INVESTIGADORES
ZAVALA Jorge Alberto
artículos
Título:
Constitutive and inducible trypsin proteinase inhibitor production incurs large fitness costs in Nicotiana attenuata.
Autor/es:
ZAVALA, J.A.; PATANKAR, A.G.; GASE, K.; BALDWIN, I.T.
Revista:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Referencias:
Año: 2004 vol. 101 p. 1607 - 1612
ISSN:
0027-8424
Resumen:
Plant trypsin proteinase inhibitors (TPIs) are potent herbivore- and
jasmonate (JA)-induced defenses, but support for the commonly
invoked explanation for their inducible expression, namely their
associated fitness costs, has been elusive. To determine whether
the expression of TPIs incurs fitness costs, we expressed 175 bp of
the seven-domain pi from Nicotiana attenuata in an antisense
orientation in a TPI-producing genotype (WT) of N. attenuata to
reduce TPI expression. Moreover, we expressed the full-length
seven-domain pi in a sense orientation under control of a constitutive
promoter to restore TPI activity in a natural genotype unable
to produce TPIs because of a mutation in its endogenous pi gene.
Lifetime reproductive output was determined from high and low
TPI-producing plants of the same genetic background with and
without JA elicitation and grown in the same pot to simulate
natural competitive and nutrient regimes. Transformants with
either low or no TPI activity grew faster and taller, flowered earlier,
and produced more seed capsules (2553%) than did neighboring
TPI-producing genotypes, and JA elicitation increased TPI production
and decreased seed capsule production further. Growth under
high light levels only marginally reduced these fitness costs.
Results were similar regardless of whether TPI activity was suppressed
or restored by transformation: the larger the difference in
TPI activity between neighbors, the larger the difference in seed
capsule production (R2 0.57). TPI production is costly for a plants
components of fitness when grown under realistic competitive
regimes and is consistent with the hypothesis that inducibility
evolved as a cost-saving mechanism.pi from Nicotiana attenuata in an antisense
orientation in a TPI-producing genotype (WT) of N. attenuata to
reduce TPI expression. Moreover, we expressed the full-length
seven-domain pi in a sense orientation under control of a constitutive
promoter to restore TPI activity in a natural genotype unable
to produce TPIs because of a mutation in its endogenous pi gene.
Lifetime reproductive output was determined from high and low
TPI-producing plants of the same genetic background with and
without JA elicitation and grown in the same pot to simulate
natural competitive and nutrient regimes. Transformants with
either low or no TPI activity grew faster and taller, flowered earlier,
and produced more seed capsules (2553%) than did neighboring
TPI-producing genotypes, and JA elicitation increased TPI production
and decreased seed capsule production further. Growth under
high light levels only marginally reduced these fitness costs.
Results were similar regardless of whether TPI activity was suppressed
or restored by transformation: the larger the difference in
TPI activity between neighbors, the larger the difference in seed
capsule production (R2 0.57). TPI production is costly for a plants
components of fitness when grown under realistic competitive
regimes and is consistent with the hypothesis that inducibility
evolved as a cost-saving mechanism.N. attenuata to
reduce TPI expression. Moreover, we expressed the full-length
seven-domain pi in a sense orientation under control of a constitutive
promoter to restore TPI activity in a natural genotype unable
to produce TPIs because of a mutation in its endogenous pi gene.
Lifetime reproductive output was determined from high and low
TPI-producing plants of the same genetic background with and
without JA elicitation and grown in the same pot to simulate
natural competitive and nutrient regimes. Transformants with
either low or no TPI activity grew faster and taller, flowered earlier,
and produced more seed capsules (2553%) than did neighboring
TPI-producing genotypes, and JA elicitation increased TPI production
and decreased seed capsule production further. Growth under
high light levels only marginally reduced these fitness costs.
Results were similar regardless of whether TPI activity was suppressed
or restored by transformation: the larger the difference in
TPI activity between neighbors, the larger the difference in seed
capsule production (R2 0.57). TPI production is costly for a plants
components of fitness when grown under realistic competitive
regimes and is consistent with the hypothesis that inducibility
evolved as a cost-saving mechanism.pi in a sense orientation under control of a constitutive
promoter to restore TPI activity in a natural genotype unable
to produce TPIs because of a mutation in its endogenous pi gene.
Lifetime reproductive output was determined from high and low
TPI-producing plants of the same genetic background with and
without JA elicitation and grown in the same pot to simulate
natural competitive and nutrient regimes. Transformants with
either low or no TPI activity grew faster and taller, flowered earlier,
and produced more seed capsules (2553%) than did neighboring
TPI-producing genotypes, and JA elicitation increased TPI production
and decreased seed capsule production further. Growth under
high light levels only marginally reduced these fitness costs.
Results were similar regardless of whether TPI activity was suppressed
or restored by transformation: the larger the difference in
TPI activity between neighbors, the larger the difference in seed
capsule production (R2 0.57). TPI production is costly for a plants
components of fitness when grown under realistic competitive
regimes and is consistent with the hypothesis that inducibility
evolved as a cost-saving mechanism.pi gene.
Lifetime reproductive output was determined from high and low
TPI-producing plants of the same genetic background with and
without JA elicitation and grown in the same pot to simulate
natural competitive and nutrient regimes. Transformants with
either low or no TPI activity grew faster and taller, flowered earlier,
and produced more seed capsules (2553%) than did neighboring
TPI-producing genotypes, and JA elicitation increased TPI production
and decreased seed capsule production further. Growth under
high light levels only marginally reduced these fitness costs.
Results were similar regardless of whether TPI activity was suppressed
or restored by transformation: the larger the difference in
TPI activity between neighbors, the larger the difference in seed
capsule production (R2 0.57). TPI production is costly for a plants
components of fitness when grown under realistic competitive
regimes and is consistent with the hypothesis that inducibility
evolved as a cost-saving mechanism.R2 0.57). TPI production is costly for a plants
components of fitness when grown under realistic competitive
regimes and is consistent with the hypothesis that inducibility
evolved as a cost-saving mechanism.