A microtechnique for the analysis of free and conjugated indole-3-acetic acid in milligram amounts of plant tissue using a benchtop gas chromatograph-mass spectrometer

• Published in: Planta Vol. 204; no. 1; pp. 1 - 7
• Main Authors: Ribnicky, D.M, Cooke, T.J, Cohen, J.D
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 1998; Springer
• Subjects: AIA; Analytical, structural and metabolic biochemistry; Arabidopsis - chemistry; ARABIDOPSIS THALIANA; AUXINAS; AUXINE; AUXINS; AVENA SATIVA; Biological and medical sciences; BIOLOGICAL DEVELOPMENT; Biotechnology; CHROMATOGRAPHIE EN PHASE GAZEUSE; COLEOPTILE; COLEOPTILES; COLEOPTILOS; CRECIMIENTO; CROISSANCE; CROMATOGRAFIA DE GASES; DESARROLLO BIOLOGICO; DEVELOPPEMENT BIOLOGIQUE; FRISCHGEWICHT; Fundamental and applied biological sciences. Psychology; GAS CHROMATOGRAPHY; Gas Chromatography-Mass Spectrometry - methods; GROWTH; Growth regulators; HIDROLISIS; HYDROLYSE; HYDROLYSIS; IAA; Indoleacetic Acids - analysis; Insulin antibodies; MENGE; Metabolism; METHODE; METHODS; Methylation; METODOS; Oats; Other biological molecules; PHYTOHORMON; PLANT GROWTH SUBSTANCES; Plant physiology and development; PLANT TISSUES; Plants; PLANTULAS; PLANTULE; SEEDLINGS; Solvents; SUBSTANCE DE CROISSANCE VEGETALE; SUSTANCIAS DE CRECIMIENTO VEGETAL; TEJIDOS VEGETALES; TISSU VEGETAL; Trees - chemistry; Avena sativa; Monocotyledones; Auxin; Microassay; Arabidopsis thaliana; Gas chromatography; Cruciferae; Gramineae; Dicotyledones; Indoleacetic acid; Angiospermae; Plant growth substance; Spermatophyta; Conjugated compound; Mass spectrometry; Quantitative analysis
• ISSN: 0032-0935; 1432-2048

A microtechnique was developed for the quantification of indole-3-acetic acid (IAA) in plant samples of one milligram fresh weight or less. The method permitted quantification of both free and conjugated IAA using a benchtop gas chromatograph-mass spectrometer. New methods for sample purification with high recovery at microscale levels, together with simple changes that result in enhanced sensitivity of the instrumentation, allowed for a significant reduction in the amount of plant material required for analysis. Single oat (Avena sativa L.) coleoptile tips could be studied with this method and were found to contain free and total IAA levels of 137 and 399 pg·mg-1 fresh weight, respectively. A single 5-d-old Arabidopsis thaliana (L.) Heynh. seedling was shown to contain 61 pg·mg-1 fresh weight free IAA and 7850 pg·mg-1 fresh weight of total IAA following basic hydrolysis. This microtechnique provides a way to accurately measure IAA levels in very small structures and individual seedlings, thus making it a valuable research tool for elucidating the role and distribution of auxin in relation to growth and development.