Regulation of Metabolism
Li, Ling , Nettleton, Dan , Wurtele, Eve .
Down-regulation of a novel small gene confers a starch excess phenotype in Arabidopsis.
SS3 is one of six isoforms of starch synthase involved in starch synthesis. Leaves of Arabidopsis SS3 knockouts display a starch excess phenotype. The effects of eliminating SS3 expression were examined by global mRNA profiling between Atss3 mutant and WT. The genes with up-regulated transcripts are involved in transporting starch synthesis precursors and starch degradation products, and in starch and sucrose metabolism. Their altered transcript accumulation suggested a possible explanation to the Atss3 mutant phenotype. A gene (QQ) had the most significant transcript change in the “Genotype” comparison between the Atss3 mutant and WT. QQ encodes a unique small protein (59 aa) with unknown function and has no sequence similarity to any other protein in Arabidopsis or in any other organism. To test the possible role of QQ in starch metabolism, we generated Arabidopsis translines that are down-regulated in expression of the QQ gene. Leaves of QQ RNAi plants have a starch excess phenotype at the end of light period. In contrast, the starch levels at the end of the dark are indistinguishable from WT. We hypothesize that this small unique gene might be involved in regulating starch accumulation.
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Arabidopsis starch metabolism network
1 - Iowa State University, Department of Genetics, Development and Cell Biology, 433 Bessey Hall, Ames, IA, 50011, USA
2 - Iowa State University, Department of Statistics
3 - Iowa State University, Department of Genetics, Development and Cell Biology
novel small gene
Presentation Type: ASPB Minisymposium
Location: Continental A/Hilton
Date: Wednesday, July 11th, 2007
Time: 10:40 AM