Early perception of stink bug damage in developing seeds of field-grown soybean induces chemical defences and decreases bug attack

GIACOMETTI ROMINA; BARNETO JESICA; BARRIGA LUCIA; SARDOY PEDRO; BALESTRASSE KARINA; ANDRADE ANDREA; PAGANO EDUARDO; ALEMANO SERGIO; ZAVALA JORGE

PEST MANAGEMENT SCIENCE

JOHN WILEY & SONS LTD

Lugar: Londres; Año: 2016 vol. 72 p. 1585 - 1594

1526-498X

Southern green stink bugs (Nezara viridula) invade field-grown soybean crops, where they feed on developing seeds and inject phytotoxic saliva that causes yield reduction. Although leaf responses to herbivory are well studied, no information is available about the regulation of defenses in seeds.ResultsThis study demonstrated that mitogen-activated protein kinases (MPK)3, MPK4 and MPK6 are expressed and activated in developing seeds of field-grown soybean, and regulates a defensive response after stink bug damage. Although 10 to 20 min after stink bug feeding of seeds induced expression of MPK3, MPK6 and MPK4, only MPK6 was phosphorylated after damage. Herbivory induced an early peak of jasmonic acid (JA) accumulation and ethylene (ET) emission after 3 h in developing seeds, whereas salicylic acid (SA) was also early induced and with increasing levels up to 72 h after damage. Damaged seeds up-regulated defensive genes typically modulated by JA/ET or SA, which in turn decreased the activity of digestive enzymes in the gut of stink bugs. Induced seeds were less preferred by stink bugs.ConclusionThis study shows that stink bug damage induces seed defenses, which is perceived early by MPKs that may activate defense metabolic pathways in developing seeds of field grown-soybean.