Spider mites suppress tomato defenses downstream of jasmonate and salicylate independently of hormonal crosstalk.
Bottom Line: We characterized timing and magnitude of phytohormone accumulation and defense-gene expression, and determined if mites that cannot suppress defenses benefit from sharing a leaf with suppressors.Suppression occurred downstream of JA and SA accumulation, independently of the JA-SA antagonism, and was powerful enough to boost the reproductive performance of nonsuppressors up to 45%.Our results show that suppressing defenses not only brings benefits but, within herbivore communities, can also generate a considerable ecological cost when promoting the population growth of a competitor.
Affiliation: Department of Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE, Amsterdam, the Netherlands.Show MeSH
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Mentions: In line with the previous results, infestation with 15 T. urticae Santpoort-2 mites resulted in strongly induced JA and SA defenses (Fig.4a,b). The plant's defense responses to Santpoort-2 mites increased in a density-dependent manner (Fig. S7). The 15 T. evansi Viçosa-1 mites caused minor increases in JA-Ile and SA concentrations, but higher densities of T. evansi Viçosa-1 did not further elevate hormone concentrations or PI-IIc expression, while even lowering that of PR-1a (Fig. S7).
Affiliation: Department of Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE, Amsterdam, the Netherlands.