Acetyltransferase involved in UDP-N-acetylglucosamine (UDP-GlcNAc) biosynthesis. UDP-GlcNAc is an essential metabolite that serves as an initial sugar donor for N-glycan synthesis and thus plays an important role in protein and lipid glycosylation. acetyl-CoA + D-glucosamine 6-phosphate = CoA + H(+) + N-acetyl-D-glucosamine 6-phosphate Optimum pH is 7.0-8.0. Optimum temperature is 35 degrees Celsius. Nucleotide-sugar biosynthesis; UDP-N-acetyl-alpha-D-glucosamine biosynthesis; N-acetyl-alpha-D-glucosamine 1-phosphate from alpha-D-glucosamine 6-phosphate (route I): step 1/2. Homodimer. Expressed in roots, leaves, stems, cauline leaves, flowers and siliques. Retarded vegetative growth, delayed flowering and short and thick inflorescence stems and siliques. The mutant lignescens (lig) was originally isolated as a temperature-sensitive mutant that exhibits ectopic lignin deposition and growth defects under high-temperature conditions. Belongs to the acetyltransferase family. GNA1 subfamily.