Rhizobium Lipooligosaccharides Rescue a Carrot Somatic Embryo Mutant.

At a nonpermissive temperature, somatic embryos of the temperature-sensitive (ts) carrot cell mutant ts11 only proceed beyond the globular embryo stage in the presence of medium conditioned by wild-type embryos. The causative component in the conditioned medium has previously been identified as a 32-kD acidic endochitinase. In search of a function for this enzyme in plant embryogenesis, several compounds that contain oligomers of N-acetylglucosamine were tested for their ability to promote ts11 embryo formation. Of these compounds, only the Rhizobium lipooligosaccharides or nodulation (Nod) factors were found to be effective in rescuing the formation of ts11 embryos. These results suggest that N-acetylglucosamine-containing lipooligosaccharides from bacterial origin can mimic the effect of the carrot endochitinase. This endochitinase may therefore be involved in the generation of plant analogs of the Rhizobium Nod factors.

[1]  J. Ohnishi,et al.  Arabidopsis , 2008, Springer New York.

[2]  J. Schell,et al.  Rhizobium NodB protein involved in nodulation signal synthesis is a chitooligosaccharide deacetylase. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[3]  S. C. Vries,et al.  Secreted proteins in plant cell cultures. , 1993 .

[4]  Robert F. Fisher,et al.  Rhizobium–plant signal exchange , 1992, Nature.

[5]  J. Vandekerckhove,et al.  A carrot somatic embryo mutant is rescued by chitinase. , 1992, The Plant cell.

[6]  C. Bulawa,et al.  CSD2, CSD3, and CSD4, genes required for chitin synthesis in Saccharomyces cerevisiae: the CSD2 gene product is related to chitin synthases and to developmentally regulated proteins in Rhizobium species and Xenopus laevis , 1992, Molecular and cellular biology.

[7]  S. D. de Vries,et al.  Extracellular proteins in plant embryogenesis. , 1992, Trends in genetics : TIG.

[8]  E. P. Kennedy,et al.  A novel highly unsaturated fatty acid moiety of lipo-oligosaccharide signals determines host specificity of Rhizobium , 1991, Nature.

[9]  P. Sterk,et al.  Cell-specific expression of the carrot EP2 lipid transfer protein gene. , 1991, The Plant cell.

[10]  K. Palme,et al.  Auxin receptors take shape , 1991, Current Biology.

[11]  P. Lerouge,et al.  Sulphated lipo-oligosaccharide signals of Rhizobium meliloti elicit root nodule organogenesis in alfalfa , 1991, Nature.

[12]  G. Stacey,et al.  Studies on the Function of Rhizobium Meliloti Nodulation Genes , 1991 .

[13]  Philippe Roche,et al.  Symbiotic host-specificity of Rhizobium meliloti is determined by a sulphated and acylated glucosamine oligosaccharide signal , 1990, Nature.

[14]  N. Sandal,et al.  Some nodulin and Nod proteins show similarity to specific animal proteins , 1990 .

[15]  N. Benhamou,et al.  Attempted localization of a substrate for chitinases in plant cells reveals abundant N‐acetyl‐d‐glucosamine residues in secondary walls , 1989 .

[16]  J. Schell,et al.  Rhizobium meliloti nodA and nodB genes are involved in generating compounds that stimulate mitosis of plant cells. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[17]  G. Michaels,et al.  Accumulation and decay of DG42 gene products follow a gradient pattern during Xenopus embryogenesis. , 1988, Developmental biology.

[18]  K. Cox.  Analysis of plant gene expression , 1988 .

[19]  E. Cabib.  Endochitinase from wheat germ , 1988 .

[20]  A. Komamine,et al.  Identification and Isolation of Single Cells that Produce Somatic Embryos at a High Frequency in a Carrot Suspension Culture. , 1985, Plant physiology.

[21]  I. Polacheck,et al.  An endochitinase from wheat germ. Activity on nascent and preformed chitin. , 1979, The Journal of biological chemistry.