Perspectives on deciphering mechanisms underlying plant heat stress response and thermotolerance.

Global warming is a major threat for agriculture and food safety and in many cases the negative effects are already apparent. The current challenge of basic and applied plant science is to decipher the molecular mechanisms of heat stress response (HSR) and thermotolerance in detail and use this information to identify genotypes that will withstand unfavorable environmental conditions. Nowadays X-omics approaches complement the findings of previous targeted studies and highlight the complexity of HSR mechanisms giving information for so far unrecognized genes, proteins and metabolites as potential key players of thermotolerance. Even more, roles of epigenetic mechanisms and the involvement of small RNAs in thermotolerance are currently emerging and thus open new directions of yet unexplored areas of plant HSR. In parallel it is emerging that although the whole plant is vulnerable to heat, specific organs are particularly sensitive to elevated temperatures. This has redirected research from the vegetative to generative tissues. The sexual reproduction phase is considered as the most sensitive to heat and specifically pollen exhibits the highest sensitivity and frequently an elevation of the temperature just a few degrees above the optimum during pollen development can have detrimental effects for crop production. Compared to our knowledge on HSR of vegetative tissues, the information on pollen is still scarce. Nowadays, several techniques for high-throughput X-omics approaches provide major tools to explore the principles of pollen HSR and thermotolerance mechanisms in specific genotypes. The collection of such information will provide an excellent support for improvement of breeding programs to facilitate the development of tolerant cultivars. The review aims at describing the current knowledge of thermotolerance mechanisms and the technical advances which will foster new insights into this process.

[Molecular aspects of allergy to plant products. Part III. Panallergens and breeding of hypoallergenic cultivars]. / Molekularne aspekty alergii na produkty pochodzenia roslinnego. Cz. III. Panalergeny oraz hodowla odmian hypoalergogennych.

In addition to major allergens, also minor allergens, i.e. panallergens have been shown to be responsible for many IgE cross-reactions even between unrelated pollen and plant food allergen sources. It can be explained also by cross-allergenicity underlying the T cell response to conserved regions of panallergens. In this article, we focus on known panallergens which presently comprise a few protein families, including non-specific lipid transfer proteins (nsLTP) (PR-14), thaumatin like proteins (TLP) (PR-5), profilins, and polcalcins. Food allergy has an impact on the quality of life of an allergic patient. The way of developing novel plant cultivars with decreased allergenicity and possibility of down-regulating the expression of an allergen by genetic modification are discussed.

[Molecular aspects of allergy to plant products. Part I. Class I and II allergens and crossreactivity of IgE antibodies]. / Molekularne aspekty alergii na produkty pochodzenia roslinnego. Czesc I. Alergeny klasy I i II oraz mechanizm reaktywnosci krzyzowej przeciwcial IgE.

Food allergies are adverse immunologic reactions that might be due to IgE--or none IgE-mediated immune mechanisms or mixed. One of the more common and typically most mild forms of IgE- mediated food allergy is the so-called oral allergy syndrome (OAS), although systemic symptoms after ingesting a particular fruit or vegetable can occur. Pollen food syndrome is the most common food allergy in adolescents and adults. It develops as a consequence of shared epitopes in the primary and tertiary structures of pollen and food allergens. The authors describe class I and class II allergens, as well as molecularly determined IgE-crossreactivity phenomenon. Also the problem of symptom-free consumed pollen-related food allergens, which might cause T cell-mediated late-phase skin reactions in patients with pollen allergy and atopic dermatitis, is taken up.

[Molecular aspects of allergy to plant products. Part II. Pathogenesis-related proteins (PRs), apple allergenicity governed by Mal d 1 gene]. / Molekularne aspekty alergii na produkty pochodzenia roslinnego. Cz. II. Bialka zwiazane z patogeneza (PR), alergogennosc jablek warunkowana genem Mal d 1.

Of the plant allergens listed in the Official Allergen Database of the International Union of Immunological Societies, approximately 25% belong to the group of pathogenesis-related proteins (PRs). They have been classified into 17 PR families based on similarities in their amino acid sequence, enzymatic activities, or other functional properties. Plant-derived allergens have been identified with sequence similarities to PR families 2, 3, 4, 5, 8, 10, and 14. The main birch allergen in northern Europe is a class 10 (PR-10) protein from the European white birch (Betula pendula) termed Bet v 1. Pollen of other Fagales species contains PR-10 homologues that share epitopes with Bet v 1, as do several fruits, nuts and vegetables. Among the plant food fruits of the Rosaceae family are the most frequently responsible for allergenic reactions. It is documented, that approximately 2% of European population is allergic to apples. The article presents molecular characterization of PR-10 proteins with regard to their structure and function as well as apple Mal d 1 gene-determined allergenicity.

Fire blight resistance of pear genotypes from different European countries.

Several old cultivars, and breeding clones of European pear Pyrus communis L. originating from Belgium, England, Sweden, and Switzerland were evaluated for their resistance/susceptibility to fire blight. Studies were carried out during three consecutive years 2007-2009 in the greenhouse of Warsaw University of Life Sciences, Poland. Strain 691 of Erwinia amylovora was used for artificial infection of plants. Genotypes included in this study considerably varied in their resistance to fire blight. The most resistant was the old English cultivar 'Hessle'. The other two genotypes, i.e., 'Gränna Rödpäron' originating from Sweden, and Pyrus communis FG 1606 from Switzerland were included in a group of low susceptible ones. The most susceptible were Cra Py H 18, Cra Py V 22 and Cra Py W 14 from Belgium.