Data from: Plant defence responses to volatile alert signals are population-specific

Herbivore-induced volatiles are widespread in plants. They can serve as
alert signals that enable neighbouring leaves and plants to pre-emptively
increase defences and avoid herbivory damage. However, our understanding
of the factors mediating volatile organic compound (VOC) signal
interpretation by receiver plants and the degree to which multiple
herbivores affect VOC signals is still limited. Here we investigated
whether plant responses to damage-induced VOC signals were population
specific. As a secondary goal, we tested for interference in signal
production or reception when plants were subjected to multiple types of
herbivore damage. We factorially crossed the population sources of paired
Phaseolus lunatus plants (same versus different population sources) with a
mechanical damage treatment to one member of the pair (i.e. the VOC
emitter, damaged versus control), and we measured herbivore damage to the
other plant (the VOC receiver) in the field. Prior to the experiment, both
emitter and receiver plants were naturally colonized by aphids, enabling
us to test the hypothesis that damage from sap-feeding herbivores
interferes with VOC communication by including emitter and receiver aphid
abundances as covariates in our analyses. One week after mechanical leaf
damage, we removed all the emitter plants from the field and conducted
fortnightly surveys of leaf herbivory. We found evidence that receiver
plants responded using population-specific ‘dialects’ where only receivers
from the same source population as the damaged emitters suffered less leaf
damage upon exposure to the volatile signals. We also found that the
abundance of aphids on both emitter and receiver plants did not alter this
volatile signalling during both production and reception despite
well-documented defence crosstalk within individual plants that are
simultaneously attacked by multiple herbivores. Overall, these results
show that plant communication is highly sensitive to genetic relatedness
between emitter and receiver plants and that communication is resilient to
herbivore co-infestation.