7-Hydroxymethyl chlorophyll a reductase functions in metabolic channeling of chlorophyll breakdown intermediates during leaf senescence

► HCAR functions in chlorophyll breakdown during leaf senescence in Arabidopsis. ► HCAR interacts with LHCII in vivo and with SGR, NYC1, NOL and RCCR in yeast. ► HCAR is a component of the SGR-CCE-LHCII complex in senescing chloroplasts. ► HCAR and NOL seem to function in the chlorophyll cycle during vegetative growth.