Growth responses and fitness costs after induction of pathogen resistance depend on environmental conditions

Abstract

Fitness costs of resistance are among the most widely discussed explanations for the evolution of induced resistance, but studies on induced resistance to pathogens are scarce and contradictory. In the present study the influence of nitrogen supply, length of the growing period and competition on the seed production of Arabidopsis in response to treatment with the chemical resistance elicitor BION ® was investigated. BION ® treatment elicited resistance to the bacterial pathogen Pseudomonas syringae , and biochemical changes after BION ® treatment were similar to those observed after bacterial infection. Induced plants grew more slowly during the first week after resistance induction, for which they then compensated by exhibiting faster growth than controls. Whether or not induced plants produced less seeds than controls depended on growing conditions. Costs, no costs and even higher seed production by induced plants were observed in experiments differently combining abiotic conditions. A higher seed production by induced plants arose particularly when the vegetation period was short, most probably a consequence of senescence-related processes that had been activated by resistance elicitation. Induced plants, however, produced less seeds when competing with controls and experiencing a full growing period. Studies controlling only some of the critical environmental factors can easily lead to apparently contradictory results, which in fact represent different outcomes of a complex interplay of factors.

Quantifying the Impacts of Systemic Acquired Resistance to Pitch Canker on Monterey Pine Growth Rate and Hyperspectral Reflectance

“…Previous work has shown that SAR may or may not be associated with reduced growth [12,25], whereas enhanced growth is also possible [15]. Most studies on SAR have involved annual plants [13] and thus do not provide information on long term effects of induced resistance. Our data showed no significant effect of induced resistance on growth of P. radiata during the first 12 months after trees were induced by inoculation with F. circinatum.…”

“…Fitness costs associated with SAR have been identified in several other plant hosts, including both wheat [12] and Arabidopsis [13] chemically primed for resistance with acibenzolar-S-methyl (BION), and barley induced by an avirulent Erysiphe graminis isolate [14]. However, other studies have shown no impact of SAR on fitness [7].…”

Neonicotinoid insecticides induce salicylate-associated plant defense responses

“…However, this fitness cost may not be the result of enhanced accumulation of SA per se, as the overproduction of SA in tobacco using constitutively expressed bacterial transgenes did not noticeably alter its development or appearance (39). With chemical SAR-inducers, fitness cost or benefit is dependent upon the chemical dosage, the age, and exposure of the plants to (a)biotic stress (40)(41)(42). The exogenous application of SARinducers tends to benefit plant fitness and yield when it primes the plant for a rapid response to subsequent stress that is then encountered.…”

Control of Bacterial Spot of Tomato and Activation of Enzymes Related to Resistance by Chemicals Under Field Conditions

“…Our results are consistent with those of Paradela et al (2001) and Quezado-Duval et al (2005a) for tomato, and those of Romero et al (2001) for chili pepper. There is evidence that acibenzolar-S-methyl controls the disease by inducing plant resistance, but the product is implicated in reducing plant productivity (Godard et al, 1999;Dietrich et al, 2005). Plants that allocate their resources to defense against pathogens are www.ccsenet.org/jas Journal of Agricultural Science Vol.…”