Molecular and Physical Plant Physiology
To assess the role played by the endogenous hormone balance on developmental processes, physiological responses are studied of plants, that has been genetically transformed and are characterized by an increased or decreased endogenous cytokinin content. Several plants, each characterized by a specific transformed genetic construction are used. The effect of the transformation (cytokinine- and CKX-plants) is studied on plant development, phytohormone content and on several parameters of the photochemical and non-photochemical quenching analysis, capacity of the electron transport system, biochemical activities of the chloroplast and sugar metabolism. Analysis of transcription and translation products are performed using several molecular-biological and proteome techniques. On the plant level, gas-exchange measurements and fluorescence image analysis are used to study the physiological respons of the plants on several abiotic (e.g. heavy metals) and biotic (infection with pathogens) stresses. The production of good quality fruit is still an important economic issue. To improve the assessment of the quality of apples and pears, non-destructive technology is being developed. Hereby, fluorescence induction induced by several light qualities (red, blue and UV-light) is analyzed by imaging technology. Several well known quality parameters such as for instance sugar and starch content, firmness, background color, internal breakdown and scald are analyzed using physical and biochemical techniques. Analysis of secondary metabolites (phenol derivatives) with chemical methods (HPLC-MS) and enzymatic measurements support the analysis of specific fluorescence-emission patterns. Correlation studies are performed to link the non-destructive fluorescence signals with the other analysis.