Regulation of Metabolism
Shui, Wang , Guirong, Zhang , Wang, Hongyun , Ulanov, Alexander , Lozovaya, Vera , Lin, Yun .
A regulatory role of histidine in Arabidopsis metabolism and growth revealed by the low oil 1 mutant that corresponds to ATP-Phosphoribosyl Transferase 1, a key enzyme of histidine biosynthesis.
Amino acid sensory mechanisms are known to coordinate metabolism and growth in microbes and animals. However, evidence for their existence in plants has been elusive. In a genetic screen for Arabidopsis seed oil and protein deposition mutants, the low oil 1 (loo1) was isolated and map-based gene cloning identified a missense mutation in the first histidine biosynthetic enzyme ATP-phosphoribosyl transferase 1 (ATP-PRT1). The loo1 mutant exhibited development and growth defects throughout the entire lifespan. The severely retarded root elongation of loo1 seedlings was rescued by supplemental histidine in the growth medium. Transcript and metabolite profiling and real-time RT-PCR revealed a global integrated response involving primary metabolic pathways, storage protein pathways, phytohormone pathways, and stress pathways. Consistent with gene expression and metabolomic data, loo1 seedling growth and seed germination exhibited altered responses to ABA and sugar. We propose that the level of histidine modulates various plant functions by acting as a direct signal and by modifying secondary signals including phytohormones and metabolites. The existence of a regulatory response to the level of histidine was further supported by the modified development of rosette leaves, flowers, and siliques in transgenic lines over-expressing ATP-PRT1 or ATP-PRT2. Comparison of plant amino acid sensory functions with fungi and animals is discussed.
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Home page of Yun Lin
1 - Duke University, Department of Biology
2 - University of Illinois, Crop Sciences
3 - University of Illinois, Department of Crop Sciences
4 - University of Illinois, Deparment of Crop Sciences, 1101 W. Peabody Dr., 183 NSRC, Urbana, IL, 61801, USA
Presentation Type: ASPB Minisymposium
Location: Continental A/Hilton
Date: Wednesday, July 11th, 2007
Time: 11:30 AM