A signal from the cell wall decides that, in the dark, seeds grow into long yellow sprouts, instead of turning green and forming leaves. The signal that switches on the darkness programme in seedling development has not hitherto been identified. Earlier studies had shown that these processes involve photoreceptors inside plant cells.
Though it may look haphazard, the network of intertwining plant roots snaking through the soil actually represents a deliberate process. Root growth is guided by chemical snapshots taken by the young roots, allowing them to detect obstructions and coordinate the paths they take, new research led by Florida Institute of Technology finds.