Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/24/2003
Publication Date: 4/10/2003
Citation: Lingle, S.E., Dyer, J.M., Veremis, J.C. 2003. Genotypic variation in the promoter region of sucrose synthase-2 in the genus saccharum [abstract]. International Society of Sugar Cane Technologists Molecular Biology Workshop. Available: http://issct.intnet.mu/mo/abstracts.htm.
Technical Abstract: Sucrose synthase (EC 184.108.40.206) is an important enzyme of sucrose metabolism in sugarcane (Saccharum sp. hybrids). One of the genes for sucrose synthase (Sus2) is more highly expressed in sucrose-storing genotypes than low-sucrose genotypes. We designed primers to amplify the 5' end of the Sus2 gene (homologous to maize Sh1) from about 2000 nucleotides (nt) upstream of the transcription start site to the start of the third exon. Using these primers we amplified, cloned and sequenced the 5' end of Sus2 from a number of Saccharum species and interspecific hybrids.. The PCR products were distinguished by large inserts of about 240 nt. Some of these were highly homologous to regions of the Candystripe (Cs1) transposon in sorghum (Sorghum bicolor). Others were similar to Tourist-type Miniature Inverted Transposable Elements (MITES). The latter are approximately twice the size of previously reported MITES in rice (Oryza sativa), and may represent MITES inserted into other MITES, as has been recently suggested in rice. At least one of the Cs1-like inserts appeared to be specific to S. officinarum, while at least one MITE-like insert appeared specific to S. spontaneum. Primers were designed around the insertions, and PCR using these primers produced polymorphic patterns in different genotypes, and thus may be useful genetic markers. While it is not yet known if any of these inserts influence transcription of the gene, these differences may be useful for the selection of the highly expressed form of the gene.