TY  - JOUR
A1  - Tomiolo, Sara
A1  - Metz, Johannes
A1  - Blackwood, Christopher B.
A1  - Djendouci, Karin
A1  - Henneberg, Lorenz
A1  - Mueller, Caroline
A1  - Tielboerger, Katja
T1  - Short-term drought and long-term climate legacy affect production of chemical defenses among plant ecotypes
JF  - Environmental and Experimental Botany
N2  - Long and short-term climatic variation affect the ability of plants to simultaneously cope with increasing abiotic stress and biotic interactions. Specifically, ecotypes adapted to different climatic conditions (i.e., long-term legacy) may have to adjust their allocation to chemical defenses against enemies under acute drought (i.e., short-term response). Although several studies have addressed drought effects on chemical defense production, little is known about their intraspecific variation along resource gradients. Studying intraspecific variation is important for understanding how different environments select for defense strategies and how these may be affected directly and indirectly by changing climatic conditions. We conducted greenhouse experiments with the annual Biscutella didyma (Brassicaceae) to test the effects of long-term climatic legacy versus short-term drought stress on the concentrations of defense compounds (glucosinolates). To this aim, four ecotypes originating from a steep aridity gradient were exposed to contrasting water treatments. Concentrations of chemical defenses were measured separately in leaves of young (8 weeks) and old (14 weeks) plants, respectively. For young plants, ecotypes from the wettest climate (long-term legacy) as well as plants receiving high water treatments (short-term response) were better defended. A marginally significant interaction suggested that wetter ecotypes experienced a larger shift in defense production across water treatments. Older plants contained much lower glucosinolate concentrations and showed no differences between ecotypes and water treatments. Our results indicate that younger plants invest more resources into chemical defenses, possibly due to higher vulnerability to tissue loss compared to older plants. We propose that the strong response of wet ecotypes to water availability may be explained by a less pronounced adaptation to drought.
KW  - Plant chemical defense
KW  - Glucosinolates
KW  - Climatic legacy
KW  - Short-term drought
KW  - Brassicaceae
KW  - Gradients
Y1  - 2017
U6  - https://doi.org/10.1016/j.envexpbot.2017.07.009
SN  - 0098-8472
SN  - 1873-7307
VL  - 141
SP  - 124
EP  - 131
PB  - Elsevier
CY  - Oxford
ER  -