The Isolation and Characterization of Kronos, a Novel Caulobacter Rhizosphere Phage that is Similar to Lambdoid Phages

Abstract

Despite their ubiquity, relatively few bacteriophages have been characterized. Here, we set out to explore Caulobacter bacteriophages (caulophages) in the rhizosphere and characterized Kronos, the first caulophage isolated from the rhizosphere. Kronos is a member of the Siphoviridae family since it has a long flexible tail. In addition, an analysis of the Kronos genome indicated that many of the predicted proteins were distantly-related to those of bacteriophages in the lambdoid family. Consistent with this observation, we were able to demonstrate the presence of cos sites that are similar to those found at ends of lambdoid phage genomes. Moreover, Kronos displayed a relatively rare head and tail morphology compared to other caulophages but was similar to that of the lambdoid phages. Taken together, these data indicate that Kronos is distantly related to lambdoid phages and may represent a new Siphoviridae genus.

Genes related to redox and cell curvature facilitate interactions between Caulobacter strains and Arabidopsis

“…Since bacterial cell shape has been linked to colonization abilities [ 33 , 40 ], and Caulobacter cells can colonize plant roots both in artificial environments [ 23 ] and in natural environments [ 41 ], we tested whether the cell curvature of Caulobacter cells (i.e., using CB15 as a proxy for PGP Caulobacter strains since cell curvature is a conserved feature among the Caulobacter strains that we previously tested [ 22 ]) contributes to Caulobacter -mediated plant growth enhancement by conducting our plant bioassays with CB15Δ creS (rod shaped as opposed to the typical crescent shape of C . crescentus cells).…”