Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 03/2009 |
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<mark>Journal</mark> | Phytochemistry |
Issue number | 5 |
Volume | 70 |
Number of pages | 8 |
Pages (from-to) | 664-671 |
Publication Status | Published |
<mark>Original language</mark> | English |
Plants produce various compounds in response to water deficit. Here, the presence and identification of a drought-inducible non-protein amino acid in the leaves of two C4 grasses is first reported. The soluble amino acids extracted from the leaves of three different species were measured by high-performance liquid chromatography of derivatives formed with o-phthaldialdehyde and β-mercaptoethanol. One amino acid that increased in amount with drought stress had a retention time not corresponding to any common amino acid. Its identity was determined by metabolite profiling, using 1H NMR and GC-MS. This unusual amino acid was present in the dehydrated leaves of Cynodon dactylon (L.) Pers. and Zoysia japonica Steudel, but was absent from Paspalum dilatatum Poir. Its identity as 2-amino-5-hydroxypentanoic acid (5-hydroxynorvaline, 5-HNV) was confirmed by synthesis and co-chromatography of synthetic and naturally occurring compounds. The amount of 5-HNV in leaves of the more drought tolerant C4 grasses, C. dactylon and Z. japonica, increased with increasing water deficit; therefore, any benefits from this unusual non-protein amino acid for drought resistance should be further explored.