TY - JOUR
T1 - Effects of limitation stress and of disruptive stress on induced antigrazing defense in the bladder wrack Fucus vesiculosus
AU - Weinberger, Florian
AU - Rohde, Sven
AU - Oschmann, Yvonne
AU - Shahnaz, Laila
AU - Dobretsov, Sergey
AU - Wahl, Martin
PY - 2011/4/12
Y1 - 2011/4/12
N2 - We assessed the effects of light limitation and temperature shift on palatability and induced antiherbivore defense in the brown alga Fucus vesiculosus L. Incubation for 2 wk at light intensities above the compensation point of photosynthesis and in the absence of grazers increased the palatability of F. vesiculosus and its subsequent consumption by the omnivorous isopod Idotea baltica Pallas. This effect correlated with an increased C:N ratio and mannitol content in the algal tissue, presumably due to increased photosynthetic carbon fixation. Mannitol, the primary product of photosynthesis in F. vesiculosus, proved to be a feeding cue for I. baltica, and depletion of the mannitol pool may therefore account for the reduced palatability during light limitation. At light intensities above the compensation point of photosynthesis, F. vesiculosus responded with decreasing palatability when it was exposed to I. baltica grazing. Irrespective of the preceding light regime, such defense induction was prevented during incubation under light limitation. Thus, under low light, defense induction is not only inhibited, but also less necessary due to the relative absence of feeding cues. Upward or downward shifts in water temperature by approximately 10°C also inhibited inducible defense in F. vesiculosus. However, such shifts did not affect algal growth and were therefore the consequence of an impairment of specific defense-related components rather than of resource limitation, unless compensatory growth was given priority over defense.
AB - We assessed the effects of light limitation and temperature shift on palatability and induced antiherbivore defense in the brown alga Fucus vesiculosus L. Incubation for 2 wk at light intensities above the compensation point of photosynthesis and in the absence of grazers increased the palatability of F. vesiculosus and its subsequent consumption by the omnivorous isopod Idotea baltica Pallas. This effect correlated with an increased C:N ratio and mannitol content in the algal tissue, presumably due to increased photosynthetic carbon fixation. Mannitol, the primary product of photosynthesis in F. vesiculosus, proved to be a feeding cue for I. baltica, and depletion of the mannitol pool may therefore account for the reduced palatability during light limitation. At light intensities above the compensation point of photosynthesis, F. vesiculosus responded with decreasing palatability when it was exposed to I. baltica grazing. Irrespective of the preceding light regime, such defense induction was prevented during incubation under light limitation. Thus, under low light, defense induction is not only inhibited, but also less necessary due to the relative absence of feeding cues. Upward or downward shifts in water temperature by approximately 10°C also inhibited inducible defense in F. vesiculosus. However, such shifts did not affect algal growth and were therefore the consequence of an impairment of specific defense-related components rather than of resource limitation, unless compensatory growth was given priority over defense.
KW - Alga-herbivore interaction
KW - Defense induction
KW - Idotea
KW - Seaweed-herbivore interaction
KW - Stress effects
UR - http://www.scopus.com/inward/record.url?scp=79954544649&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79954544649&partnerID=8YFLogxK
U2 - 10.3354/meps09044
DO - 10.3354/meps09044
M3 - Article
AN - SCOPUS:79954544649
SN - 0171-8630
VL - 427
SP - 83
EP - 94
JO - Marine Ecology Progress Series
JF - Marine Ecology Progress Series
ER -