br Conclusions Cereal seeds like the seeds of all
Conclusions Cereal seeds, like the seeds of all plants, are responsible for the development, protection, dispersal, and nutrition of the next generation. Moreover, cereal caryopses have a high nutritional value for humans and animals. The stable and proper growth of cereal seeds is made possible through the balance between the proteases (particularly the cysteine proteases) and their inhibitors, because proteolysis is indispensable for the development of cereal tissue, for the activation of storage proteins and for their hydrolysis in germinating seeds. The presence of GA- and ABA-responsive elements in the promoter regions of the HPF encoding proteases and their inhibitors confirms their important role in regulating the growth of cereal seeds. The direction of changes in growing seeds depends on the ratio of internal GA and ABA, the type of transcription factors present and their integration. The binding of these factors to the cis-acting elements contributes to the fine-tuning of the development, dormancy and germination of the caryopsis.
Acknowledgement This work was supported by the statutory research fund of the Department of Biochemistry (Warsaw University of Life Sciences–SGGW, Poland).
Introduction While vaccinology within bacteriology and virology is based on a long range of effective products, research within parasite vaccinology still awaits the same success. An important reason for this is the differences with regard to size, chemical composition, invasion mode and replication that exist between bacteria and virus on one hand and parasites on the other hand. Bacteria are single celled prokaryotic organisms carrying a cell wall, mostly a few micrometres in length, and viruses consist of genetic materials, a protein coat and in some cases an envelope (10–300nm). Parasites, however, can be either unicellular- or multicellular organisms ranging from a few micrometres to several metres and their surface coating is extremely diverse. Parasites are more complicated organisms, which induce complex immunological interactions  and antiparasitic immunity is often multifaceted depending on the type of parasite invading the host. Successful antiparasitic vaccines often contain several antigens combined with adjuvants . In this context surface proteins from parasites have mainly been investigated as potent antigens but recent work suggests that enzymes such as proteases may be potent targets as well. Cysteine proteases are essential for parasite life cycles in which they undertake several functions, including immunoevasion, excystment, host penetration and moulting. While they are important for survival of the parasite within the host they are highly immunogenic which target them as potential vaccine candidates. In mammals cysteine proteases may modulate Th1/Th2 responses in the parasites’ favour, but this also suggests that targeted vaccination methods including these antigens may be able to skew the Th response towards the most protective one for the host. The DNA vaccine technology should be investigated in this respect due to the fact that DNA vaccines also are able to skew immune responses towards Th1 or Th2 depending on the administration techniques, the dose or the antigen itself. This vaccination technology has not proven to be as effective as desired in higher mammals ,  but with new administration techniques, new adjuvants and better antigens, efficacy is expected to increase , , . In theory DNA vaccinations are an ingenious way of making the host, by the use of its own cellular machinery, produce immunogenic antigens, which can lead to protective immune responses. This vaccination strategy also has the advantage of being very safe and cheap when the protective antigens have been discovered. In fish several highly efficacious DNA-vaccines have been produced and one of these, the IHNV-vaccine, has been licensed , . Due to the high efficacy of DNA vaccines in fish this system represents a highly valuable model system for the development of future DNA vaccines and further studies on the mechanisms behind the successful vaccination strategy in fish should be investigated.