Fig. 4.

Schematic representation of NAC regulation in plant abiotic stress tolerance. Upon encountering stress, the NAC gene is induced by ABA dependent/independent pathway, which in turn binds to the promoter sequences of other genes (COR, DREB etc.), thereby regulating ROS, GSTF, FT expression. On the other hand, accumulation of unfolded/misfolded proteins triggers unfolded protein response (UPR) in the ER. Thus, membrane bound NAC domain proteins (NTLs) are activated by ER stress and undergo conformational changes (TMD cleavage) to modulate the expression of stress-induced gene. NTLs thus, plays important role in communicating ER stress signaling from PM to nucleus to mitigate the ER stress. NACRS NAC recognition site/sequence, COR Cold regulated, RD responsive to desiccation, ER endoplasmic reticulum, NTL NAC with Transmembrane Motif 1″-Like, TMD transmembrane domain, AREB abscisic acid-responsive element-binding protein, DREB drought-responsive element-binding, ROS reactive oxygen species, GSTF glutathione S-transferase; FT flowering locus T; UPR unfolded protein response, PM plasma membrane