Glyoxysomes

Glyoxysomes are specialized peroxisomes found in plants (particularly in the fat storage tissues of germinating seeds) and also in filamentous fungi. Seeds that contain fats and oils include corn, soybean, sunflower, peanut and pumpkin. As in all peroxisomes, in glyoxysomes the fatty acids are oxidized to acetyl-CoA by peroxisomal β-oxidation enzymes. When the fatty acids are oxidized hydrogen peroxide (H₂O₂) is produced as oxygen (O₂) is consumed. Thus the seeds need oxygen to germinate. Besides peroxisomal functions, glyoxysomes possess additionally the key enzymes of the glyoxylate cycle (isocitrate lyase and malate synthase) which accomplish the glyoxylate cycle bypass.