Effect of cytokinins on the expression of LHCP-genes.

Abstract

The light-harvesting chlorophyll a/b-binding proteins (LHCP) function as carrier- proteins of antenna-pigments and are located in the thylakoïd membrane of chloroplasts. They consist of a large family of polypeptides. To get a better insight in the regulation of their genes, we use transgenic tobacco plants with an elevated cytokinin- level. Using a special construct (Pssu-ipt) with a light-inducible promotor (from Pisum sativum), the concentration of cytokinins in the plants can be changed. Accumulation of cytokinins affects the photosynthetic apparatus (Synkova, H. et al., 1999 J. Plant Physiol. 155 173-182). More specific, the effect of cytokinins on the expression of the nuclear-encoded Lhcb-genes will be examined. Plants (Nicotiana tabacum L. cv. Petit Havana SR1) are cultivated on grodan in a greenhouse. This is done for WT as well as for the transgenic plants. Additional illumination is provided 16h a day with Agroson T (400W) and HTQ (400W) lamps (200µmol quanta m-2s-1). Samples are analysed by 2D-electrophoresis and Western blotting.