1. Determination of the activity signature of key carbohydrate metabolism enzymes in phenolic-rich grapevine tissuesElizabeth Dunn Covington, Thomas Roitsch, Marina Dermastia, 2016, original scientific article Abstract: Physiological studies in plants often require enzyme extraction from tissues containing high concentrations of phenolsand polyphenols. Unless removed or neutralized, such compounds may hinder extraction, inactivate enzymes, and inter-fere with enzyme detection. The following protocol for activity assays for enzymes of primary carbohydrate metabo-lism, while based on our recently published one for quantitative measurement of activities using coupled spectrophoto-metric assays in a 96-well format, is tailored to the complexities of phenolic- and anthocyanin-rich extracts from grape-vine leaf. As a case study we applied the protocol to grapevine leaf samples infected with plant pathogenic bacteriašCandidatusPhytoplasma solani’, known to alter carbohydrate metabolism in grapevine. The described adaptations maybe useful for determination of metabolic fingerprints for physiological phenotyping of other plant species with inhe-rently high levels of phenolic compounds.
Keywords: AGPase, carbohydrates, invertases, sucrose synthase, panel of enzyme activity assays, phytoplasma
Published in DiRROS: 25.07.2024; Views: 1285; Downloads: 716
 Full text (986,06 KB)
This document has many files! More... |
2. Metabolic consequences of infection of grapevine (Vitis vinifera L.) cv. ʺModra frankinjaʺ with flavescence dorée phytoplasmaNina Prezelj, Elizabeth Covington, Thomas Roitsch, Kristina Gruden, Lena Fragner, Wolfram Weckwerth, Marko Chersicola, Maja Vodopivec, Marina Dermastia, 2016, original scientific article Abstract: Flavescence dorée, caused by the quarantine phytoplasma FDp, represents the most devastating of the grapevine yellows diseases in Europe. In an integrated study we have explored the FDp–grapevine interaction in infected grapevines of cv. “Modra frankinja” under natural conditions in the vineyard. In FDp-infected leaf vein-enriched tissues, the seasonal transcriptional profiles of 14 genes selected from various metabolic pathways showed an FDp-specific plant response compared to other grapevine yellows and uncovered a new association of the SWEET17a vacuolar transporter of fructose with pathogens. Non-targeted metabolome analysis from leaf vein-enriched tissues identified 22 significantly changed compounds with increased levels during infection. Several metabolites corroborated the gene expression study. Detailed investigation of the dynamics of carbohydrate metabolism revealed significant accumulation of sucrose and starch in the mesophyll of FDp-infected leaves, as well as significant up-regulation of genes involved in their biosynthesis. In addition, infected leaves had high activities of ADP-glucose pyrophosphorylase and, more significantly, sucrose synthase. The data support the conclusion that FDp infection inhibits phloem transport, resulting in accumulation of carbohydrates and secondary metabolites that provoke a source-sink transition and defense response status.
Keywords: fructose utilization, gene expression, invertase, metabolome, soluble sugars, starch, sucrose synthase, SWEET, VvDMR6
Published in DiRROS: 25.07.2024; Views: 1754; Downloads: 1049
Full text (2,49 MB)
This document has many files! More... |
