A technique was optimized for the in situ detection of nodulation (nod) gene activity in Rhizobium leguminosarum bv. viciae symbiosis with compatible plant hosts Vicia tetrasperma (L.) SCHREB. and Pisum sativum L. The transcription of nodABC-lacZ fusion was visualized as beta-galactosidase (beta-Gal) activity after reaction with the chromogenic substrate X-Gal and subsequent light microscopy, while the background of the indigenous beta-Gal activity of rhizobia and the host plant was eliminated by glutaraldehyde treatment. V. tetrasperma was suggested as a suitable model plant for pea cross-inoculation group due to its advantages over the common model of V. hirsuta (L.) S.F. GRAY: compactness of the plant, extremely small seeds, fast development and stable nodulation under laboratory conditions. In the roots of both plants, a certain extent of nod gene activity was detectable in all rhizobia colonizing the rhizoplane. In pea 1 d after inoculation (d.a.i.), the maximum was localized in the region of emerging root hairs (RH) later (3 and 6 d.a.i.) shifting upwards from the root tip. Nodulation genes sustained full expression even in the infection threads inside the RH and the root cortex, independently of their association with nodule primordia. Comparison of two pea symbiotic mutant lines, Risnod25 and Risnod27, with the wild type did not reveal any differences in the RH formation, RH curling response and rhizoplane colonization. Both mutants appeared to be blocked at the infection thread initiation stage and in nodule initiation, consistent with the phenotype caused by other mutant alleles in the pea sym8 locus. Judging from the nod gene expression level and pattern in the rhizoplane, flavonoid response upon inoculation is preserved in both pea mutants, being independent of infection thread and nodule initiation.

Institute of Microbiology Academy of Sciences of the Czech Republic 142 20 Prague Czechia

Zobrazit více v PubMed

J Hered. 2003 Mar-Apr;94(2):191-3 PubMed

Mol Microbiol. 1999 May;32(4):837-49 PubMed

Nature. 2002 Jun 27;417(6892):959-62 PubMed

Curr Opin Plant Biol. 1999 Dec;2(6):483-9 PubMed

Microb Ecol. 2001 Feb;41(4):325-332 PubMed

Plant J. 1998 Sep;15(5):605-614 PubMed

Plant Physiol. 1988 Apr;86(4):1298-303 PubMed

Plant Cell. 2001 Aug;13(8):1835-49 PubMed

J Bacteriol. 1986 May;166(2):552-8 PubMed

Plant Cell. 2000 Sep;12(9):1647-66 PubMed

Ann Bot. 2002 Apr;89(4):357-66 PubMed

Plant Cell. 1990 Dec;2(12):1157-1170 PubMed

Plant Mol Biol. 1987 Jan;9(1):27-39 PubMed

Science. 1997 Jan 24;275(5299):527-30 PubMed

J Exp Bot. 2002 Aug;53(375):1735-45 PubMed

J Bacteriol. 1991 Jul;173(14):4277-87 PubMed

J Bacteriol. 1989 Jul;171(7):4045-53 PubMed

Theor Appl Genet. 1987 Oct;74(6):711-3 PubMed

Appl Environ Microbiol. 1987 Oct;53(10):2539-43 PubMed

Physiol Plant. 2004 Apr;120(4):546-555 PubMed

Plant Mol Biol. 1991 May;16(5):841-52 PubMed

Theor Appl Genet. 2002 Jun;104(8):1312-1316 PubMed

Mol Plant Microbe Interact. 2001 Apr;14(4):471-6 PubMed

Genes Dev. 1990 Mar;4(3):344-56 PubMed

Annu Rev Microbiol. 2000;54:257-88 PubMed

Determination of symbiotic nodule occupancy in the model Vicia tetrasperma using a fluorescence scanner

Visualization of symbiotic tissue in intact root nodules of Vicia tetrasperma using GFP-marked Rhizobium leguminosarum bv. viciae

Xyn11A, a multidomain multicatalytic enzyme from Pseudobutyrivibrio xylanivorans Mz5T