Screening of aromatic secondary metabolites and glycoalcaloids in two pvyntn - infected potato cultivars (Solanum tuberosum L.)

Abstract

Secondary metabolites fingerprint screening procedure showed, that potato cultivars ’Saskia’ and ‘Santé’ significantly differed in their respond to PVYNTN virus inoculation/infection of plant material. A typical chemical profile (with characteristic "virus peaks") was observed in virus - sensitive ’Saskia’ but not in virus tolerant ’Santé’ plant extracts. Low temperature stress (4 °C) caused a reduction in growth of both cultivars and typical "low temperature" chromatograms with polar aromatic secondary metabolites. Exogenous abscisic acid (ABA), when applied at low temperature, in both cultivars influenced a further growth decrease, but diminished "low temperature signals" of fingerprint profile. When applied to control plants at 18 °C, ABA lost its growth inhibitory effect, although fingerprint "ABA signal" was clearly visible. Results of TLC semiquantitive determination of potato glycoalkaloids show, that a-chaconin may vary depending on temperature stress or ABA spraying of plant material. Cv. ’Saskia’ responds to low temperature with significantly raise of a-chaconin content in plant tissue (32.0 mg/100g fresh weight, fw) when compared with samples grown at normal temperature (17.0 mg/100g fw). PVYNTN infection did not affect the contents of a-chaconin (19.0 mg/100 g fw) in leaves of cv.’Saskia’, when compared with noninfected samples (17.0 mg/100 g fw). The content of a-solanin in leaves extracts was generally low (in case of virus infected material under the detection limit of 7.5 mg/100g fw). Results of the study indicate that, from a biochemical point of view, infection with PVYNTN virus can be considered as a specific stress reaction of virus - sensitive cultivars.

Keywords

• potato
• virus
• aromatic secondary metabolites
• glycoalkaloids
• PVYNTN
• stress