Ceratocystis ulmi

P.S. Russo, F.D. Blum, J.D. Ipsen, Y.J. Abul-Hajj and W.G. Miller, Solubility and surface activity of the Ceratocystis ulmi toxin cerato-ulmin, Physiol. Plant Path. 19 (1981) 113-126. 

S. Takai and W.C. Richards, Cerato-ulmin, a wilting toxin of Ceratocystis-ulmi, Isolation and some properties of cerato-ulmin from culture of C.-ulmi, Phytopath. Z. 91 (1978) 129-146. 

The pathogenic fungus Ceratocystis ulmi (C. ulmi), responsible for Dutch elm disease, causes a blockade in the vascular tissue that can lead to the eventual death of the... 

Phenolic metabolites of Ceratocystis ulmi, N. Claydon, J.F. Grove and M. 

Note that the natural pheromone is the S-enantiomer, and the (synthetic) R-enantiomer is inactive or has a very low activity. The parent alcohol, 4-methyl-3-heptanol, exists in four stereoisomers. Only one of these stereoisomers (3S, 4S) is used as an aggregation pheromone by the elm bark beetle (Scotylutus multistriatus), the beetle responsible as the vector of the Dutch elm disease fungus (Ceratocystis ulmi). 

Ceratocystis ulmi. These sesquiterpenes quinones possess antifungal properties. None of the mansonones was detected by TLC in extracts from healthy U. Americana. Accumulation of mansonones A, C, D and G in... 

Bark beetles. Insects related to the weevils that bore into the wood and bark of trees and often cause extreme economic damage to forests. Many species live in symbiosis with fungi the elm bark beetle Scolytus multistriatus transmits the feared elm tree disease caused by the fungus Ceratocystis ulmi. Some B. species are controlled by the application of synthetic pheromones in trap devices, that contain combinations of pheromones with synthetic insecticides see also bre-vicomin, chalcogran, conophthorin, frontalin, ipsdienol, lineatin, multistriatin, pityol, sulcatol, seudenol. 

CgH.gO, Mr 130.23, bp. 160-161 °C. The (3S,45)-iso-mer, [a]n -23.3° (hexane), an important component of the aggregation pheromone (see pheromones) of bark beetles of the genus Scolytus, e.g. the smaller European bark beetle. S. multistriatus is a carrier of the fungus Ceratocystis ulmi causing death of elm trees. It also occurs in ants. The (3/ ,45)-stereoisomer is a trail pheromone of the ant Leptogenys diminuta, see also multistriatin. 

Fig. 5.25. Phytotoxins from the Dutch elm disease fungus, Ceratocystis ulmi.

Dutch elm disease, caused by the fungus Ceratocystis ulmi, is disseminated by a bark beetle of the genus Scolytus. The fungus produces toxins that cause necrotic lesions and leaf wilting. These toxins consist of a mixture of glycoproteins and three low-molecular-weight phenolic compounds (Fig. 5.25) (Claydon et al., 1974 Harbome, 1982, 1986 Wood et al., 1972). 

Claydon, N., j. G. Grove, and M. Hoskbn, Phenolic metabolites of Ceratocystis ulmi. Phytochemistry, 13, 2567-2571 (1974). 

As discussed previously see Chapter 5), pathogenic bacteria and fungi synthesize a number of compounds that help to break down host tissues and to weaken the host plant. Similar phytotoxins, especially those produced by bacteria, are peptides typically with molecular weights less than 600. However, in contrast to the compounds of fungi, most bacterial toxins exhibit an overall lack of specificity (Mitchell, 1981). In some cases, these phytotoxins are produced in conjunction with phytotoxins from other biosynthetic groups of compounds. For example, in addition to the polyketide-derived compounds involved in the attack on elm trees by Ceratocystis ulmi, phytotoxic glycoproteins are also released (Harbome, 1988 Wood et al., 1972). 

Polyketides Ceratocystis toxins (D 3.3.2) Products of Ceratocystis ulmi, causing Dutch elm disease... 

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