Hypersensitive-like response in Brassica plants is specifically induced by molecules from egg-associated secretions of cabbage white butterflies

Plants perceive and respond to herbivore insect eggs. Upon egg deposition on leaves, a strong hypersensitive response (HR)-like cell death can be activated leading desiccation and/or dropping. In Brassica spp., including many crops, the HR-like mechanism against eggs of cabbage white butterflies ( Pieris spp.) is poorly understood. Using two species, crop B. rapa its wild relative nigra , we studied cellular molecular plant brassicae characterized potential egg-associated patterns (EAMPs) inducing death. We found that P. induced typical hallmarks early immune responses, such as callose deposition, production reactive oxygen species in leaf tissue, also plants did not express However, elevated levels ethylene upregulation salicylic acid-responsive genes were only detected accession expressing Eggs wash from contains compounds but generalist moth Mamestra not. Furthermore, made hatched eggs, glue, accessory reproductive glands (ARG) produce this death, whereas washes unfertilized dissected ovaries or removal glue resulted no reduced response. This suggests there one multiple associated pattern (EAMP) located teresponse specific species. Lastly, our results indicate EAMP neither lipidic nor proteinaceous. Our study expands knowledge - -egg interaction step closer toward identification EAMPs corresponding receptor(s) Brassica.