GLUCOSE, FRUCTOSE AND SACCHAROSE METABOLISM IN DIPSACUS SILVESTRIS INFECTED BY CUCUMBER MOSAIC VIRUS

Dipsacus silvestris Miller (or Fuller’s Teasel) (Dipsacaceae) showing stunting, chlorotic leaf mosaic and narrowing of the lamina, has been found for the first time in Italy naturally infected by Cucumber mosaic virus (CMV). This virus was detected in PAS-ELISA tests and molecularly characterized by applying RT-PCR, using specific primers for the movement protein gene of RNA3 (forward 5’ CTA GGC TTT CCA AGC TAC CAG 3’; reverse 5’ CTA AAG ACC GTT AAC CAC CTG C 3’). The content of glucose, fructose and saccharose, determined by HPLC analysis, was calculated in both healthy (h) and CMV-infected (i) D. silvestris plants during the chronic infection period. An higher content of these carbohydrates was observed in healthy leaves and roots: 5,57% (h) and 1,98% (i) for the leaves; 12,47% (h) and 6,49% (i) for the roots. In particular, in the roots of CMV-infected plants, glucose was found at a significantly lower level (5 %) in comparison to the percentage in healthy plants (8,73 %); the same observation was done for fructose (1,5% in infected roots and 3,35% in the healthy ones). These results are in harmony with previous reports indicating that in virus infected plants the decreased phytosyntetic activity, coupled with an increased respiratory rate, produce a lower carbohydrate concentration. Considering that some of the most important components of this medicinal species are glucosides (i.e., scobioside), determination of sugar content, in particular glucose level, can be useful for a market value of the drug.