ABSTRACT
Plants sequester carbon in specialized reproductive organs (e.g., storage roots, tubers, and seeds) as a source of energy and as carbon skeletons for the onset of growth the following season. Starch, a polymer of glucose, is the most prevalent form of stored carbon. It is composed of a mixture of straight-chain (amylose) and branched (amylopectin) molecules, the ratio of which is genetically controlled. Amylose contains 200 to 1,000 glucose subunits linked via
α
-(1-4) glucosidic bonds, while amylopectin is substantially larger, 2,000 to 200,000 subunits with similar bonds; however, every 20 to 25 glucose molecules there is a branch formed through an
α
-(1-6) bond (Kays and Paull, 2004). Inulin, in contrast, is a mixture of fructose polymers used as a means of carbon storage in a number of species, though as the primary storage form of carbon in only a few species, including Jerusalem artichoke.
