# 17-26-021

phototropism

change in the direction of growth of plant parts (cells, tissues, and/or organs) in response to a directional source of optical radiation

EXAMPLE Plant stems will typically bend towards a source of optical radiation and leaves will change orientation such that their upper surfaces tend to be perpendicular to a source of optical radiation.

Note 1 to entry: This entry was numbered 17-947 in CIE S 017:2011.

Publication date: 2020-12