Darwin proposed that the “brain” of a plant resides in its roots. Subsequent research has shown that roots integrate environmental information about resource availability, competitors, etc., to determine critical life history traits of the shoots, such as the timing of resource allocations to reproduction, growth, defense and senescence. We have explored the importance of a new sensory modality of roots, that of light-perception, in plant growth and development. While previous studies showed that photoreceptors were expressed in roots, we did not know what the functions of these root-photoreceptors are, and how they were activated. Our research provides evidence that root-photoreceptor, especially root-phytochrome B, is directly activated by stem-piped light and modulates root architecture.
For the full story see the press release from the Max-Planck Institute for Chemical Ecology
Figure: Photoreceptors in the roots are directly activated by light which is transmitted from the shoots to the underground roots through the stem. Graphic: Rakesh Santhanam, Angela Overmeyer, Max Planck Institute for Chemical Ecology.
Reference
Stem-piped light activates phytochrome B to trigger light responses in Arabidopsis thaliana roots. Lee, H.-J., Ha, J.-H., Kim, S.-G., Choi, H.-K., Kim, Z. H., Han, Y.-J., Kim, J.-I., Oh, Y., Fragoso, V., Shin, K., Hyeon, T., Choi, H.-G., Oh, K.-H., Baldwin, I. T., Park, C.-M. (2016). Science Signaling. Vol. 9, Issue 452, pp. ra106.