Elicitation of Systemic Acquired Resistance by a Novel Plant-Derived Biostimulant Composition Confers Robust Protection Against Botrytis cinerea in Tomato (Solanum lycopersicum L.)

Aleisha Wulandari (Department of Nutrition, JTC Medical Center, Jakarta, Indonesia)
Sudarto Sudarto (Department of Botanical Sciences, CMHC Research Center, Palembang, Indonesia)
Fifia Ardinanti (Department of Agricultural Science, CMHC Research Center, Palembang, Indonesia)
Bryan Helsey (Department of Biomolecular Science, Quezon Medical Center, Quezon, Philippines)
Yi-Fen Huang (Department of Biotechnology, Thimphu Agricultural Institute, Thimphu, Bhutan)

Natural Sciences Engineering and Technology Journal
Vol. 5 No. 2 (2025): Natural Sciences Engineering and Technology Journal

Gray mold, caused by the necrotrophic fungus Botrytis cinerea, is a devastating disease in tomato production worldwide, necessitating the development of sustainable and effective control strategies. Plant-derived biostimulants offer a promising eco-friendly alternative to synthetic fungicides by enhancing the plant's innate immune system. This study, conducted in greenhouse facilities in Palembang, Indonesia, evaluated the efficacy of a novel plant-derived biostimulant (PDB-MX7), a composition of Ascophyllum nodosum and Moringa oleifera extracts, in controlling gray mold in tomato (Solanum lycopersicum L. cv. 'Mutiara'). Tomato plants were treated with PDB-MX7 and subsequently inoculated with a virulent B. cinerea isolate. We assessed disease progression, plant growth parameters, and a suite of underlying defense mechanisms. These included the quantification of oxidative stress markers (H₂O₂, MDA), the activity of key defense-related enzymes (PAL, PPO, SOD, CAT), the accumulation of defense phytohormones (salicylic acid, jasmonic acid), and the expression levels of pathogenesis-related genes (PR-1, PDF1.2) via RT-qPCR. Pre-treatment with PDB-MX7 significantly reduced gray mold disease severity by 76.4% and lesion diameter by 71.8% compared to untreated, inoculated plants. This protective effect was associated with a significant priming of the plant's defense system. PDB-MX7-treated plants exhibited lower levels of H₂O₂ and MDA upon infection, indicating reduced oxidative stress. Furthermore, these plants showed a rapid and potent induction of PAL and PPO activity (3.1-fold and 2.8-fold higher than controls at 48 hpi, respectively). This was corroborated by a significant accumulation of salicylic acid and a more than 5-fold upregulation in the expression of the SA-responsive gene PR-1, indicating the activation of Systemic Acquired Resistance (SAR). In conclusion, the novel biostimulant composition PDB-MX7 confers substantial resistance against B. cinerea in tomato by priming the plant's innate immunity, primarily through the activation of the SA-mediated SAR pathway. This study highlights the potential of PDB-MX7 as a powerful tool for integrated pest management programs in sustainable tomato cultivation.