Papaya (Carica papaya) is a major fruit crop cultivated in tropical and subtropical regions. The treelike, herbaceous papaya plant grows quickly and typically reaches a height of 6–9 meters (20–30 feet). The commercially important fruits cluster together at the top of the trunk, directly below the canopy of the leaves. Papaya fruits are yellow, green, orange, or red in color, and they have loose, smooth skins. When the fleshy fruit is cut open, numerous black seeds are revealed in an inner cavity. See also: Fruit; Fruit, tree; Papaya; Physiological ecology (plant); Seed
Carica papaya is indigenous to tropical Central America and southern Mexico, but it is now grown as a commercial crop throughout parts of the globe with suitable climates. (Papaya plants are not tolerant to frost.) Brazil, Nigeria, Mexico, and India are the world’s major producers of papaya. In the United States, cultivation occurs in Hawaii, southern Florida, and southern California. See also: Agricultural science (plant); Horticultural crops
Papaya can be infected by papaya ringspot virus, which causes small dark rings on the surface of the fruit and premature mottling and malformation of the leaves. The chief insect pest is the papaya fruit fly (Toxotrypana curvicauda). See also: Plant pathology
Papain, a proteolytic enzyme protein, is obtained from the juice of the fruit and from leaves of the plant. It is used for a variety of industrial and food biotechnological purposes, including the tenderizing of meat. In addition, the papain found in papaya is medically used as a digestive aid. Importantly, the DNA sequence of the papaya genome was the first genome of any fruit species to be determined. This determination proved helpful in genetic research, improving the quality and productivity of genetically modified (transgenic) papaya fruits. See also: Biotechnology; Enzyme; Food manufacturing; Gastrointestinal tract disorders; Genetically engineered plants; Genomics
