For over 10 years, TMV -based vectors have been used as plant expression tools to examine gene regulation and function, protein processing, pathogen elicitors, to manipulate biosynthetic pathways, and to produce high levels of enzymes, proteins, or peptides of interest in different locations in a plant cell. TMV vectors often exhibit genetic stability of foreign RNA sequences through multiple passages in plant hosts. Foreign coding sequences can be expressed in plants where the stability, intracellular fate and enzymatic or biological activities of the recombinant proteins can be rapidly evaluated and optimized. These properties make viral vectors attracti ve expression vehicles for testing and production of a wide variety of recombinant peptides and proteins, for structural analyses of post-translational modifications and for assessing gene function and metabolic control. Finally, the utility of both CP fusion and dual subgenomic vectors has extended beyond the laboratory and greenhouse to field-scale production and purification of recombinant products for commercial use (Grill, 1992; Grill, 1993; Turpen et at. , 1997). REFERENCES Copeman RJ, Hartman IR and Watterson IC. 1969. Tobacco mosaic virus in inoculated and systemically infected tobacco leaves. Phytopathology 59: 1012-1013. Dawson WO, Beck DL, Knorr DA and Grantham GL. 1986. cDNA cloning of the complete genome of tobacco mosaic virus and production of infectious transcripts. Proc. Natl. Acad. Sci. (USA) 83: 1832-1836. Dawson WO and Lehto KM. 1990. Regulation of tobamovirus gene expression. Ad. Virus Res. 38:307-342. Dawson WOo 1992. Tobamovirus-Plant Interactions. Virology 186:359-367.

Volume II/26 supplements the previous compilations II/l, II/9 and II/17 of the magnetic properties of free radicals which were published in 1965, 1977-1980 and 1986-90. In the form of books and CD ROM it covers the literature from about 1985 to 2001. Due to the still rapid growth of the field and the necessary inclusion of new subjects the volume is divided into subvolumes which will appear in fast succession. Together with the earlier publications volume II/26 offers an up-to-date and comprehensive survey and collection of structures and data on the important chemical intermediates, namely radicals, polyradicals and related species such as carbenes, nitrenes, etc. As before the species have been grouped according to chemical aspects. The contents of the individual subvolumes are indicated on the inside of the front covers. For each group of substances the literature has been compiled and extracted by experts in the fields. A small overlap between the chapters is intentional and allows a maximum of coherence and comprehensiveness of the display. For the reader's convenience an index of substances follows in the last subvolume. Data retrieval is also facilitated by helpful links in the CD ROM version. We wish to thank all the authors for their careful and experienced work and the most agreeable cooperation, the Landolt- Bornstein office, especially Mrs. A."

For over 10 years, TMV -based vectors have been used as plant expression tools to examine gene regulation and function, protein processing, pathogen elicitors, to manipulate biosynthetic pathways, and to produce high levels of enzymes, proteins, or peptides of interest in different locations in a plant cell. TMV vectors often exhibit genetic stability of foreign RNA sequences through multiple passages in plant hosts. Foreign coding sequences can be expressed in plants where the stability, intracellular fate and enzymatic or biological activities of the recombinant proteins can be rapidly evaluated and optimized. These properties make viral vectors attracti ve expression vehicles for testing and production of a wide variety of recombinant peptides and proteins, for structural analyses of post-translational modifications and for assessing gene function and metabolic control. Finally, the utility of both CP fusion and dual subgenomic vectors has extended beyond the laboratory and greenhouse to field-scale production and purification of recombinant products for commercial use (Grill, 1992; Grill, 1993; Turpen et at. , 1997). REFERENCES Copeman RJ, Hartman IR and Watterson IC. 1969. Tobacco mosaic virus in inoculated and systemically infected tobacco leaves. Phytopathology 59: 1012-1013. Dawson WO, Beck DL, Knorr DA and Grantham GL. 1986. cDNA cloning of the complete genome of tobacco mosaic virus and production of infectious transcripts. Proc. Natl. Acad. Sci. (USA) 83: 1832-1836. Dawson WO and Lehto KM. 1990. Regulation of tobamovirus gene expression. Ad. Virus Res. 38:307-342. Dawson WOo 1992. Tobamovirus-Plant Interactions. Virology 186:359-367.