Enzymes are proteins that perform specific functions in the cell metabolism of all living creatures. Plant enzymes are involved in the defence against fungus and bacteria responsible for diseases. They perform vital processes, such as the germination of seeds and ripening of fruit, and they play a role in the growth of leaves and in the restoration of cell-walls.
Plant cell walls are made of cellulose and other polysaccharide, which are long molecules of sugars. Some bacteria and plants, such as rice, cabbage and mustard, produce glycoside hydrolases and polysaccharide lyases. When produced by bacteria, these enzymes degrade the cellulose molecule in the cell-wall, causing plant diseases, according to the Proceedings of the National Academy of Sciences of the United States of America. However, plant-produced glycoside hydrolases are essential in cell-wall polysaccharide metabolism, according to Springer Links. Some plants can contain 29 families of different glycoside hydrolases.
In 2008, scientists at Brookhaven National Laboratory identified enzymes important in the modification of isoflavonoids, which help plants resist fungal infections. Isoflavonoid-synthesis enzymes are naturally found in white clover, soybean and alfalfa, among other plants. These enzymes perform many functions related to plant growth, disease resistance and synthesis of big molecules, as well as cell-wall modification, according to Brookhaven National Laboratory.
The beer-making process involves the malting of the barley grains, which happens when the seeds are wet and begin to germinate. This requires the action of enzymes that are able to turn starch into sugar, such as alpha-glucosidases, naturally found in barley plants and grains. Through biotechnology techniques, researchers are able to modify enzymes and introduce them into plants, thus improving commercial performance. In the case of alpha-glucosidase, scientists increased its tolerance to the high heat imposed by the malting process.