Tangeretin-based plant-derived fungicide for rice blast disease control

Overview

Rice blast, caused by the fungus Magnaporthe oryzae, is one of the most destructive diseases affecting global rice production. This research proposes tangeretin, a naturally occurring polymethoxylated flavone found in citrus peels, as a novel plant-derived fungicide for managing rice blast disease. The work reveals a previously unrecognized mechanism of action: tangeretin appears to act as a specific inhibitor of ferroptosis, a form of iron-dependent cell death driven by lipid peroxidation, in fungal conidia. By blocking conidial ferroptosis, tangeretin disrupts a critical step in the pathogen's infection cycle. The solution offers an environmentally friendly alternative to conventional synthetic fungicides, with potential applications in integrated pest management and sustainable agriculture.

Technical specifications

• Active compound: Tangeretin, a polymethoxylated flavone (PMF) sourced from citrus plants, tested at 200 micromolar concentration
• Mechanism of action: Acts as an antioxidant that reduces lipid peroxidation in M. oryzae conidia, thereby inhibiting ferroptosis, a prerequisite for pathogenicity
• Biological effects:
  • Significantly delays appressorium formation and maturation, the critical infection structure required for host penetration
  • Blocks blast disease lesion formation on rice leaves
  • Reduces invasive hyphal growth within rice leaf sheath tissue (statistically significant, p<0.05)
• Safety profile: No observed harmful effects on rice plants under tested conditions
• Validation systems: Rice seedlings, rice leaf sheath assays, and barley detached leaf assays inoculated with M. oryzae conidia
• Future development: Screening of tangeretin derivatives and other PMFs with anti-blast activity, since tangeretin's current cost limits large-scale agricultural use
• Target application: Fungicide formulation optimization for field deployment in rice blast management

Technology readiness level

The technology is currently at an early-to-mid stage of development. Laboratory validation has been completed, demonstrating efficacy in controlled plant infection assays across multiple test systems including rice seedlings, leaf sheath inoculation, and barley detached leaves. The next critical step involves field trials to evaluate real-world performance under agricultural conditions. Additionally, the research team is actively screening for more cost-effective tangeretin derivatives or alternative PMFs that retain anti-blast activity but are economically viable for crop protection at scale. The research group is actively seeking industry partners to collaborate on optimizing fungicide formulations based on tangeretin or its derivatives for commercial agricultural use.