Elicitor

Knight, M. R., Campbell, A. K., Smith, S. M., and Trewavas, A. J. (1991). Transgenic plant aequorin reports the effects of touch and cold-shock and elicitors on cytoplasmic calcium. Nature 352 524-526. 

Application of an aldolase to the synthesis of the tricyclic microbial elicitor (-)-syringolide (Figure 10.34) is another excellent example that enzyme-catalyzed aldolizations can be used to generate sufficient quantities of enantiopure material in multistep syntheses of complex natural and unnatural products [159]. Remarkably, the aldolase reaction established absolute and relative configuration of the only chiral centers that needed to be externally induced in the adduct (95) from achiral precursor (94) during the subsequent cyclization events, all others seemed to follow by kinetic preference. 

Figure 10.34 Aldolase-based creation of two independent chiral centers in the total synthesis of the complex microbial plant defence elicitor (—)-syringolide.

We observed the activation of chitin-specific PO during infection with the causative agents of a number of diseases in wheat under the influence of Btpolaris soroktntana and the elicitors (Fig. 4), Septoria nodorum (Yusupova et al, 2006) and Tilletia caries (Khairullin et al., 2000) in potato infected by Phytophthora infestans (Maksimov et al., 2011), and in Aegilops umbellulata infected by Septoria nodorum (Maksimov et al, 2006). 

Yamaguchi T. Ito Y. Shibuya N.(2000) Oligosaccharide elicitors and their receptors for plant defence responses / / Tr. Glycisci. Glykotech. V. 12. P. 113-120. 

Fig. 4. Comparison of the two signal-reaction chains leading either to the UV light-induced formation of flavonoids or to the elicitor-induced formation of furanocoumarins and related compounds with antimicrobial activity. From Hahlbrock et al. (1985). PR -proteins are pathogenesis-related proteins.

In addition to the proteins mentioned above, there have been many reports of the induction of pathogenesis-related proteins (PRPs) in a number of plant species infected by viruses, viroids, bacteria or fungi (Van Loon, 1985). It has been shown that in cultured parsley cells, increased transcription of two PRP genes occurs within a few minutes of exposure to fungal elicitors (Somssich et al., 1986). Although several PRPs from tobacco have been purified and their cDNAs isolated (Hooft van Huijsduij-nen. Van Loon Bol, 1986), the exact action of these proteins remains unclear. 

Chappel, J. Hahlbrock, K. (1984). Transcription of plant defence genes in response to UV or fungal elicitor. Nature, 311, 76-8. 

Chappell, J., Hahlbrock, K. Boiler, T. (1984). Rapid induction of ethylene biosynthesis in cultured parsley cells by fungal elicitor and its relationship to the induction of phenylalanine ammonia-lyase. Planta, 161, 475-80. 

Cramer, C.L., Ryder, T.B., Bell, J.N. Lamb, C.J. (1985). Rapid switching of plant gene expression induced by fungal elicitor. Science, 227, 1240-2. 

Lawton, M.A., Dixon, R.A., Rowell, P.M., Bailey, J.A. Lamb, C.J. (1983). Rapid induction of the synthesis of phenylalanine ammonia-lyase and of chalcone synthase in elicitor-treated plant cells. European Journal of Biochemistry, 129, 593-601. 

Accumulation of hydroxyproline-rich glycoprotein mRNAs in response to fungal elicitor and infection. Proceedings of the National Academy of Sciences, USA, 82, 6551-5. 

Anaphylaxis most commonly starts with symptoms on the skin or the respiratory tract (table 2). The symptomatology is variable there is no obligatory involvement of all organ systems. A major characteristic of anaphylaxis is the rather rapid onset of symptoms after contact with the elicitor. The interval varies between a few seconds or minutes until 1 or 2 h, partly dependent upon the route of application (rapid onset after intravenous allergen exposure) and degree of sensitization. Experience in insect sting anaphylaxis in... 

Another way to classify anaphylactic reactions regards the eliciting agents the most common elicitors of anaphylaxis are drugs, insect venoms, foods, additives,... 

In one study, 26% of anaphylactic reactions were reported to have developed after a combination of elicitors [4]. In other patients with mastocytosis, anaphylaxis remains idiopathic despite an extensive search for an allergic basis. 

If patients have experienced anaphylaxis, the identification of any possible elicitor is important to help avoid further episodes. With skin tests and specific IgE antibodies combined with history, a relevant allergy may be detected. Cellular tests monitoring basophil histamine release or basophil activation may be helpful in some patients who resist diagnosis by standard means [26,31]. 

We will now provide an overview of the results obtained using these technologies for the most common elicitors of anaphylaxis. 

Insect venoms, together with foods and drugs, are the most frequent elicitors of anaphylaxis in men. The insect venom is applied by stings which must have occurred for more than 100,000 years, since human beings exist. Conflicts between stinging insects and humans occur while fighting for food, like honey or foods consumed outdoors, or while venomous insects feel threatened by human beings, most often near their nests. 

After a painful sting the elicitor of Hymenoptera venom-induced anaphylaxis is usually clear. However the identification of the responsible species is often difficult. 

While in anaphylaxis caused by other frequent elicitors like food and drugs, allergen-specific immunotherapy is not established, immimotherapy with Hymenoptera venoms has been shown to be effective in three prospective controlled trials (table 4) [38-40] and also in a number of studies where patients were submitted to a sting challenge with the responsible insect during venom immimotherapy (table 5) [44]. While over 90% of vespid venom-allergic patients are fully protected and do not develop any... 

Contrary to other elicitors of non-immune anaphylactic reactions (radiocontrast media, neuromuscular blocking agents, non-steroidal anti-inflammatory drugs (NSAIDs)) where there are at least hypothetical concepts regarding the pathomecha-nism of these reactions via increased mediator release (e.g. histamine release, shift in arachidonic acid metabolism from prostaglandins towards leukotrienes, etc.) [26], there is almost no literature regarding the pathomechanism of these reactions after LA application. 

LA preparations are common elicitors of adverse reactions, i.e. ca. 0.1-1% of applications in dental and other procedures. The clinical symptoms often correspond to anaphylactic reactions with tachycardia, hypotension, and subjective feelings such as... 

Preliminary allergy emergency card with suspected elicitor... 

Table 4. Studies showing evidence of an oxidative burst in plant systems, stimulated by soiu-ces other than a pathogen or elicitor ...

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