Exposure to artificially damaged goldenrod volatiles increases saponins in seeds of field-grown soybean plants

Abstract

We previously reported that the exposure of field-grown black soybean seedlings (Glycine max ‘Hyokei Kuro-3’) to artificially damaged goldenrod volatiles (ADGVs) resulted in a significant increase in isoflavonoids in their seeds. Here, we used field-grown soybean seedlings to study the effects of the exposure to ADGVs on the production of seed saponins that are particularly abundant in soybean seeds. We used black soybean plants and yellow soybean plants (G. max ‘Yumesayou’). The exposure of black soybean parental plants to ADGVs resulted in a significant increase in the seed saponins Ab, βa, and Bc when compared with control seeds from non-exposed parental plants. In yellow soybean seeds, exposure resulted in a significant increase in the seed saponins Af, Ab, αg, βg, γg, and γa when compared with the control. Bb and Bc, the degradation products, were detected in black soybean seeds but not in yellow soybean seeds. This is the first evidence that environmental condition such as exposure to ADGVs affects to saponin content in plants.