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Overcompensation of herbivore reproduction through hyper‐suppression of plant defenses in response to competition
Author(s) -
Schimmel Bernardus C. J.,
Ataide Livia M. S.,
Chafi Rachid,
Villarroel Carlos A.,
Alba Juan M.,
Schuurink Robert C.,
Kant Merijn R.
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14543
Subject(s) - tetranychus urticae , biology , solanum , mite , spider mite , herbivore , infestation , jasmonate , generalist and specialist species , botany , alate , ecology , gene , genetics , pest analysis , arabidopsis , aphididae , homoptera , habitat , mutant
Summary Spider mites are destructive arthropod pests on many crops. The generalist herbivorous mite Tetranychus urticae induces defenses in tomato ( Solanum lycopersicum ) and this constrains its fitness. By contrast, the Solanaceae‐specialist Tetranychus evansi maintains a high reproductive performance by suppressing tomato defenses. Tetranychus evansi outcompetes T. urticae when infesting the same plant, but it is unknown whether this is facilitated by the defenses of the plant. We assessed the extent to which a secondary infestation by a competitor affects local plant defense responses (phytohormones and defense genes), mite gene expression and mite performance. We observed that T. evansi switches to hyper‐suppression of defenses after its tomato host is also invaded by its natural competitor T. urticae . Jasmonate ( JA ) and salicylate ( SA ) defenses were suppressed more strongly, albeit only locally at the feeding site of T. evansi , upon introduction of T. urticae to the infested leaflet. The hyper‐suppression of defenses coincided with increased expression of T. evansi genes coding for salivary defense‐suppressing effector proteins and was paralleled by an increased reproductive performance. Together, these observations suggest that T. evansi overcompensates its reproduction through hyper‐suppression of plant defenses in response to nearby competitors. We hypothesize that the competitor‐induced overcompensation promotes competitive population growth of T. evansi on tomato.