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Drought stress affects response of phytopathogen vectors and their parasitoids to infection‐ and damage‐induced plant volatile cues
Author(s) -
MARTINI XAVIER,
STELINSKI LUKASZ L.
Publication year - 2017
Publication title -
ecological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.865
H-Index - 81
eISSN - 1365-2311
pISSN - 0307-6946
DOI - 10.1111/een.12439
Subject(s) - diaphorina citri , biology , methyl salicylate , parasitoid , herbivore , radiata , host (biology) , botany , horticulture , attraction , vector (molecular biology) , pathogen , biological pest control , vigna , ecology , microbiology and biotechnology , gene , linguistics , philosophy , biochemistry , hemiptera , recombinant dna
1. The response of a phytopathogen vector to pathogen‐induced plant volatiles was investigated, as well as the response of the phytopathogen vector's parasitoid to herbivore‐induced plant volatiles released from plants with and without drought stress. 2. These experiments were performed with A sian citrus psyllid ( Diaphorina citri ), vector of the plant pathogen Candidatus L iberibacter asiaticus ( C L as) and its parasitoid Tamarixia radiata as models. Candidatus L iberibacter asiaticus is the presumed causal pathogen of huanglongbing ( HLB ), also called citrus greening disease. 3. Diaphorina citri vectors were attracted to headspace volatiles of C L as‐infected citrus plants at 95% of their water‐holding capacity ( WHC ); such attraction to infected plants was much lower under drought stress. Attraction of the vector to infected and non‐stressed plants was correlated with greater release of methyl salicylate ( M e SA ) as compared with uninfected and non‐stressed control citrus plants. Drought stress decreased M e SA release from C L as‐infected plants as compared with non‐stressed and infected plants. 4. Similarly, T. radiata was attracted to headspace volatiles released from D. citri ‐infested citrus plants at 95% of their WHC . However, wasps did not show preference between headspace volatiles of psyllid‐infested and uninfested plants when they were at 35% WHC , suggesting that herbivore‐induced defences did not activate to recruit this natural enemy under drought stress. 5. Our results demonstrate that herbivore‐ and pathogen‐induced responses are environmentally dependent and do not occur systematically following damage. Drought stress affected both pathogen‐ and herbivore‐induced plant volatile release, resulting in concomitant decreases in behavioural response of both the pathogen's vector and the vector's primary parasitoid.