“…PIFs), and positively acting HLH factors (e.g. HFR1, PRE6/KIDARI, PAR1, PAR2, HECs and possibly others) (Fairchild et al, 2000;Fankhauser and Chory, 2000;Hyun and Lee, 2006;Kim et al, 2002;Lorrain et al, 2009;RoigVillanova et al, 2006;Zhou et al, 2014;Zhu et al, 2016). Similar to the established antagonistic relationship between bHLH and HLH proteins in eukaryotic systems (Littlewood and Evans, 1998;Toledo-Ortiz et al, 2003), HFR1 sequesters PIF1/PIF4/PIF5/PIF7 to regulate red light-induced seed germination and shade avoidance responses (Hersch et al, 2014;Hornitschek et al, 2009;Shi et al, 2013).…”