PARENT SESSION
Posters P3C C3 and Rubisco. Abstracts (617-630)

Functional analysis of the role of tomato fruit photosynthesis in metabolism and development. Anna Lytovchenko^*,1, Lothar Willmitzer¹, Alisdair Fernie¹, ¹ Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany

ABSTRACT- Tomato fruit undergoes a transition from photosynthetic to heterotrophic metabolism during development, however as yet there have been no reports in which the contribution of fruit photosynthesis to metabolism and growth has been directly assessed. Therefore our goal is to assess the contribution of tomato (Lycopersicon esculentum Mill.) fruit photosynthesis to metabolism and development by direct experimentation. For this purpose we focus on the generation and genetic, physiological and biochemical analyses of transgenic tomato plants exhibiting independent antisense inhibition of the small subunit of Rubisco and phosphoenolpyruvate carboxylase as an attempt to directly reduce carbon dioxide fixation inside the fruit and glutamate 1-semialdehyde aminotransferase to down regulate fruit photosynthesis through reduced chlorophyll content. These transgenic plants were constructed under the control of a green fruit specific promoter. Techniques to be used in this study include direct measurements of gas exchange and radiolabelling studies of photosynthesis, metabolic profiling using a combination of gas chromatography and liquid chromatography - mass spectrometry and transcript profiling. Particular focus will be paid to the effect of reducing fruit photosynthesis on aspects of fruit ripening, fruit size and fruit metabolism. With respect to the latter the use of labelling experiments will be used in order to elucidate metabolic pathways that are closely associated to primary carbon assimilation. Preliminary results from these transgenic plants will be presented and discussed.

KEY WORDS: fruit photosynthesis inhibition, tomato fruit, fruit metabolism, metabolic network analysis