Catalyzes the NADPH-dependent reduction of glyoxylate to glycolate as well as succinic semialdehyde (SSA) to gamma-hydroxybutyrate in vitro. May function in redox homeostasis and play a role in oxidative stress tolerance by detoxifying glyoxylate and SSA generated in glycolate metabolism and GABA metabolism, respectively. glycolate + NADP(+) = glyoxylate + H(+) + NADPH 4-hydroxybutanoate + NADP(+) = H(+) + NADPH + succinate semialdehyde The ratio of NADPH/NADP(+) may regulate enzymatic activity. According to PubMed:22309191, GLYR1 does not localize in the peroxisome as initially described in PubMed:18495639. By salinity, drought, submergence, cold and heat stresses, and ozone. Follows a sequentially ordered Bi-Bi catalytic mechanism involving the complexation of NADPH to the enzyme before glyoxylate or SSA, and the release of NADP(+) before glycolate or gamma-hydroxybutyrate, respectively. Although GLYR1 acts as an aldo/keto reductase, it has no significant homology with either mammalian and bacterial NADPH-dependent SSA reductases. Belongs to the HIBADH-related family. NP60 subfamily.