Future perspectives and challenges
Glycosylation is one of the most important physiological and biochemical reactions in nature given its crucial role in a multitude of essential processes. This intrinsic importance has attracted long-standing and wide research attention on the characteristics of GTs to facilitate their application in glycosylation reactions for the metabolic engineering of natural product biosynthesis. Although several GTs have been found to be suitable for altering glycosylation patterns, low catalytic activity and stringent substrate specificity remain limiting factors in the diversification of PNPs for industrial fermentation systems.
Many enzymes and genes are involved in flavonoid pathways and have been characterized. However, many aspects of flavonoid biology remain unidentified. The expression patterns and activity of some transcription factors that regulate this branched pathway have not yet been identified. Very little evidence exists for protein-protein interactions that form metabolic channels and increase the efficiency of this pathway. These problems can be solved by achieving efficient engineering of flavonoid pathways in plants. The great biodiversity of plants that arose during evolution has generated a concomitant variety of flavonoid structures known to date, many of which are yet to be discovered. Further analysis of different plant species will allow the discovery of novel structures and possibly new metabolic pathways. Future studies will also contribute to the improvement of floricultural, food, pharmaceutical, and chemical industries. Moreover, evidence of beneficial functions of flavonoids in human health and the use of natural compounds for the prevention and treatment of different pathologies are continuously increasing worldwide, and interest will continue to grow among researchers in the coming years.