Glyoxysome
Glyoxysomes are specialized peroxisomes found in plants 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 is produced as oxygen is consumed. Thus the seeds need oxygen to germinate. Besides peroxisomal functions, glyoxysomes possess additionally the key enzymes of glyoxylate cycle which accomplish the glyoxylate cycle bypass.
Thus, glyoxysomes contain enzymes that initiate the breakdown of fatty acids and additionally possess the enzymes to produce intermediate products for the synthesis of sugars by gluconeogenesis. The seedling uses these sugars synthesized from fats until it is mature enough to produce them by photosynthesis.
Plant peroxisomes also participate in photorespiration and nitrogen metabolism in root nodules.
