Required for glycerol-3-phosphate (G3P) accumulation during systemic acquired resistance (SAR) establishment. NAD(+) + sn-glycerol 3-phosphate = dihydroxyacetone phosphate + H(+) + NADH Homodimer. Compromised in systemic acquired resistance (SAR) triggered by Pseudomonas syringae DC3000 avrRpt2 probably because of a reduced accumulation of glycerol-3-phosphate (G3P). Belongs to the NAD-dependent glycerol-3-phosphate dehydrogenase family. Truncated N-terminus. Truncated N-terminus.