Gibberellins

Head of Research Program: Dana Tarkowská

 

The research team is primarily focused on qualitative and quantitative analysis of naturally occurring gibberellins, a class of diterpenoid carboxylic acids that include biologically active compounds as well as their inactive biosynthetic precursors and metabolites. The current concept of this research team is targeted profiling of gibberellins in tissues of different biological origin to study biochemical processes involving these signalling molecules. This helps us to better understand how they participate in the regulation of physiological responses in planta both alone and/or in concert with members of other plant hormone groups. Like other classes of plant hormones, concentrations of GAs in plant tissues are usually extremely low (generally pg/mg FW) while substances that interfere with their analysis are present in far greater concentrations. Thus, very sensitive analytical methods are required for their detection. Instrumentally, the research team approaches are based mainly on ultra high performance liquid chromatography (UHPLC) coupled to tandem mass spectrometry (MS/MS). Very effective and high throughput strategy of purification of plant extracts allows us to separate and analyse 20 endogenous gibberellins in single chromatographic run using starting amounts of tissue weighing between 10 and 30 mg FW. The LC–MS/MS analysis offers  fast separation, high chromatographic resolution, with sufficient selectivity and a satisfactory sensitivity with limits of detection ranging between 0.08 and 10 fmol and linear ranges over four orders of magnitude  using a very precise standard isotope dilution method. The qualitative analysis is usually performed using hybrid Q-TOF MS technology that allows identification of compounds of interest using MS/MS spectra including exact mass determination giving the elemental composition of the analyte. The biochemistry and molecular biology of dioxygenases involved in gibberellin biosynthesis is also the subject of this research team.

Team members:

Danuše Tarkowská

Terezie Urbanová

Andrea Novotná