title: Characterization of the spatial and temporal expression of the OsSSII-3 gene encoding a key soluble starch synthase in rice.
abstract: BACKGROUND
  Starch, the major component of rice grain, consists of amylose and amylopectin. SSIIa, a key soluble starch synthase involved in the biosynthesis of rice amylopectin, is a major factor that controls the gelatinization temperature of rice grain. Extensive work has been done and impressive progress has been made in elaborating the function of the gene encoding SSIIa (OsSSII-3). However, the systematic expression analysis of OsSSII-3 is still rare.
  
  
  RESULTS
  In the present study, we performed a comprehensive expression analysis of OsSSII-3 in both the developing seeds and other tissues of indica rice 9311 by using quantitative real-time PCR. The results showed that the gene was dominantly expressed in the developing seeds. In addition, the promoter sequence of OsSSII-3 was cloned and fused with the GUS reporter gene and its expression was carefully monitored in the transgenic rice. The data from both histochemical and fluorometric analyses showed that the OsSSII-3 promoter was capable of driving the target gene to have an endosperm-specific expression, which may be due to the existing of several endosperm-specific motifs in the promoter, including the -300 elements, AACA motifs and GCN4 motifs. This result was quite consistent with that of the endogenous transcription analysis of OsSSII-3.
  
  
  CONCLUSIONS
  This study not only advanced our understanding of the spatial and temporal expression characteristics of OsSSII-3, but also provided a valuable promoter for future application in generating elite rice varieties with high nutritional or medicinal value.
authors.affiliation: Key Laboratory of Plant Functional Genomics of Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College, Yangzhou University, Jiangsu, 225009, China; Institute of Plant Molecular Biology and Agri-Biotechnology, Department of Biology, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Qian-Feng
authors.initials: QF
authors.lastname: Li
authors.forename: Samuel S-M
authors.initials: SS
authors.lastname: Sun
authors.forename: Qiao-Quan
authors.initials: QQ
authors.lastname: Liu
mesh_terms: D000687:Amylopectin / Q000096:biosynthesis / Q000502:physiology; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D056625:Endosperm / Q000201:enzymology; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter / Q000235:genetics; D012275:Oryza / Q000201:enzymology*; D030821:Plants, Genetically Modified / Q000201:enzymology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D012639:Seeds / Q000201:enzymology* / Q000254:growth & development; D013214:Starch Synthase / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D011993:Recombinant Fusion Proteins; D000687:Amylopectin; D013214:Starch Synthase
keywords: endosperm-specific expression; promoter analysis; rice; starch synthase IIa (SSIIa)