phytoplasma

bacterium

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Last updated

July 21, 2026

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A phytoplasma is a type of bacteria related to mycoplasmas that causes plant diseases. These bacteria infect the phloem tissue of plants and are often transmitted by insects. For a long time, phytoplasmas were mistakenly identified as viruses because they are difficult to grow in artificial media, which also hinders research into their biology and genetic makeup.1

Phytoplasmas are assigned temporary taxonomic names because they cannot be cultured in labs, a requirement for official bacterial nomenclature. They are also referred to as mycoplasma-like organisms (MLOs). Examples of diseases caused by phytoplasmas include aster yellows and elm yellows.1

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aster yellows
…plant disease, caused by a phytoplasma bacterium, affecting over 300 species of herbaceous broad-leafed plants. Aster yellows is found over much of the world wherever air temperatures do not persist much above 32 °C (90 °F). As its name implies, members of the family Asteraceae are vulnerable to infection, though…
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…plant disease, caused by a phytoplasma bacterium, affecting over 300 species of herbaceous broad-leafed plants. Aster yellows is found over much of the world wherever air temperatures do not persist much above 32 °C (90 °F). As its name implies, members of the family Asteraceae are vulnerable to infection, though…
Read More