Utilizing antisense ODN technology as a means for silencing starch biosynthetic genes in wheat

Introduction

· Starch biosynthesis is an important area of study as nearly fifty percent of the calories in the human diet is supplied by starch-based products.

· There is also an increasing demand for industrial starches.

· In wheat, starch is the major source of carbohydrates, accounting for two-thirds to three-quarters of the grain weight. Due to its importance for human consumption, there has been interest to improve wheat starch yield and composition (Chibbar et al. 2007). (More information here.)To achieve this, a better understanding of starch biosynthesis is needed.

· Antisense ODN technology is based on the hybridization of an oligodeoxynucleotide (ODN) to a complementary mRNA sequence, preventing the mRNA from being translated. It has been proposed that when hybridization between the ODN and the RNA molecule occurs, the endogenous enzyme RNase H recognizes the DNA:RNA hybrid and degrades the RNA in the duplex (Jansson et al. 2007).

Figure 1. Proposed antisense ODN down-regulation mechanism. (a) normal protein synthesis; (b) suppression of translation due to antisense ODNs hybridizing to mRNA. The endogenous enzyme RNase H degrades the RNA in the DNA:RNA hybrid and consequently the protein is not synthesized.

Source: Scott Adams