Plant acclimation to elevated CO2 affects important plant functional traits, and concomitantly reduces plant colonization rates by an herbivorous insect
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Plants growing under elevated CO2 concentration may acclimatize to this environmental change by modification of chemical, physiological, and/or morphological traits. As a consequence, not only plant functioning but also plant–insect interactions might be altered, with important consequences particularly for agricultural systems. Whereas most studies have focused on the plant acclimation effects of elevated CO2 with regard to crop growth and productivity, acclimation effects on the behavioral response of insects associated with these plants have been largely neglected. In this study, we used a model system comprised of Brussels sprout Brassica oleraceae var. gemmifera and a specialized herbivorous insect, the cabbage aphid Brevicoryne brassicae, to test for the effects of various periods of exposure to an elevated (2× ambient) CO2 concentration on key plant functional traits and on host plant location behavior by the insect, assessed as plant colonization rates. Elevated CO2 had no measurable effect on colonization rates or total plant volatile emissions after a 2-week exposure, but it led to 15 and 26 % reductions in plant colonization rates after 6- and 10-week exposures, respectively. This reduction in plant colonization was associated with significant decreases in leaf stomatal conductance and plant volatile emission. Terpene emission, in particular, exhibited a great reduction after the 10-week exposure to elevated CO2. Our results provide empirical evidence that plants might acclimatize to a future increase in CO2, and that these acclimation responses might affect host plant choice and colonization behavior by herbivorous insects, which might be advantageous from the plant’s perspective.
KeywordsBrevicoryne brassicae Carbon dioxide Plant volatiles Stomatal conductance Terpenes
We thank Cornelia Sauer (Agroscope Wädenswil) for providing aphids, Dr. Markus Kalisch (Seminar for Statistics ETH) for statistical advice, Jana Collatz, Heather Kirk (Applied Entomology ETH), Rainer Messmer (Crop Science ETH) and two anonymous reviewers for constructive comments on the manuscript, and Andrea Klaiber for help with plant breeding.
- Adams R (1995) Identification of essential oil components by gas chromatography/mass spectrometry. Allured Publishing Corporation, ILGoogle Scholar
- Blackman RL, Eastop VF (1990) Specificity in aphid/plant genetic interactions, with particular attention to the role of the alate colonizer. In: Campbell RK, Eikenbary RD (eds) Aphid–plant genotype interactions. Elsevier, Amsterdam, pp 251–274Google Scholar
- Blackman RL, Eastop VF (2000) Aphids on the world’s crops, an identification and information guide. The Natural History Museum, LondonGoogle Scholar
- Constable JVH, Litvak ME, Greenberg JP, Monson RK (1999) Monoterpene emission from coniferous trees in response to elevated CO2 concentration and climate warming. Glob Change Biol 5:255–267Google Scholar
- Dixon AFG (1998) Aphid ecology. Chapman and Hall, LondonGoogle Scholar
- Drewry DT, Kumar P, Long S, Bernacchi C, Liang XZ, Sivapalan M (2010) Ecohydrological responses of dense canopies to environmental variability: 2. Role of acclimation under elevated CO2. J Geophys Res Biogeosci 115:G04023Google Scholar
- Himanen SJ, Nissinen A, Dong WX, Nerg AM, Stewart CN, Poppy GM, Holopainen JK (2008) Interactions of elevated carbon dioxide and temperature with aphid feeding on transgenic oilseed rape: Are Bacillus thuringiensis (Bt) plants more susceptible to nontarget herbivores in future climate? Glob Change Biol 14:1437–1454CrossRefGoogle Scholar
- Himanen SJ, Nerg AM, Nissinen A, Pinto DM, Stewart CN, Poppy GM, Holopainen JK (2009) Effects of elevated carbon dioxide and ozone on volatile terpenoid emissions and multitrophic communication of transgenic insecticidal oilseed rape (Brassica napus). New Phytol 181:174–186PubMedCrossRefGoogle Scholar
- Houghton J, Ding Y, Griggs D et al (2001) Climate change 2001: the scientific basis. Cambridge University Press, CambridgeGoogle Scholar