Exogenously applied indole-3-acetic acid (IAA) strongly promoted stem elongation over the long term in intact light-grown seedlings of both dwarf (cv Progress No. 9) and tall (cv Alaska) peas (Pisum sativum L.), with the relative promotion being far greater in dwarf plants. In dwarf seedlings, solutions of IAA (between 10-4 and 10-3 M), when continuously applied to the uppermost two internodes ...

Explaining how the small molecule auxin triggers diverse yet specific responses is a long-standing challenge in plant biology. An essential step in auxin response is the degradation of Auxin/Indole-3-Acetic Acid (Aux/IAA, referred to hereafter as IAA) repressor proteins through interaction with auxin receptors. To systematically characterize diversity in degradation behaviors among IAA|receptor...

The synthesis of H(2)O-soluble and NaOH-hydrolyzable bound forms of indole-3-acetic acid (IAA) in petiole slices of Nicotiana glauca, Nicotiana langsdorffii, and their tumorous and nontumorous hybrids in the presence of exogenous (14)C-IAA was investigated. The synthesis of conjugates progressively increased during 6 hours of incubation in (14)C-IAA. The results showed that the rate of synthesi...

The enzymatic oxidlation of 3-indoleacetic aci(l (IAA) which was first described in detail by Tang and Bonner (16, 17), has been observed in several types of plants, e.g., fungi (13), ferns (14), monocotyledonous plants (20), and dicotyledonous plants (16, 17, 19). Although differences have been observed in regard to the enzyme's requirement for a phenolic cofactor, and in the pH optimum, the r...

The Auxin/indole-3-acetic acid (Aux/IAA) gene family plays key roles in the primary auxin-response process and controls a number of important traits in plants. However, the characteristics of the Aux/IAA gene family in hexaploid bread wheat (Triticum aestivum L.) have long been unknown. In this study, a comprehensive identification of the Aux/IAA gene family was performed using the latest draft...

Jasmonate (JA) and auxin are essential hormones in plant development and stress responses. While the two govern distinct physiological processes, their signaling pathways interact at various levels. Recently, members of the Arabidopsis indole-3-acetic acid (IAA) amidohydrolase (IAH) family were reported to metabolize jasmonoyl-isoleucine (JA-Ile), a bioactive form of JA. Here, we characterized ...

We examined the sensitivity and the specificity of three versions of the Salkowski colorimetric technique. Two of these allowed the detection of indoleacetic acid (IAA) over a low range of concentrations (0.5 to 20 (mu)g/ml), while the third permitted the detection of IAA over a range of higher concentrations (5 to 200 (mu)g/ml). Overall, the three formulations reacted not only with auxin (IAA)...

Transcription of the AUX/IAA family of genes is rapidly induced by the plant hormone auxin, but evidence that AUX/IAA genes mediate further responses to auxin has been elusive. Changes in diverse auxin responses result from mutations in the Arabidopsis AXR3 gene. AXR3 was shown to be a member of the AUX/IAA family, providing direct evidence that AUX/IAA genes are central in auxin signaling. Mol...

The replicase protein of Tobacco mosaic virus (TMV) disrupts the localization and stability of interacting auxin/indole acetic acid (Aux/IAA) proteins in Arabidopsis, altering auxin-mediated gene regulation and promoting disease development (M. S. Padmanabhan, S. P. Goregaoker, S. Golem, H. Shiferaw, and J. N. Culver, J. Virol. 79:2549-2558, 2005). In this study, a similar replicase-Aux/IAA int...

The performance characteristics of two bone alkaline phosphatase (ALP; EC 3.1.3.1) assays, a wheat germ agglutinin (WGA) precipitation assay and a new immunoadsorption assay (IAA), were compared. The withinand between-run imprecision of the IAA (3.6-4.2% and 3.6-7.7%) was comparable with that of the WGA assay. The mean crossreactivity with liver ALP appeared to be 4% in the WGA assay and 11 % i...