ISSN:
1573-8469
Keywords:
Nicotiana tabacum
;
tobacco mosaic virus
;
polyacrylamide gel electrophoresis
;
enzyme-linked immunosorbent assay
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract This review describes the discovery and identification of the pathogenesis-related proteins (PRs) from tobacco. In crude leaf extracts the PRs are distinguished from the proteins in uninfected plants by their solubility at pH 3, resistance to a range of proteases, and mobility in polyacrylamide gels upon electrophoresis (PAGE) in non-denaturing conditions. PAGE has been used as a qualitative and semi-quantitative assay for PRs, and their migration in gels made from different acrylamide concentrations has been used to identify charge and size isomers and electrophoretically identical PRs in different tobacco cultivars. The subunit composition and molecular weight (mol. wt) of the four PRs identified first in ‘Xanthi-nc’ were determined by SDS-PAGE; staining the gels has shown that these same four proteins in ‘Samsun NN’ did not contain carbohydrate, lipid or nucleic acid, nor were they isozymic forms of twenty five enzymes known to increase in activity following infection with TMV. Evidence suggests that most of the PRs in ‘Xanthi-nc’ and ‘Samsun NN’ are extracellular. The purification of several PRs from ‘Xanthi-nc’, ‘Samsun NN’ and other tobaccos is described, as well as their mol. wt, subunit and amino acid composition. PRs 1a, b and c consist of a single polypeptide and have similar mol. wt and amino acid compositions. Antisera prepared against purified ‘Xanthi-nc’ b1 protein have been used to determine serological relationships between PRs and form the basis of a very sensitive quantitative assay using ELISA. The regulation of synthesis of some PRs has been shown to involve translational control.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01995260
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