Abstract
We constructed a novel system with which we can control the environment of a leaf segment or an isolated epidermis and observe their stomata using a microscope. The chamber for the sample is consisted of two (45 x 55 x 10 mm) brass blocks. Both half-chambers have glass windows. By circulating water from a water bath, the chamber temperature is controlled. The sample is placed on filter paper and the paper extruded from the chamber is immersed in an incubation buffer. The gas composition is controlled using mass flow controllers and the dew point using a condenser having Peltier elements. The sample temperature is measured with thermocouples. The CO2 concentration and dew point are monitored by an infrared gas analyzer. The sample illuminated with a ring-shaped light guide is viewed under a microscope having a long focal length objective lens. It has been suggested that the mesophyll signal is involved in regulation of stomatal apertures. For clarifying whether mesophyll photosynthesis is essential for signal production, we are currently observing stomatal behavior of the isolated epidermis placed on mesophyll both from variegated Commelina communis.
