The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells
The role of the Lotus japonicus LjSym4 gene during the symbiotic interaction with Mesorhizobium loti and arbuscular mycorrhizal (AM) fungi was analyzed with two mutant alleles conferring phenotypes of different strength. Ljsym4-1 and Ljsym4-2 mutants do not form nodules with M. loti.Normal root hair...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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The American Phytopathological Society
2000-10-01
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| Series: | Molecular Plant-Microbe Interactions |
| Subjects: | |
| Online Access: | https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.10.1109 |
| _version_ | 1819085078664314880 |
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| author | Paola Bonfante Andrea Genre Antonella Faccio Isabella Martini Leif Schauser Jens Stougaard Judith Webb Martin Parniske |
| author_facet | Paola Bonfante Andrea Genre Antonella Faccio Isabella Martini Leif Schauser Jens Stougaard Judith Webb Martin Parniske |
| author_sort | Paola Bonfante |
| collection | DOAJ |
| description | The role of the Lotus japonicus LjSym4 gene during the symbiotic interaction with Mesorhizobium loti and arbuscular mycorrhizal (AM) fungi was analyzed with two mutant alleles conferring phenotypes of different strength. Ljsym4-1 and Ljsym4-2 mutants do not form nodules with M. loti.Normal root hair curling and infection threads are not observed, while a nodC-dependent deformation of root hair tips indicates that nodulation factors are still perceived by Ljsym4 mutants. Fungal infection attempts on the mutants generally abort within the epidermis, but Ljsym4-1 mutants allow rare, successful, infection events, leading to delayed arbuscule formation. On roots of mutants homozygous for the Ljsym4-2 allele, arbuscule formation was never observed upon inoculation with either of the two AM fungi, Glomus intraradices or Gigaspora margarita. The strategy of epidermal penetration by G. margarita was identical for Ljsym4-2 mutants and the parental line, with appressoria, hyphae growing between two epidermal cells, penetration of epidermal cells through their anticlinal wall. These observations define a novel, genetically controlled step in AM colonization. Although rhizobia penetrate the tip of root hairs and AM fungi access an entry site near the base of epidermal cells, the LjSym4 gene is necessary for the appropriate response of this cell type to both microsymbionts. We propose that LjSym4 is required for the initiation or coordinated expression of the host plant cell's accommodation program, allowing the passage of both microsymbionts through the epidermis layer. |
| first_indexed | 2024-12-21T20:58:38Z |
| format | Article |
| id | doaj.art-e347d9c2ca9041348dd770f1746954b6 |
| institution | Directory Open Access Journal |
| issn | 0894-0282 1943-7706 |
| language | English |
| last_indexed | 2024-12-21T20:58:38Z |
| publishDate | 2000-10-01 |
| publisher | The American Phytopathological Society |
| record_format | Article |
| series | Molecular Plant-Microbe Interactions |
| spelling | doaj.art-e347d9c2ca9041348dd770f1746954b62022-12-21T18:50:30ZengThe American Phytopathological SocietyMolecular Plant-Microbe Interactions0894-02821943-77062000-10-0113101109112010.1094/MPMI.2000.13.10.1109The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal CellsPaola BonfanteAndrea GenreAntonella FaccioIsabella MartiniLeif SchauserJens StougaardJudith WebbMartin ParniskeThe role of the Lotus japonicus LjSym4 gene during the symbiotic interaction with Mesorhizobium loti and arbuscular mycorrhizal (AM) fungi was analyzed with two mutant alleles conferring phenotypes of different strength. Ljsym4-1 and Ljsym4-2 mutants do not form nodules with M. loti.Normal root hair curling and infection threads are not observed, while a nodC-dependent deformation of root hair tips indicates that nodulation factors are still perceived by Ljsym4 mutants. Fungal infection attempts on the mutants generally abort within the epidermis, but Ljsym4-1 mutants allow rare, successful, infection events, leading to delayed arbuscule formation. On roots of mutants homozygous for the Ljsym4-2 allele, arbuscule formation was never observed upon inoculation with either of the two AM fungi, Glomus intraradices or Gigaspora margarita. The strategy of epidermal penetration by G. margarita was identical for Ljsym4-2 mutants and the parental line, with appressoria, hyphae growing between two epidermal cells, penetration of epidermal cells through their anticlinal wall. These observations define a novel, genetically controlled step in AM colonization. Although rhizobia penetrate the tip of root hairs and AM fungi access an entry site near the base of epidermal cells, the LjSym4 gene is necessary for the appropriate response of this cell type to both microsymbionts. We propose that LjSym4 is required for the initiation or coordinated expression of the host plant cell's accommodation program, allowing the passage of both microsymbionts through the epidermis layer.https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.10.1109cell deathcell wall |
| spellingShingle | Paola Bonfante Andrea Genre Antonella Faccio Isabella Martini Leif Schauser Jens Stougaard Judith Webb Martin Parniske The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells Molecular Plant-Microbe Interactions cell death cell wall |
| title | The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells |
| title_full | The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells |
| title_fullStr | The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells |
| title_full_unstemmed | The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells |
| title_short | The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells |
| title_sort | lotus japonicus ljsym4 gene is required for the successful symbiotic infection of root epidermal cells |
| topic | cell death cell wall |
| url | https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.10.1109 |
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