Poster: Plant Pathogen Interactions
P48067: Biosynthesis and regulation of 3-deoxyanthocyanidin phytoalexins induced during Sorghum-Colletotrichum interaction: Heterologous expression in maize.
Chopra, Surinder Contact Presenter||Authors||Chopra, Surinder (A) Gaffoor, Iffa (A) Ibraheem, Farag (B) |
(A): Pennsylvania State University|
(B): University of Illinois
Leaf blight is one of the main foliar fungal diseases of maize. The disease inoculum survives in the field debris and can repeatedly infect the maize plant at any stage during its life cycle. Although disease incidence can be reduced by tilling and rotating with non-cereal crops, identification of resistant germplasm is more promising. Unfortunately, most of the maize germplasm screened to date is susceptible to the disease. Sorghum bicolor, a close relative of maize produces a class of compounds (3-deoxyanthocyanidins) in response to fungal attack. These compounds have antifungal properties and confer resistance to leaf blight. Biosynthesis of these compounds is not very well understood but based on their structural similarities these compounds may be arising through the flavonoid pathway. Although maize produces numerous flavonoid compounds, it does not produce 3-deoxyanthocyanidins in leaves in response to fungal attack. We have identified candidate genes and transformed maize in an effort to engineer the biosynthesis of these antifungal compounds and thereby enhance resistance to leaf blight. We have also identified important cis-regulatory elements in promoter of one of the Myb transcription factor genes. We have further characterized the response of transgenic maize lines when infected with the fungus that causes southern corn leaf blight. Profiling of several different flavonoid compounds using HPLC and LC-MS has been performed. Results showing induction of specific compounds will be presented.