engleski

Phytoplasma genotype-dependant effects on specialized metabolism of grapevine leaves

Phytoplasmas (genus Candidatus Phytoplasma) are a diverse group of bacterial intracellular pathogens causing significant damage in agriculture worldwide. However, due to inability of obtaining a pure phytoplasma culture in vitro, they remain insufficiently investigated. With the aim of studying the interactions between plants and phytoplasmas, grapevine (Vitis vinifera ; Vv) and flavescence dorée phytoplasma (FDp ; ribosomal group 16SrV), one of the main causative agents of grapevine yellows disease and a quarantine pathogen in Europe, were chosen as a model pathosystem. Leaves of symptomatic and asymptomatic plants from Continental Central Croatia were sampled three times during the development of symptoms. Using triplex real-time PCR assay, infection of Vv by FDp was confirmed in symptomatic plants. To assess the genetic structure of phytoplasmas, map gene was amplified and sequence d followed by phylogenetic analysis. In order to investigate changes in concentration of specialized metabolites between infected and uninfected Vv leaves, high performance liquid chromatography and spectrophotometric assays were used. Two different mapFD-genotypes (M38 and M54) were identified among analysed samples. Metabolomic analyses revealed a high dynamics of specialized metabolite concentrations (metabolite groups and individual compounds) during the development of infection. Furthermore, results point to a phytoplasma genotype-dependant effect on specialized metabolism of infected Vv leaves, as suggested by different patterns of change in phenolics concentration in investigated time points between plants infected with two different phytoplasma genotypes. The results contribute to the understanding of grapevine response to infection with different FDp genotypes and reveal potential protective mechanisms of Vv against phytoplasma infection.

phytoplasma ; specialized metabolism ; phenolics ; flavescence dorée

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