Bacteriology

PLANT BIOLOGY AND BIOTECHNOLOGY / Crop Improvement

Research Interests

Cell-cell signaling and bacterial communities in plant associated bacteria. Bacteria, Quorum sensing, Endophytes, LuxR solos, Pseudomonas

Description of Research

The main interest of the laboratory is cell-cell communication in plant-associated bacteria using rice as out model plant. The focus for many years has been on the N-acyl homoserine lactone quorum sensing system of Gram-negative bacteria. Questions that we are addressing on this quorum sensing system are (i) the role of in forming and stabilizing bacterial plant communities, (ii) how these system are regulated in the plant environment and (ii) the role of LuxR solos in cell-cell communication.

Recently we have also developed an interest in how plant microbiomes are affected upon the arrival of rice bacterial pathogens. We are using two rice diseases as models; rice sheath brown rot caused by Pseudomonas fuscovaginae and rice foot rot caused by Dickeya zeae. Interests are whether bacterial pathogens significantly affect microbiomes at the infection sites and if interspecies or interkingodm interactions takes place among microbial members of the microbiota.

We are also using the plant microbiome for the isolation and identification of beneficial endophytes: Endophytes are harmless or beneficial microorganisms that live inside plants. The relationship they develop with the plant as well as their potential role in plant health is at large unexplored. Endophytes which display the trait of plant growth promotion and these are being studied for their potential use as bioinoculants/biofertilizers.

Current collaborations include (i) an Italy-Vietnam collaboration on the pathobiome of rice foot rot and rice bacterial leaf blight funded by the Italian MAE, (ii) an Italy-Slovenia project on biocontrol bacteria of grapevine funded by the Interreg program, (iii) and Italy-Burundi project with the IRRI outstation in Bujumbura on the pathobiome of rice sheath rot and (iv) a pilot experiment of the rhizomicrobiome of coffee plants in Ethipoia and Colombia funded by Illy SpA.

Bacteriology Figure
Epifluorescent pictures of olive knots, a plant disease caused by Pseudomonas savastanoi pv. savastanoi (PSV). Top 4 sets show inside the knot PSV establishing a cooperative interspecies community with harmless Erwinia toletana. ET and PSV co-localize and cross-communicate with their quorum sensing signals. ET regulates via QS loci involved in the metabolism of carbohydrates and bottom 4 sets show a garL mutant of ET affects the ET PSV interpecies community since they do not co-localize properly and result in a smaller knot.

Recent Publications

Caballo-Ponce, E., Meng, X., Uzelac, G., Halliday, N., Camara, M.,
Licastro, D., Passos da Silva, D., Ramos, C., Venturi, V. 2018. Quorum sensing in Pseudomonas savastanoi pv. savastanoi and Erwinia toletana: role in virulence and interspecies interactions in the olive knot. Appl Environ Microbiol 84 pii: e00950-18. doi: 10.1128/AEM.00950-18 PubMed link

Uzelac, G., Patel, H.K., Devescovi, G., Licastro, D., Venturi, V. 2017. Quorum sensing and RsaM regulons of the rice pathogen Pseudomonas fuscovaginae. Microbiology 163, 765-777 PubMed link

Bertani, I., Abbruscato, P., Piffanelli, P., Subramoni, S., Venturi, V. 2016. Rice bacterial endophytes: isolation of a collection, identification of beneficial strains and microbiome analysis. Environ Microbiol Rep 8, 388-98. Pub Med link

Venturi, V., Keel, C. Signaling in the rhizosphere. 2016. Trends Plant Sci. 21: p. 187-198. PubMed link

Lamichhane, J.R., Venturi, V. 2015. Synergisms between microbial pathogens in plant disease complexes: a growing trend. Front Plant Sci. 6: p. 385. PubMed link

Venturi, V., Ahmer, B.M. 2015. Editorial: LuxR Solos are Becoming Major Players in Cell-Cell Communication in Bacteria. Front Cell Infect Microbiol 5, 89 PubMed link