THERE IS A CRITICAL NEED TO DEVELOP NEW HERBICIDES. JUGLONE IS AN HERBICIDAL NATURAL PRODUCT EXCRETED BY BLACK WALNUT (JUGLANS NIGRA) WITH A MECHANISM OF ACTION UNLIKE ANY CURRENT HERBICIDE. DESPITE ADVANCES IN UNDERSTANDING JUGLONE BIOSYNTHESIS IT WILL NOT BE POSSIBLE TO ENGINEER JUGLONE-PRODUCING CROPS WITHOUT A CORRESPONDING RESISTANCE TRAIT TO PREVENT JUGLONE AUTOTOXICITY. BASED ON PRELIMINARY DATA, I HYPOTHESIZE THAT BLACK WALNUT CONJUGATES JUGLONE WITH GLUCOSE AND THEN CONTROLS ITS RELEASE INTO THE RHIZOSPHERE TO PREVENT AUTOTOXICITY. FUNDING FOR THIS RESEARCH WILL BE USED TO IDENTIFY AND CHARACTERIZE THE GLUCOSYLTRANSFERASE(S) INVOLVED IN CONVERTING JUGLONE TO HYDROJUGLONE GLUCOSIDE AND THE Β-GLUCOSIDASE(S) HYDROLYZING IT BACK TO JUGLONE AND GLUCOSE. I WILL FUNCTIONALLY SCREEN GLUCOSYLTRANSFERASE AND Β-GLUCOSIDASE CANDIDATES IDENTIFIED TO EXHIBIT EXPRESSION PATTERNS LIKE OTHER JUGLONE METABOLIC GENES. THIS RESEARCH WILL IMPROVE UNDERSTANDING OF STRATEGIES PLANTS EVOLVED TO PREVENT ALLELOCHEMICAL AUTOTOXICITY AND PROVIDES SYNTHETIC BIOLOGY "PARTS" FOR ENGINEERING CROPS RESISTANT TO JUGLONE. THIS NATURAL PRODUCT-BASED HERBICIDE APPROACH WILL HELP COMBAT HERBICIDE-RESISTANT WEEDS AND REDUCE DEPENDENCE ON SYNTHETIC HERBICIDES.

Purdue University, West Lafayette IN

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