Establishment of a library of membrane and effector proteins of ´Candidatus P. mali´ to identify host-(apple)-pathogen interactions and to disrupt them

假丝酵母植原体马里(‘ca.P.Mali‘)是一种植物病原性韧皮部原核生物，在欧洲所有气候温和的产区都能引起苹果繁殖，是苹果的一种重要经济病害。这种疾病是通过属于Cacophalla属的昆虫媒介传播的。到目前为止，苹果增殖病的防治主要依靠施药。直到最近，植原体一直抵抗在无细胞培养基中培养的所有尝试，因此这些病原体在生理和生化基础上的特征很差。最近，‘Ca’的基因组。马里植原体和其他三种植原体的基因组被完全测序。其基因组大小约为600.000个碱基，开放阅读框为497个。马里植原体在大小和组织结构上与其他三个已知植原体基因组不同。第一，结果表明，植原体的免疫优势膜蛋白和可能的效应蛋白都与植原体疾病的发病有关。因此，我们将建立一个酵母双杂交(Y2H)的细胞膜蛋白和效应蛋白的文库。鉴定这些相互作用的蛋白质将有助于更好地理解苹果扩散病的发病机理，并使创新的管理策略得以发展。因此，我们将通过噬菌体展示来选择能够干扰和/或破坏这些相互作用的适体。此外，我们还将评估这些适配子的应用策略。

Candidatus Phytoplasma mali (´Ca. P.mali´) is a plant pathogenic phloem colonizing prokaryote causing apple proliferation, an economically important disease in apple in all European production areas with moderate climates. The disease is transmitted by insect vectors belonging to the genus Cacopsylla. Up to now the apple proliferation disease is controlled only by the application of insecticides. Until recently phytoplasmas have resisted all attempts of cultivation in cell free media, therefore these pathogens are poorly characterized on a physiological and biochemical basis. Recently the genome of ´Ca. P. mali´ and three other phytoplasmas genomes were completely sequenced. With a size of approximately 600.000 bp and 497 open reading frames the genome of `Ca. P. mali´ differs in size and organisation from the three other known phytoplasma genomes.First results indicate that both immunodominant membrane proteins and putative effector proteins of phytoplasmas are relevant in the pathogenesis of phytoplasma diseases. Therefore we will establish a yeast two hybrid (Y2H) library of membrane and effector proteins of ´Ca. P. mali´ ("Prey") to identify interactions of host-(apple-) proteins with phytoplasma proteins based on a screening with a Y2H library deriving from a cDNA library of Malus x domestica cv Golden ("Bait") .The identification of these interacting proteins will lead to a better understanding of the pathogenesis of the apple proliferation disease and moreover, enable the development of innovative management strategies. In consequence we will select aptamers via phage display which are able to disturb and/or disrupt these interactions. Moreover we will evaluate strategies for the application of these aptamers.