Thermoplasmataceae

The family Thermoplasmataceae consists of unique microorganisms belonging to the class Mollicutes. In agriculture, these organisms are recognized as significant pathogens that induce complex systemic diseases in various plant species. Lacking a rigid cell wall, these pathogens exhibit unique biological properties that complicate traditional control and diagnostic efforts.

These organisms are primary causative agents of phytoplasmosis. The disease is characterized by the colonization of the plant's vascular system, specifically the phloem. By disrupting the flow of nutrients and phytohormones, the pathogen causes profound physiological dysfunction that affects the overall growth and reproductive capacity of the plant.

A wide range of economically important crops are susceptible to these pathogens, including vegetables, fruit trees, and perennial ornamentals. The host range often expands due to the high mobility of insect vectors such as leafhoppers and psyllids, which facilitate the rapid spread of the disease within agricultural landscapes.

Symptoms are often distinct and progressive, including severe leaf yellowing (chlorosis), stunting of growth, and the development of dense, broom-like clusters of thin, stunted shoots known as «witches' broom». Flowers may become deformed or sterile, and fruit development is frequently inhibited or results in poor-quality yields.

Effective management requires an integrated approach. Because direct chemical control of the intracellular pathogen is currently unavailable, prevention is the primary strategy. This includes the elimination of insect vectors through targeted insecticide application, the use of certified pathogen-free seeds or grafts, and the strict removal of host weeds that harbor the pathogen throughout the growing season.