Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules
In addition to rhizobia, many types of co-existent bacteria are found in leguminous root nodules, but their habitats are unclear. To investigate this phenomenon, we labeled Bradyrhizobium diazoefficiens USDA122 and Bradyrhizobium sp. SSBR45 with Discosoma sp. red fluorescent protein (DsRed) or enhan...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2023-12-01
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| Series: | Plant Signaling & Behavior |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/15592324.2023.2245995 |
| _version_ | 1827379109850775552 |
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| author | Shingo Hata Risa Tsuda Serina Kojima Aiko Tanaka Hiroshi Kouchi |
| author_facet | Shingo Hata Risa Tsuda Serina Kojima Aiko Tanaka Hiroshi Kouchi |
| author_sort | Shingo Hata |
| collection | DOAJ |
| description | In addition to rhizobia, many types of co-existent bacteria are found in leguminous root nodules, but their habitats are unclear. To investigate this phenomenon, we labeled Bradyrhizobium diazoefficiens USDA122 and Bradyrhizobium sp. SSBR45 with Discosoma sp. red fluorescent protein (DsRed) or enhanced green fluorescent protein (eGFP). USDA122 enhances soybean growth by forming effective root nodules, but SSBR45 does not form any nodules. Using low-magnification laser scanning confocal microscopy, we found that infected cells in the central zone of soybean nodules appeared to be occupied by USDA122. Notably, high-magnification microscopy after co-inoculation of non-fluorescent USDA122 and fluorescence-labeled SSBR45 also revealed that SSBR45 inhabits the intercellular spaces of healthy nodules. More unexpectedly, co-inoculation of eGFP-labeled USDA122 and DsRed-labeled SSBR45 (and vice versa) revealed the presence of USDA122 bacteria in both the symbiosomes of infected cells and in the apoplasts of healthy nodules. We then next inspected nodules formed after a mixed inoculation of differently-labeled USDA122, without SSBR45, and confirmed the inhabitation of the both populations of USDA122 in the intercellular spaces. In contrast, infected cells were occupied by single-labeled USDA122. We also observed Mesorhizobium loti in the intercellular spaces of active wild-type nodules of Lotus japonicus using transmission electron microscopy. Compatible intercellular rhizobia have been described during nodule formation of several legume species and in some mutants, but our evidence suggests that this type of colonization may occur much more commonly in leguminous root nodules. |
| first_indexed | 2024-03-08T13:08:34Z |
| format | Article |
| id | doaj.art-a172cccafaf04f1987a3d8e7ff9bfc5f |
| institution | Directory Open Access Journal |
| issn | 1559-2316 1559-2324 |
| language | English |
| last_indexed | 2024-03-08T13:08:34Z |
| publishDate | 2023-12-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Plant Signaling & Behavior |
| spelling | doaj.art-a172cccafaf04f1987a3d8e7ff9bfc5f2024-01-18T15:58:23ZengTaylor & Francis GroupPlant Signaling & Behavior1559-23161559-23242023-12-0118110.1080/15592324.2023.22459952245995Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodulesShingo Hata0Risa Tsuda1Serina Kojima2Aiko Tanaka3Hiroshi Kouchi4Ryukoku UniversityRyukoku UniversityRyukoku UniversityNagoya UniversityInternational Christian UniversityIn addition to rhizobia, many types of co-existent bacteria are found in leguminous root nodules, but their habitats are unclear. To investigate this phenomenon, we labeled Bradyrhizobium diazoefficiens USDA122 and Bradyrhizobium sp. SSBR45 with Discosoma sp. red fluorescent protein (DsRed) or enhanced green fluorescent protein (eGFP). USDA122 enhances soybean growth by forming effective root nodules, but SSBR45 does not form any nodules. Using low-magnification laser scanning confocal microscopy, we found that infected cells in the central zone of soybean nodules appeared to be occupied by USDA122. Notably, high-magnification microscopy after co-inoculation of non-fluorescent USDA122 and fluorescence-labeled SSBR45 also revealed that SSBR45 inhabits the intercellular spaces of healthy nodules. More unexpectedly, co-inoculation of eGFP-labeled USDA122 and DsRed-labeled SSBR45 (and vice versa) revealed the presence of USDA122 bacteria in both the symbiosomes of infected cells and in the apoplasts of healthy nodules. We then next inspected nodules formed after a mixed inoculation of differently-labeled USDA122, without SSBR45, and confirmed the inhabitation of the both populations of USDA122 in the intercellular spaces. In contrast, infected cells were occupied by single-labeled USDA122. We also observed Mesorhizobium loti in the intercellular spaces of active wild-type nodules of Lotus japonicus using transmission electron microscopy. Compatible intercellular rhizobia have been described during nodule formation of several legume species and in some mutants, but our evidence suggests that this type of colonization may occur much more commonly in leguminous root nodules.http://dx.doi.org/10.1080/15592324.2023.2245995apoplastglycine maxfluorescencelotus japonicusrhizobiaroot nodule |
| spellingShingle | Shingo Hata Risa Tsuda Serina Kojima Aiko Tanaka Hiroshi Kouchi Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules Plant Signaling & Behavior apoplast glycine max fluorescence lotus japonicus rhizobia root nodule |
| title | Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules |
| title_full | Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules |
| title_fullStr | Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules |
| title_full_unstemmed | Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules |
| title_short | Both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules |
| title_sort | both incompatible and compatible rhizobia inhabit the intercellular spaces of leguminous root nodules |
| topic | apoplast glycine max fluorescence lotus japonicus rhizobia root nodule |
| url | http://dx.doi.org/10.1080/15592324.2023.2245995 |
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