Phytoplasma effectors: Small molecules that manipulate the plant physiology

Phytoplasmas are bacteria belonging to class Mollicutes that are able to infect a wide diversity of plant crops, causing significant economic losses worldwide. During the last decade, the typical symptoms exhibited by phytoplasma infected plants, like phyllody, excessive shoot proliferation and loss of apical dominance have been associated to the secretion of small peptides called effectors. In the present review the pathways and cellular compounds influenced by identified effector families and the response of the host plants to their presence are discussed.