Abstract
Endophytic Rhizobium species represent promising bioinoculants for enhancing crop performance and nutritional profiles. This study investigated the impact of Rhizobium sp. CRRU65 inoculation on blackberry (Rubus sp.) plants, with emphasis on fruit phytochemical composition and cross-kingdom bioactivity. Inoculated plants exhibited a significant increase in yield and elevated levels of phenolic compounds, notably sanguiin H6 and cyanidin-3-O-glucoside, as quantified by HPLC-DAD-MS. Antioxidant functionality was evaluated using Caenorhabditis elegans under oxidative stress. Extracts from inoculated fruits significantly improved nematode survival, accompanied by transcriptional upregulation of skn-1 and hsp-16, genes involved in stress response and proteostasis. These findings demonstrate that Rhizobium sp. CRRU65 enhances not only agronomic traits but also the nutraceutical quality of blackberry fruits, with beneficial effects extending across biological kingdoms. This work underscores the potential of endophytic bacteria to contribute to sustainable agriculture and functional food innovation through molecular and physiological modulation in both plants and animal models.