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Descripción
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| Phytohormones are small signaling molecules that regulate plant growth and development. One of these phytohormones is indole-3-acetic acid (IAA), the most abundant naturally occurring auxin (Davies, 2004). Although much is known about the physiology of auxin, its biosynthesis is still uncertain. It is proposed that there are different pathways operating either in parallel or in a redundant manner for IAA production (Woodward and Bartel, 2005; Pollmann et al., 2006). One of these pathways, the IAM-pathway, is designated by its hallmark-intermediate (indole-3-acetamide, IAM). In the IAM-pathway, amidase enzymes capable of converting IAM into IAA contribute to auxin biosynthesis (Pollmann et al., 2003). We have characterized three allelic Arabidopsis thaliana ami1 (amidase 1) mutants, who share defects in the IAM-specific hydrolase, a homolog of the auxin synthesis-related iaaH gene from Agrobacterium. The ami1 mutants have lower IAM hydrolase activities and reduced levels of IAA. In addition, they show a subtle root phenotype that becomes more pronounced under stress conditions. AMI1 is predominantly expressed in proliferating tissues throughout plant development. The overexpression of AMI1 led to a significant alteration of root development, curled leaf growth, and premature establishment of reproductive organs. The overexpressors displayed higher amidase activities and increased auxin contents. Furthermore, we quantitatively analyzed AMI1 transcription levels in numerous auxin biosynthetic mutants. The obtained results point towards sophisticated relationships between the pathways. As we were able to isolate and characterize AMI1-homologs from various plant species, we conclude that IAM hydrolase-dependent IAA biosynthesis is a widely distributed concept in the plant kingdom. | |
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Internacional
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Si |
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Nombre congreso
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New fronters in Plant Biology |
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Tipo de participación
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970 |
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Lugar del congreso
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Centro de Biotecnología y Genómica de Plantas |
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Revisores
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Si |
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ISBN o ISSN
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0000-0000 |
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DOI
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Fecha inicio congreso
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15/06/2016 |
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Fecha fin congreso
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17/06/2016 |
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Desde la página
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35 |
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Hasta la página
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35 |
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Título de las actas
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AMIDASE1 of Arabidopsis is involved in auxin biosynthesis. |