Association of AAA+ ATPases and FtsH proteases with phloem bleeding of proliferation-diseased apple trees

To examine the mechanisms involved in the virulence of the apple proliferation pathogen ‘Candidatus Phytoplasma mali’ a considerable number of genes encoding ATPase AP460 and FtsH protease AP382 were sequenced. Analysis showed that these and other AAA+ proteins are closely related to the virulence of ‘Ca. P. mali’. From the deduced protein sequences of AP382 and AP460 markers were developed that are specific for virulence and avirulence. However, the interpretation of the results was sometimes difficult by either shifts in the phytoplasma population or by a too narrow specificity of the markers. For this it is planned to develop additional markers based on ATPase protein AP406.