Abstract
Plant growth is significantly affected by environmental parameters, such as light, water, atmospheric composition and pressure, temperature, humidity and nutrients. High growth rate of plants should be attained by means of modulating such environmental parameters. These parameters also affect plant physiological responses and quality and quantity of metabolites. In this study, an environment-controlled chamber (Plant Growing Chamber; PGC) was designed and fabricated to offer a variety of growth conditions to plants. The newly developed PGC enabled to modulate temperature, humidity, light intensity, light wavelength, air pressure, etc. Using the PGC, we focused on pressure to examine its effects on plant growth. An aquatic plant, Spirodela polyrrhiza, was used as a test plant to evaluate its growth rate under the elevated pressure varying from 0.1 to 0.4 MPa. Effects of the elevated pressure on the growth rate were analyzed by an imaging processor. The results showed that the growth rate increased up to 1.3 times under 0.2 MPa. These results open possibility that photosynthesis could be improved under the conditions of elevated pressure.
