Phytotoxic compounds produced

Many phytotoxic compounds produced by higher plants are phenolic compounds. Several of these have been implicated in allelopathy. Based on the biosynthetic pathway from which they are derived, phenolic compounds produced by higher plants fall into two general categories 1) terpenoid phenolic compounds derived from five... 

Among phytotoxic compounds produced by lichens, usnic acid (74) is one that is unique and relatively abundant.48 Usnic acid also effectively inhibits HPPD.37... 

PhYtotoxIc Compounds Produced bv Funoal Weed Pathogens... 

Brian PW, Dawkins AW, Grove JF, Hemming HG, Lowe D, Norris GLF (1961) Phytotoxic Compounds Produced by Fusarium equiseti. J Exp Bot 12 1... 

Dawkins, A. W. Phytotoxic compounds produced by Fusarium equiseti II. The chemistry of diacetoxyscirpenol. J. Chem. Soc. (C) 1966, 116. 

Chou CH, Patrick ZA (1976) Identification and phytotoxic activity of compounds produced during decomposition of com and rye residues in soil. J Chem Ecol 2 369-387 Christians NE (1993) The use of com gluten meal as a natural preemergence weed control in turf. Int Turfgrass Society Res J 7 284—290... 

Phytotoxic compounds are produced by many crop species, and some of these compounds may play a role as allelochemicals in plant interference. This has bear hard to prove, much less taken advantage of in weed management. Many crops have been screened for allelopathic potential [28]. However, in all but a few cases, the effects of crop allelopathy are quite subtle compared to the effects of chemical herbicides. Efforts to produce allelopathic crop varieties through conventional breeding have not generated commercial varieties sold with this trait. Molecular biology approaches to this problem might be helpful. 

Phytotoxin a compound produced by a fungal or bacterial plant parasite, which is toxic to the plant. The term should not be confused with Plant toxin (see). Compared with the large number of plant parasites with demonstrable phytotoxic activity, ordy relatively few phytotoxins have been identified. See separate entries Altemaria altemata toxins, Coronatine, Fusicoccin, Gibberellins, Ophiobolanes Stemphylo-toxins, Tabtoxins... 

Chiou CT (1989) Theoretical consideration of the partition uptake of nonionic organic compounds by soil oiganic matter. In Sawhney BK (ed) Reactions and movement of organic chemicals in soils, SSSA Special Publication 22. Soil Sdence Society of America, Madison, WI, pp 1-29 Chou CH, Patrick ZA (1976) Identification and phytotoxic activity of compounds produced during decomposition of com and rye residues in soil. J Chem Ecol 2 369-387 Connors KA, Lipari JM (1976) Effects of cycloamyloses on apparent dissociation constemts of carboxylic acids and phenols equilibrium analytical selectivity induced by complex formation. J Pharmaceut Sci 65 379-383... 

With the extraction procedure we employed (22), ferulic acid was isolated as the most inhibitory component in wheat straw. There could also be other unknown compounds in the straw which would not be evident with this procedure. In addition, we ignored the possible influence of toxin-producing microorganisms. Microorganisms may have influenced the phytotoxicity exhibited by the aqueous wheat extract in Table IX. Although the present study was not concerned with the phytotoxic effects of microbially decomposed wheat straw, an influence of microbial activity on ferulic acid phytotoxicity was observed. From the results shown in Table XI, it appears that the presence of the prickly sida seed carpel enhanced the inhibitory effects of ferulic acid. In addition to ferulic acid in test solutions containing prickly sida seeds with carpels, a second compound, 4-hydroxy-3-methoxy styrene, was also found to be present. This compound is formed by the decarboxylation of ferulic acid and was produced by a bacterium present on the carpel of prickly sida seed. The decarboxylation of ferulic acid was detected in aqueous solutions of ferulic acid inoculated with the bacterium isolated from the carpels of prickly sida seed. No conversion occurred when the bacterium was not present. 

It is unlikely that any one particular compound could be responsible for reduced weed growth in no-till. Higher plants and microorganisms produce a myriad of phytotoxic substances. If these substances are present in the right combination and concentration, phytotoxic effects may be observed. With the proper choice and management of various cover crops and plant residues, it may be possible to supplement if not reduce the number and amount of... 

Although ozone and PAN are considered the two primary phytotoxic oxidants in the photochemical complex, the specific response of plants to many simulated atmospheres suggests the existence of other phytotoxic oxidants. The symptoms associated with many of these reactant mixtures are closely related to those caused by ozone and PAN. In some tests, the mixtures used would not have produced either ozone or PAN. In other cases, leaf age or the pattern of injury on sensitive test plants suggested one or more pollutants other than ozone or PAN. Field injury symptoms often resemble those reported for ozone or PAN, but the response pattern is sufficiently different that accurate diagnosis is difficult. Brennan et al. correlated development of oxidant symptoms with aldehyde concentrations in New Jersey and suggested that aldehyde may be a major phytotoxic component of the photochemical-oxidant complex. The symptoms were probably not responses to the aldehyde, but rather to some compound or group of compounds present under the same conditions as the aldehyde. ... 

State produces 95% of the broccoli grown commercially in the United States ( ) and it has been reported that residues of broccoli are phytotoxic and inhibit the establishment of other crops ( ). Both species, campestris and oleracea var. italica, belong to the Brassicaceae, which contain as a characteristic chemical compounds the glucosinolates , . Species from the Brassicaceae family have... 

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