Supporting Information

Abstract

Fig. S1 The hydroponic split-root culture system used for (a) N deficiency-induced and (b) dark-induced senescence. (a) Four days-old barley plants with split-root systems were precultured for 9 d under Fe supply, then the Fe-supplied part of the root system was removed to avoid Fe translocation from apoplastic Fe pools. Plants were continued to grow for 4 d with or without Fe before transfer to either N-free or N-supplied nutrient solution. Plants were harvested just before and 8 d after transfer to N treatments. +Fe+N: control, complete nutrient