Submitted to: National Soybean Rust Symposium
Publication Type: Abstract only
Publication Acceptance Date: 11/15/2007
Publication Date: 12/12/2007
Citation: Lygin, A., Li, S., Widholm, J., Lozovaya, V. 2007. Involvement of Phenylpropanoids in Soybean Rust Resistance. National Soybean Rust Symposium. P 6 Interpretive Summary:
Technical Abstract: Little is known about the metabolic responses of soybean plants to Phakopsora pachyrhizi (rust) attack. It is important to understand what metabolic pathways in soybean plants are involved in the disease response in order to assist in the development of cultivars with improved resistance that produce more stable yields. Our past studies of soybean plant/pathogen interactions showed that the soybean phytoalexin, glyceollin and cell wall phenolics are critical for plant resistance to different important pathogens. Our new data also indicate that isoflavonoid and flavonoid synthesis in soybean leaves was strongly stimulated in response to rust infection. Several fold increases of flavonoids (quercetin and kempferol) and phenolic acid levels were found in leaves of rust infected plants compared to the control. While the precursor of glyceollin daidzein and the phytoalexin glyceollin were not detected in leaves of uninfected plants, accumulation of both compounds at marked levels occurred in rust infected leaves indicating that glyceollin is involved in the plant defense response to the soybean rust pathogen. Thus increased synthesis of specific compounds in the phenylpropanoid pathway, such as the phytoalexin glyceollin that are toxic to the fungus could help increase soybean rust resistance.