Definition of phototropism in US English:



  • The orientation of a plant or other organism in response to light, either toward the source of light (positive phototropism) or away from it (negative phototropism).

    Compare with heliotropism, phototaxis
    • ‘The latter is known as a photoreceptor, for example, for phototropism, stomatal aperture and entrainment of endogenous rhythms in plants and animals.’
    • ‘Phototropins mediate photomovement responses such as phototropism, chloroplast relocation and stomatal opening.’
    • ‘Like other interactions between organisms and their environments, plant phototropism can be thought of as a process involving three phases: perception, transduction and response.’
    • ‘One of the earliest noted auxin effects was in phototropism, the curvature of stems toward a light source.’
    • ‘The nucleus-localized, flavin-binding gene products, CRY1 and CRY2 are involved in several blue light responses, including phototropism.’