Involved in peroxisomal fatty acid beta-oxidation during seed germination. Possesses enoyl-CoA hydratase activity against long chain substrates (C14-C18) and 3-hydroxyacyl-CoA dehydrogenase activity against chains of variable sizes (C6-C18) (PubMed:10521521, PubMed:16507084, PubMed:20463021). Possesses 3-hydroxy-3-phenylpropionyl-CoA dehydrogenase activity and is involved in the peroxisomal beta-oxidation pathway for the biosynthesis of benzoic acid (BA). Required for the accumulation in seeds of substituted hydroxybenzoylated choline esters, which are BA-containing secondary metabolites (PubMed:24254312). Fatty acid beta-oxidation pathway in peroxisomes regulates gene silencing, histone acetylation and DNA methylation (PubMed:31064880). a (3S)-3-hydroxyacyl-CoA = a (2E)-enoyl-CoA + H2O a 4-saturated-(3S)-3-hydroxyacyl-CoA = a (3E)-enoyl-CoA + H2O (3S)-3-hydroxybutanoyl-CoA = (2E)-butenoyl-CoA + H2O (3S)-hydroxyoctanoyl-CoA = (2E)-octenoyl-CoA + H2O (3S)-3-hydroxydodecanoyl-CoA = (2E)-dodecenoyl-CoA + H2O (3S)-hydroxytetradecanoyl-CoA = (2E)-tetradecenoyl-CoA + H2O (3S)-hydroxyhexanoyl-CoA = (2E)-hexenoyl-CoA + H2O a (3Z)-enoyl-CoA = a 4-saturated (2E)-enoyl-CoA a (3E)-enoyl-CoA = a 4-saturated (2E)-enoyl-CoA (3S)-3-hydroxybutanoyl-CoA = (3R)-3-hydroxybutanoyl-CoA a (3S)-3-hydroxyacyl-CoA + NAD(+) = a 3-oxoacyl-CoA + H(+) + NADH (3S)-3-hydroxybutanoyl-CoA + NAD(+) = acetoacetyl-CoA + H(+) + NADH (3S)-hydroxyhexanoyl-CoA + NAD(+) = 3-oxohexanoyl-CoA + H(+) + NADH (3S)-hydroxyoctanoyl-CoA + NAD(+) = 3-oxooctanoyl-CoA + H(+) + NADH (3S)-3-hydroxydodecanoyl-CoA + NAD(+) = 3-oxododecanoyl-CoA + H(+) + NADH (3S)-hydroxytetradecanoyl-CoA + NAD(+) = 3-oxotetradecanoyl-CoA + H(+) + NADH Lipid metabolism; fatty acid beta-oxidation. Highly expressed in senescing leaves and at lower levels in flowers and siliques. Expression increases rapidly during seed germination to reach a peak at 2-3 days after imbibition (DAI) and then declines to basal levels at 5 DAI. The epimerase and isomerase activities are contained in the N-terminal region while the dehydrogenase activity is in the C-terminal region. Accumulation of long-chain acyl-CoA substrates and increased size of peroxisomes. In the N-terminal section; belongs to the enoyl-CoA hydratase/isomerase family. In the central section; belongs to the 3-hydroxyacyl-CoA dehydrogenase family.