Photosynthate partitioning in tomato leaves as affected by temperature

Temperature dependence of photosynthate partitioning in intact leaf tissue of tomato (Lycopersicon esculentum Mill. cv. Abunda) was studied by using a temperature gradient cuvette system. At the low photon flux density (PFD, 85 mumol m-2 s-1) and saturated CO2 concentration, the total saccharides production was similar over the temperature range from 14 to 30-degrees-C. The starch formation decreased with decreasing temperature. Formation of the soluble saccharides was affected by the temperature only slightly. This differential effect of the temperature resulted in an increase of the soluble saccharides/starch ratio in tomato leaves under chilling conditions.