Nodule development induced by Mesorhizobium loti mutant strains affected in polysaccharide synthesis.

D’ANTUONO, ALEJANDRA L.,; CASABUONO ADRIANA,; COUTO ALICIA,; UGALDE RODOLFO A.; LEPEK VIVIANA C..

MOLECULAR PLANT-MICROBE INTERACTIONS

APS Press- USA.

Año: 2005 vol. 18 p. 446 - 457

0894-0282

The role of Mesorhizobium loti surface polysaccharides on the nodulation process is not yet fully understood. In this article, we describe the nodulation phenotype of mutants affected in the synthesis of lipopolysaccharide (LPS) andMesorhizobium loti surface polysaccharides on the nodulation process is not yet fully understood. In this article, we describe the nodulation phenotype of mutants affected in the synthesis of lipopolysaccharide (LPS) and β(1,2) cyclic glucan. M. loti lpsβ 2 mutant produces LPS with reduced amount of O-antigen, whereas M. loti lpsβ1 mutant produces LPS totally devoid of O-antigen. Both genes are clustered in the chromosome. Based on amino acid sequence homology, LPS sugar composition, and enzymatic activity, we concluded that lpsβ 2 codes for an enzyme involved in the transformation of dTDP-glucose into dTDPrhamnose, the sugar donor of rhamnose for the synthesis of O-antigen. On the other hand, lpsβ1 codes for a glucosyltransferase involved in the biosynthesis of the O-antigen. Although LPS mutants elicited normal nodules, both show reduced competitiveness compared with the wild type. M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.lpsM. loti lps(1,2) cyclic glucan. M. loti lpsβ 2 mutant produces LPS with reduced amount of O-antigen, whereas M. loti lpsβ1 mutant produces LPS totally devoid of O-antigen. Both genes are clustered in the chromosome. Based on amino acid sequence homology, LPS sugar composition, and enzymatic activity, we concluded that lpsβ 2 codes for an enzyme involved in the transformation of dTDP-glucose into dTDPrhamnose, the sugar donor of rhamnose for the synthesis of O-antigen. On the other hand, lpsβ1 codes for a glucosyltransferase involved in the biosynthesis of the O-antigen. Although LPS mutants elicited normal nodules, both show reduced competitiveness compared with the wild type. M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.lpsM. loti lpsβ1 mutant produces LPS totally devoid of O-antigen. Both genes are clustered in the chromosome. Based on amino acid sequence homology, LPS sugar composition, and enzymatic activity, we concluded that lpsβ 2 codes for an enzyme involved in the transformation of dTDP-glucose into dTDPrhamnose, the sugar donor of rhamnose for the synthesis of O-antigen. On the other hand, lpsβ1 codes for a glucosyltransferase involved in the biosynthesis of the O-antigen. Although LPS mutants elicited normal nodules, both show reduced competitiveness compared with the wild type. M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.lps, we concluded that lpsβ 2 codes for an enzyme involved in the transformation of dTDP-glucose into dTDPrhamnose, the sugar donor of rhamnose for the synthesis of O-antigen. On the other hand, lpsβ1 codes for a glucosyltransferase involved in the biosynthesis of the O-antigen. Although LPS mutants elicited normal nodules, both show reduced competitiveness compared with the wild type. M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.lpsβ1 codes for a glucosyltransferase involved in the biosynthesis of the O-antigen. Although LPS mutants elicited normal nodules, both show reduced competitiveness compared with the wild type. M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.M. loti β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.β(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsLotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgsM. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.