What is "phytoplasma"

n. Any of various specialized bacteria that are obligate parasites of plant phloem tissue and of some insects, characterized by the lack of a cell wall, a pleiomorphic or filamentous shape (normally with a diameter of less than one micrometer), and their very small genomes.

Phytoplasmas are specialised bacteria that are obligate parasites of plant phloem tissue and transmitting insects ( vectors). They were discovered by scientists in 1967 and were named mycoplasma-like organisms or MLOs. Since their discovery, phytoplasmas have resisted all attempts to be cultured in vitro in any cell free media, hence routine cultivation in artificial media is still to be established. Nevertheless, still under trial stage, phytoplasma growth in specific artificial media has recently been shown. They are characterised by their lack of a cell wall, a pleiomorphic or filamentous shape, normally with a diameter less than 1 μm, and their very small genomes.

Phytoplasmas are pathogens of agriculturally important plants, including coconut, sugarcane, and sandalwood, causing a wide variety of symptoms that range from mild yellowing to death of infected plants. They are most prevalent in tropical and subtropical regions of the world. They require a vector to be transmitted from plant to plant, and this normally takes the form of sap-sucking insects such as leaf hoppers, in which they are also able to survive and replicate.