STARCH: BIOSYNTHESIS, GRANULE STRUCTURE AND GENETIC MODIFICATIONS

Year 2008, Issue: 016, 1 - 12, 15.09.2008

Hülya Ölçer Betül Akın

Abstract

Starch is the main product of photosynthesis and its the most dominant reserve polysaccaride that stored in photosynthetic and non-photosynthetic tissues. Starch is a staple food in human and animal diets, but also a raw material widely used for industrial purposes, such as food, paper and textile. Starch granule structure, amylose and amylopectin moleculer structure, amylose and amylopectin ratio, and also lipid, protein and phosphate content are the main determinants that effect the functional properties of starch, in turn, its industrial application. For example, in food industry high amylose starches are prefered in sweet and fried products, while amylose free starches are used in frozen foods. In fact, starch is generally modified by physical, enzymatic or chemical treatments to alter structural and functional properties for endustrial applications. Today starches with improved functionality has also been produced from mutant and genetically modified plants. Increased knowledge about enzymes that are involved in starch biosynthesis and improvement in plant biotechnology made possible to alter starch composition by genetic modifications. This rewiev focus on the starch granule structure, starch biosynthetic enzymes in storage tissues and their genetic modifications with potantial benefits.

Keywords

Amylose, amylopectin, granule bound starch synthase, waxy mutant

NİŞASTA: BİYOSENTEZİ, GRANÜL YAPISI VE GENETİK MODİFİKASYONLAR

Abstract

Nişasta bitkilerde fotosentezin temel ürünüdür ve polisakkaritlerin hem fotosentetik hem de fotosentetik olmayan dokulardaki en yaygın depo şeklidir. Nişasta insan ve hayvan beslenmesinde temel olarak tüketilen bir gıda olmakla sınırlı kalmayıp yiyecek endüstrisi başta olmak üzere kağıt, tekstil ve diğer birçok endüstriyel alan için de temel bir ham maddedir. Nişastanın granül yapısı ve şekli, amiloz ve amilopektinin moleküler yapısı, amiloz-amilopektin oranı, lipid, protein ve fosfat miktarı gibi faktörler nişastanın fonksiyonel özelliklerini dolayısıyla endüstriyel kullanım alanını belirler. Örneğin yiyecek endüstrisinde, tatlılar ve kızartılmış ürünlerde yüksek amiloz içeren nişastalar tercih edilirken, dondurulmuş ürünlerde ise amiloz içermeyen nişastalar tercih edilmektedir. Bu sebeple endüstriyel amaçlı kullanılan nişasta genellikle fiziksel, kimyasal veya enzimatik olarak modifiye edilerek yapısal özellikleri ve bununla bağlantılı olarak fonksiyonel özellikleri değiştirilir. Günümüzde ise fonksiyonelliği geliştirilmiş bu tip nişastalar özellikle mutant ve genetik modifikasyona uğratılmış bitkilerden üretilmektedir. Gerek bitki biyoteknolojisindeki gelişmeler gerekse nişasta biyosentezinde rol oynayan enzimler ve özelliklerinin ortaya konması genetik modifikasyonları mümkün kılmıştır. Bu derlemede nişasta granül yapısı, depo dokularda nişasta biyosentezinde rol alan enzimler ve bunların genetik modifikasyonu üzerinde durulmuş olup bu modifikasyonların potansiyel yararları tartışılmıştır.

Keywords

Amiloz, amilopektin, granüle bağlı nişasta sentaz, waxy (mumlu) mutant

References

• [1] Burrell, M.M., “Starch: the need for improved quality or quantitiy-an overview”, Journal of Experimental Botany, 54 (382): 451-456, (2003).
• [2] National Starch δ Chemical. URL: http:// nationalstarch.com
• [3] Andersson, L., “Studies on starch structure and the differential properties of starch branching enzymes,Doctoral thesis, Swedish University of Agricultural Sciences, Uppsala, 13, (2001).
• [4] Information Systems for Biotechnology.URL: www.nbiap.vt.edu.
• [5] Grusak, M.A. and DellaPenna, D., “Improving the nutrient composition of plant to enhance human nutrition and health”, Annual Review of Plant Physiology and Plant Molecular Biology, 50: 133-161 (1999).
• [6] Herbers, K., “Vitamin production in transgenic plants”, Journal of Plant Physiology, 160: 821-829 (2003).
• [7] Ölçer, H and Ortaca, Ş., “Plants genetically enhanced with vitamins and microelements”, DPÜ. Fen Bilimleri Dergisi, 9: 27-40 (2005).
• [8] Dunwell, J.M., “Transgenic crops: The next generation, or an example of 2020 vision”, Annals of Botany, 84: 269-277 (1999).
• [9] Pilion-Smit, E and Pilion, M. “Phytoremediation of metals using transgenic plants”, Critical Reviews in Plant Science, 21(5): 439-456 (2002).
• [10] Ölçer, H., “Fito-iyileştirme ve metal biriktiren bitkiler”, DPÜ. Fen Bilimleri Dergisi, 8: 163-178 (2005).
• [11] Shewmaker, C.K. and Stalker, D.M., “Modifying starch biosynthesis with transgenes in potato”, Plant Physiology, 100: 1083-1086 (1992).
• [12] Biotechnology and GMOs Information System. URL: http://gmoinfo.jrc.it
• [13] Tester, R.F., Karkalas, J. and QI, X., “Starch structure and digestibility Enzyme-Substrate relationship”, World’s Poultry Science Journal, 60: 186-195 (2004).
• [14] Smith, A.M., “The Biosynthesis of starch granules”, Biomacromolecules, 2: 335-341 (2001).
• [15] Preiss, J., “Modulation of starch synthesis”, In A Molecular Approach to Primary Metabolism in Higher Plants, eds, Christine H. Foyer and W. Paul Quick, Taylor & Francis (1998).
• [16] Jobling, S., “Improving starch for food and industrial applications”, Current Opinion in Plant Biology, 7: 210-218 (2004).
• [17] Ball, S.G., van de Wal M.H.B.J. and Visser, R.G.F., “Progress in understanding the biosynthesis of amylose”, Trends in Plant Science, 3(12): 462-467 (1998).
• [18] Dennis, D.T. and Blakeley, S.D., “Carbohydrate metabolism”, In Biochemisty & Molecular Biology of Plants, ed. Bob B. Buchanan, Wilhelm Gruissem and Russell L. Jones, American Society of Plant Biology, pp 630-675 (2000). 10 D.P.Ü. Fen Bilimleri Enstitüsü Nişasta: Biyosentezi, Granül Yapısı Ve Genetik Modifikasyonlar 16. Sayı Eylül 2008 H.ÖLÇER & B.AKIN
• [19] Singh, N., Sandhu, K.S. and Kaur, M., “Physicochemical properties ıncluding granular morphology,amylose content, swelling and solubility, thermal and pasting properties of starches from normal, waxy,high amylose and sugary corn”, Progress in Food Biopolymer Research, 1: 44-54 (2005).
• [20] Slattery, J.C., Kavakli, H. And Okita, T.W., “Engineering strach for increased quantity and quality”, Trends in Plant Science, 5(7): 291-298 (2000).
• [21] Morell, M.K. and Myers, A.M., “Towards the rational design of cereal starches”, Current Opinion in Plant Biology, 8: 204-210 (2005).
• [22] Shimada, T., Otani, M., Hamada, T. and Kim, S-H., “Increase of amylose content of sweetpotato starch by RNA interference of starch branching enzyme II gene”, Plant Biotechnology, 23: 85-90 (2006).
• [23] Myers, A.M., Morell, M.K., James, M.G. and Ball, S.G., “Recent progress toward understanding biosynthesis of the amylopectin crystal”, Plant Physiology, 122: 989-997 (2000).
• [24] Yanagisawa, T., Kiribuchi-Otobe, C. and Fujita, M., “Increase in apparent amylose content and changes in starch pasting properties at cool growth temperatures in mutant wheat”, Cereal Chemistry, 81(1): 26-30 (2004).
• [25] Shure, M., Wessler, S. and Fedoroff, N., “Molecular identification and isololation of the waxy locus in maize”, Cell, 35: 225-233 (1983).
• [26] Macdonald, F.D. and Preiss, J., “Partial purification and characterization of granule-bound starch synthases from normal and waxy maize”, Plant Physiology, 78: 849-852 (1985).
• [27] Enes, P., Panserat, S., Kaushik, S., Oliva-Teles, A., “Effect of normal and waxy maize starch on growth, food utilization and hepatic glucose metabolism in European sea bass (Dicentrarchus labrax) juveniles”,Comparative Biochemistry and Physiology, Part A 143 89–96 (2006).
• [28] Shelton, J. L., Matthews, J. O., Southern, L. L., Higbie, A. D., Bidner, T. D., Fernandez, J. M. and Pontif, J.E., “Effect of nonwaxy and waxy sorghum on growth, carcass traits, and glucose and insulin kinetics of growing-finishing barrows and gilts”, Journal of Animal Science, 82:1699-1706 (2004).
• [29] Cooperative Research Center for Sustainable Rice Production. URL: www. ricecrc.org
• [30] Sasaki, T., “Effect of wheat starch characteristics on the gelatinization, retrogradation and gelation properties”, JARQ 39 (4), 253 – 260 (2005). [31] Mason, W.R. Research Associate National Starch and Chemical Company,10 Finderne Aveenue Bridgewater, NJ URL: www.foodinnovation.com
• [32] The GRAİN Center. Suppliers of value enhanced grains. URL: www. vegrains.org
• [33] Visser, R.G., Somhorst, I., Kuipers, G.J., Ruys, N.J., Feenstra, W.J. and Jacobsen E., “Inhibition of the expression of the gene for granule-bound starch synthase in potato by antisense constructs”, Molecular and General Genetics, 225: 289-296 (1991).
• [34] Raemakers, K., Schreuder, M., Suurs, L., Furrer-Verhost, H., Wincken, J-P., Vetten, N., Jacobsen, E. And Visser, R.G.F., “Improved cassava starch by antisense inhibition of granule-bound starch synthase I.”,Molecular Breeding, 16: 163-172 (2005). 11 D.P.Ü. Fen Bilimleri Enstitüsü Nişasta: Biyosentezi, Granül Yapısı Ve Genetik Modifikasyonlar 16. Sayı Eylül 2008 H.ÖLÇER & B.AKIN 12
• [35] Craig J., Lloyd, J.R., Tomlinson, K., Barber, L., Edwards, A., Wang, T.L., Martin, C., Hedley, C.L. and Smith, A.M., “Mutations in the gene encoding starch synthase II profoundly alter amylopektin structure in pea embryos”, Plant Cell, 10: 413-426, (1998).
• [36] Gao, M., Wanat, J., Stinard, P.S., James, M.G. and Myers, A.M., “Characterization of dull1, a maize mutant gene coding for a novel starch synthase”, Plant Cell, 10: 399-412. (1998).
• [37] Lloyd, J.R., Landschu, V. And Kossmann, J., “Simultaneous antisense inhibition of two starch-synthase isoforms in potato tubers leads to accumulation of grossly modified amylopectin”, Biochemistry Journal, 338: 515-521 (1999).
• [38] Jobling, S.A., Westcott, R.J., Tayal, A., Jeffcoat, R. And Schwall, G.P., “Production of a freze-thaw-stable potato starch by antisense intibition of three starch synthase genes”, Nature Biotechnology, 20: 295-299 (2002). [39] Jobling, S.A., Schwall, G.P., Westcott, R.J., Sidebottom C.M., Debet, M., Gidley, M.J., Jeffcoat, R.,Safford, R., “A minor form of starch branching enzyme in potato (Solanum tuberosum L.) tubers has a mojor on starch structure: cloning and characterisation of multiple forms of SBE A”, The Plant Journal, 18: 163-171 (1999). [40] Schwall, G.P., Safford, R., Westcott, R.J., Jeffcoat, R., Tayal, A., Shi, Y.C., Gidley M.J. and Jobling, S.A., “Production of very-high-amilose potato starch by inhibition of SBE A and B”, Nature Biotechnology, 18:551-554 (2000).
• [41] Blennow, A., Wischmann, B., Houborg, K., Ahmt, T., Jørgensen, K., Engelsen, S. B., Bandsholm, O. and Poulsen, P., “Structure function relationships of transgenic starches with engineered phosphate substitution and starch branching” , International Journal of Biological Macromolecules, 36: 159-168 (2005).
• [42] Yu, T. S., Kofler, H., Häusler, R. E., Hille, D., Flügge, U. I., Zeeman, S. C., Smith, A. M., Kossmann, J., Lloyd, J., Ritte, G., Steup, M., Lue, W. L., Chen, J. and Weber, A., “The Arabidopsis sex1Mutant Is Defective in the R1 Protein, a General Regulator of Starch Degradation in Plants, and Not in the Chloroplast Hexose Transporter” , The Plant Cell, 13: 1907-1918 (2001).
• [43] Mikkelsen, R., Mutenda, K. E., Mant, A., Schürmann, P. and Blennow, A., “Glucan, water dikinase (GWD): A plastidic enzyme with redox-regulated and coordinated catalytic activity and binding affinity” , PNAS, 102: 1785-1790 (2005).
• [44] Lorberth, R., Ritte, G., Willmitzer, L., and Kossmann, J., “Inhibition of a starch-granule-bound protein leads to modified starch and repression of cold sweetening” , Nat. Biotechnol., 16 : 473–477 (1998).
• [45] Kötting, O., Pusch, K, Tiessen, A., Geigenberger, P., Steup, M. and Ritte, G., “Identification of a Novel Enzyme Required for Starch Metabolism in Arabidopsis Leaves. The Phosphoglucan, Water Dikinase” , Plant Physiology, 137: 242–252 (2005).
• [46] Jenner, C.F., Denyer, K. and Guerin, J., “Thermal characteristics of soluble starch synthase form wheat endosperm”, Australian Journal of Plant Physiology, 22: 703-709 (1995).
• [47] Lexmon, A., “Sweden approves first genetically engineered product for commercial planting”, USDA Foreign Agricultural Servise GAIN Report (SW4005),URL: www.fas.usda.gov. (2004).
• [48] EFSA-GMO-UK-2005-14, “Opinion of The Scientific Panel on Genetically Modified Organisms on application for the placing on the market of genetically modified potato EH92-527-1 with altered strach composition, for production of starch and food/feed uses, under Regulation (EC)”, No 1829/2003 from BASF Plant Science, The EFSA Journal, 324: 1-20 (2006).