Starch Biosynthesis: Impact on Crop Production

797 Words2 Pages

Starch is polysaccharide which play important role in the metabolism of living organisms. In addition, starch are raw materials in the food and materials industry. Increasing the starch content of crops based on improving the activity of some genes encoding enzymes plays an important role in the process of biosynthesis and accumulation of starch, which is one of the research are of interest. Like in bacteria, the process of starch biosynthesis in plants occurs by using ADP-Glc as raw materials to made long link chain α-1.4-glucoside. ADP-Glcpyrophosphorylase (AGPase) has important role in biosynthesis of ADP-Glc molecule, and therefore AGPase is an critical enzyme of glycogen synthesis in bacteria and starch in plants. In this study, the gene …show more content…

Beside, cassava is used for many different purposes in industrial starch, such as cosmetics, pharmaceuticals, especially biofuels (Sriroth, Piyachomkwan et al. 2000). Along with economic development, the amount of starch needed for industry is increasing remarkably in developing countries. To meet the starch used, the scientists have applied technical scientific advances mainly transgenic techniques in plant breeding. The synthesis of starch in plants needed 3 enzymes are ADP glucose pyrophosphorylase (AGPase; EC 2.7.7.23), starch synthase (SS; EC 2.4.1.21) and starch branching enzyme (SBE; EC 2.4.1.28) (Fernie, Willmitzer et al. 2002). To improve starch content, we can enhance the activity of three enzymes. The rate of starch synthesis is determined mainly by the activity of AGPase, the first enzyme in the pathway (Zeeman, Kossmann et al. 2010). AGPase catalyzes the first step in the biosynthesis of starch in the plastids by converting Glc1P and ATP into ADPGlc and PPI (Tiessen, Hendriks et al. 2002). The enzyme AGPase has been successfully transfered into a number of crops such as cassava (Ihemere, Arias‐Garzon et al. 2006), potatoes (Ball, Marianne et al. 1991, Stark, Timmerman et al. 1992, Thro 1996), wheat (Smidansky, Clancy et al. 2002), rice (Smidansky, Clancy et al. 2002, Sakulsingharoj, Choi …show more content…

The antibiotic kanamycin, rifamicine, cefotaxime, carbecillin were purchased from Merck.
Synthetized genes encoding AGPase enzyme
Based on the genetic structure of glgC (code V00281.1) encoding AGPase enzymes in E. coli has been published in GenBank and characteristics of the AGPase enzyme in plants, we modified the sequence of glgC gene by creating G336D mutation.
Nucleotide segment encodes for signal peptide chain protein in chloroplasts are derived from the rbcS gene encoding the small section of ribulose 1.5 bisphosphate carboxylase enzyme in Arabidopsis is attached on the 5’ position, and the sequence coding for the tail of c-myc and KDEL is attached on the 3’ position of the DNA segment. Recognized location of XbaI restriction enzyme is attached on5’ position and the recognized location of SacI is added on 3’ position of the gene. AGPase encoding gene (Lan1_opt) is purchased from Integrated DNA Technologies (USA) and is cloned in the vector pUCIDT-AMP.
Design transgenic plant vector carrying pBI121 structure: Lan1_opt Lan1_opt target gene was amplified by transforming the vector pUCAMP: Lan1_opt into E. coli

Open Document