A unified approach to the estimation and interpretation of resistance costs in plants

Abstract

International audiencePlants exhibit a number of adaptive defence traits that endow resistance to past and current abiotic and biotic stresses. It is generally accepted that these adaptations will incur a cost when plants are not challenged by the stress to which they have become adapted--the so-called 'cost of adaptation'. The need to minimise or account for allelic variation at other fitness-related loci (genetic background control) is frequently overlooked when assessing resistance costs associated with plant defence traits. We provide a synthesis of the various experimental protocols that accomplish this essential requirement. We also differentiate those methods that enable the identification of the trait-specific or mechanistic basis of costs (direct methods) from those that provide an estimate of the impact of costs by examining the evolutionary trajectories of resistance allele frequencies at the population level (indirect methods). The advantages and disadvantages for each proposed experimental design are discussed. We conclude that plant resistance systems provide an ideal model to address fundamental questions about the cost of adaptation to stress. We also propose some ways to expand the scope of future studies for further fundamental and applied insight into the significance of adaptation costs

The evolution of mutualism from reciprocal parasitism: more ecological clothes for the Prisoner’s Dilemma

“…there are additional costs of induced resistance during the interaction) then in the pay-off matrix, this cost would act additively with respect to a and can therefore be subsumed in a new parameter, say a', such that mutualism would still only evolve if c [ a'; it would not change our basic conclusions. However, in many, if not all, host-parasite interactions, costs of resistance are present even in the absence of a pathogen (Biere and Antonovics 1996;Vila-Aiub et al 2011;Webster and Woolhouse 1999;Tschirren et al 2012;Baker and Antonovics 2012) and are likely to be quite general, as without such costs organisms would just accumulate ever increasing resistances. In other studies, costs have been posited by the inclusion of ''punishment'' in models of the evolution of mutualism (Boyd and Richerson 1992;Dreber et al 2008), and these are imposed differentially during the interaction itself.…”

“…Resistance costs to parasitism have been shown in plants (Biere and Antonovics 1996;Vila-Aiub et al 2011), animals (Webster and Woolhouse 1999;Tschirren et al 2012), and humans (Baker and Antonovics 2012) and are likely to be ubiquitous, as without such costs, all resistances would be expected to go to fixation. To represent a cost of resistance in X 2 and Y 2 , we include the parameters c x , c y in the pay-off matrix:…”

Effects of Environmental Factors on Seed Germination and Emergence of Glyphosate Resistant and Susceptible Sourgrass

“…Alleles that generate resistance to herbicides can cause pleiotropic effects in the life cycle of a plant, with germination being the sum of the effect of these alleles and environmental effects. This effect has already been reported for some cases of weed resistance to herbicides inhibiting ACCase (Vila-Aiub et al, 2011;Délye et al, 2013). The selection of weed biotypes resistant to glyphosate has increased in recent years (Heap, 2016).…”

Parâmetros fisiológicos e nutricionais de cultivares de soja resistentes ao glifosato em comparação com cultivares isogênicas próximas

“…A grande interação de fatores relacionados a cultivares, diponibilidade de nutrients, e efeito do herbicida, por exemplo, difi culta a realização de estudos sobre variação de adaptação em soja GR. As avaliações do efeito de variação de adaptação relacionado a resistência a herbicidas deve contemplar um maior número de genótipos, a fi m de proporcionar o isolamento dos efeitos pleiotrópicos relacionados à resistência em relação ao efeito do ambiente e demais causas de diversidades genética entre os genótipos em avaliação (VILA-AIUB et al, 2011).…”