Materials and Reagents

1. Rice (Oryza sativa) cultivar Nipponbare
   Note: Rice (O. sativa) cultivar Nipponbare plants were grown at 28 °C under a photoperiod of 14 h light/10 h dark or in a greenhouse at room temperature (25-32 °C). Mature leaves, from 4-week-old plants, were used in gas-exchange measurements.
   

Equipment

1. Portable gas-exchange system, Li-6400XT (Licor, USA), with standard chamber
   Licor gas-exchange systems, especially the Li-6400 and Li-6400XT, are used widely in photosynthesis and stomatal conductance measurements. The standard chamber, as a basic accessory for the Li-6400XT, is assembled with a high-precision temperature sensor and an internal light sensor (see Figure 1). Because stomatal conductance is a function of leaf temperature (von Caemmerer and Farquhar, 1981), precise control of the leaf temperature is important. Moreover, to induce specific stomatal blue light response, an internal light sensor to measure extra red light and blue light (for the light source see below) is needed. Therefore, the standard chamber, with a high precision temperature sensor and an internal light sensor, is suitable for this experiment.
   
2. Light source
   Light is provided via a fiber-optic illuminator with a halogen projector lamp (15 V/150 W; Philips, Netherlands) as the light source. A power supply (MORITEX, catalog number: MHAB-150W-100V ) was used to power the lamp. Red light (660 nm) and blue light (470 nm) are obtained with filters (#2-61 and #5-60, Corning, USA)
   

Procedure