Biology (Jun 2024)

<i>Morinda citrifolia</i> Essential Oil: A Plant Resistance Biostimulant and a Sustainable Alternative for Controlling Phytopathogens and Insect Pests

  • Bruna Leticia Dias,
  • Renato Almeida Sarmento,
  • Madelaine Venzon,
  • Luis Oswaldo Viteri Jumbo,
  • Lucas Samuel Soares dos Santos,
  • Wellington de Souza Moura,
  • Dalmarcia de Souza Carlos Mourão,
  • Paulo Ricardo de Sena Fernandes,
  • Taila Renata Neitzke,
  • João Victor de Almeida Oliveira,
  • Tiago Dias,
  • Mateus Sunti Dalcin,
  • Eugênio E. Oliveira,
  • Gil Rodrigues dos Santos

DOI
https://doi.org/10.3390/biology13070479
Journal volume & issue
Vol. 13, no. 7
p. 479

Abstract

Read online

With the growing demand for sustainable and safe agricultural practices, plant compounds emerge as a solution for biological activities. Here, we evaluated the potential of using Morinda citrifolia essential oil to induce plant resistance and to control phytopathogens (Curvularia lunata) and insect pests (Daubulus maidis). We conducted a chromatographic analysis to unveil the essential oil components. We also quantified the activity levels of antioxidant enzymes and chitinase for resistance induction. The antifungal action was evaluated through disease progression and the inhibition of mycelial growth in addition to in silico studies that made it possible to predict the interaction site between the fungal protein and the compounds. We assessed the toxicity and repellent actions towards the D. maidis. Octanoic acid (58.43%) was identified as the essential oil major compound. Preventive treatment with essential oil and octanoic acid (25.0 µL mL−1) increased not only the plant defense activities (i.e., the activity of the enzymes superoxide dismutase, catalase, phenol peroxidase, ascorbate peroxidase, and chitinase) but also controlled Curvularia leaf spot. The stable interactions between octanoic acid and tyrosine-tRNA ligase from C. lunata suggested protein synthesis inactivation. The essential oil inhibited 51.6% of mycelial growth, and this effect was increased to 75.9% with the addition of adjuvants (i.e., angico gum). The essential oil reduced 76% of the population of D. maidis adults and repelled 50% of the number of D. maidis after 48 h under field conditions. The repellency effect in the field reduced the population of D. maidis adults, transmitters of the stunting complex, by 50%. The results highlight the potential of M. citrifolia as a resistance activator, fungicide, insecticide, and an effective biorational alternative.

Keywords