These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Sinorhizobium fredii HH103 cgs mutants are unable to nodulate determinate- and indeterminate nodule-forming legumes and overproduce an altered EPS.
    Author: Crespo-Rivas JC, Margaret I, Hidalgo A, Buendía-Clavería AM, Ollero FJ, López-Baena FJ, del Socorro Murdoch P, Rodríguez-Carvajal MA, Soria-Díaz ME, Reguera M, Lloret J, Sumpton DP, Mosely JA, Thomas-Oates JE, van Brussel AA, Gil-Serrano A, Vinardell JM, Ruiz-Sainz JE.
    Journal: Mol Plant Microbe Interact; 2009 May; 22(5):575-88. PubMed ID: 19348575.
    Abstract:
    Sinorhizobium fredii HH103 produces cyclic beta glucans (CG) composed of 18 to 24 glucose residues without or with 1-phosphoglycerol as the only substituent. The S. fredii HH103-Rifr cgs gene (formerly known as ndvB) was sequenced and mutated with the lacZ-gentamicin resistance cassette. Mutant SVQ562 did not produce CG, was immobile, and grew more slowly in the hypoosmotic GYM medium, but its survival in distilled water was equal to that of HH103-Rifr. Lipopolysaccharides and K-antigen polysaccharides produced by SVQ562 were not apparently altered. SVQ562 overproduced exopolysaccharides (EPS) and its exoA gene was transcribed at higher levels than in HH103-Rifr. In GYM medium, the EPS produced by SVQ562 was of higher molecular weight and carried higher levels of substituents than that produced by HH103-Rifr. The expression of the SVQ562 cgsColon, two colonslacZ fusion was influenced by the pH and the osmolarity of the growth medium. The S. fredii cgs mutants SVQ561 (carrying cgs::Omega) and SVQ562 only formed pseudonodules on Glycine max (determinate nodules) and on Glycyrrhiza uralensis (indeterminate nodules). Although nodulation factors were detected in SVQ561 cultures, none of the cgs mutants induced any macroscopic response in Vigna unguiculata roots. Thus, the nodulation process induced by S. fredii cgs mutants is aborted at earlier stages in V. unguiculata than in Glycine max.
    [Abstract] [Full Text] [Related] [New Search]