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

Abstract

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 Chlorella fusca was found to prime innate immunity against Pseudomonas syringae in Arabidopsis thaliana. However, the capacity of Chlorella culture supernatants to prevent or delay aging in higher plants has not been elucidated. In this study, roots of the ornamental flowering plant Erinus alpinus L. were drenched with cell-free supernatants from three Chlorella species. Flower and leaf senescence in E. alpinus was significantly reduced and delayed with all three Chlorella supernatants. Investigations of the mode of action underlying delayed senescence showed that the Chlorella supernatants did not act as a chemical trigger to elicit plant immunity or as a growth-promoting fertilizer in E. alpinus. The mechanisms underlying the anti-aging effects remain undetermined, and several possible hypotheses are discussed. Several Chlorella 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 Chlorella supernatant and discusses the potential of using industrial waste supernatants in agriculture and horticulture to reduce reliance on chemical pesticides and genetic modification.

Interference of Climate Change on Plant-Microbe Interaction: Present and Future Prospects

“…Scytonema hofmanni provides salt tolerance in the rice (Rodríguez et al, 2006). Chlorella fusca and Chlorella strains (ABC001 & HS2) delays plant senescence in Erinus alpinus (Lee et al, 2020). Furthermore, several evidences of abiotic stress tolerance by algal communities in the plant species has been reported (Li et al, 2014;Arroussi et al, 2018;Lee and Ryu, 2021).…”

Effect of Scenedesmus sp. CHK0059 on Strawberry Microbiota Community

“…Induced systemic resistance (ISR) response of cucumber to Colletotrichum orbiculare was reported [ 12 ], and D-lactic acid produced by CHK0059 has been found to induce ISR in Arabidopsis [ 12 ]. Additionally, in Erinus alpines , CHK0059 exhibited an anti-aging effect [ 13 ].…”

Microalgae cross-fertilization: short-term effects of Galdieria phlegrea extract on growth, photosynthesis and enzyme activity of Chlorella sorokiniana cells

“…As for the reason of chlorophylls rise, this could be due to i) ex novo biosynthesis powered by the nitrogen supply present in the added extract; ii) reduced chlorophyll degradation, and thus, delayed senescence. Indeed, in higher plants the application of microalgae extracts and the consequently higher chlorophyll concentration is both associated with delayed senescence (Mutale-joan et al 2020;Colla and Rouphael 2020;Lee et al 2020) and improved nitrogen uptake and use (Di Mola et al 2019;Mutale-joan et al 2020). While we cannot dissect among these two possible causes of chlorophyll increase, this is to our knowledge the first report indicating such an effect in a microalgal culture enriched with a second microalga.…”