Impacts of autophagy on nitrogen use efficiency in plants

Abstract

Crop productivity greatly depends on nitrogen (N) fertilization. Large inputs of N fertilizer impact on both the farmer and the environment. Accordingly, improving N use efficiency (NUE) for crop productivity is important for sustainable agriculture. Much plant nitrogen is allocated into the chloroplasts in leaves to constitute proteins involved in photosynthesis, and remobilization of N from senescent leaves greatly affects crop productivity. Autophagy, a highly conserved system used to degrade intracellular components in eukaryotes, is responsible for degrading chloroplasts and their proteins during leaf senescence. In this paper, we review recent studies establishing that autophagy is a key for maintaining high NUE during vegetative growth and for efficiently remobilizing N to grains.