Display options
Share it on

Biotechnol Biofuels. 2015 Oct 29;8:175. doi: 10.1186/s13068-015-0357-1. eCollection 2015.

A photorespiratory bypass increases plant growth and seed yield in biofuel crop Camelina sativa.

Biotechnology for biofuels

Jyoti Dalal, Harry Lopez, Naresh B Vasani, Zhaohui Hu, Jennifer E Swift, Roopa Yalamanchili, Mia Dvora, Xiuli Lin, Deyu Xie, Rongda Qu, Heike W Sederoff

Affiliations

  1. Department of Crop Science, North Carolina State University, Campus Box 7287, Raleigh, NC 27695-7287 USA.
  2. Department of Plant and Microbial Biology, North Carolina State University, Campus Box 7612, Raleigh, NC 27695-7612 USA.

PMID: 26516348 PMCID: PMC4625952 DOI: 10.1186/s13068-015-0357-1

Abstract

BACKGROUND: Camelina sativa is an oilseed crop with great potential for biofuel production on marginal land. The seed oil from camelina has been converted to jet fuel and improved fuel efficiency in commercial and military test flights. Hydrogenation-derived renewable diesel from camelina is environmentally superior to that from canola due to lower agricultural inputs, and the seed meal is FDA approved for animal consumption. However, relatively low yield makes its farming less profitable. Our study is aimed at increasing camelina seed yield by reducing carbon loss from photorespiration via a photorespiratory bypass. Genes encoding three enzymes of the Escherichia coli glycolate catabolic pathway were introduced: glycolate dehydrogenase (GDH), glyoxylate carboxyligase (GCL) and tartronic semialdehyde reductase (TSR). These enzymes compete for the photorespiratory substrate, glycolate, convert it to glycerate within the chloroplasts, and reduce photorespiration. As a by-product of the reaction, CO2 is released in the chloroplast, which increases photosynthesis. Camelina plants were transformed with either partial bypass (GDH), or full bypass (GDH, GCL and TSR) genes. Transgenic plants were evaluated for physiological and metabolic traits.

RESULTS: Expressing the photorespiratory bypass genes in camelina reduced photorespiration and increased photosynthesis in both partial and full bypass expressing lines. Expression of partial bypass increased seed yield by 50-57 %, while expression of full bypass increased seed yield by 57-73 %, with no loss in seed quality. The transgenic plants also showed increased vegetative biomass and faster development; they flowered, set seed and reached seed maturity about 1 week earlier than WT. At the transcriptional level, transgenic plants showed differential expression in categories such as respiration, amino acid biosynthesis and fatty acid metabolism. The increased growth of the bypass transgenics compared to WT was only observed in ambient or low CO2 conditions, but not in elevated CO2 conditions.

CONCLUSIONS: The photorespiratory bypass is an effective approach to increase photosynthetic productivity in camelina. By reducing photorespiratory losses and increasing photosynthetic CO2 fixation rates, transgenic plants show dramatic increases in seed yield. Because photorespiration causes losses in productivity of most C3 plants, the bypass approach may have significant impact on increasing agricultural productivity for C3 crops.

Keywords: Biofuel; Camelina; Photorespiratory bypass; Photosynthesis; Seed yield

References

  1. Tree Physiol. 2006 Apr;26(4):517-25 - PubMed
  2. Plant Cell Environ. 2015 Nov;38(11):2462-74 - PubMed
  3. Plant Physiol. 1977 May;59(5):842-8 - PubMed
  4. J Exp Bot. 2009;60(6):1799-809 - PubMed
  5. PLoS One. 2014 Apr 11;9(4):e91798 - PubMed
  6. Biochim Biophys Acta. 1971 Apr 14;235(1):237-44 - PubMed
  7. BMC Genomics. 2013 Mar 05;14:146 - PubMed
  8. Bioinformatics. 2010 Jan 1;26(1):139-40 - PubMed
  9. Biochim Biophys Acta. 1972 May 25;267(2):227-37 - PubMed
  10. Plant Cell Environ. 2012 May;35(5):839-56 - PubMed
  11. Plant Biol (Stuttg). 2013 Jul;15(4):648-55 - PubMed
  12. Plant J. 2007 Sep;51(6):1126-36 - PubMed
  13. Arch Biochem Biophys. 1983 Dec;227(2):425-33 - PubMed
  14. Science. 1977 Jun 24;196(4297):1450-1 - PubMed
  15. Phytochemistry. 2013 Nov;95:168-76 - PubMed
  16. Proc Natl Acad Sci U S A. 2009 Mar 3;106(9):3597-602 - PubMed
  17. Cell. 2015 Mar 26;161(1):56-66 - PubMed
  18. Proc Natl Acad Sci U S A. 2004 Aug 3;101(31):11506-10 - PubMed
  19. Planta. 1988 Dec;176(3):415-24 - PubMed
  20. Physiol Plant. 2010 Oct;140(2):111-27 - PubMed
  21. Biochem J. 1961 Nov;81:273-84 - PubMed
  22. Plant Physiol. 1984 May;75(1):7-12 - PubMed
  23. Plant Biotechnol J. 2014 Aug;12(6):734-42 - PubMed
  24. Proc Natl Acad Sci U S A. 1987 Jul;84(14):4870-4 - PubMed
  25. Plasmid. 2015 Sep;81:55-62 - PubMed
  26. Nat Protoc. 2013 Aug;8(8):1494-512 - PubMed
  27. Nat Methods. 2012 Jul;9(7):671-5 - PubMed
  28. Plant Cell Environ. 2007 Sep;30(9):1035-40 - PubMed
  29. J Exp Bot. 2001 Jul;52(360):1383-400 - PubMed
  30. Plant Physiol. 1996 Mar;110(3):903-912 - PubMed
  31. Plant Cell. 2013 Feb;25(2):694-714 - PubMed
  32. Bioinformatics. 2005 Sep 15;21(18):3674-6 - PubMed
  33. Ambio. 2002 Mar;31(2):132-40 - PubMed
  34. Plant Physiol. 2004 Jan;134(1):520-7 - PubMed
  35. Biotechniques. 2003 Feb;34(2):374-8 - PubMed
  36. Nat Biotechnol. 2007 May;25(5):593-9 - PubMed
  37. Plant J. 2006 Feb;45(4):616-29 - PubMed
  38. Science. 2010 May 14;328(5980):899-903 - PubMed
  39. Arabidopsis Book. 2010;8:e0130 - PubMed
  40. Plant Signal Behav. 2008 Dec;3(12):1122-5 - PubMed
  41. PLoS One. 2011 Jan 31;6(1):e16438 - PubMed
  42. Planta. 1980 Jun;149(1):78-90 - PubMed
  43. J Exp Bot. 2001 Dec;52(365):2313-22 - PubMed
  44. Plant Physiol. 1983 Jun;72(2):420-5 - PubMed
  45. Methods Mol Biol. 2015;1309:91-117 - PubMed
  46. Plant Physiol. 2015 Feb;167(2):574-85 - PubMed
  47. Can J Biochem Physiol. 1959 Aug;37(8):911-7 - PubMed
  48. Plant Cell Rep. 1992 Oct;11(11):586-91 - PubMed
  49. Ecol Evol. 2014 Aug;4(16):3218-35 - PubMed
  50. Phytochemistry. 2006 May;67(9):904-15 - PubMed
  51. Theor Appl Genet. 2002 Sep;105(4):505-514 - PubMed
  52. Front Plant Sci. 2012 Feb 28;3:38 - PubMed
  53. Proc Natl Acad Sci U S A. 2014 Nov 25;111(47):16967-72 - PubMed
  54. Plant Physiol. 2000 Jul;123(3):1143-52 - PubMed
  55. Plant Physiol. 1969 Feb;44(2):242-50 - PubMed
  56. PLoS One. 2013 Apr 19;8(4):e62036 - PubMed
  57. Methods Mol Biol. 2011;684:321-5 - PubMed
  58. Bioinformatics. 2009 Jul 15;25(14):1754-60 - PubMed
  59. Nat Cell Biol. 2006 Apr;8(4):391-7 - PubMed
  60. Plant Cell Rep. 2008 Feb;27(2):273-8 - PubMed
  61. Plant Physiol. 1983 Jun;72(2):415-9 - PubMed
  62. Arch Biochem Biophys. 1962 Jul;98 :164-71 - PubMed
  63. J Biomol Tech. 2007 Sep;18(4):185-7 - PubMed
  64. Proc Natl Acad Sci U S A. 2003 Apr 15;100(8):4939-44 - PubMed
  65. Science. 2006 Jun 30;312(5782):1918-21 - PubMed
  66. Plant Physiol. 1980 May;65(5):888-92 - PubMed
  67. Plant Methods. 2010 Jul 02;6:17 - PubMed
  68. Physiol Plant. 2009 Jul;136(3):299-309 - PubMed
  69. Plant Cell. 2008 Jun;20(6):1603-22 - PubMed
  70. Plant Physiol. 1978 Dec;62(6):954-67 - PubMed
  71. Tree Physiol. 2008 Apr;28(4):607-14 - PubMed

Publication Types