- Preparation of synthetic auxin-amino acid conjugates
-
Auxin amide conjugates are regulators of the most important auxin, indole-3-acetic acid (IAA), which is considered responsible for many important processes within the plants. Herein, amide conjugates of IAA were synthesized employing a simple and efficient coupling method with WSCI·HCl, a water-soluble condensing reagent, in the presence of 1-hydroxybenzotriazole. IAA conjugates with 10 amino acids along with their corresponding methyl esters were prepared in excellent yields, up to 95%, aiming to facilitate their identification in plant species. Eight IAA-amino acid methyl ester conjugates are characterized here for the first time.
- Revelou, Panagiota-Kyriaki,Constantinou-Kokotou, Violetta
-
supporting information
p. 1708 - 1712
(2019/05/15)
-
- Modification of auxinic phenoxyalkanoic acid herbicides by the acyl acid amido synthetase GH3.15 from Arabidopsis
-
Herbicide-resistance traits are the most widely used agriculture biotechnology products. Yet, to maintain their effectiveness and to mitigate selection of herbicide-resistant weeds, the discovery of new resistance traits that use different chemical modes of action is essential. In plants, the Gretchen Hagen 3 (GH3) acyl acid amido synthetases catalyze the conjugation of amino acids to jasmonate and auxin phytohormones. This reaction chemistry has not been explored as a possible approach for herbicide modification and inactivation. Here, we examined a set of Arabidopsis GH3 proteins that use the auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) as substrates along with the corresponding auxinic phenoxyalkanoic acid herbicides 2,4-dichlorophenoxylacetic acid (2,4-D) and 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB). The IBA-specific AtGH3.15 protein displayed high catalytic activity with 2,4-DB, which was comparable to its activity with IBA. Screening of phenoxyalkanoic and phenylalkyl acids indicated that side-chain length of alkanoic and alkyl acids is a key feature of AtGH3.15’s substrate preference. The X-ray crystal structure of the AtGH3.15?2,4-DB complex revealed how the herbicide binds in the active site. In root elongation assays, Arabidopsis AtGH3.15-knockout and -overexpression lines grown in the presence of 2,4-DB exhibited hypersensitivity and tolerance, respectively, indicating that the AtGH3.15-cata-lyzed modification inactivates 2,4-DB. These findings suggest a potential use for AtGH3.15, and perhaps other GH3 proteins, as herbicide-modifying enzymes that employ a mode of action different from those of currently available herbicide-resistance traits.
- Sherp, Ashley M.,Lee, Soon Goo,Schraft, Evelyn,Jez, Joseph M.
-
p. 17731 - 17738
(2018/12/12)
-
- Stable-isotope labeled metabolites of the phytohormone, indole-3-acetic acid
-
1,3-Dicyclohexylcarbodiimide-mediated condensation of [3a,4,5,6,7,7a-13C6]indole-3-acetic acid with the bis(tert-butyl) esters of L-aspartic or L-glutamic acids, followed by removal of the ester groups by dilute alkali, afforded N-([3a,4,5,6,7,7a-13C6]indol-3-ylacetyl)-L-aspartic and N-([3a,4,5,6,7,7a-13C6]indol-3-ylacetyl)-L-glutamic acids, labeled forms of compounds involved in the regulation of plant growth and development. The corresponding conjugates of (R,S)-2,3-dihydro-2-oxoindole-3-acetic acid, which are likewise of physiological significance, were labeled with 15N in the amino acid moieties and were synthesized via the N-hydroxysuccinimide ester.
- Illic, Nebojsa,Magnus, Volker,Oestin, Anders,Sandberg, Goeran
-
p. 433 - 440
(2007/10/03)
-