Indirect plant defenses: volatile organic compounds and extrafloral nectar

Author(s)

Bezerra, Ranna Heidy Santos ^[1] ; Sousa-Souto, Leandro ^[1] ; Santana, Antonio Euzebio Goulart ^[2] ; Ambrogi, Bianca Giuliano ^[1]

Affiliation

^[1] Univ Fed Sergipe, Dept Ecol, Lab Ecol Quim, Programa Pos Grad Ecol & Conservacao, BR-49100000 Sao Cristovao, SE - Brazil

^[2] Univ Fed Alagoas, Lab Pesquisas Recursos Nat LPqRN, Campus Engn & Ciencias Agr CECA, BR-57100000 Maceio, AL - Brazil

• Document type: Review article
• Source: ARTHROPOD-PLANT INTERACTIONS; v. 15, n. 4, p. 467-489, AUG 2021.
• Web of Science Citations: 0

Abstract

Indirect plant defense is an important component in regulating population dynamics and the structure of numerous communities in different ecosystems. These defenses mainly involve the emission of volatile organic compounds (VOCs) induced after damage by an herbivore. VOCs can play several ecological roles, such as help natural enemies locate prey or hosts, attract or repel other herbivores, mediate communication between neighboring plants and among different parts of the same plant, and affect the behavior of pollinators and seed dispersers. In addition to VOCs, some plants produce extrafloral nectar, which can enhance plant defense, by attracting, retaining, and increasing the efficiency of some natural enemies; however, among the associated costs, these compounds can attract other herbivorous species and exclude some natural enemies due to competition. Many factors can influence the production of indirect defenses by plants, such as the individual species, life stage, density of herbivores, age, abiotic factors, as well as the association of plants with symbiotic microorganisms. The potential of indirect plant defenses to reduce herbivory and increase the plant fitness has been well demonstrated. Indirect plant defenses may have ecological costs but can express phenotypic plasticity, as plants can reduce or increase the production of defenses according to the associated herbivory rate. Such variable expression of characteristics provides a barrier against the evolution of resistance by the associated herbivores. In this article, we intend to provide a review on volatile organic compounds and extrafloral nectar as indirect plant defenses, including some costs and benefits of these defense mechanisms. (AU)

• FAPESP's process: 14/50871-0 - INCT 2014: National Institute of Science and Technology of Semiochemicals in Agriculture
• Grantee: José Roberto Postali Parra
• Support Opportunities: Research Projects - Thematic Grants