Metabolite profiling by capillary electrophoresis-mass spectrometry reveals aberrant putrescine accumulation associated with idiopathic symptoms of gentian plants

SummaryThe disease, yellow dwarf-like symptom (YDS), in gentians has the characteristics of leaf etiolation, gall formation, and shortening of the stem internodes. This disease leads to plant death, and has thus become a serious problem in commercial gentian production. Despite intensive pathological investigation, the aetiology of the disease remains unclear. To increase our knowledge about YDS, we conducted metabolome analysis using capillary electrophoresis-mass spectrometry. Quantification of the metabolites in YDS-affected tissues showed that YDS particularly affected arginine-derived metabolites, including arginine, ornithine, citrulline, and putrescine. The concentration of putrescine increased 83-fold, and was accompanied by increased expression of the arginine decarboxylase gene. Thus putrescine synthesis and its accumulation appear to be the key metabolic changes associated with YDS in gentians.