New applications of photoacoustics to the study of photosynthesis

Photoacoustic methods offer unique capabilities for photosynthesis research . Phenomena that are readily observed by photoacoustics include the storage of energy by electron transport, oxygen evolution by leaf tissue at micros econd time resolution, and the conformational changes of photosystems cause d by charge separation. Despite these capabilities, photoacoustic methods h ave not been widely exploited in photosynthesis research. One factor that h as contributed to their slow adoption is uncertainty in the interpretation of photoacoustic signals. Careful experimentation is resolving this uncerta inty, however, and technical refinements of photoacoustic methods continue to be made. This review provides an overview of the application of photoaco ustics to the study of photosynthesis with an emphasis on the resolution of uncertainties in the interpretation of photoacoustic signals. Recent devel opments in photoacoustic technology are also presented, including a microph otoacoustic spectrometer, gas permeable photoacoustic cells, the use of pho toacoustics to monitor phytoplankton populations, and the use of photoacous tics to study protein dynamics.