Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil
Seeds of castor (<i>Ricinus communis</i>) are enriched in oil with high levels of the industrially valuable fatty acid ricinoleic acid (18:1OH), but production of this plant is limited because of the cooccurrence of the ricin toxin in its seeds. Lesquerella (<i>Physaria fendleri<...
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MDPI AG
2021-05-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/10/6/1093 |
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| author | Grace Q. Chen Kumiko Johnson Tara J. Nazarenus Grisel Ponciano Eva Morales Edgar B. Cahoon |
| author_facet | Grace Q. Chen Kumiko Johnson Tara J. Nazarenus Grisel Ponciano Eva Morales Edgar B. Cahoon |
| author_sort | Grace Q. Chen |
| collection | DOAJ |
| description | Seeds of castor (<i>Ricinus communis</i>) are enriched in oil with high levels of the industrially valuable fatty acid ricinoleic acid (18:1OH), but production of this plant is limited because of the cooccurrence of the ricin toxin in its seeds. Lesquerella (<i>Physaria fendleri</i>) is being developed as an alternative industrial oilseed because its seeds accumulate lesquerolic acid (20:1OH), an elongated form of 18:1OH in seed oil which lacks toxins. Synthesis of 20:1OH is through elongation of 18:1OH by a lesquerella elongase, PfKCS18. Oleic acid (18:1) is the substrate for 18:1OH synthesis, but it is also used by fatty acid desaturase 2 (FAD2) and FAD3 to sequentially produce linoleic and linolenic acids. To develop lesquerella that produces 18:1OH-rich seed oils such as castor, RNA interference sequences targeting <i>KCS18</i>, <i>FAD2</i> and <i>FAD3</i> were introduced to lesquerella to suppress the elongation and desaturation steps. Seeds from transgenic lines had increased 18:1OH to 1.1–26.6% compared with that of 0.4–0.6% in wild-type (WT) seeds. Multiple lines had reduced 18:1OH levels in the T<sub>2</sub> generation, including a top line with 18:1OH reduced from 26.7% to 19%. Transgenic lines also accumulated more 18:1 than that of WT, indicating that 18:1 is not efficiently used for 18:1OH synthesis and accumulation. Factors limiting 18:1OH accumulation and new targets for further increasing 18:1OH production are discussed. Our results provide insights into complex mechanisms of oil biosynthesis in lesquerella and show the biotechnological potential to tailor lesquerella seeds to produce castor-like industrial oil functionality. |
| first_indexed | 2024-03-10T10:53:55Z |
| format | Article |
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| language | English |
| last_indexed | 2024-03-10T10:53:55Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-add976b6b127496696b836f633392fcf2023-11-21T22:00:47ZengMDPI AGPlants2223-77472021-05-01106109310.3390/plants10061093Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed OilGrace Q. Chen0Kumiko Johnson1Tara J. Nazarenus2Grisel Ponciano3Eva Morales4Edgar B. Cahoon5Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USAWestern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USADepartment of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE 68588, USAWestern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USAWestern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan St., Albany, CA 94710, USADepartment of Biochemistry and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE 68588, USASeeds of castor (<i>Ricinus communis</i>) are enriched in oil with high levels of the industrially valuable fatty acid ricinoleic acid (18:1OH), but production of this plant is limited because of the cooccurrence of the ricin toxin in its seeds. Lesquerella (<i>Physaria fendleri</i>) is being developed as an alternative industrial oilseed because its seeds accumulate lesquerolic acid (20:1OH), an elongated form of 18:1OH in seed oil which lacks toxins. Synthesis of 20:1OH is through elongation of 18:1OH by a lesquerella elongase, PfKCS18. Oleic acid (18:1) is the substrate for 18:1OH synthesis, but it is also used by fatty acid desaturase 2 (FAD2) and FAD3 to sequentially produce linoleic and linolenic acids. To develop lesquerella that produces 18:1OH-rich seed oils such as castor, RNA interference sequences targeting <i>KCS18</i>, <i>FAD2</i> and <i>FAD3</i> were introduced to lesquerella to suppress the elongation and desaturation steps. Seeds from transgenic lines had increased 18:1OH to 1.1–26.6% compared with that of 0.4–0.6% in wild-type (WT) seeds. Multiple lines had reduced 18:1OH levels in the T<sub>2</sub> generation, including a top line with 18:1OH reduced from 26.7% to 19%. Transgenic lines also accumulated more 18:1 than that of WT, indicating that 18:1 is not efficiently used for 18:1OH synthesis and accumulation. Factors limiting 18:1OH accumulation and new targets for further increasing 18:1OH production are discussed. Our results provide insights into complex mechanisms of oil biosynthesis in lesquerella and show the biotechnological potential to tailor lesquerella seeds to produce castor-like industrial oil functionality.https://www.mdpi.com/2223-7747/10/6/1093hydroxy fatty acidricinoleic acidlesquerolic acidtriacylglycerol<i>Physaria fendleri</i>lesquerella |
| spellingShingle | Grace Q. Chen Kumiko Johnson Tara J. Nazarenus Grisel Ponciano Eva Morales Edgar B. Cahoon Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil Plants hydroxy fatty acid ricinoleic acid lesquerolic acid triacylglycerol <i>Physaria fendleri</i> lesquerella |
| title | Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil |
| title_full | Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil |
| title_fullStr | Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil |
| title_full_unstemmed | Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil |
| title_short | Genetic Engineering of Lesquerella with Increased Ricinoleic Acid Content in Seed Oil |
| title_sort | genetic engineering of lesquerella with increased ricinoleic acid content in seed oil |
| topic | hydroxy fatty acid ricinoleic acid lesquerolic acid triacylglycerol <i>Physaria fendleri</i> lesquerella |
| url | https://www.mdpi.com/2223-7747/10/6/1093 |
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