Exogenous treatment with salicylic acid attenuates ultraviolet-B radiation stress in soybean seedlings

Abstract

Soybean (Glycine max L.) seedlings were sprayed with salicylic acid (SA) and treated with UV-B radiation of 7.1 Wm-2. Exposure of UV-B significantly reduced the shoot height, root length, shoot and root fresh weight. Exogenous application of SA moderated the reduction of growth. UV-B significantly reduced contents of chlorophyll (Chl) a and b, photosynthetic rate (Pn), stomatal conductance (gs), but increased carotenoids (Car) and flavonoids content. Exogenous application of SA mitigated the reduction of Chl, Car, Pn, gs and the increase of flavonoids in plants treated with UV-B. Exogenous application of SA did not moderate transpiration rate (E) and water use efficiency (WUE) reduction. There was no significant difference in Fv/Fm and Fv/Fo in all treatments. Foliar spray of SA counteracted the UV-B effects on soybean. © 2012 Springer-Verlag GmbH.