Abstract
The phytohormone auxin regulates nearly all aspects of plant growth and development. Tremendous achievements have been made in elucidating the tryptophan (Trp)-dependent auxin biosynthetic pathway; however, the genetic evidence, key components, and functions of the Trp-independent pathway remain elusive. Here we report that the Arabidopsis indole synthase mutant is defective in the long-anticipated Trp-independent auxin biosynthetic pathway and that auxin synthesized through this spatially and temporally regulated pathway contributes significantly to the establishment of the apical-basal axis, which profoundly affects the early embryogenesis in Arabidopsis. These discoveries pave an avenue for elucidating the Trp-independent auxin biosynthetic pathway and its functions in regulating plant growth and development.
Keywords:
Arabidopsis thaliana; IAA biosynthesis; embryogenesis; phytohormone; tryptophan.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Arabidopsis / embryology*
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Arabidopsis / genetics
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Arabidopsis / metabolism*
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Arabidopsis Proteins / genetics
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Arabidopsis Proteins / metabolism
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Gene Expression Regulation, Developmental
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Gene Expression Regulation, Plant
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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Indoleacetic Acids / metabolism*
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Microscopy, Confocal
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Multienzyme Complexes / genetics
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Multienzyme Complexes / metabolism
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Mutation
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Ovule / genetics
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Ovule / metabolism
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Plant Components, Aerial / genetics
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Plant Components, Aerial / metabolism
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Plants, Genetically Modified
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Reverse Transcriptase Polymerase Chain Reaction
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Seedlings / genetics
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Seedlings / metabolism
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Seeds / embryology*
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Seeds / genetics
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Tryptophan / metabolism
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Tryptophan Synthase / genetics
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Tryptophan Synthase / metabolism
Substances
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Arabidopsis Proteins
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Indoleacetic Acids
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Multienzyme Complexes
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indole-3-acetic acid synthase
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Green Fluorescent Proteins
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indoleacetic acid
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Tryptophan
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Tryptophan Synthase