Phytooncology

the branch of phytopathology that studies pathological neoplasms in plants. The term “phytooncology” was introduced by the Soviet scientist V. L. Ryzhkov in 1960. Because plants and animals are similar in cell structure, mechanism of cell division, and causes of tumor development, it is possible to use neoplasms in plants as convenient models for the study of the general principles of tumor growth. The study of plant neoplasms is especially helpful because plants lack endocrine, nervous, circulatory, and lymphatic systems, whose functions interfere in the analysis of the origin of tumors in animals.

The most important methods of phytooncology are the infection of plants with agents that cause pathological growth; the induction of pathological growth by means of blastomogenic compounds; the cultivation of isolated organs, tissues, and cells of neoplasms on artificial nutrients; and transplantation. Modern phytooncology studies the principles of the tumorous transformation of cells and tissues and the origin of autonomous pathological growth, as well as the reasons for the absence of autonomy. It also studies the role of foreign messenger macromolecules in pathological growth. Specialists investigate the ways in which cells and tissues defend themselves against carcinogenic agents in the course of their vital functions and analyze the possibilities of restoring pathologically transformed cells and tissues to their normal state. Of special significance are the detection of tumor-related symptoms in plant organisms and the comparison of these symptoms with those that occur in animal organisms, including man.