Abstract
Transgenic cereals are an attractive option for the accumulation of foreign proteins when large volumes and low cost are required. Previous work has shown maize germ to be a particularly good location for accumulating enzymes that target cellulose for degradation. In this study, recently identified embryo-preferred promoters were used to investigate their ability to increase the accumulation of the enzymes endoglucanase E1 and cellobiohydrolase CBHI. The effect of increasing copy numbers of identical transcription units, as well as multiple copies of the enzyme driven by different promoters, was explored. Results show that accumulation of the E1 or CBHI enzymes can be significantly increased, particularly when using constructs with multiple copies of the transcription units. These findings demonstrate the highest levels of these enzymes obtained in a commercially relevant plant species observed thus far. The methodology described here may provide a low-cost plant-based source of enzymes enabling an economically viable solution for the conversion of cellulose to ethanol.
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References
Austin-Phillips S, Ziegelhoffer T, Will J (1999) Expression of bacterial cellulase genes in transgenic alfalfa (Medicago sativa L.), potato (Solanum tuberosum L.) and tobacco (Nicotiana tabacum L.). Mol Breeding 5(4):309–318. doi:10.1023/A:1009646830403
Nigam PS, Singh A (2011) Production of liquid biofuels from renewable resources. Prog Energ Combust 37(1):52–68. doi:10.1016/j.pecs.2010.01.003
Baker JO, Ehrman CI, Adney WS, Thomas SR, Himmel ME (1998) Hydrolysis of cellulose using ternary mixtures of purified celluloses. Appl Biochem Biotech 70(1):395–403. doi:10.1007/BF02920154
Shoemaker S, Schweickart V, Ladner M, Gelfand D, Kwok S, Myambo K, Innis M (1983) Molecular cloning of exo–cellobiohydrolase I derived from Trichoderma reesei strain L27. Nat Biotechnol 1(8):691–696. doi:10.1038/nbt1083-691
Mohagheghi A, Grohmann K, Wyman CE (1990) Production of cellulase on mixtures of xylose and cellulose in a fed-batch process. Biotechnol Bioeng 35(2):211–216. doi:10.1002/bit.260350213
Adney WS, Tucker MP, Nieves RA, Thomas SR, Himmel ME (1995) Low molecular weight thermostable b-d-glucosidase from Acidothermus cellulolyticus. Biotechnol Lett 17(1):49–54. doi:10.1007/BF00134195
Howard JA (2007) Commercialization of plant-based vaccines from research and development to manufacturing. Anim Health Res Rev 5(2):243–245. doi:10.1079/AHR200476
Hood EE, Love R, Bray J, Lane J, Clough RC, Pappu K, Drees C, Hood KR, Yoon S, Ahmad A, Howard JA (2007) Subcellular targeting is a key condition for high-level accumulation of cellulase protein in transgenic maize seed. Plant Biotechnol J 5:709–719
Ziegelhoffer T, Will J, Austin-Phillips S (1999) Expression of bacterial cellulase genes in transgenic alfalfa (Medicago sativa L.), potato (Solanum tuberosum L.) and tobacco (Nicotiana tabacum L.). Molecular Breeding New Strategies in Plant Improvement 5(4):309–318
Tsai GJ, Wu ZY, Su WH (2000) Antibacterial activity of a chitooligosaccharide mixture prepared by cellulase digestion of shrimp chitosan and its application to milk preservation. J Food Protect 63(6):747–752
Oraby H, Venkatesh B, Dale B, Ahmad R, Ransom C, Oehmke J, Sticklen M (2007) Enhanced conversion of plant biomass into glucose using transgenic rice-produced endoglucanase for cellulosic ethanol. Transgenic Res 16(6):739–749. doi:10.1007/s11248-006-9064-9
Ziegler M, Thomas S, Danna K (2000) Accumulation of a thermostable endo-1,4-b-d-glucanase in the apoplast of Arabidopsis thaliana leaves. Mol Breeding 6(1):37–46. doi:10.1023/A:1009667524690
Biswas G, Ransom C, Sticklen M (2006) Expression of biologically active Acidothermus cellulolyticus endoglucanase in transgenic maize plants. Plant Science 171(5):617–623
Brunecky R, Selig MJ, Vinzant TB, Himmel ME, Lee D, Blaylock MJ, Decker SR (2011) In planta expression of A. cellulolyticus Cel5A endocellulase reduces cell wall recalcitrance in tobacco and maize. Biotechnol Biofuels 4(1):1–10, 1186/1754-6834-4-1
Hood EE, Horn ME, Howard JA (2003) Production and Application of Proteins from Transgenic Plants. In: Vasil I (ed) Plant Biotechnology 2002 and Beyond, Proceedings of the 10th IAPTC&B Congress, Orlando, FL, Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 377–382
Workentine ML, Chang L, Ceri H, Turner RJ (2009) The GacS-GacA two-component regulatory system of Pseudomonas fluorescens: a bacterial two-hybrid analysis. FEMS Microbiol Lett 292(1):50–56. doi:10.1111/j.1574-6968.2008.01445.x
Ransom C, Balan V, Biswas G, Dale B, Crockett E, Sticklen M (2007) Heterologous Acidothermus cellulolyticus 1, 4-b-endoglucanase E1 produced within the corn biomass converts corn stover into glucose. Appli Biochem Biotech 137(1):207–219. doi:10.1007/978-1-60327-181-3_20
Kusnadi AR, Evangelista RL, Hood EE, Howard JA, Nikolov ZL (1998) Processing of transgenic corn seed and its effect on the recovery of recombinant b-glucuronidase. Biotechnol Bioeng 60(1):44–52. doi:10.1002/(SICI)1097-0290(19981005)60:1<44::AID-BIT5>3.0.CO;2
Howard JA, Hood E (2005) Bioindustrial and biopharmaceutical products produced in plants. Adv Agron 85:91–124
Belanger FC, Kriz AL (1989) Molecular characterization of the major maize embryo globulin encoded by the glb1 gene. Plant Physiol 91(2):636–643. doi:10.1104/pp.91.2.636
Streatfield SJ, Bray J, Love RT, Horn ME, Lane JR, Drees CF, Egelkrout EM, Howard JA (2010) Identification of maize embryo-preferred promoters suitable for high-level heterologous protein production. GM Crops 1(3):162–172. doi:10.4161/gmcr.1.3.12816
Rogers JC (1985) Two barley alpha-amylase gene families are regulated differently in aleurone cells. J Biol Chem 260(6):3731–3738
Holwerda BC, Padgett HS, Rogers JC (1992) Proaleurain vacuolar targeting is mediated by short contiguous peptide interactions. Plant Cell 4(3):307–318. doi:10.1105/tpc.4.3.307
Ishida Y, Saito H, Ohta S, Hiei Y, Komari T, Kumashiro T (1996) High efficiency transformation of maize (Zea mays L.) mediated by Agrobacterium tumefaciens. Nat Biotechnol 14(6):745–750. doi:10.1038/nbt0696-745
Hiei Y, Ohta S, Komari T, Kumashiro T (1994) Efficient transformation of rice (Oryza sativa L.) mediated by Agrobacterium and sequence analysis of the boundaries of the T-DNA. Plant J 6(2):271–282. doi:10.1046/j.1365-313X.1994.6020271.x
Hood EE, Helmer GL, Fraley RT, Chilton MD (1986) The hypervirulence of Agrobacterium tumefaciens A281 is encoded in a region of pTiBo542 outside of T-DNA. J Bacteriol 168(3):1291–1301
Armstrong C, Green C, Phillips R (1991) Development and availability of germplasm with high Type II culture formation response. Maize Genet Coop Newsletter 65:92–93
Southern EM (1975) Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol 98(3):503–517
Daniell H, Khan MS, Allison L (2002) Milestones in chloroplast genetic engineering: an environmentally friendly era in biotechnology. Trends Plant Sci 7(2):84–91. doi:10.1016/S1360-1385(01)02193-8
Padh H, Desai PN, Shrivastava N (2010) Production of heterologous proteins in plants: Strategies for optimal expression. Biotechnol Adv 28(4):427–435. doi:10.1016/j.biotechadv.2010.01.005
Streatfield SJ, Love R, Bray J (2007) Globulin-1 promoter from maize and method of using same USA Patent 7,169,967, January 30, 2007
Boothe J, Nykiforuk C, Shen Y, Zaplachinski S, Szarka S, Kuhlman P, Murray E, Morck D, Moloney MM (2010) Seed based expression systems for plant molecular farming. Plant Biotechnol J 8(5):588–606. doi:10.1111/j.1467-7652.2010.00511.x
Zheng W, Schingoethe DJ, Stegeman GA, Hippen AR, Treacher RJ (2000) Determination of when during the lactation cycle to start feeding a cellulase and xylanase enzyme mixture to dairy cows. J Dairy Sci 83(10):2319–2325. doi:10.3168/jds.S0022-0302(00)75119-8
Gray BN, Ahner BA, Hanson MR (2009) High-level bacterial cellulase accumulation in chloroplast-transformed tobacco mediated by downstream box fusions. Biotechnol Bioeng 102(4):1045–1054. doi:10.1002/bit.22156
Gray BN, Bougri O, Carlson AR, Meissner J, Pan S, Parker MH, Zhang D, Samoylov V, Ekborg NA, Michael Raab R (2011) Global and grain specific accumulation of glycoside hydrolase family 10 xylanases in transgenic maize (Zea mays). Plant Biotechnol J 9(9):1100–1108. doi:10.1111/j.1467-7652.2011.00632.x
Petersen K, Bock R (2011) High-level expression of a suite of thermostable cell wall-degrading enzymes from the chloroplast genome. Plant Mol Biol 76(3–5):311–321. doi:10.1007/s11103-011-9742-8
Gale SE, Westover EJ, Dudley N, Krishnan K, Merlin S, Scherrer DE, Han X, Zhai X, Brockman HL, Brown RE, Covey DF, Schaffer JE, Schlesinger P, Ory DS (2009) Side chain oxygenated cholesterol regulates cellular cholesterol homeostasis through direct sterol-membrane interactions. J Biol Chem 284(3):1755–1764. doi:10.1074/jbc.M807210200
Halpin C (2005) Gene stacking in transgenic plants–the challenge for 21st century plant biotechnology. Plant Biotechnol J 3(2):141–155. doi:10.1111/j.1467-7652.2004.00113.x
Aluru M, Xu Y, Guo R, Wang Z, Li S, White W, Wang K, Rodermel S (2008) Generation of transgenic maize with enhanced provitamin A content. J Exp Bot 59(13):3551–3562. doi:10.1093/jxb/ern212, 2008/08/30 edn
Naqvi S, Zhu C, Farre G, Ramessar K, Bassie L, Breitenbach J, Perez Conesa D, Ros G, Sandmann G, Capell T, Christou P (2009) Transgenic multivitamin corn through biofortification of endosperm with three vitamins representing three distinct metabolic pathways. Proc Natl Acad Sci USA 106(19):7762–7767. doi:10.1073/pnas.090141210
Naqvi S, Farre G, Zhu C, Sandmann G, Capell T, Christou P (2010) Simultaneous expression of Arabidopsis r-hydroxyphenylpyruvate dioxygenase and MPBQ methyltransferase in transgenic corn kernels triples the tocopherol content. Transgenic Res 20(1):177–181. doi:10.1007/s11248-010-9393-6
Hennegan K, Yang DC, Nguyen D, Wu LY, Goding J, Huang JM, Guo FL, Huang N, Watkins S (2005) Improvement of human lysozyme expression in transgenic rice grain by combining wheat (Triticum aestivum) puroindoline b and rice (Oryza sativa) Gt1 promoters and signal peptides. Transgenic Res 14(5):583–592. doi:10.1007/s11248-004-6702-y
Acknowledgments
This work was supported by grant #DOE DE FG36 GO88025, Foundation, Walton Family Foundation, and Arkansas State University Biosciences Institute. We would also like to acknowledge the technical assistance of Aaron Harry, Mackenzie Tageson, and Raghavendra Rayadurg in this project.
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Egelkrout, E., McGaughey, K., Keener, T. et al. Enhanced Expression Levels of Cellulase Enzymes Using Multiple Transcription Units. Bioenerg. Res. 6, 699–710 (2013). https://doi.org/10.1007/s12155-012-9288-x
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DOI: https://doi.org/10.1007/s12155-012-9288-x