Improvement of plant biomass production seems to be one of the few reasonable alternatives for decreasing our recent dependence on fossil fuels. Secondary thickening is a specific process of plant development that is characterized by tremendous growth and is responsible for most of the wood production in trees. Recently it was found that Arabidopsis is a suitable model allowing to study the molecular determinants of ST in plants.
Onset of secondary thickening is defined by formation of secondary meristem called cambium. Cell proliferating activity of cambium is responsible for biomass production during ST. Accumulation of plant hormone auxin was shown to act as a trigger of cambium formation. Other phytohormones cytokinins (CKs) were shown to be necessary for the onset of ST, too. However, the molecular mechanism of CK action and its crosstalk with auxin during the onset of ST is not known.