Abstract

Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C-4 photosynthetic pathway of many of the world's most damaging weeds. In contrast, many of the most important crop plants use C-3 photosynthesis. Here, we show that 2', 3', 4', 3, 4-Pentahydroxychalcone (IC50 = 600 nM) and 2', 3', 4'-Trihydroxychalcone (IC50 = 4.2 mu M) are potent inhibitors of C-4 PEPC but do not affect C-3 PEPC at a same concentration range (selectivity factor: 15-45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C-4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C-4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C-3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C-4 PEPC inhibitors known to date. They offer a novel approach to combat C-4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C-4 plant key enzyme.

Published in

Scientific Reports
2016, Volume: 6, article number: 27333

UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1038/srep27333

Permanent link to this page (URI)

https://res.slu.se/id/publ/84693