INVESTIGADORES
ZAVALA Jorge Alberto
artículos
Título:
Fitness benefits of trypsin proteinase inhibitor expression in Nicotiana attenuata are greater than their costs when plants are attacked.
Autor/es:
ZAVALA, J.A.; BALDWIN, I.T.
Revista:
BMC Ecology
Referencias:
Año: 2004 vol. 4 p. 1 - 15
ISSN:
1472-6785
Resumen:
Background: The commonly invoked cost-benefit paradigm, central to most of functional biology,
explains why one phenotype cannot be optimally fit in all environments; yet it is rarely tested.
Trypsin proteinase inhibitors (TPIs) expression in Nicotiana attenuata is known to decrease plant
fitness when plants compete with unattacked conspecifics that do not produce TPIs and also to
decrease the performance of attacking herbivores.The commonly invoked cost-benefit paradigm, central to most of functional biology,
explains why one phenotype cannot be optimally fit in all environments; yet it is rarely tested.
Trypsin proteinase inhibitors (TPIs) expression in Nicotiana attenuata is known to decrease plant
fitness when plants compete with unattacked conspecifics that do not produce TPIs and also to
decrease the performance of attacking herbivores.Nicotiana attenuata is known to decrease plant
fitness when plants compete with unattacked conspecifics that do not produce TPIs and also to
decrease the performance of attacking herbivores.
Results: In order to determine whether the putative benefits of TPI production outweigh its cost,
we transformed N. attenuata to silence endogenous TPI production or restore it in a natural mutant
that was unable to produce TPIs. We compared the lifetime seed production of N. attenuataIn order to determine whether the putative benefits of TPI production outweigh its cost,
we transformed N. attenuata to silence endogenous TPI production or restore it in a natural mutant
that was unable to produce TPIs. We compared the lifetime seed production of N. attenuataN. attenuata to silence endogenous TPI production or restore it in a natural mutant
that was unable to produce TPIs. We compared the lifetime seed production of N. attenuataN. attenuata
genotypes of the same genetic background with low or no TPI to that of genotypes with high TPI
levels on which M. sexta larvae were allowed to feed freely. Unattacked low TPI-producing
genotypes produced more seed capsules than did plants with high TPI levels. Caterpillar attack
reduced seed capsule production in all genotypes and reversed the pattern of seed capsule
production among genotypes. M. sexta larvae attacking genotypes with high TPI activity consumed
more TPI, less protein, and move later to the young leaves. Larval masses were negatively
correlated (R2 = 0.56) with seed capsule production per plant.M. sexta larvae were allowed to feed freely. Unattacked low TPI-producing
genotypes produced more seed capsules than did plants with high TPI levels. Caterpillar attack
reduced seed capsule production in all genotypes and reversed the pattern of seed capsule
production among genotypes. M. sexta larvae attacking genotypes with high TPI activity consumed
more TPI, less protein, and move later to the young leaves. Larval masses were negatively
correlated (R2 = 0.56) with seed capsule production per plant.M. sexta larvae attacking genotypes with high TPI activity consumed
more TPI, less protein, and move later to the young leaves. Larval masses were negatively
correlated (R2 = 0.56) with seed capsule production per plant.2 = 0.56) with seed capsule production per plant.
Conclusions: Our results demonstrate that the fitness benefits of TPI production outweigh their
costs in greenhouse conditions, when plants are attacked and that despite the ongoing evolutionary
interactions between plant and herbivore, TPI-mediated decreases in M. sexta performance
translates into a fitness benefit for the plant.Our results demonstrate that the fitness benefits of TPI production outweigh their
costs in greenhouse conditions, when plants are attacked and that despite the ongoing evolutionary
interactions between plant and herbivore, TPI-mediated decreases in M. sexta performance
translates into a fitness benefit for the plant.M. sexta performance
translates into a fitness benefit for the plant.