Host-specific attractants

Figure (2). Structure of some host-specific attractants for oomycete zoospores...

Activities i) Host-specific attraction, ii) Encystment induction... 

Host-specific attractants of oomycete phytiqmthogens known so far are shown in Table 1. For example, indole-3-carbal hyde (1) isolated fiom cabbage seedlings is a chemoattractant down to concentration of 1 nM for A. raphani zoospores 12). Pninetin (2) isolated from pea seedlings (13) is a potent attractant (down to 10 nM) for zoospores of the A. eutewhes, while the... 

Our preliminary experiments to detect the putative receptor responsible for the host-specific attractant cochliophilin A (5), by using a probe 5,7-dihydroxyflavone incorporated with 7-O-biotinyl and 4 -azido groups slmw that the receptors are locate on the cell membrane (44). Detailed characterization of the cochliophilin A receptor would be a starting point to unravel the signal transduction pathway in zoospore chemotaxis and differentiation by host-specific plant signals. 

The ovlposltlon behavior of Paplllo butterflies has been studied In some detail. Gravid females of the citrus butterfly, Paplllo demoleus, are attracted to host and non-host plants almost equally by color. But the specific attractant emitted from citrus plants Increases the chances of landing on these plants. Then contact chemical stimuli elicit the ovlposltlonal response of the butterflies (44). 

Figures 53 and 54 show the structure of the 3/98d complex as it exists in the unit cell [154, 303], Unlike the complexes with 98a-c, the 98d complex has both hydroxyl groups of one 3 hydrogen bonded to both carbonyl groups of one molecule of 98d. As a result, the diyne backbone is curved (Figure 53) [154, 303], There is no reason to believe that the walls of the reaction cavity experienced by 98d or by transients, lOld and 102d derived from it, in optically active 3 complexes are any more rigid or contain less free volume than do the other complexes. The enantiomeric purity of the product must result from specific attractive host-guest interactions retained along the...

The blossoms of Cucurbitaceae are well known to be highly attractive to many species of Diabrotica beetles. However, the volatile compounds that act as attractants differ in different Diabrotica species. Cinnamaldehyde strongly attracts the spotted cucumber beetle, Diabrotica undecimpunctata hoivardi, whereas 4-methoxycinnamaldehyde is a specific attractant for the western corn rootworm, Diabrotica virgifera virgifera.51 The northern corn rootworm, Diabrotica barberi, and Diabrotica cristata are attracted to eugenol, cinnamyl alcohol, and 2-(4-methoxyphenyl)ethanol. Volatiles of maize, one of the host plants, also attract D. v. virgifera... 

A very short asymmetric synthesis of an insect attractant, (lS,35,5f )-l,3-dimethyl-2,9-dioxabicyclo[3.3.1]nonane, has been realized with high enantio- and diastereo-selectivity by means of an (5)-3f-mediated aldol reaction strategy (Eq. 52) [43c]. This compound is a host-specific substance for the ambrosia beetle that infests the bark of the Norway spruce. 

HOST-SPECIFIC ZOOSPORE ATTRACTANTS OF THE FUNGUS APHANOMYCES COCHLIOIDES, THE CAUSE OF SPINACH ROOT ROT... 

Here we review our research results concerning zoospore attractants, repellents, cytotoxins and inhibitors of zoospore motility together with bioassay systems to survey chemical regulators toward zoospores. The first part of this review described some new findings on the effects of host-specific plant signals on chemotaxis and differentiation of oomycete zoospores. The potential role and mode of action of nonhost secondary... 

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