1. Extended darkness induces internal turnover of glucosinolates in Arabidopsis thaliana leaves
- Author
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Brandt, Saskia, Fachinger, Sara, Tohge, Takayuki, Fernie, Alisdair R., Braun, Hans-Peter, and Hildebrandt, Tatjana M.
- Subjects
Proteomics ,Leaves ,Arabidopsis thaliana ,Light ,Carboxylic Acids ,Arabidopsis ,lcsh:Medicine ,Plant Science ,Biochemistry ,Dewey Decimal Classification::500 | Naturwissenschaften::580 | Pflanzen (Botanik) ,darkness ,Aminohydrolases ,TGG1 protein ,lcsh:Science ,nitrilase ,nitrile ,Organic Compounds ,Plant Anatomy ,Monosaccharides ,protein processing ,Eukaryota ,food and beverages ,glucosinolate ,Plants ,Darkness ,unclassified drug ,Chemistry ,ddc:580 ,Experimental Organism Systems ,Physical Sciences ,carboxylic acid ,plant development ,transcription regulation ,Research Article ,Chemical Elements ,circadian rhythm ,Glycoside Hydrolases ,Arabidopsis Thaliana ,Glucosinolates ,Carbohydrates ,Brassica ,Research and Analysis Methods ,Article ,Model Organisms ,Plant and Algal Models ,Nitriles ,controlled study ,plant leaf ,thioglucosidase ,nonhuman ,Arabidopsis Proteins ,Organic Chemistry ,fungi ,lcsh:R ,Organisms ,Chemical Compounds ,Biology and Life Sciences ,TGG2 protein ,Plant Leaves ,Glucose ,lcsh:Q ,Acids ,Protein Processing, Post-Translational ,Protein Abundance ,Sulfur - Abstract
Prolonged darkness leads to carbohydrate starvation, and as a consequence plants degrade proteins and lipids to oxidize amino acids and fatty acids as alternative substrates for mitochondrial ATP production. We investigated, whether the internal breakdown of glucosinolates, a major class of sulfur-containing secondary metabolites, might be an additional component of the carbohydrate starvation response in Arabidopsis thaliana (A. thaliana). The glucosinolate content of A. thaliana leaves was strongly reduced after seven days of darkness. We also detected a significant increase in the activity of myrosinase, the enzyme catalyzing the initial step in glucosinolate breakdown, coinciding with a strong induction of the main leaf myrosinase isoforms TGG1 and TGG2. In addition, nitrilase activity was increased suggesting a turnover via nitriles and carboxylic acids. Internal degradation of glucosinolates might also be involved in diurnal or developmental adaptations of the glucosinolate profile. We observed a diurnal rhythm for myrosinase activity in two-week-old plants. Furthermore, leaf myrosinase activity and protein abundance of TGG2 varied during plant development, whereas leaf protein abundance of TGG1 remained stable indicating regulation at the transcriptional as well as post-translational level.
- Published
- 2018