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T. Bisseling

Publications and source records attributed to T. Bisseling.

7 recordsLinked to original sources

Microsynteny between the Medicago truncatula SYM2-orthologous genomic region and another region located on the same chromosome arm.

A synteny based positional cloning approach was started to clone the pea SYM2 gene by using locally conserved genome structure with the model plant Medicago truncatula. We reported that a pea marker tightly linked to SYM2 was used to screen a M. truncatula BAC library, and two contigs named C1/C2 and C3 were constructed that are both located on the long arm of M. truncatula chromosome 5 and separated by 9 cM. C1/C2 is highly microsyntenic to the pea SYM2 genomic region and corresponds to the M. truncatula SYM2-orthologous region, which is delimitated to 350 kbp. In this manuscript we analyze the distribution in the three contigs of 22 sequences and their homologues, including eight C1/C2 and two pea RFLP markers linked to SYM2. Among the analyzed sequences are several different (receptor) kinase-like gene sequences and two classes of LRR-containing resistance protein-like sequences. From all the studied sequences only four detected homologous sequences in C3, and their distribution is comparable in C1/C2 and C3, suggesting that a 70-kbp and a 120-kbp segments of these two contigs, respectively, arose through a duplication. The implications of these findings for the cloning of SYM2 are discussed.

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Sym2 of Pea Is Involved in a Nodulation Factor-Perception Mechanism That Controls the Infection Process in the Epidermis.

In pea (Pisum sativum) up to 50 nodulation mutants are known, several of which are affected in the early steps of the symbiotic interaction with Rhizobium sp. bacteria. Here we describe the role of the sym2 gene in nodulation (Nod) factor perception. Our experiments show that the sym2A allele from the wild pea variety Afghanistan confers an arrest in infection-thread growth if the Rhizobium leguminosarum bv viciae strain does not produce Nod factors with a NodX-mediated acetylation at their reducing end. Since the induction of the early nodulin gene ENOD12 in the epidermis and the formation of a nodule primordium in the inner cortex were not affected, we conclude that more than one Nod factor-perception mechanism is active. Furthermore, we show that sym2A-mediated control of infection-thread growth was affected by the bacterial nodulation gene nodO.

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Root Hair Deformation Activity of Nodulation Factors and Their Fate on Vicia sativa.

We used a semiquantitative root hair deformation assay for Vicia sativa (vetch) to study the activity of Rhizobium leguminosarum bv viciae nodulation (Nod) factors. Five to 10 min of Nod factor-root interaction appears to be sufficient to induce root hair deformation. The first deformation is visible within 1 h, and after 3 h about 80% of the root hairs in a small susceptible zone of the root are deformed. This zone encompasses root hairs that have almost reached their maximal size. The Nod factor accumulates preferentially to epidermal cells of the young part of the root, but is not restricted to the susceptible zone. In the interaction with roots, the glucosamine backbone of Nod factors is shortened, presumably by chitinases. NodRlv-IV(C18:4,Ac) is more stable than NodRlv-V(C18:4,Ac). No correlation was found between Nod factor degradation and susceptibility. Degradation occurs both in the susceptible zone and in the mature zone. Moreover, degradation is not affected by NH4NO3 and is similar in vetch and in the nonhost alfalfa (Medicago sativa).

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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.

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Nodulin Gene Expression and ENOD2 Localization in Effective, Nitrogen-Fixing and Ineffective, Bacteria-Free Nodules of Alfalfa.

Alfalfa plants form bacteria-free nodules in response to a number of agents, including Rhizobium meliloti exo mutants, Agrobacterium tumefaciens transconjugants carrying cloned R. meliloti nodulation genes, and compounds that function as auxin transport inhibitors, N-( 1-naphthyl)phthalamic acid or 2,3,5-triiodobenzoic acid. These bacteria-free nodules contain transcripts for the nodulins Nms30 and MsENOD2; transcripts for late nodulins like leghemoglobin are not detected. In situ hybridization studies demonstrated that ENOD2 transcripts were localized in parenchyma cells at the base and along the periphery of nitrogen-fixing alfalfa root nodules. The ENOD2 gene was also expressed in a tissue-specific manner in nodules elicited by N-( 1-naphthyl)phthalamic acid and 2,3,5-triiodobenzoic acid. In bacteria-free nodules induced by R. meliloti exo mutants and A. tumefaciens transconjugants carrying either one or both R. meliloti symbiotic plasmids, ENOD2 transcripts were also detected but were usually localized to parenchyma cells at the base instead of along the periphery of the nodule. On the basis of the pattern of ENOD2 gene expression, we conclude that the developmental pathway of bacteria-free nodules, whether bacterially or chemically induced, is the same as that of nitrogen-fixing nodules, and, furthermore, that the auxin transport inhibitors in their action mimic some factor(s) that trigger nodule development.

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