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Tyrosine Aminomutase TAM1 Is Required for β-Tyrosine Biosynthesis in Rice.
- Source :
- Plant Cell; Apr2015, Vol. 27 Issue 4, p1265-1278, 14p
- Publication Year :
- 2015
-
Abstract
- Non-protein amino acids, often isomers of the standard 20 protein amino acids, have defense-related functions in many plant species. A targeted search for jasmonate-induced metabolites in cultivated rice (Oryza sativa) identified (R)-β-tyrosine, an isomer of the common amino acid (S)-α-tyrosine in the seeds, leaves, roots, and root exudates of the Nipponbare cultivar. Assays with 119 diverse cultivars showed a distinct presence/absence polymorphism, with β-tyrosine being most prevalent in temperate japonica cultivars. Genetic mapping identified a candidate gene on chromosome 12, which was confirmed to encode a tyrosine aminomutase (TAM1) by transient expression in Nicotiana benthamiana and in vitro enzyme assays. A point mutation in TAM1 eliminated β-tyrosine production in Nipponbare. Rice cultivars that do not produce β-tyrosine have a chromosome 12 deletion that encompasses TAM1. Although β-tyrosine accumulation was induced by the plant defense signaling molecule jasmonic acid, bioassays with hemipteran and lepidopteran herbivores showed no negative effects at physiologically relevant β-tyrosine concentrations. In contrast, root growth of Arabidopsis thaliana and other tested dicot plants was inhibited by concentrations as low as 1 μM. As β-tyrosine is exuded into hydroponic medium at higher concentrations, it may contribute to the allelopathic potential of rice. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10404651
- Volume :
- 27
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Plant Cell
- Publication Type :
- Academic Journal
- Accession number :
- 158018290
- Full Text :
- https://doi.org/10.1105/tpc.15.00058