Kai, Kenji, et al. Phytochemistry, 2007, 68(20), 2512-2522.
The plant hormone indole-3-acetic acid (IAA, 1) is an important signaling molecule that regulates many aspects of plant growth and development. In this work, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used to search for indole-3-acetic acid (IAA) conjugates in rice (Oryza sativa) to elucidate the unknown metabolic pathways of IAA. N -β- d -glucopyranosyl indole-3-acetic acid (IAA- N -Glc) was found in the alkaline hydrolyzate of rice extract, mostly in the form of conjugation with aspartic acid and glutamic acid.
In this study, although no 13C incorporation into IAA-N-Glc (9) was observed in rice seedlings fed with [13C6]IAA (13C6-1), it is still possible that direct N-glycosylation of IAA (1) occurs exclusively in developing seeds. There is ample evidence that IAA metabolism in plants depends on growth and/or developmental stage.
In the quantitative analysis, the following transitions from precursor ([M+H]+) to product ions were used for multiple reaction monitoring (MRM): IAA (1), 176 → 130; [13C6]IAA (13C6-1), 182 → 136; IAA-Asp (3), 291 → 130; [2',2'- d2]IAA-Asp (3-d2), 293 → 132; IAAGlu (4), 305 → 130; [2',2'- d2]IAA-Glu (4-d2), 307 → 132; IAA-N-Glc (9), 338 → 176; IAA-N-[6,6-d2]Glc (9-d2), 340 → 176; IAA-Asp-N-Glc (10), 453 → 291; IAA-AspN-[6,6-d2]Glc (10-d2), 455 → 291; IAA-Glu-N-Glc (11), 467 → 305.
