+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Expression of nodule-specific genes in alfalfa root nodules blocked at an early stage of development



Expression of nodule-specific genes in alfalfa root nodules blocked at an early stage of development



Genes and Development 2(6): 677-687



To help dissect the molecular basis of the Rhizobium-legume symbiosis, we used in vitro translation and Northern blot analysis of nodule RNA to examine alfalfa-specific genes (nodulins) expressed in two types of developmentally defective root nodules elicited by Rhizobium meliloti. Fix- nodules were elicited by R. meliloti nif mutants; these nodules were invaded by rhizobia and contained differentiated bacteroids. 'Empty' nodules were elicited by R. meliloti exo and ndv mutants and by Agrobacterium tumefaciens strains carrying the R. meliloti nod genes; these nodules contained a nodule meristem but lacked infection threads, intracellular bacteria, and bacteroids. Fix- nodules contained a spectrum of nodulins similar to wild-type nodules. In contrast, only two nodulins, Nms-30 and a nodulin homologous to ENOD2 of soybean, were detected in empty nodules. Although R. meliloti ndv and exo mutants elicited nodules with the same defective phenotype, ndv and exo mutants (except for exoC mutants) had distinct biochemical phenotypes. R. meliloti ndvA and ndvB mutants were deficient in cyclic glucan production but not the acidic exopolysaccharide; the converse was true for exoA, exoB, and exoF mutants. exoC mutants were defective in both exopolysaccharide and cyclic glucan biosynthesis. Our results support the model that the R. meliloti nod genes produce a signal that results in nodule meristem induction. Both the exopolysaccharide and cyclic glucan, however, appear to act at the next step in the developmental process and are involved in the production of a signal (or structure) that allows infection thread formation and invasion of the nodule.

(PDF emailed within 0-6 h: $19.90)

Accession: 040109042

Download citation: RISBibTeXText

PMID: 3417147

DOI: 10.1101/gad.2.6.677


Related references

Regulation of plant nodule-specific genes expressed in alfalfa nodules arrested at an early stage of development. Plant Science (Limerick) 101(1): 65-73, 1994

Developmental regulation of nodule-specific genes in alfalfa root nodules. Molecular Plant-Microbe Interactions 1(2): 66-74, 1988

Analysis of nodule-specific gene expression in ineffective alfalfa root nodules and callus cultures derived from ineffective root nodules. Current plant science and biotechnology in agriculture: ) 112-114, 1987

Characterization of nodule specific complementary dna clones from sesbania rostrata and expression of the corresponding genes during the initial stages of stem nodules and root nodules formation. Molecular Plant-Microbe Interactions 2(3): 122-127, 1989

Nodule-specific polypeptides from effective alfalfa root nodules and from ineffective nodules lacking nitrogenase. Plant Physiology 77(4): 833-839, 1985

Nodule specific polypeptides from effective alfalfa medicago sativa root nodules and from ineffective nodules lacking nitrogenase. Plant Physiology 77(4): 833-839, 1985

Induction and expression of nodule-specific host genes in effective and ineffective root nodules of soybean. Biochemistry 20(5): 1300-1306, 1981

Expression of nodulin genes during nodule development from effective and ineffective root nodules. Advances in nitrogen fixation research: 579-586, 1984

Expression of leg hemo globin and other nodule specific plant genes in effective and ineffective root nodules of soybean glycine max. European Journal of Cell Biology 22(1): 52, 1980

Expression of leghemoglobin genes of alfalfa medicago sativa l. vernal during root nodule development. Bothe, H , F J De Bruijn And W E Newton (Ed ) Nitrogen Fixation: Hundred Years After; 7th International Congress, Cologne, West Germany, March 13-20, Xxi+878p Vch Publishers, Inc : New York, New York, Usa; Vch Verlagsgesellschaft Mbh: Weinheim, West Germany; Gustav Fischer Verlag: Stuttgart, West Germany Illus 636, 1988

Induction and expression of nodule specific host genes in effective and ineffective root nodules of soybean glycine max cultivar prize. Biochemistry 20(5): 1300-1306, 1981

Differential expression of nodule-specific (nodulin) genes in the infected, uninfected and cortical cells of soybean (Glycine max) root nodules. Journal of plant physiology 135(5): 608-617, 1990

Identification of two groups of leghemoglobin genes in alfalfa (Medicago sativa) and a study of their expression during root nodule development. Plant Molecular Biology 11(6): 761-772, 1988

In vitro translation of nodule specific messenger rna from alfalfa medicago sativa root nodules. Korean Biochemical Journal 19(2): 203-206, 1986

ENOD8, a novel early nodule-specific gene, is expressed in empty alfalfa nodules. Molecular Plant-Microbe Interactions 6(6): 715-721, 1993