Phytotoxins from Plant Pathogens as Potential Herbicides

Abstract

Plant pathogens remain a largely untapped reservoir of natural compounds with potential as herbicides or as herbicide leads. Many preliminary studies have identified a variety of non-host-specific phytotoxins isolated from pathogenic bacteria and fungi that deserve further investigation. Host-specific phytotoxins are less numerous and have sometimes been shown to have broader spectra when tested on a variety of plants, including weeds. This may allow the application of these toxins or their analogs in weed management. The study of phytotoxins produced by weed pathogens is relatively new. This may be where the greatest chance of developing commercial herbicides lies. Because they are derived from weed-infesting pathogens, such phytotoxins may have more chance of being toxic to weeds and less likelihood of damaging crops. However, much work still needs to be done, including isolation, purification, and host specificity testing, as well as production and safety studies. Since the traditional methods of herbicide discovery are becoming less productive, the study of microbially-derived herbicides could be a major source of new herbicides and herbicide templates in the future. More effort should be expended in this area of research in the future, despite the obstacles that exist.