Darkened leaves use different metabolic strategies for senescence and survival (Plant Physiol.)

Put a plant into full darkness and it will gradually senesce, whereas as individually darkened leaf (IDL) will undergo radid senescence. Law et al. used transcriptomic and metabolomic methods to identify the metabolic responses of plants to these two conditions. In fully darkened plants, metabolism is generally suppressed and photosynthetic capacity retained, which is in effect a survival strategy. Shade avoidance responses including stem or petiole elongation also occurs through cell wall loosening. By contrast, an IDL shows a more active catabolic response typical of developmental leaf senescence, resulting in a mobilizing of resources from the leaf. The authors observe that these studies will help to develop strategies to enhance the quality of produce after harvest. (Summary by Mary Williams) Plant Physiol. 10.1104/pp.18.00062