Manipulation of triose phosphate/phosphate translocator and cytosolic fructose-1,6-bisphosphatase, the key components in photosynthetic sucrose synthesis, enhances the source capacity of transgenic Arabidopsis plants.
Photoassimilated carbons are converted to sucrose in green plant leaves and distributed to non-phototropic tissues to provide carbon and energy. In photosynthetic sucrose biosynthesis, the chloroplast envelope triose phosphate/phosphate translocator (TPT) and cytosolic fructose-1,6-bisphosphatase (cFBPase) are key components in photosynthetic sucrose biosynthesis. The simultaneous overexpression of TPT and cFBPase was utilized to increase the source capacity of Arabidopsis. The TPT and cFBPase overexpression lines exhibited enhanced growth with larger rosette sizes and increased fresh weights compared with wild-type (WT) plants. The simultaneous overexpression of TPT and cFBPase resulted in enhanced photosynthetic CO(2) assimilation rates in moderate and elevated light conditions. During the phototropic period, the soluble sugar (sucrose, glucose, and fructose) levels in the leaves of these transgenic lines were also higher than those of the WT plants. These results suggest that the simultaneous overexpression of TPT and cFBPase enhances source capacity and consequently leads to growth enhancement in transgenic plants.
Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea.
Man-Ho
MH
Cho
Areum
A
Jang
Seong Hee
SH
Bhoo
Jong-Seong
JS
Jeon
Tae-Ryong
TR
Hahn
D017360:Arabidopsis / Q000254:growth & development* / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002736:Chloroplasts / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005632:Fructose / Q000378:metabolism; D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D005838:Genotype; D005947:Glucose / Q000378:metabolism; D005964:Glucosyltransferases / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D010788:Photosynthesis; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry; D030821:Plants, Genetically Modified / Q000254:growth & development / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism*
D026901:Membrane Transport Proteins; D010937:Plant Growth Regulators; D005632:Fructose; D013395:Sucrose; D005964:Glucosyltransferases; C022699:sucrose synthase; D006597:Fructose-Bisphosphatase; D005947:Glucose