Light responses were even found in roots, previously thought to be largely insensitive to light. While the gravitropic response of A. thaliana root organs is their predominant tropic response, specimens treated with mutagens and selected for the absence of gravitropic action showed negative phototropic response to blue or white light, and positive response to red light, indicating that the roots also show positive phototropism.
Light responses were even found in roots, previously thought to be largely insensitive to light. While ,the gravitropic response of A. thaliana root organs is their predominant tropic response, specimens treated with mutagens and selected for the absence of gravitropic action showed negative phototropic response to blue or white light and positive response to red light, indicating that the roots also show positive phototropism.