Amyloplasts carbon transport

Although it appears that the major carbon transport system for the wheat grain amyloplast does not involve triose-P, and most likely involves hexose-P (Fig. 3), the major carbon transport systems for other amyloplasts are not certain. More recent evidence does indicate that what is true for wheat is also true for pea embryo amyloplasts, for maize, and for potato. Thus, it may be that the major transport system for most reserve, nonphotosynthetic plant systems is at the hexose-P level and not at the triose-P level. The glycolytic scheme in the amyloplast may then take on a more important function than is observed in the chloroplast, in that the scheme aids in the production of amyloplastic ATP. Amyloplastic 3PGA may then also be an indicator of the state of ATP level in the amyloplast and, on its accumula-... 

To conclude despite proposals presented by some authors and discussed in this chapter, the experimental evidence available supports mechanisms for the transport of carbon into the amyloplast and its conversion into starch, as depicted in Fig. 3. 

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