Phytotoxic Potential of Trans-chalcone on Crop Plants and Model Species

Chalcones are flavonoid precursors that recently have been found to disrupt mitochondrial function and induce apoptosis in Arabidopsis radicles. However, whether they are potentially useful for weed control as selective herbicides depends on whether they are phytotoxic for important weeds and are not toxic for crops. This work determines the phytotoxicity of chalcone for the germination and early development of a variety of crop species and associated weeds. Also, the phytotoxic potential was investigated in chalcone-watered or sprayed adult plants of Arabidopsis, a common model in phytotoxicity assays. Chalcone was detrimental mainly to the germination of Plantago lanceolata and Lactuca sativa and to the early root growth of Amaranthus retroflexus, Echinochloa crus-galli, and P. lanceolata, and likewise detrimental to the development of adult Arabidopsis. The morphology and physiology of adult Arabidopsis plants watered or sprayed with chalcone confirmed that this metabolite is also phytotoxic for adult plants and showed that the mechanism of its action on plant metabolism depends on whether it is administered by spraying or watering. These results support the role of chalcone as a plant growth regulator and its potential use in weed management in the field.