Transcriptional activator that plays a regulatory role in the development of secondary cell wall fibers (PubMed:18952777,PubMed:22133261). Involved in the regulation of cellulose and hemicellulose biosynthetic genes as well as of genes involved in lignin polymerization and signaling (PubMed:22133261). Is not a direct target of SND1 (PubMed:18952777). Expressed in protoxylem and elongating interfascicular fiber cells of elongating internodes, developing metaxylem cells and interfascicular fibers of non-elongating internodes and developing secondary xylem of roots. The NAC domain includes a DNA binding domain and a dimerization domain.