title: RNA interference-mediated silencing of the starch branching enzyme gene improves amylose content in rice.
abstract: Amylose and amylopectin are the 2 major components of plant storage starch. The rice starch branching enzyme (RBE) plays an important role in the starch components of rice. In the present study, we selected a specific 195-bp segment from the RBE3 gene to construct hairpin DNA, which was driven by an endosperm-specific high molecular weight glutenin promoter to regulate the biosynthesis of starch. An RNA interference plasmid for the RBE3 gene was constructed to form double-stranded RNA. Following Agrobacterium-mediated rice transformation (in the cultivar Zhonghua 11), 41 transgenic plants were identified using PCR and Southern blot analysis. Semi-quantitative real-time PCR revealed that RBE3 gene expression was significantly reduced in immature transgenic seeds. Transgenic rice amylose content had an average increase of 140%. The highest rice amylose content was 47.61% and the growth rate increased 238% compared to the non-transgenic controls. Branching enzyme II activity was notably reduced, and ADP-glucose pyrophosphorylase, soluble starch synthase, isoamylase, and pullulanase enzyme activity was markedly reduced in T3 seeds. Relative enzyme activity change explained the reduction in thousand-grain weight in transgenic plants. The present study indicated that amylose content was negatively correlated with branching enzyme II activity, spike size, and thousand-grain weight.
authors: Anhui Provincial Key Laboratory of Crop Biology, School of Life Science, Anhui Agricultural University, Hefei, China.
authors: H Y
authors: HY
authors: Jiang
authors: J
authors: J
authors: Zhang
authors: J M
authors: JM
authors: Wang
authors: M
authors: M
authors: Xia
authors: S W
authors: SW
authors: Zhu
authors: B J
authors: BJ
authors: Cheng
mesh_terms: D015061:1,4-alpha-Glucan Branching Enzyme / Q000235:genetics* / Q000378:metabolism; D000688:Amylose / Q000378:metabolism*; D056625:Endosperm / Q000378:metabolism; D020868:Gene Silencing; D017343:Genes, Plant; D051599:Glucose-1-Phosphate Adenylyltransferase / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D007517:Isoamylase / Q000378:metabolism; D012275:Oryza / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D013214:Starch Synthase / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D034741:RNA, Small Interfering; D000688:Amylose; D015061:1,4-alpha-Glucan Branching Enzyme; C112590:starch-branching enzyme II; D013214:Starch Synthase; D051599:Glucose-1-Phosphate Adenylyltransferase; D006026:Glycoside Hydrolases; C100181:pullulanase; D007517:Isoamylase