Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism
Homogentisate Phytyltransferase (HPT) catalyzes condensation of homogentisate (HGA) and phytyl diphosphate (PDP) to produce tocopherols, but can also synthesize tocotrienols using geranylgeranyl diphosphate (GGDP) in plants engineered for deregulated HGA synthesis. In contrast to prior tocotrienol b...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2024-02-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2024.1344095/full |
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| author | Ping Qin Peng Chen Yuanwei Zhou Wei Zhang Yunyun Zhang Jingjing Xu Lu Gan Yingnan Liu Jill Romer Peter Dörmann Edgar B. Cahoon Chunyu Zhang |
| author_facet | Ping Qin Peng Chen Yuanwei Zhou Wei Zhang Yunyun Zhang Jingjing Xu Lu Gan Yingnan Liu Jill Romer Peter Dörmann Edgar B. Cahoon Chunyu Zhang |
| author_sort | Ping Qin |
| collection | DOAJ |
| description | Homogentisate Phytyltransferase (HPT) catalyzes condensation of homogentisate (HGA) and phytyl diphosphate (PDP) to produce tocopherols, but can also synthesize tocotrienols using geranylgeranyl diphosphate (GGDP) in plants engineered for deregulated HGA synthesis. In contrast to prior tocotrienol biofortification efforts, engineering enhanced tocopherol concentrations in green oilseeds has proven more challenging due to the integral role of chlorophyll metabolism in supplying the PDP substrate. This study show that RNAi suppression of CHLSYN coupled with HPT overexpression increases tocopherol concentrations by >two-fold in Arabidopsis seeds. We obtained additional increases in seed tocopherol concentrations by engineering increased HGA production via overexpression of bacterial TyrA that encodes chorismate mutase/prephenate dehydrogenase activities. In overexpression lines, seed tocopherol concentrations increased nearly three-fold, and resulted in modest tocotrienol accumulation. We further increased total tocochromanol concentrations by enhancing production of HGA and GGDP by overexpression of the gene for hydroxyphenylpyruvate dioxygenase (HPPD). This shifted metabolism towards increased amounts of tocotrienols relative to tocopherols, which was reflected in corresponding increases in ratios of GGDP/PDP in these seeds. Overall, our results provide a theoretical basis for genetic improvement of total tocopherol concentrations in green oilseeds (e.g., rapeseed, soybean) through strategies that include seed-suppression of CHLSYN coupled with increased HGA production. |
| first_indexed | 2024-03-07T21:43:21Z |
| format | Article |
| id | doaj.art-42997f429282496782515c840cf727be |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-03-07T21:43:21Z |
| publishDate | 2024-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-42997f429282496782515c840cf727be2024-02-26T04:42:13ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2024-02-011510.3389/fpls.2024.13440951344095Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolismPing Qin0Peng Chen1Yuanwei Zhou2Wei Zhang3Yunyun Zhang4Jingjing Xu5Lu Gan6Yingnan Liu7Jill Romer8Peter Dörmann9Edgar B. Cahoon10Chunyu Zhang11National Key Laboratory of Crop Genetic Improvement and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, ChinaNational Key Laboratory of Crop Genetic Improvement and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, ChinaYichang Academy of Agricultural Science, Ministry of Agriculture and rural areas, Yichang, Hubei, ChinaNational Key Laboratory of Crop Genetic Improvement and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, ChinaIndustrial Crops Institute of Yunnan Academy of Agricultural Sciences, Ministry of Agriculture and rural areas, Kunming, ChinaNational Key Laboratory of Crop Genetic Improvement and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, ChinaDepartment of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, United StatesLincang Agricultural Technology Extension Center, Lincang, Yunnan, ChinaInstitute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, GermanyInstitute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, GermanyDepartment of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, United StatesNational Key Laboratory of Crop Genetic Improvement and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, ChinaHomogentisate Phytyltransferase (HPT) catalyzes condensation of homogentisate (HGA) and phytyl diphosphate (PDP) to produce tocopherols, but can also synthesize tocotrienols using geranylgeranyl diphosphate (GGDP) in plants engineered for deregulated HGA synthesis. In contrast to prior tocotrienol biofortification efforts, engineering enhanced tocopherol concentrations in green oilseeds has proven more challenging due to the integral role of chlorophyll metabolism in supplying the PDP substrate. This study show that RNAi suppression of CHLSYN coupled with HPT overexpression increases tocopherol concentrations by >two-fold in Arabidopsis seeds. We obtained additional increases in seed tocopherol concentrations by engineering increased HGA production via overexpression of bacterial TyrA that encodes chorismate mutase/prephenate dehydrogenase activities. In overexpression lines, seed tocopherol concentrations increased nearly three-fold, and resulted in modest tocotrienol accumulation. We further increased total tocochromanol concentrations by enhancing production of HGA and GGDP by overexpression of the gene for hydroxyphenylpyruvate dioxygenase (HPPD). This shifted metabolism towards increased amounts of tocotrienols relative to tocopherols, which was reflected in corresponding increases in ratios of GGDP/PDP in these seeds. Overall, our results provide a theoretical basis for genetic improvement of total tocopherol concentrations in green oilseeds (e.g., rapeseed, soybean) through strategies that include seed-suppression of CHLSYN coupled with increased HGA production.https://www.frontiersin.org/articles/10.3389/fpls.2024.1344095/fullchlorophyll synthasehomogentisate phytyltransferasehomogentisatephytyl diphosphategeranylgeranyl diphosphatetocopherol |
| spellingShingle | Ping Qin Peng Chen Yuanwei Zhou Wei Zhang Yunyun Zhang Jingjing Xu Lu Gan Yingnan Liu Jill Romer Peter Dörmann Edgar B. Cahoon Chunyu Zhang Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism Frontiers in Plant Science chlorophyll synthase homogentisate phytyltransferase homogentisate phytyl diphosphate geranylgeranyl diphosphate tocopherol |
| title | Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism |
| title_full | Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism |
| title_fullStr | Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism |
| title_full_unstemmed | Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism |
| title_short | Vitamin E biofortification: enhancement of seed tocopherol concentrations by altered chlorophyll metabolism |
| title_sort | vitamin e biofortification enhancement of seed tocopherol concentrations by altered chlorophyll metabolism |
| topic | chlorophyll synthase homogentisate phytyltransferase homogentisate phytyl diphosphate geranylgeranyl diphosphate tocopherol |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2024.1344095/full |
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