Location: Natural Products Utilization Research
Project Number: 6060-30400-001-001-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 25, 2026
End Date: Sep 25, 2028
Objective:
Objective 1, Genetic and metabolic engineering sorgoleone production in major agronomic crops and objective 2, Evaluation of biological efficacy of sorgoleone on multiple weed species
Approach:
Sorgoleone is a well-established plant-incorporated protectant (PIP)-based bioherbicide, in which a phytotoxic compound is synthesized and released from plant roots to suppress neighboring vegetation. It has long been recognized as a natural weed-suppressive agent, and its biosynthetic pathway and associated genes have been extensively characterized [1-4]. In contrast, the molecular mechanisms underlying sorgoleone secretion have largely remained unexplored. Recently, an ABCG transporter implicated in sorgoleone export has been identified through transcriptomics and reverse genetics-based approaches [5], providing new insight into the genetic basis of root secretion. Based on these knowledge, Objective 1 will introduce five key biosynthetic genes together with the newly identified sorgoleone ABCG transporter into heterologous plant systems using genetic engineering approaches. In parallel, metabolic engineering strategies will be employed to expand the precursor pool and increase flux through the engineered sorgoleone pathway in Arabidopsis to enhance its in planta production levels. These experiments will test whether coordinated expression of biosynthesis and transport component is sufficient to enable root secretion of sorgoleone outside of its native sorghum background and to achieve optimal production levels in planta, which are critical for PIP-based bioherbicide development. In addition to in planta engineering, Objective 2 of this project will directly evaluate the biological efficacy of sorgoleone using purified compound extracted from sorghum roots. Bioassays on petri dishes will be conducted in collaboration with weed scientists, and the effects of purified sorgoleone on germination and early growth of multiple weed species will be assessed. Together, these combined genetic and physiological studies will functionally validate sorgoleone as a PIP-based bioherbicide and establish the key requirements for its efficient production, secretion, and weed suppression.