Soybean resistance to stink bugs (Nezara viridula and Piezodorus guildinii) increases with exposure to solar UV?]B radiation and correlates with isoflavonoid content in pods under field conditions.

ZAVALA, J. A.*; MAZZA, C.A.; DILLON, F; CHLUDIL, H; BALLARÉ, C.L.

PLANT, CELL AND ENVIRONMENT (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 38 p. 920 - 928

0140-7791

Solar UV-B radiation (280?315 nm) has a significant influence on trophic relationships in natural and managed ecosystems, affecting plant?insect interactions. We explored the effects of ambient UV-B radiation on the levels of herbivory by stink bugs (Nezara viridula and Piezodorus guildinii) in field-grown soybean crops. The experiments included two levels of UV-B radiation (ambient and attenuated UV-B) and four soybean cultivars known to differ in their content of soluble leaf phenolics. Ambient UV-B radiation increased the accumulation of the isoflavonoids daidzin and genistin in the pods of all cultivars. Soybean crops grown under attenuated UV-B had higher numbers of unfilled pods and damaged seeds than crops grown under ambient UV-B radiation. Binary choice experiments with soybean branches demonstrated that stink bugs preferred branches of the attenuated UV-B treatment.We found a positive correlation between percentage of undamaged seeds and the contents of daidzin and genistin in pods. Our results suggest that constitutive and UV-B-induced isoflavonoids increase plant resistance to stink bugs under field conditions.