Priming negatively affects feeding behaviour and aphid biomass of Rhopalosiphum padi on barley

Abstract Plants have developed numerous strategies for responding to abiotic and biotic stresses. In particular, the microbiota surrounding plants may a positive effect on plant stress responses. One is reaction rhizobacteria, which can lead induced systemic resistance. Gram-negative soil bacteria that produce N -acyl homoserine lactones (AHL), example, Ensifer meliloti , induce primed state in part of inducible resistance phenomenon. Observing Rhopalosiphum padi feeding behaviour priming sensitive barley genotype, treated with AHL-producing E. strain expR + ch using electrical penetration graph technique showed decreased ingestion food. Aphids appear overcome this within eight-hour observation period, possibly explaining absence differences reproduction. Reproduction was observed period 14 days control-treated plants. Long-term observations over 40 after aphid infestation lower biomass contrast control group, interpreted as delayed population growth, an increase Priming-related genotypic effects defence response aphids were observed, no beneficial genotype when its sensitivity low. Previously, AHL-priming enhanced against fungi . The present study reports same R. These findings suggest represent new approach breeding, targeting multiple pests parallel by