Modern agriculture is characterized by the intensification of agricultural practices and cultivation of plants in dense stands. It is crucial for plants growing at high densities to perceive and respond to upcoming shade from a neighboring plant rapidly. The light quality in the canopy is determined by the Red:Far-Red light (R:FR) ratio, with high R:FR indicating sufficient light for photosynthesis and low R:FR indicating shade caused by proximate neighbors. We found previously that leaf tip touching between individuals in a dense vegetation of Arabidopsis is the earliest neighbor detection in shoots. Following touching, the leaves respond with an upward leaf movement (called hyponasty). Due to this hyponastic response the canopy architecture changes from a horizontal to a more vertical one. This vertical alignment of leaves generates FR light reflection, leading to a low R:FR signal inside the canopy. Under these conditions, the plant can detect the low R:FR signal in different parts of the leaves and respond with a further hyponasty and/or elongation of the leaf petiole. All these canopy alterations are part of the shade avoidance strategy of plants to consolidate light capture. Interestingly, touch-induced hyponasty involves a signal transduction pathway that is distinct from light-mediated hyponasty. This indicates that a canopy develops progressively though different signaling pathways towards the final shade avoidance phenotype. https://www.uu.nl/staff/CPantazopoulou