A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Inducible resistance to herbivory in Fucus vesiculosus - duration, spreading and variation with nutrient availability
Tekijät: Hemmi A, Honkanen T, Jormalainen V
Kustantaja: INTER-RESEARCH
Julkaisuvuosi: 2004
Journal: Marine Ecology Progress Series
Tietokannassa oleva lehden nimi: MARINE ECOLOGY PROGRESS SERIES
Lehden akronyymi: MAR ECOL PROG SER
Vuosikerta: 273
Aloitussivu: 109
Lopetussivu: 120
Sivujen määrä: 12
ISSN: 0171-8630
DOI: https://doi.org/10.3354/meps273109
Tiivistelmä
Inducible resistance in plants is a defense strategy for avoiding the negative consequences of herbivory on plant fitness. Since resistance is costly, the induction of resistance may 14 depend on resource availability. Resource-based plant-herbivore hypotheses predict that the cost of 14 producing carbon-based defensive metabolites will be higher when an excess of nutrients is available for growth. We tested experimentally the effect of nutrient availability on the occurrence, duration and within-alga spread of inducible resistance in the brown alga Fucus vesiculosus L. Based on feeding preference bioassays using the herbivore Idotea baltica (Pallas), simulated grazing of F vesiculosus caused a clear, rapid, induced resistance that disappeared after 10 to 38 d. Furthermore, the induction of resistance does not spread to neighboring fronds or to growing tips above the point of simulated grazing. Induced resistance against isopod grazing, however, was not explained by increased production of phlorotannins, despite their putative role in the defense against herbivory. Phlorotannin production responded most strongly to nutrient enhancement, which reduced the phlorotannin concentration of the alga. Nutrient enhancement, however, did not affect the induction of resistance. The occurrence of induced resistance together with the lack of correlation between the phlorotannin concentration and the food preferences of herbivores imply that I. baltica is not deterred by the total quantity of phlorotannins; there may, however, be other, as yet unknown, rapidly inducing substances in F. vesiculosus that are capable of functioning as feeding deterrents to isopod grazers. Resistance may also arise as a side-effect of substances with a functional role, for instance in wound-healing processes. The localized nature and short duration of such deterrence imply that it may be inefficient as a general defense against herbivory, but may benefit the alga by dispersing future damage within the individual and avoiding the breakage of whole fronds.
Inducible resistance in plants is a defense strategy for avoiding the negative consequences of herbivory on plant fitness. Since resistance is costly, the induction of resistance may 14 depend on resource availability. Resource-based plant-herbivore hypotheses predict that the cost of 14 producing carbon-based defensive metabolites will be higher when an excess of nutrients is available for growth. We tested experimentally the effect of nutrient availability on the occurrence, duration and within-alga spread of inducible resistance in the brown alga Fucus vesiculosus L. Based on feeding preference bioassays using the herbivore Idotea baltica (Pallas), simulated grazing of F vesiculosus caused a clear, rapid, induced resistance that disappeared after 10 to 38 d. Furthermore, the induction of resistance does not spread to neighboring fronds or to growing tips above the point of simulated grazing. Induced resistance against isopod grazing, however, was not explained by increased production of phlorotannins, despite their putative role in the defense against herbivory. Phlorotannin production responded most strongly to nutrient enhancement, which reduced the phlorotannin concentration of the alga. Nutrient enhancement, however, did not affect the induction of resistance. The occurrence of induced resistance together with the lack of correlation between the phlorotannin concentration and the food preferences of herbivores imply that I. baltica is not deterred by the total quantity of phlorotannins; there may, however, be other, as yet unknown, rapidly inducing substances in F. vesiculosus that are capable of functioning as feeding deterrents to isopod grazers. Resistance may also arise as a side-effect of substances with a functional role, for instance in wound-healing processes. The localized nature and short duration of such deterrence imply that it may be inefficient as a general defense against herbivory, but may benefit the alga by dispersing future damage within the individual and avoiding the breakage of whole fronds.
Turun yliopiston Tutkimustietojärjestelmän portaali