ABSTRACT
This chapter deals with the main changes of primary carbon metabolism that endow plants to cope with the most common abiotic stresses and survive in ever-changing environments. Glycolysis can be visualized as the first step of the fundamental process of intermediary metabolism known as respiration. The occurrence of raffinose seems to be universal in angiosperms, whereas Raf-derived oligosaccharides are only found in certain species. Levels of phosphoenolpyruvate (PEP)Case vary in response to different abiotic stresses. It has been reported that frost-damaged orange fruits contain increased levels of PEPCase, with this enzyme also exhibiting lower sensitivity to its natural feedback inhibitor malate. The development of molecular tools to identify the functionality of different enzymes to rationally modify plant metabolism may provide a practical way for handling plant behavior in diverse habitats. The improved tolerance of transgenic lines was associated with lower accumulation of reactive oxygen species and lipid peroxidation.
