Cloning and characterization of the granule-bound starch synthase II gene in rice: gene expression is regulated by the nitrogen level, sugar and circadian rhythm.

Abstract

A full-length coding domain sequence of a gene analogous to granule-bound starch synthase (GBSS; ADP-glucose-starch glucosyltransferase, EC 2.4.1.21) was cloned and defined as OsGBSSII based on a Nitrogen (N)-starvation-induced cDNA library constructed using the rapid subtraction hybridization method. The deduced amino acid sequence of OsGBSSII was 62-85% identical to those of GBSS proteins from other plant species. The exon/intron organization of OsGBSSII was similar to that of OsGBSSI. OsGBSSII was mainly expressed in leaves and its protein was exclusively bound to starch granules in rice leaves, which suggests that the amylose in rice leaves is synthesized by OsGBSSII. N-starvation-induced expression of OsGBSSII could be repressed by supplying nitrate, ammonia or amino acid (glutamic acid or glutamine), glucosamine (an inhibitor of hexokinase) or dark conditions. These results indicate that N-starvation induction was dependent on the photosynthetic product and hexokinase in rice leaves. Sugars induced the accumulation of OsGBSSII transcripts in excised leaves through glycolysis-dependent pathways. OsGBSSII gene expression is regulated by the circadian rhythm in rice leaves.

• Authors: Weimin Dian, Huawu Jiang, Qingshuang Chen, Feiyang Liu, Ping Wu
• Journal: Planta (Planta) Vol. 218 Issue 2 Pg. 261-8 (Dec 2003) ISSN: 0032-0935 [Print] Germany
• PMID: 12955512 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Carbohydrates
• DNA, Complementary
• Isoenzymes
• Plant Proteins
• granule-bound starch synthase I
• Starch Synthase
• Nitrogen

Topics

• Amino Acid Sequence
• Carbohydrates (pharmacology)
• Chromosome Mapping
• Circadian Rhythm (physiology)
• Cloning, Molecular
• DNA, Complementary (chemistry, genetics)
• Darkness
• Escherichia coli (genetics, metabolism)
• Gene Expression Regulation, Enzymologic (drug effects, radiation effects)
• Gene Expression Regulation, Plant (drug effects, radiation effects)
• Genes, Plant (genetics)
• Isoenzymes (genetics, metabolism)
• Light
• Molecular Sequence Data
• Nitrogen (pharmacology)
• Oryza (enzymology, genetics)
• Phylogeny
• Plant Proteins (genetics, metabolism)
• Sequence Analysis, DNA
• Sequence Homology, Amino Acid
• Starch Synthase (genetics, metabolism)