Catalyzes the desaturation of long-chain acyl-CoAs to 2-trans-enoyl-CoAs. a 2,3-saturated acyl-CoA + O2 = a (2E)-enoyl-CoA + H2O2 Induced one day after germination with a peak at day 5 and then declines steadily until day 8. Belongs to the acyl-CoA oxidase family.