Nur Izzatul Maulidah, Andi Kurniawan, Erfan Dani Septia, Akhmad Rizal Oktafian, Muammar Habibi Irsyad, Ikhwan Adhirakha Mullatif
Whitefly (Bemisia tabaci) severely constrains tomato productivity by inducing oxidative stress and disrupting carbon metabolism. This study evaluated the potential of Bacillus subtilis IZ-25 to enhance tomato resistance by activating antioxidant and phenylpropanoid defenses. IZ-25 treatment resulted in an 80% reduction in egg numbers and a 77% decrease in adult whiteflies compared to the control. IZ-25 significantly enhanced antioxidant enzyme activities, including a 55% increase in catalase and a fourfold increase in guaiacol peroxidase, accompanied by a 17% rise in ascorbate peroxidase and a 41% reduction in H₂O₂ levels. Phenylpropanoid metabolism was also markedly induced, with phenylalanine ammonia-lyase activity increasing by 22%, and total phenolics, flavonoids, and lignin increasing by 17%, 6%, and 44%, respectively. GC-MS profiling further confirmed that IZ-25 produces bioactive metabolites, including flavonoid-like and triterpenoid/steroidal compounds, which are known to possess insect-deterrent and feeding-inhibitory properties. Pearson correlation and PCA analysis demonstrated strong negative correlations between antioxidant and phenylpropanoid biomarkers and whitefly infestation (r = -0.85 to −0.96). Overall, IZ-25 induced a dual-defense strategy that integrates redox homeostasis, secondary metabolite accumulation, and bioactive compound production, highlighting its potential as an eco-friendly approach to whitefly control in tomato cultivation. Further molecular validation of JA/SA signaling is required to elucidate the comprehensive mechanistic basis of this resistance. © 2026 The Authors
Department Agrotechnology, Faculty of Agriculture and Animal Science, University of Muhammadiyah Malang, Malang, Indonesia; Department of Agronomy, Faculty of Agriculture, University of Brawijaya, Malang, Indonesia; Department of Pest and Disease, Faculty of Agriculture, University of Brawijaya, Malang, Indonesia; Department of Land and Water Management, Faculty of Agriculture, University of Brawijaya, Malang, Indonesia
