Phytoplasma infection in tomato is associated with re-organization of plasma membrane, ER stacks, and actin filaments in sieve elements.

Phytoplasmas, biotrophic wall-less prokaryotes, only reside in sieve elements of their host plants. The essentials of the intimate interaction between phytoplasmas and their hosts are poorly understood, which calls for research on potential ultrastructural modifications. We investigated modifications of the sieve-element ultrastructure induced in tomato plants by 'Candidatus Phytoplasma solani,' the pathogen associated with the stolbur disease.

Recovery from stolbur disease in grapevine involves changes in sugar transport and metabolism.

Grapevine can be severely affected by phytoplasmas, which are phytopathogenic Mollicutes invading the sieve elements of the host plant. The biochemical and molecular relationships between phytoplasmas and their hosts remain largely unexplored. Equally unknown is an interesting aspect of the pathogen-plant interaction called "recovery," which is a spontaneous remission of symptoms in previously symptomatic plants.

Phytoplasma-triggered Ca(2+) influx is involved in sieve-tube blockage.

Phytoplasmas are obligate, phloem-restricted phytopathogens that are disseminated by phloem-sap-sucking insects. Phytoplasma infection severely impairs assimilate translocation in host plants and might be responsible for massive changes in phloem physiology. Methods to study phytoplasma- induced changes thus far provoked massive, native occlusion artifacts in sieve tubes.

A polyphasic approach for the characterization of endophytic Alternaria strains isolated from grapevines.

A polyphasic approach was set up and applied to characterize 20 fungal endophytes belonging to the genus Alternaria, recovered from grapevine in different Italian regions. Morphological, microscopical, molecular and chemical investigations were performed and the obtained results were combined in a pooled cluster analysis. Following morphological analyses, all strains were grouped according to their three-dimensional sporulation pattern on PCA and to the colony characteristics on different substrates.

Interactions between 'Candidatus Phytoplasma mali' and the apple endophyte Epicoccum nigrum in Catharanthus roseus plants.

Aims: We investigated the ultrastructural and molecular interactions between 'Candidatus Phytoplasma mali' and the apple endophyte Epicoccum nigrum in the experimental host Catharanthus roseus to determine whether inoculation of endophyte could trigger defence reactions in the host.

Methods And Results: Apple proliferation (AP) symptom severity was evaluated in AP-grafted plants that were treated by E. nigrum and compared with untreated controls.