Aster yellows witches'-broom phytoplasma AYWB

Phytoplasmas have diverged from Gram-positive bacteria, and belong to the genus Phytoplasma within the class Mollicutes. They are plant pathogens, causing severe symptoms such as stunting, phyllody, witches broom, yellowing, and yield losses in over 300 economically important plant species worldwide. Transmission of phytoplasmas to plants occurs when insects feed from plant phloem. The bacteria are introduced into plant phloem with insect saliva. In plants, phytoplasmas remain restricted to the phloem tissue where they systemically spread throughout the plant. They are among the smallest self-replicating organisms known, and are characterized by a small genome with a low G+C content, and a lack of a firm cell wall. (EBI Integr8)