Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule Symbiosis
The sulfolipid sulfoquinovosyldiacylglycerol is commonly found in the thylakoid membranes of photosynthetic bacteria and plants. While there is a good correlation between the occurrence of sulfolipid and photosynthesis, a number of exceptions are known. Most recently, sulfoquinovosyldiacylglycerol w...
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| Format: | Article |
| Language: | English |
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The American Phytopathological Society
2000-06-01
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| Series: | Molecular Plant-Microbe Interactions |
| Subjects: | |
| Online Access: | https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.6.666 |
| _version_ | 1818915200309395456 |
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| author | Barbara Weissenmayer Otto Geiger Christoph Benning |
| author_facet | Barbara Weissenmayer Otto Geiger Christoph Benning |
| author_sort | Barbara Weissenmayer |
| collection | DOAJ |
| description | The sulfolipid sulfoquinovosyldiacylglycerol is commonly found in the thylakoid membranes of photosynthetic bacteria and plants. While there is a good correlation between the occurrence of sulfolipid and photosynthesis, a number of exceptions are known. Most recently, sulfoquinovosyldiacylglycerol was discovered in the non-photosynthetic, root nodule-forming bacterium Sinorhizobium meliloti. This discovery raised the questions of the phylogenetic origin of genes essential for the biosynthesis of this lipid in S. meliloti and of a function of sulfolipid in root nodule symbiosis. To begin to answer these questions, we isolated and inactivated the sqdB gene of S. meliloti. This gene and two other genes located directly 3′ of sqdB are highly similar to the sqdB, sqdC, and sqdD genes known to be essential for sulfolipid biosynthesis in the photosynthetic, purple bacterium Rhodobacter sphaeroides. This observation confirms the close phylogenetic kinship between these two species. Furthermore, the reduced similarity of sqdB to the plant ortholog SQD1 of Arabidopsis thaliana does not support a previous sqd gene transfer from the plant as a consequence of close symbiosis. A sul-folipid-deficient mutant of S. meliloti disrupted in sqdB is capable of inducing functional nodules and does not show an obvious disadvantage under different laboratory culture conditions. Thus far, no specific function can be assigned to bacterial sulfolipid, in either nodule-associated or free-living cells. S. meliloti contains a rich set of polar membrane lipids some of which, including sulfolipid, may become critical only under growth conditions that still need to be discovered. |
| first_indexed | 2024-12-19T23:58:30Z |
| format | Article |
| id | doaj.art-e276f24a31bc4c229b310ac5f8bc0ecd |
| institution | Directory Open Access Journal |
| issn | 0894-0282 1943-7706 |
| language | English |
| last_indexed | 2024-12-19T23:58:30Z |
| publishDate | 2000-06-01 |
| publisher | The American Phytopathological Society |
| record_format | Article |
| series | Molecular Plant-Microbe Interactions |
| spelling | doaj.art-e276f24a31bc4c229b310ac5f8bc0ecd2022-12-21T20:00:56ZengThe American Phytopathological SocietyMolecular Plant-Microbe Interactions0894-02821943-77062000-06-0113666667210.1094/MPMI.2000.13.6.666Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule SymbiosisBarbara WeissenmayerOtto GeigerChristoph BenningThe sulfolipid sulfoquinovosyldiacylglycerol is commonly found in the thylakoid membranes of photosynthetic bacteria and plants. While there is a good correlation between the occurrence of sulfolipid and photosynthesis, a number of exceptions are known. Most recently, sulfoquinovosyldiacylglycerol was discovered in the non-photosynthetic, root nodule-forming bacterium Sinorhizobium meliloti. This discovery raised the questions of the phylogenetic origin of genes essential for the biosynthesis of this lipid in S. meliloti and of a function of sulfolipid in root nodule symbiosis. To begin to answer these questions, we isolated and inactivated the sqdB gene of S. meliloti. This gene and two other genes located directly 3′ of sqdB are highly similar to the sqdB, sqdC, and sqdD genes known to be essential for sulfolipid biosynthesis in the photosynthetic, purple bacterium Rhodobacter sphaeroides. This observation confirms the close phylogenetic kinship between these two species. Furthermore, the reduced similarity of sqdB to the plant ortholog SQD1 of Arabidopsis thaliana does not support a previous sqd gene transfer from the plant as a consequence of close symbiosis. A sul-folipid-deficient mutant of S. meliloti disrupted in sqdB is capable of inducing functional nodules and does not show an obvious disadvantage under different laboratory culture conditions. Thus far, no specific function can be assigned to bacterial sulfolipid, in either nodule-associated or free-living cells. S. meliloti contains a rich set of polar membrane lipids some of which, including sulfolipid, may become critical only under growth conditions that still need to be discovered.https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.6.666Rhizobium |
| spellingShingle | Barbara Weissenmayer Otto Geiger Christoph Benning Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule Symbiosis Molecular Plant-Microbe Interactions Rhizobium |
| title | Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule Symbiosis |
| title_full | Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule Symbiosis |
| title_fullStr | Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule Symbiosis |
| title_full_unstemmed | Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule Symbiosis |
| title_short | Disruption of a Gene Essential for Sulfoquinovosyldiacylglycerol Biosynthesis in Sinorhizobium meliloti Has No Detectable Effect on Root Nodule Symbiosis |
| title_sort | disruption of a gene essential for sulfoquinovosyldiacylglycerol biosynthesis in sinorhizobium meliloti has no detectable effect on root nodule symbiosis |
| topic | Rhizobium |
| url | https://apsjournals.apsnet.org/doi/10.1094/MPMI.2000.13.6.666 |
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