Dutch elm disease fungus

K.J. Stevenson, J.A. Slater and S. Takai, Cerato-ulmin, wilting toxin of Dutch Elm disease fungus, Phytochem. 18 (1979) 235-238. 

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). 

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

Arciero (544) has been trapping elm bark beetles throughout the Bay area counties in California to study the seasonal variation in population and to estimate how many beetles are carrying the Dutch elm disease fungus. 

The fungus responsible for Dutch elm disease is spread by European bark beetles when they burrow into the tree Other beetles congregate at the site attracted by the scent of a mixture of chemicals some emitted by other beetles and some coming from the tree One of the compounds given off by female bark beetles is 4 methyl 3 heptanol Suggest an efficient synthesis of this pheromone from alcohols of five carbon atoms or fewer... 

The U.S. Forest Service scientists in New York have isolated and identified chemical sex attractants used by elm bark beetles that are responsible for transmitting the fungus causing Dutch elm disease. Examples of attractants are 2,4-dimethyl-5-ethyl-6,8-dioxabicyclo [3.2.1] octane (called multistriatin) and 4-methyl-3-heptanol. In field trials an artificially produced mixture of the compounds has proved attractive to the elm bark beetle. 

Multistriatin 1 is a pheromone of the elm bark beetle. This beetle distributes the fungus responsible for Dutch elm disease and it was hoped that synthetic multistriatin might trap the beetle and prevent the spread of the disease. It is a cyclic compound with two oxygen atoms both joined to the same carbon atom (C-6 in 1) and we call such ethers acetals. 

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... 

Multistriatin (3) is one of the pheromones of the elm bark beetle, a volatile compound released by a virgin female beetle when she has found a good source of food—an elm tree. Male beetles, which carry the fungus causing Dutch elm disease, are attracted by the pheromone, the tree becomes infected and soon dies. 

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). 

Dutch elm disease is caused by a fungus transmitted to elm trees by the elm hark heede. The female heede, when she has located an attractive elm tree, releases several pheromones, including multistriatin, helow. These pheromones attract male beetles, which bring with them the deadly fungus. 

Dutch elm disease, named after the Dutch scientist who identified the fungus that causes the disease, spread to the United States in crates made of diseased elm wood. 

To elucidate the chemical basis of host resistance against Dutch elm disease, FT-IR microspectroscopy (single-point measurements) was performed [195]. Spectra of resistant elm seedlings showed increased formation of lignin and suberin after inoculation with the pathogenic fungus Opiostoma novo-ulmi. 

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