The rhizosphere is a narrow and dynamic soil zone where bacteria and fungi establish symbiotic and synergistic relationships with each other and with plants, collectively influencing nutrient cycling, soil health, and overall ecosystem functioning. Mycorrhiza Helper Bacteria (MHB) are a diverse group of bacterial taxa that promote mycorrhiza establishment, together with those that positively influence already established symbiotic associations. MHB have been largely described from the perspectives of interaction mechanisms, ecological functions, or agricultural applications, treating them as generalized fungal growth-promoters or biofertilizers. However, how their effects change throughout fungal development has received little attention. This review addresses this knowledge gap by reframing MHB not as generic growth promoters, but as stage-specific regulators of the fungal development program. We integrate current evidence on transcriptional responses, metabolite-mediated signaling, and emerging small RNA regulatory networks across five sequential phases of the fungal life cycle: spore germination, presymbiotic hyphal growth, mycelial expansion, root colonization, and nutrient uptake. Elucidating these stage-specific regulatory mechanisms may provide the basis for the rational, stage-targeted design of MHB-based innovative strategies for sustainable agriculture.
A. Pennesi, Antonietta Mello, M. Acquaviva et al.· Frontiers in Plant Science· 0 citations
Background/Objectives: Sarcopenia involves a gradual decline in skeletal muscle mass that may occur during aging or in association with chronic pathological conditions. It markedly reduces muscle strength and mobility, thereby impairing quality of life. Because sarcopenia’s severity directly correlates with frailty, it represents an important predictor of prognosis and disease risk. Current preventive and therapeutic strategies rely mainly on physical activity, which is not feasible for all patients. This study investigated the biological effects of two independently prepared Tuber borchii (T. borchii) extracts in an in vitro model of sarcopenic stress. Methods: The activity of T. borchii extracts was investigated in a cell-based model of sarcopenia, following previous observations that these preparations influence proliferation-related pathways, including ERK1/2 phosphorylation. Specifically, differentiated myotubes were exposed to D-galactose to reproduce atrophy-associated cellular changes, and the impact of T. borchii extracts on protein synthesis, turnover, and cell morphology was assessed. Results: T. borchii extracts enhanced protein synthesis and turnover in myotubes. Furthermore, the treatment significantly reduced the expression of key galactose-induced sarcopenia and atrophy markers, such as MuRF1. Morphological analysis confirmed this protective effect, showing that treated myotubes maintained greater thickness and exhibited a larger cross-sectional area despite exposure to the sarcopenic stimulus. Conclusions: These results indicate that T. borchii extracts can attenuate selected cellular alterations associated with muscle aging. Future identification of the most active components may support their development as nutraceutical supplements.
Vincenzo Aiello, L. Lupacchini, M. Belli et al.· Nutrients· 0 citations