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 cell-cell signaling in forming and stabilizing bacterial plant communities, (ii) how these regulatory systems 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 form and how they are affected upon the arrival of 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 bacterial endophytes. Endophytes are harmless or beneficial microorganisms that live inside plants. Endophytes which display the trait of plant growth promotion are being studied for their potential use as bioinoculants/biofertilizers. In this aspect we are collaboration with the private sector via our initiative called Strains4Plants.

Rice sheath rot in Burundi

Rice with symptoms of sheath rot was studied in Burundi (a) (necrosis, seeds rotten and sterile). b Burundi rice ecology and field sites (lowland and highland) of the outstation of IRRI-Burundi. Red star designates the IRRI field sites in lowland and highland. The symptomatic (diseased) and asymptomatic (healthy) rice sheath plants were sampled in two locations (lowland: Gihanga-Bubanza and highland: Gisha-Ngozi) in two seasons; wet season (April 2017) and dry season (December 2018). The pathobiomes were then determined in order to elucidate the pathogenic agent (Musonerimana et al., 2020).

Recent Publications

Musonerimana S, Bez C, Licastro D, Habarugira G, Bigirimana J, Venturi V.2020. Pathobiomes revealed that Pseudomonas fuscovaginae and Sarocladium oryzae are independently associated with rice sheath rot. Microb Ecol doi:10.1007/s00248-020-01529-2.

Mosquito S, Meng X, Devescovi G, Bertani I, Geller AM, Levy A, Myers MP, Bez C, Covaceuszach S, Venturi V.2020. LuxR solos in the plant endophyte Kosakonia sp. strain KO348. Appl Environ Microbiol 86.

Mosquito S, Bertani I, Licastro D, Compant S, Myers MP, Hinarejos E, Levy A, Venturi V.2020. In planta colonization and role of T6SS in two rice Kosakonia endophytes. Mol Plant Microbe Interact 33:349-363

Bez C, Javvadi SG, Bertani I, Devescovi G, Guarnaccia C, Studholme DJ, Geller AM, Levy A, Venturi V.2020. AzeR, a transcriptional regulator that responds to azelaic acid in Pseudomonas nitroreducens. Microbiology 166:73-84.

Venturi V, Subramoni S, Sabag-Daigle A, Ahmer BMM.2018. Methods to study solo/orphan quorum-sensing receptors. Methods Mol Biol 1673:145-159

Levy A, Salas Gonzalez I, Mittelviefhaus M, Clingenpeel S, Herrera Paredes S, Miao J, Wang K, Devescovi G, Stillman K, Monteiro F, Rangel Alvarez B, Lundberg DS, Lu TY, Lebeis S, Jin Z, McDonald M, Klein AP, Feltcher ME, Rio TG, Grant SR, Doty SL, Ley RE, Zhao B, Venturi V, Pelletier DA, Vorholt JA, Tringe SG, Woyke T, Dangl JL.2018. Genomic features of bacterial adaptation to plants. Nat Genet 50:138-150