Scientists are using genetic engineering, method for creating new forms of plants faster than by traditional selection, techniques without modifying the main agronomic characteristics of basic strains.
In molecular selection the desired characters are obtained by insertion of individual sense genes into the plant genome. For example, plants resistant to diseases caused by phytopathogens (bacteria and fungi) are thus evolved. Another trend is in improving the taste qualities. These two problems can be solved simultaneously now and then.
Tertiary structure of the thaumatin protein molecule in two projections: A) frontal; B) lateral.
Numerous proteins protect plants from diseases caused by phytopathogens (bacteria and fungi). Biologists have classified these proteins: by now about 10 groups are known, for example, the family of pathogenesis-related proteins (PR-5). It unites substances initially isolated from the West African thaumatococcus (Thaumatococcus danielli) and the common maize (Zea mays) and called by the Latin names of these plants: thaumatin-zeamatin-like substances. These substances were found to be widespread and in this or that form, present in virtually all plants, accounting for their resistance to phytopathogenic fungi, together with chitinase (chitin-destroying enzyme; chitin is present in the fungal mycelium).
Thaumatin is formed in the thaumatococcus by the time of fruit maturation. Spontaneous mutation of the gene coding for this protein must have developed in the course of evolution. As a result of this mutation the peripheral part of the protein molecule was modified, primarily with respect to the spatial location of lysine residues. Thaumatococcus fruit became very sweet and tasty for chimpanzees and gorillas. These primates started consuming this fruit and spreading its seeds, thus contributing to the evolutionary fixation of its character. It is noteworthy that only higher primates can perceive the sweet taste of thaumatin, due ... Read more