FLUORESCENT METABOLITES IN VIRUS- OR RUST-INFECTED BEAN LEAVES

Abstract

The fluorescent substances in un-infected and virus- or rust-infected primary bean leaves were examined by paper chromatography 11 to 20 days after seeding.A relatively constant total of 17 fluorescent materials was recorded in normal leaves. For local, necrotic virus infections, totals of 20 additional fluorescent materials were recorded between [Formula: see text] and 7 days after inoculation for tobacco necrosis (TNV) and 15 between [Formula: see text] and 9 days for tobacco mosaic (TMV). Thirteen of the new materials in TMV infections appeared to be the same as some of those from TNV infections, but were quantitatively greater for the more extensively necrotic TNV lesions. One of the most prominent metabolites associated with the hypersensitive virus infections was occasionally present in trace amounts following mild leaf abrasion.Only eight materials additional to those in healthy leaves were detected in extracts from non-necrotic rusted tissue between 1 and 6 days after inoculation. Five of these were tentatively identified as common to both TNV and TMV infections and a sixth as common to TNV infections. No abnormal fluorescent materials were recorded from inoculated leaves bearing symptomless 3-day-old infections of bean strain of TMV and only a trace of one 8 days after inoculation. A rough correlation was apparent between the degree of necrosis and formation of new fluorescent compounds.Abnormal fluorescent materials were also detected in cowpea leaves bearing local lesion infections of TNV. Many of these were different from those of TNV-infected bean. The appearance of abnormal fluorescent compounds coincided with incipient virus lesion formation on bean and cowpea.Six fluorescent materials in healthy bean were tentatively identified as derivatives of caffeic acid, p-coumaric acid, or quercetin. Six major abnormal fluorescent metabolites in bean showed evidence of phenolic nature.