Biology subjects

Cazorla, F. M.

Publications and source records attributed to Cazorla, F. M..

2 recordsLinked to original sources

bioRxiv2020

A Volatile Signal Controls Virulence in the Plant Pathogen Pseudomonas syringae pv. syringae and a Strategy for Infection Control in Organic Farming

Pseudomonas syringae is an important pathogen of many agriculturally valuable crops. Among the various pathovars described P. syringae pv. syringae (Pss) has a particularly wide host range, infecting primarily woody and herbaceous host plants. The ability of Pss to cause bacterial apical necrosis of mango trees is dependent on the production of the antimetabolite toxin mangotoxin. The production of this toxin was shown to be regulated by a self-produced signaling molecule. In this study, we determined the structure of the Pss signal molecule belonging to the recently described family of diazeniumdiolate communication molecules. Employing a targeted mass spectrometry-based approach, we provide experimental evidence that the major signal produced by Pss is the volatile compound leudiazen, which controls mangotoxin production and virulence in a detached tomato leaflet infection model. Experimental results demonstrate that KMnO4 solution inactivates leudiazen and that treatment of infected leaves with KMnO4 abolishes necrosis. This strategy represents the first example of chemically degrading a signaling molecule to interfere with bacterial communication. The application of KMnO4 solution, which is regulatorily approved in organic farming, may constitute an environmentally friendly strategy to control Pss infections.

microbiology↗

bioRxiv2018

Extracellular matrix components are required to protect Bacillus subtilis colonies from T6SS-dependent Pseudomonas invasion and modulate co-colonization of plant

Bacteria adapt to environmental changes and interact with other microorganisms using a wide array of molecules, metabolic plasticity, secretion systems and the formation of biofilms. Some research has looked at changes in the expression of biofilm related genes during interactions between different bacterial species, however no studies have directly demonstrated the functional significance of biofilms in modulating such interactions. In this study, we have explored this fundamental question by studying the interaction between Bacillus subtilis 3610 and Pseudomonas chlororaphis PCL1606. We demonstrate the important role of the extracellular matrix in protecting B. subtilis colonies from infiltration by Pseudomonas. Surprisingly, we find that the Pseudomonas type VI secretion system (T6SS) is required in the cell-to-cell contact with matrix-impaired B. subtilis cells, revealing a novel role for T6SS against Gram-positive bacteria. In response to P. chlororaphis infiltration, we find that B. subtilis activates sporulation and expresses motility-related genes. Experiments using plant organs demonstrate the functional importance of these different bacterial strategies in their coexistence as stable bacterial communities. The findings described here further our understanding of the functional role played by biofilms in mediating bacterial social interactions.

microbiology↗