Figure 2 Comparison of phylogenetic trees constructed from core and panCB genes. Maximum-likelihood phylogenetic trees of 16 Rhizobiales constructed using the concatenated nucleic acid sequences of 10 housekeeping genes (a) or panC and panB concatenated genes (b). Bootstrap values are

shown over each branch (based on 100 pseudo-replicates). The panCB genes do not fully complement the growth deficiency of a R. etli CFN42 p42f cured derivative in MM It was reported previously that R. etli CFNX186, a Pexidartinib nmr p42f-cured derivative of R. etli CFN42, is unable to grow in MM [18]. To assess if the growth deficiency of strain CFNX186 in MM was due to the absence of the panC and panB genes, plasmid pTV4 (panCB) was introduced into strain CFNX186. The growth of the transconjugant (CFNX186-4) after 15 hours of culture in MM was only 50% that of the WT strain FK228 datasheet grown under the same conditions (Figure 3a). The growth of selleck chemical CFNX186-4 did not improve even after 72 h in culture (data not shown). Interestingly, strain CFNX186-4 had the same growth rate as strain CFNX186 cultured in MM supplemented with 1 μM calcium pantothenate (Figure 3b). This shows that the growth deficiency of CFNX186 is only partly due to the absence of the panCB genes and indicates that other functions encoded in plasmid

p42f are required for growth in MM. Figure 3 panCB genes do not fully restore the growth deficiency of CFNX186. Growth of R. etli CFN42 wild-type strain, its p42f-cured derivative CFNX186, CFNX186 complemented with the panCB genes (CFNX186-4) and CFNX186 complemented with a 20 kb EcoRI fragment of plasmid p42f containing the panC, panB, oxyR and katG genes (CFNX186-24) in: (a) minimal medium, (b) minimal medium supplemented with 1 μM pantothenate. Growth curves are the mean of at least three independent experiments; error bars represent standard deviations. Previous studies have demonstrated that the katG gene, which encodes else the sole catalase-peroxidase

expressed in free-living growth conditions, is located on plasmid p42f of R. etli CFN42. These studies also revealed that the growth rate of a katG mutant in MM was significantly reduced in comparison with that of the wild-type parental strain [19]. On plasmid p42f katG, as well as its putative transcriptional regulator protein encoded by oxyR, are located 80 bp downstream of the panCB genes. We speculated that introduction of the panCB genes together with the katG and oxyR genes might improve the growth of CFNX186 in MM. To test this hypothesis, we used pCos24, which contains a 20 kb fragment of p42f carrying panCB, katG and oxyR (see Material and Methods). pCos24 was introduced into CFNX186 and the resulting transconjugant (CFNX186-24) grown in MM. Figure 3 shows that after 15 hours of culture there was no significant difference between the growth rate of CFNX186 complemented only with panCB (CFNX183-4), and CFNX186 complemented with cosmid pCos24 (CFNX186-24).