E. amylovora was inoculated into apple stems with different genes that encode to aiiA and yhjH proteins. In such cases, disease was visible three days after inoculation and was developed to similar levels gradually until it reached the 8th day and the disease considerably increased its expansion through the leaf. However, differences in disease development both the severity of disease and the time of disease onset) were seen both between the Erwinia amylovora wild ones and Erwinia amylovora aiiA. Bacterial inocula were prepared by growing an overnight culture of E.amylovora electroporated with aiiA in LB broth enriched with sucrose at 28°C in a shaking incubator.

The virulence factors of Erwinia amylovora depends on cellular density, AHL’s are responsible/involved in EPS synthesis; amylovoran and levan. AHL in E. amylovora appears to contribute to the expression of virulence factors and symptom development, which is similar to the role that AHL’s play at any other pathogenic plant bacteria. When incorporating a plasmid expression vector of aiiA gene, we obtained a negative effect for the necrosis of the leaf, in comparison with the Erwinia amylovora wild, as shown on figure X; there was a development of this process from day 0 to day 8th. It also inhibited the production of exudate that is characteristic of Amylovora and Levan Exopolysaccharides (EPS), and by the same time dismiss the infection that is presented by the Type Three Secretion System (T3SS). This gene expressed the enzyme AHL-lactose, which is involved in the hydrolysis of these molecules, after this degradation, AHL-EamR bind is stopped, therefore, this activator will not stimulate the operon which is responsible for EamI transcription for intracellular AHL´s and other genes that codifies for the other virulence factors.