Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis
A fundamental limitation of photosynthetic carbon fixation is the availability of CO2. In C4 plants, primary carboxylation occurs in mesophyll cytosol, and little is known about the role of CO2 diffusion in facilitating C4 photosynthesis. We have examined the expression, localization, and functional...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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eLife Sciences Publications Ltd
2021-11-01
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| Series: | eLife |
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| Online Access: | https://elifesciences.org/articles/70095 |
| _version_ | 1818026611648233472 |
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| author | Maria Ermakova Hannah Osborn Michael Groszmann Soumi Bala Andrew Bowerman Samantha McGaughey Caitlin Byrt Hugo Alonso-cantabrana Steve Tyerman Robert T Furbank Robert E Sharwood Susanne von Caemmerer |
| author_facet | Maria Ermakova Hannah Osborn Michael Groszmann Soumi Bala Andrew Bowerman Samantha McGaughey Caitlin Byrt Hugo Alonso-cantabrana Steve Tyerman Robert T Furbank Robert E Sharwood Susanne von Caemmerer |
| author_sort | Maria Ermakova |
| collection | DOAJ |
| description | A fundamental limitation of photosynthetic carbon fixation is the availability of CO2. In C4 plants, primary carboxylation occurs in mesophyll cytosol, and little is known about the role of CO2 diffusion in facilitating C4 photosynthesis. We have examined the expression, localization, and functional role of selected plasma membrane intrinsic aquaporins (PIPs) from Setaria italica (foxtail millet) and discovered that SiPIP2;7 is CO2-permeable. When ectopically expressed in mesophyll cells of Setaria viridis (green foxtail), SiPIP2;7 was localized to the plasma membrane and caused no marked changes in leaf biochemistry. Gas exchange and C18O16O discrimination measurements revealed that targeted expression of SiPIP2;7 enhanced the conductance to CO2 diffusion from the intercellular airspace to the mesophyll cytosol. Our results demonstrate that mesophyll conductance limits C4 photosynthesis at low pCO2 and that SiPIP2;7 is a functional CO2 permeable aquaporin that can improve CO2 diffusion at the airspace/mesophyll interface and enhance C4 photosynthesis. |
| first_indexed | 2024-12-10T04:34:46Z |
| format | Article |
| id | doaj.art-03d8535519cd4f69b0bfbc6e492119a8 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-12-10T04:34:46Z |
| publishDate | 2021-11-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-03d8535519cd4f69b0bfbc6e492119a82022-12-22T02:02:02ZengeLife Sciences Publications LtdeLife2050-084X2021-11-011010.7554/eLife.70095Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridisMaria Ermakova0https://orcid.org/0000-0001-8466-4186Hannah Osborn1Michael Groszmann2https://orcid.org/0000-0002-5015-6156Soumi Bala3Andrew Bowerman4https://orcid.org/0000-0003-1729-7843Samantha McGaughey5https://orcid.org/0000-0001-6133-0415Caitlin Byrt6https://orcid.org/0000-0001-8549-2873Hugo Alonso-cantabrana7https://orcid.org/0000-0002-5462-5861Steve Tyerman8https://orcid.org/0000-0003-2455-1643Robert T Furbank9https://orcid.org/0000-0001-8700-6613Robert E Sharwood10https://orcid.org/0000-0003-4993-3816Susanne von Caemmerer11https://orcid.org/0000-0002-8366-2071Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaARC Centre of Excellence in Plant Energy Biology, School of Agriculture Food and Wine, University of Adelaide, Adelaide, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, Australia; Hawkesbury Institute for the Environment, Western Sydney University, Richmond, AustraliaAustralian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, Canberra, AustraliaA fundamental limitation of photosynthetic carbon fixation is the availability of CO2. In C4 plants, primary carboxylation occurs in mesophyll cytosol, and little is known about the role of CO2 diffusion in facilitating C4 photosynthesis. We have examined the expression, localization, and functional role of selected plasma membrane intrinsic aquaporins (PIPs) from Setaria italica (foxtail millet) and discovered that SiPIP2;7 is CO2-permeable. When ectopically expressed in mesophyll cells of Setaria viridis (green foxtail), SiPIP2;7 was localized to the plasma membrane and caused no marked changes in leaf biochemistry. Gas exchange and C18O16O discrimination measurements revealed that targeted expression of SiPIP2;7 enhanced the conductance to CO2 diffusion from the intercellular airspace to the mesophyll cytosol. Our results demonstrate that mesophyll conductance limits C4 photosynthesis at low pCO2 and that SiPIP2;7 is a functional CO2 permeable aquaporin that can improve CO2 diffusion at the airspace/mesophyll interface and enhance C4 photosynthesis.https://elifesciences.org/articles/70095Setaria viridisSetaria italicaaquaporinmesophyll conductancec4 photosynthesisco2 diffusion |
| spellingShingle | Maria Ermakova Hannah Osborn Michael Groszmann Soumi Bala Andrew Bowerman Samantha McGaughey Caitlin Byrt Hugo Alonso-cantabrana Steve Tyerman Robert T Furbank Robert E Sharwood Susanne von Caemmerer Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis eLife Setaria viridis Setaria italica aquaporin mesophyll conductance c4 photosynthesis co2 diffusion |
| title | Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis |
| title_full | Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis |
| title_fullStr | Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis |
| title_full_unstemmed | Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis |
| title_short | Expression of a CO2-permeable aquaporin enhances mesophyll conductance in the C4 species Setaria viridis |
| title_sort | expression of a co2 permeable aquaporin enhances mesophyll conductance in the c4 species setaria viridis |
| topic | Setaria viridis Setaria italica aquaporin mesophyll conductance c4 photosynthesis co2 diffusion |
| url | https://elifesciences.org/articles/70095 |
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