Inactivation of thioredoxin f1 leads to decreased light activation of ADP-glucose pyrophosphorylase and altered diurnal starch turnover in leaves of Arabidopsis plants.

摘要: Chloroplast thioredoxin f (Trx f) is an important regulator of primary metabolic enzymes. However, genetic evidence for its physiological importance largely lacking. To test the functional significance Trx fi n vivo, Arabidopsis mutants with insertions in trx f1 gene were studied, showing a drastic decrease leaf content. Knockout led to strong attenuation reductive light activa- tion ofADP-glucose pyrophosphorylase (AGPase),the key enzyme starch synthesis, leaves during day and isolated chloroplasts, while sucrose-dependent redox acti- vation AGPase darkened was not affected. The light-activation ofAGPase accom- panied by accumulation, increase sucrose levels starch-to-sucrose ratio. Analysis metabolite at end shows that inhibition synthesis unlikely due shortage substrates or changes allosteric effectors. Metabolite profiling gas chromatography-mass spectrometry pin- points only small number metabolites affected, includ- ing sugars, organic acids ethanolamine. Interestingly, data indicate carbon mutant night. Overall, results provide planta role played activation photosynthetic partitioning plants.