Plant anti-aging: Delayed flower and leaf senescence in Erinus alpinus treated with cell-free Chlorella cultivation medium
Authors and Affiliations
Authors and Affiliations
Sang-Moo Leea,b, Bongsoo Leec, Chang-Ki Shimd, Yong-Keun Change, and Choong-Min Ryua,b,*
aMolecular Phytobacteriology Laboratory, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, S. Korea; bDepartment of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, S. Korea; cDepartment of Microbial
and Nano Materials, College of Science and Technology, Mokwon University, Daejeon, S. Korea; dOrganic Agricultural Division, National Institute of Agriculture Sciences, Wanju, S. Korea; eDepartment of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, S. Korea
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.
KEYWORDS: Chlorella supernatant, ornamental flowering plant, plant senescence, PGPR, plant anti-aging, Erinus alpinus L