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ARS Home » Southeast Area » Oxford, Mississippi » Natural Products Utilization Research » Research » Publications at this Location » Publication #297537
Title: Phomalactone from a phytopathogenic fungus infecting Zinnia elegans (Asteraceae) leaves

Author
item Meepagala, Kumudini
item JOHNSON, ROBERT
item TECHEN, NATASHA - UNIVERSITY OF MISSISSIPPI
item WEDGE, DAVID
item DUKE, STEPHEN

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2015
Publication Date: 7/2/2015
Citation: Meepagala, K.M., Johnson, R.D., Techen, N., Wedge, D.E., Duke, S.O. 2015. Phomalactone from a phytopathogenic fungus infecting Zinnia elegans (Asteraceae) leaves. Journal of Chemical Ecology. 41:602-612.

Interpretive Summary: Zinnias are ornamental plants that produce colorful flowers. These plants are infected by a fungus that causes dark red spots particularly in late spring to the middle of summer in the Mid-South part of the United States. This fungal disease when untreated causes the leaves and flowers to wilt and eventually kills the plant. The fungus was isolated, cultured in the lab. Compound that is responsible for the symptoms of the fungal disease has been isolated and identified as phomalactone. This compound has shown phytotoxic activity in laboratory tests. The fungus has potential as a source of obtaining the phytotoxin in large scale.

Technical Abstract: Zinnia elegans plants are infected by a fungus that causes necrosis with dark red spots particularly in late spring to the middle of summer in the Mid-South part of the United States. This fungal disease when untreated causes the leaves to wilt and eventually kills the plant. The fungus was isolated, cultured in potato dextrose broth, and identified as a member in Sordariomycetes class. Two major metabolites were isolated and identified as the lactones phomalactone and catenioblin A. Electrolyte leakage studies on cucumber leaf disks have indicated that phomalactone causes cellular leakage, and this effect is related to the mechanism of action of this fungus causing wilting in Z. elegans plants. The fungus has potential as a source of obtaining the phytotoxin in large scale.