Increase of grain yields by manipulating starch biosynthesis

Abstract

Starch is the main carbohydrate storage reserve in many plants. This carbohydrate not only serves as the major caloric source for much of the world’s population and as a key feedstock for renewable energy but is also utilized in many food and industrial applications. As the demand for starch as a source of food and energy feedstock will continue to increase in the coming years, increased production of starchy cereals and tuber crops will be needed, a goal that will be moderated by the loss of arable land and unpredictable environmental conditions due to global warming. In this chapter, we provide an update on starch biosynthesis occurring in photoautotrophic and heterotrophic organs, the role of ADPglucose pyrophosphorylase and other enzymes in this process, and the various molecular strategies for increasing starch in cereals. Although extensive efforts have been made, relatively small improvements have been accomplished in enhancing starch content and grain yield, necessitating the employment of new strategies to meet this goal.