Toxins in plants

Plant toxins have been known for many centuries. Rotenoids (rotenone), alkaloids (nicotine, coniine, strychnine), terpenoids (ovabin and hymenovin) are among the classes of natural products which provide numerous toxins (3-12). Toxins in plants often have the role of feeding repellents. They appear to be synthesized by plants as a defense against insects and other animals. 

Durbin, R.D. "Toxins in Plant Disease" Academic Press New York, 1981. 

Toxic substances acquired from the host plaint may provide resistance to parasitoids (24), pathogens (25), and predators (45). By avoiding some toxins in plant material and selecting superior food tissues, insects feeding on variable hosts may become more susceptible to some enemies. Of course, other substances in preferred tissues may still be toxic to certain of these enemies, but this is less likely than it would be were plant compounds uniformly encountered by the host insect. 

The exposure of organisms includes man-made chemicals as well as natural compounds. Natural compounds are, for example, toxins in plants, ozone, or natural occurring metals. The total number of man-made chemicals is vast. To assess exposure, the ambient concentrations of chemicals resulting from man-made sources need to be known or estimated. Chemical Abstracts, covering more than 8000 journals since 1907, registers more than 20 million entries. This section focuses on man-made chemicals. In Europe, around 30,000 chemicals are commonly used and thereby emitted to the environment (EC 2001). 

Ballio, A. (1981) In R.D. Durbin (Ed.), Toxins in Plant Disease. Academic Press, New York, London, Toronto, Sydney, San Francisco, 395 141. 

Daub, M.E. K.-R. Chung. Cercosporin A photoactivated toxin in plant disease. 2007, www.ap-snet.org/online/feature/Cercosporin. 

Kono, Y., H. W. Knoche, and J. M. Daly, Structure Fungal host-specific, in Toxins in Plant Disease (R. D. Durbin, ed.), 221-257, Academic Press, New York, 1981. 

IDENTIFICATION OF TOXINS IN PLANT SCREENINGS FOR RESEARCH OR DEVELOPMENT PURPOSES... 

Durbin, R. D. Toxins in Plant Disease, Academic Press, New York 1981... 

Rich, D.H., In Toxins in Plant Disease. Mechanism of Action Durbin, R.D., Ed. Academic New York, 1981. Physiological Ecology Series, Chapter 8. 

Toxins in plants have their greatest economic impact in the relationship between plants and animals. A direct economic loss of 245 million dollars has been calculated for... 

As in the case of the plant toxins involved in plant-plant and plant-insect interactions, the variety of toxins involved in plant-animal relationships are numerous and represent a broad spectrum of chemical types. Several books which include comprehensive reviews of the variety of plant toxins in plant animal relationships are available (Keeler and Tu, 1983 Cheeke, 1985 Cheeke, 1989a Cheeke, 1989b Keeler and Tu, 1991). In this discussion, I will again provide examples of representative toxins which will be described according to their site of action. 

Huxtable, C. R. 1994. Some Characteristics of Neurones Which Endow Vulnerability to Chemical Toxins. In.-Plant-Associated Toxins Agricultural, Phytochemical and Ecological Aspects, Colegate, S. M., and Dorling, P. R., eds. Wallingford, UK, CAB International, pp.357-362. 

It is unknown how the elevated levels of free sphingoid bases caused by FB and AAL-toxin in plants might mediate the physiological changes observed. It is possible that changes in membrane permeability are involved. The structural analogy with sphingosine... 

---