Abstract
Plant growth is significantly affected by such environmental parameters as light, water, atmosphericcomposition
and pressure, temperature, humidity, and nutrients. A higher growth rate for plants might
be attained by modulating such environmental parameters, which also affect the plant’s physiological
responses and quality and quantity of metabolites. In this study, we designed and fabricated an
environment-controlled chamber called a plant growing chamber (PGC) to offer a variety of growth
conditions for plants. Our PGC modulates temperature, humidity, light intensity, light wavelength, air
pressure, etc. Using it, we focused on atmospheric pressure to examine its effects on plant growth. We
used an aquatic plant, Spirodela polyrrhiza, as a test plant and evaluated its growth rate under elevatedatmospheric
pressure varying from 0.1 to 0.4 MPa. The effects of elevated pressure on the growth rate
were analyzed by an imaging processor. The growth rate increased up to 1.25 times under 0.2 MPa,
suggesting that photosynthesis can be improved under conditions of elevated pressure.
