Transcription activator that binds to the secondary wall NAC binding element (SNBE), 5'-(T/A)NN(C/T)(T/C/G)TNNNNNNNA(A/C)GN(A/C/T)(A/T)-3', in the promoter of target genes (e.g. genes involved in secondary wall biosynthesis, cell wall modification such as xylan accumulation, and programmed cell death). Involved in xylem formation in roots and shoots, especially regulating protoxylem vessel differentiation by promoting immature xylem vessel-specific genes expression. Can activate the expression of several genes including XCP1, MYB46, NAC010/SND3, MYB103, MYB58, MYB63, MYB83, KNAT7, ASL19 and ASL20.; Required for the soilborne fungal pathogen Verticillium longisporum-induced transdifferentiation of chloroplast-containing bundle sheath cells to functional xylem elements leading to stunted growth, vein clearing, and leaf chloroses, as well as xylem hyperplasia within the vasculature of leaves, hypocotyls, and roots due to reinitiation of cambial activity and transdifferentiation of xylem parenchyma cells. This developmental reprogramming mediates also an increased drought stress tolerance.
