Conversion of Indole-3-Butyric Acid to Indole-3-Acetic Acid in Shoot Tissue of Hazelnut (Corylus) and Elm (Ulmus)

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• 作者：Molly Kreiser ; Chad Giblin ; Ryan Murphy ; Paul Fiesel…
• 刊名：Journal of Plant Growth Regulation
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：35
• 期：3
• 页码：710-721
• 全文大小：1,024 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Plant Sciences
  Cell Biology
  Agriculture
  Forestry
  
• 出版者：Springer New York
• ISSN：1435-8107
• 卷排序：35

文摘

Indole-3-butyric acid (IBA) is an endogenous compound that appears to regulate both lateral and adventitious root formation in many plant species and is also the auxin most available commercially for application to promote rooting. IBA is converted to indole-3-acetic acid (IAA) by β-oxidation in the peroxisomes. This process has been observed in a number of plant species and has been shown to be critical for normal root development in response to treatment with IBA. In this study, we investigated this process in hybrid hazelnut (Corylus americana × C. avellana), American elm (Ulmus americana), and Cathedral hybrid elm (U. pumila × U. davidiana var. japonica ‘Cathedral’), in which adventitious rooting is a major bottleneck for vegetative propagation, and the efficacy of IBA treatment is highly variable across different cultivars and at different collection times. Using differentially stable isotope-labeled IBA and IAA tracer and internal standard, respectively, and using gas chromatography coupled with selected reaction monitoring mass spectrometry, IBA-derived IAA was measured in shoot tissue treated with stable isotope-labeled IBA. In elm, higher levels of IBA-to-IAA conversion were generally observed in cultivars which formed adventitious roots most easily in softwood stem cutting trials. IBA-to-IAA conversion was observed in hazelnut genotypes with different rooting abilities and suggested a complex relationship exists between IBA conversion and root organogenesis. In both hazelnut and elm, endogenous free IAA levels were not significantly different across the genotypes examined. High rates of root formation is a key trait for establishment of large-scale production systems. Screening for optimal rates of IBA-to-IAA conversion may facilitate selection against genotypes which respond poorly to exogenous IBA and are thus difficult to propagate using hormone treatment.KeywordsIndole-3-butyric acidIndole-3-acetic acidAdventitious rootingβ-OxidationCorylus americanaUlmus americana