Hostname: page-component-7b7567c8c-lpg2g Total loading time: 0 Render date: 2026-11-15T18:16:13.236Z Has data issue: false hasContentIssue false

Perspectives on Discovery of Microbial Phytotoxins with Herbicidal Activity

Published online by Cambridge University Press:  12 June 2017

Horace G. Cutler*
Affiliation:
USDA, ARS, Plant Physiol. Unit, Richard B. Russell Cent., P. O. Box 5677, Athens, GA 30613

Abstract

Biologically active natural products of microbial origin are attractive candidates for possible use in agriculture. They may be obtained by fermentation, used in their natural state, or subjected to synthetic modification for specific uses. These natural products are characterized by high specific activity and high selectivity, and they are biodegradable. The structures are extremely diverse and represent many classes of compounds ranging from very complex to simple. Cyclocarbamide A and B, from Streptoverticillium sp., have marked preemergence herbicidal activity. Nigerazine A and B, from Aspergillus niger van Tieghem, also inhibit root growth in certain plants. Citreoviridin, from Penicillium charlesii Smith, preferentially controls the growth of monocotyledonous plants, as does a synthetic derivative of cladosporin, from Aspergillus repens DeBary, which bleaches chloroplasts. The 12-membered fungal macrolides (macrocyclic lactones) also inhibit root growth in many test plants and offer templates for further synthetic work. Herbicidins, from Streptomyces saganonensis, are particularly effective against barnyardgrass, goosegrass, tufted mannagrass, and green panicum. Alternaria eichorniae Nag Raj et Ponnappa produces a toxin that is active against waterhyacinth and represents one of the more exotic structures. The macrocyclic trichothecenes are a significant class of natural products that tend to concentrate against a gradient in seeds of certain plants, which resist these microbially derived metabolites thereby producing seed with “built-in” natural herbicides.

Information

Type
Symposium
Copyright
Copyright © 1988 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable