Plant anti-aging: Delayed flower and leaf senescence in treated with cell-free cultivation medium.

Plant tissues naturally senesce over time. Attempts to improve plant robustness and increase longevity have involved genetic modification, application of synthetic chemicals, and use of beneficial microbes. Recently, culture supernatant from a microalga was found to prime innate immunity against in . However, the capacity of culture supernatants to prevent or delay aging in higher plants has not been elucidated. In this study, roots of the ornamental flowering plant L. were drenched with cell-free supernatants from three species. Flower and leaf senescence in was significantly reduced and delayed with all three supernatants. Investigations of the mode of action underlying delayed senescence showed that the supernatants did not act as a chemical trigger to elicit plant immunity or as a growth-promoting fertilizer in . The mechanisms underlying the anti-aging effects remain undetermined, and several possible hypotheses are discussed. Several species are industrially cultivated, and disposal of cell-free supernatant can be economically and environmentally challenging. This study provides a novel method for extending plant lifespan through use of supernatant and discusses the potential of using industrial waste supernatants in agriculture and horticulture to reduce reliance on chemical pesticides and genetic modification.