Hydroperoxy fatty acid reductase essential for the removal of lipid hydroperoxides under normal and stress conditions, leading to the protection of membrane integrity. a hydroperoxy polyunsaturated fatty acid + H(+) + NADPH = a hydroxy polyunsaturated fatty acid + H2O + NADP(+) Mercaptosuccinate, pCMB, and nethylmaleimide act as inhibitors of the catalytic activity. Optimum pH is 8.2. Optimum temperature is 37 degrees Celsius. Monomer. High light, methylviologen, t-butyl hydroperoxide, and salt stress conditions increase the expression level. Belongs to the glutathione peroxidase family.