Ricerc@Sapienza

Pectin is synthesized in a highly methylesterified form in the Golgi cisternae and partially de-methylesterified in muro by pectin methylesterases (PMEs). Arabidopsis thaliana produces a local and strong induction of PME activity during the infection of the necrotrophic fungus Botrytis cinerea. AtPME17 is a putative A. thaliana PME highly induced in response to B. cinerea. Here, a fine tuning of AtPME17 expression by different defence hormones was identified.

Grape quality and yield are affected by bunch rot disease, caused by the necrotrophic fungus Botrytis cinerea. Primary infection often occurs at blooming, although the fungus remains quiescent until maturity and egresses at ripening, causing bunch rot. The molecular dialogue between B. cinerea and the grapevine inflorescence/berry from bloom until maturity is not completely elucidated, although its understanding is vital to implement proper management. In this study, a molecular characterization of the B.

Oligogalacturonides (OGs) are fragments of pectin released from the plant cell wall during insect or pathogen attack. They can be perceived by the plant as damage signals, triggering local and systemic defence responses. Here, we analyse the dynamics of local and systemic responses to OG perception in tomato roots or shoots, exploring their impact across the plant and their relevance in pathogen resistance.

Total extracts and kuwanon G from Morus nigra root bark showed antifungal activity against several phytopathogenic fungi, with minimal inhibitory concentration (MIC50) ranging from 32 to 128 ?g/ml and from 16 to 64 ?g/ml, respectively. Acetonic extracts inhibited 60% B. cinerea biofilm formation at concentration of 128 ?g/ml.

The plant cell wall is the barrier that pathogens must overcome to cause a disease and to this purpose they secrete degrading enzymes of the various cell wall components. Due to the complexity of these components, several types of oligosaccharide fragments may be released during pathogenesis and some of these can act as Damage-Associated Molecular Pattern (DAMPs). Well-known DAMPs are the oligogalacturonides (OGs) released upon degradation of homogalacturonan and the products of the cellulose breakdown, i.e. the cellodextrins (CDs).

For the first time the antifungal activity of dimethyl sulfoxide (DMSO) was evaluated against Botrytis cinerea, that it is one of the phytopathogenic fungi which causes the greatest damage in agriculture. In in-vitro tests, the greatest inhibitory effect of DMSO on fungal grow was recorded at pH 6. A significant growth inhibition was caused by 0.5% DMSO at 96 h post-inoculation. With higher DMSO concentrations, significant effects were recorded starting from 48 h post-inoculation. As the medium pH decreased, the inhibitory effect of DMSO also decreased.