Benefits of jasmonate-dependent defenses against vertebrate herbivores in nature.

Ricardo Ar Machado,Matthias Erb,Mark Mcclure,Maxime R Hervé,Ian T Baldwin

doi:10.7554/elife.13720

Abstract

Endogenous jasmonates are important regulators of plant defenses. If and how they enable plants to maintain their reproductive output when facing community-level herbivory under natural conditions, however, remains unknown. We demonstrate that jasmonate-deficient Nicotiana attenuata plants suffer more damage by arthropod and vertebrate herbivores than jasmonate-producing plants in nature. However, only damage by vertebrate herbivores translates into a significant reduction in flower production. Vertebrate stem peeling has the strongest negative impact on plant flower production. Stems are defended by jasmonate-dependent nicotine, and the native cottontail rabbit Sylvilagus nuttallii avoids jasmonate-producing N. attenuata shoots because of their high levels of nicotine. Thus, endogenous jasmonates enable plants to resist different types of herbivores in nature, and jasmonate-dependent defenses are important for plants to maintain their reproductive potential when facing vertebrate herbivory. Ecological and evolutionary models on plant defense signaling should aim at integrating arthropod and vertebrate herbivory at the community level.

Highlights

IntroductionBy removing plant tissues and interrupting essential physiological processes, herbivory can negatively affect plant fitness, impose selection pressure, and drive the evolution of plant defenses (Zust et al, 2012; Agrawal et al, 2012; Huber et al, 2016a; 2016b)
In nature, plants are attacked by a multitude of herbivore species
In the Lytle plot, jasmonate-deficient plants suffered more stem peeling and leaf removal by vertebrates, but similar arthropod damage compared to wild type plants

Summary

Introduction

By removing plant tissues and interrupting essential physiological processes, herbivory can negatively affect plant fitness, impose selection pressure, and drive the evolution of plant defenses (Zust et al, 2012; Agrawal et al, 2012; Huber et al, 2016a; 2016b). Herbivory does not necessarily reduce plant survival and reproduction, (Bruelheide and Scheidel, 1999; Morris et al, 2007; Corbett et al, 2011). Herbivory that reduces competitor abundance may benefit a given individual (Agrawal et al, 2012). Measuring the impact of herbivory on plant reproductive fitness in an ecologically relevant setting (e.g., one that includes the full suite of native herbivores), is essential for identifying the selective forces underlying the evolution of plant defenses

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Results

Conclusion