This study shows that stink bug damage induces seed defences, which is perceived early by MPKs that may activate defence metabolic pathways in developing seeds of field-grown soybean. © 2015 Society of Chemical Industry.

BACKGROUND Recently, in temperate and neotropical regions of South America the generalist stink bug Dichelops furcatus (Hemiptera: Pentatomidae) became a new pest of corn (Zea mays) seedlings. Implementation of no‐tillage cultivation system left organic matter covering the soil, which shelters adults of stink bugs during winter. In spring, corn is sowed under soybean stubble and D. furcatus adults start to feed on seedlings. To determine corn‐derived volatile organic compounds (VOCs) that attract this stink bug species, we evaluated stink bug preferences from two corn hybrids with contrast germplasm backgrounds, a temperate and a tropical hybrid. RESULTS Stink bugs preferred to feed on temperate seedlings rather than on the tropical ones. GC–MS and PCA analysis of VOCs suggested that hybrids emitted contrasting blends. Linalool represented 68% of total VOCs emitted from temperate corn, while in the tropical hybrid this compound represented 48%. Olfactometer experiments demonstrated that linalool was attractive to stink bugs. However, 2 h of D. furcatus attack induced emission of 14 additional VOCs in temperate seedlings, and olfactometer bioassay and blend of VOCs emission suggested that perceived volatiles by stink bugs induced feeding avoidance. The increment of VOCs emission was associated with the induction of JA, JA‐Ile, ABA, and IAA, and decreasing of SA concentrations. CONCLUSION This is the first time showing a complete profile of defensive phytohormones induced by stink bugs feeding on corn, and further demonstrating that a blend of corn seedling‐associated VOCs, mainly composed by linalool, modulates D. furcatus adults' behavior and feeding preferences. © 2021 Society of Chemical Industry

Lupinus species are commonly used as annual forage and for grain production. They are considered alternative crops to soybean due to their adaptation to cool environments and dry soils. The present study is an analysis of the chemical changes coming from biomass removal in a sweet genotype of Lupinus angustifolius. Mechanical damage induced significant increases in antioxidant activity (12.4%), as well as in flavonoid and phenolic content (36.6% and 12.0%, respectively). This sweet lupin also exhibited a higher induced response (68.2%) in the alkaloid content after the damage. These same alkaloids were identified in the control samples and all of them, except lupanine, showed higher relative abundances in response to mechanical damage. Traces of a-isolupanine were detected in control samples and showed a 23.5-fold increase in response to biomass removal. Mechanical damage also produced a striking increase (8.6-fold) in relative abundance of genistin.