Virus infection mediates the effects of elevated CO2 on plants and vectors

Piotr Trębicki,Glenn J. Fitzgerald,Beatriz Dader,Jo E. Luck,Nilsa A. Bosque-Pérez,Alan L. Yen,Kevin S. Powell,Rebecca K. Vandegeer,Angela J. Freeman

doi:10.1038/srep22785

Abstract

Atmospheric carbon dioxide (CO2) concentration has increased significantly and is projected to double by 2100. To increase current food production levels, understanding how pests and diseases respond to future climate driven by increasing CO2 is imperative. We investigated the effects of elevated CO2 (eCO2) on the interactions among wheat (cv. Yitpi), Barley yellow dwarf virus and an important pest and virus vector, the bird cherry-oat aphid (Rhopalosiphum padi), by examining aphid life history, feeding behavior and plant physiology and biochemistry. Our results showed for the first time that virus infection can mediate effects of eCO2 on plants and pathogen vectors. Changes in plant N concentration influenced aphid life history and behavior, and N concentration was affected by virus infection under eCO2. We observed a reduction in aphid population size and increased feeding damage on noninfected plants under eCO2 but no changes to population and feeding on virus-infected plants irrespective of CO2 treatment. We expect potentially lower future aphid populations on noninfected plants but no change or increased aphid populations on virus-infected plants therefore subsequent virus spread. Our findings underscore the complexity of interactions between plants, insects and viruses under future climate with implications for plant disease epidemiology and crop production.

Highlights

Atmospheric carbon dioxide (CO2) concentration has increased significantly and is projected to double by 2100
Increased CO2 concentration had a positive effect on growth of both noninfected and Barley yellow dwarf virus (BYDV)-infected plants (Fig. S4). This is the first report that demonstrates that plant virus infection can mediate the effects of elevated CO2 on plants and insect vectors of pathogens
The fact that BYDV infection increased the relative aboveground N plant concentration under elevated CO2 (eCO2) (Fig. 6), and that no negative effect of BYDV infection was observed on aphid performance and phloem ingestion (Table 1, Figs 2–5), indicate that a major factor influencing aphids under eCO2 is plant nitrogen content

Summary

Introduction

Atmospheric carbon dioxide (CO2) concentration has increased significantly and is projected to double by 2100. Studies that have investigated the influence of climate change on plant disease epidemiology indicate positive, negative or neutral effects[8,9]. Different climate factors including changes to temperature and CO2, drought, storm severity and rainfall, might affect the life cycle of plants, pathogens, and insect vectors and their dispersal as well as their interactions, and have the potential to alter the rate of infestation and pathogen spread[10,11,12,13,14]. Changes to plant biochemistry occur when plants are exposed to higher CO2 levels, with a reduction of foliar nitrogen (N) concentration and a relative increase of carbon (C) (higher C:N ratios) due to the higher photosynthetic rates and growth[3]. Hemiptera, including aphids, there are reports suggesting an increase, decrease or no change to insect population

Objectives

Methods

Results

Conclusion