Ferulic acid in C<sub>4</sub> grasses.

Abstract

In order to identify the phenolic substance that is responsive in a new C4-safranin histochemical test for determination of the photosynthetic pathway in grasses, we developed a fluorescence microscopy aided protocol for extraction and quantification of the target substance, with subsequent mass spectrometry analysis for molecular identification. The results indicate the target phenolic substance in C4 grasses' bundle sheath cells is ferulic acid.In addition, we observed differences in distribution and compartmentalization of ferulic acid depending on the plants' photosynthetic pathway. In C3 grasses, ferulic acid is restricted to mesophyll cells and concentrated on cell walls, while in C4 grasses it is restricted to bundle sheath cells, and concentrated in the membrane adjacent to radial and tangential walls. Taken together these results indicate that ferulic acid may have an important function related to the