Photosynthetic activity measurement of plants using photoacoustic spectroscopy combined with confocal scanning microscopy

Photoacoustic spectroscopy (PAS) has recently received much attention espec ially for plant photosynthesis research, because this technique is capable of performing nondestructive measurement without any pre-treatment of speci mens. So far we have developed a PAS system equipped with an open photoacou stic cell (OPC), which allows in situ and in vivo measurements of plant pho tosynthesis of intact undetached leaves. In this study, we have measured ph otosynthesis reaction using OPC and developed a Confocal Scanning Photoacou stic Microscopy (CSPAM) system, in which PAS is combined with confocal scan ning laser microscopy. The system allows simultaneous measurement of acoust ic signal and another signal such as fluorescence, and also gives two- and three- dimensional intensity distributions of these signals, thereby giving two- and three-dimensional information about photosynthetic activity of pl ants.