Inhibition of the gene expression for granule-bound starch synthase I by RNA interference in sweet potato plants.
Granule-bound starch synthase I (GBSSI) is one of the key enzymes catalyzing the formation of amylose, a linear alpha(1,4)D-glucan polymer, from ADP-glucose. Amylose-free transgenic sweet potato plants were produced by inhibiting sweet potato GBSSI gene expression through RNA interference. The gene construct consisting of an inverted repeat of the first exon separated by intron 1 of GBSSI driven by the CaMV 35S promoter was integrated into the sweet potato genome by Agrobacterium tumefaciens-mediated transformation. In over 70% of the regenerated transgenic plants, the expression of GBSSI was inactivated giving rise to storage roots containing amylopectin but not amylose. Electrophoresis analysis failed to detect the GBSSI protein, suggesting that gene silencing of the GBSSI gene had occurred. These results clearly demonstrate that amylose synthesis is completely inhibited in storage roots of sweet potato plants by the constitutive production of the double-stranded RNA of GBSSI fragments. We conclude that RNA interference is an effective method for inhibiting gene expression in the starch metabolic pathway.
Otani
Motoyasu
M
Research Institute of Agricultural Resources, Ishikawa Prefectural University, Nonoichi, Ishikawa 921-8836, Japan. otani@ishikawa-pu.ac.jp
Hamada
Tatsuro
T
Katayama
Kenji
K
Kitahara
Kakefumi
K
Kim
Sun-Hyung
SH
Takahata
Yasuhiro
Y
Suganuma
Toshihiko
T
Shimada
Takiko
T
D000688:Amylose / Q000032:analysis / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D027723:Ipomoea batatas / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D035281:Plant Tubers / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D034622:RNA Interference; D013214:Starch Synthase / Q000235:genetics* / Q000378:metabolism; D014170:Transformation, Genetic
D000688:Amylose; C434607:granule-bound starch synthase I; D013214:Starch Synthase