Pathway prediction analysis using KEGG (Kyoto Encyclopedia for Genes and Genomes) and COG (clusters of orthologous genes) databases identified metabolic pathways associated with biocontrol properties against pathogens. We confirmed the metagenome data in vitro, which demonstrated their PGP potential and antimicrobial properties. For instance, S. indicus produced high concentration of indole-3-acetic acid, a PGP phytohormone, that can stimulate plant growth. In addition, an antimicrobial susceptibility assay suggested that bacterial extracts displayed activity against Xanthomonas, a primary pathogen causing the pomegranate wilt disease. In conclusion, this study suggests that S. indicus, B. kalamazoonesis, and P. cellulosum can potentially be PGP and biocontrol agents that may contribute to increased crop productivity in pomegranate cultivation. These agents and their combinations warrant future research with an eye on SDGs and so as to enable and innovate organic farming and pomegranate agricultural practices.
摘要：
粮食生产必须进行系统变革，以实现可持续发展目标。例如,具有植物生长促进（PGP）和生物控制功能的土壤微生物可以增强有机农业。在这种情况下，关于石榴的研究有限。我们研究了石榴“Bhagwa”品种根际的微生物多样性及其在PGP和生物防治中的潜在作用。分析了大块和根际土壤样品的理化性质。使用IlluminaNovaSeq6000平台进行整个宏基因组测序。令人惊讶的是,我们发现散装和根际土壤样品具有相当的微生物多样性。宏基因组测序显示了印度链霉菌的丰度，缓生根瘤菌，和根际纤维素假单胞菌，这是农业文献中首次报道的。使用KEGG（京都基因和基因组百科全书）和COG（直系同源基因簇）数据库的途径预测分析确定了与针对病原体的生物控制特性相关的代谢途径。我们在体外证实了宏基因组数据，证明了它们的PGP潜力和抗菌性能。例如,美国indicus产生高浓度的吲哚-3-乙酸，PGP植物激素,可以刺激植物生长。此外,抗微生物药敏试验表明，细菌提取物显示出抗黄单胞菌的活性，引起石榴枯萎病的主要病原体。总之,这项研究表明，S.indicus，B.kalamazoonesis,和P。cellulosum可能是PGP和生物控制剂，可能有助于提高石榴种植中的作物生产力。这些制剂及其组合值得未来研究着眼于可持续发展目标，以实现和创新有机农业和石榴农业实践。
