Measuring chlorophyll a and C-labeled photosynthate in aquatic angiosperms by the use of a tissue solubilizer

A compound that quantitatively correlated with chlorophyll a could be measured fluorometrically in the extracts of leaves of three aquatic angiosperms (Myriophyllum heterophyllum Michx., Potamogeton crispus L., Elodea canadensis Michx.) treated with the tissue solubilizer BTS-450. Fluorescent characteristics of the solubilized plant tissues were stable for several weeks in the dark at temperatures up to 60 degrees C but rapidly degraded in sunlight or when acidified. (14)C-Labeled photosynthate, which had been fixed by leaf discs during 1- to 10-hour exposure to H(14)CO(3), was also readily extracted by the tissue solubilizer. Solubilizer extraction can, therefore, be used to determine both chlorophyll a content and (14)C incorporation rates in the same leaf sample. The method is practical, because no grinding is required, the fluorescent characteristics of the extracts are stable, and analyses can be performed with very little plant material (about 3 milligrams).