INVESTIGADORES
ADLER Conrado
congresos y reuniones científicas
Título:
Canker control by the siderophore Pyochelin from Pseudomonas fluorescens
Autor/es:
ADLER CONRADO; LAMI, MARÍA JESUS; DE CRISTOBAL RE; FILIPPONE, PAULA; CASTAGNARO, ATILIO; VINCENT PAULA
Lugar:
Valencia, España
Reunión:
Congreso; International Citrus Congress; 2012
Institución organizadora:
Instituto Valenciano de Investigaciones Agrarias IVIA
Resumen:
This work shows the identification of a compound able to inhibit Xanthomonas citri pv. citri growth in vitro and in vivo. Firstly, we isolated from environmental samples, bacteria able to inhibit X. citri pv. citri (citrus cankeragent) in vitro. Among the selected isolates, we focused in one showing a remarkable activity. The strain was characterized as Pseudomonas fluorescens after sequencing its 16S rDNA and analyzing the sequence withBLASTn. Purification and chemical analysis of the active compound allowed us to assign the inhibitory activity to pyochelin (Pch). Since this molecule is a siderophore, we wondered if the inhibition observed was a resultof iron scavenging. Surprisingly, when we supplemented media with an excess of iron, we observed practically no change in the inhibition activity. In an attempt to identify the action mechanism of pyochelin, weevaluated the ability of pyochelin to generate reactive oxygen species (ROS) within a culture of X. citri pv. citri and its correlation with the inhibitory activity. In fact, we observed increased ROS levels when Pch wasadded. In addition, the reducer agent ascorbic acid, lowered ROS levels and the antibiotic activity implying that inhibition is probably caused by oxidative stress. Finally, we studied the use of Pch in a model of cankerdisease. Pch showed to reduce canker formation on leaves of Eureka and Lisbon variety plants. These results show Pch as a promising compound for citrus canker biocontrol.