The Site of Indole-3-acetic Acid Synthesis in Mesophyll Cells of Spinacia oleracea

Abstract Using [14C]tryptophan as a precursor, the intracellular localization of indole-3-acetic acid biosynthesis in spinach mesophyll cells was investigated. Chloroplasts as well as extraplastidic compartments were able to transform tryptophan into indole-3-acetic acid.The cofactor requirement of plastidic and extraplastidic indole-3-acetic acid synthesis is shown.Light and abscisic acid treatment inhibited preparations.

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Subcellular Compartmentation of Indole-3-acetic Acid in Mesophyll Cells of Spinacia oleracea

Zeitschrift für Naturforschung C ◽

10.1515/znc-1981-7-828 ◽

1981 ◽

Vol 36 (7-8) ◽

pp. 679-685 ◽

Cited By ~ 5

Author(s):

B. Heilmann ◽

W. Hartung ◽

H. Gimmler

Keyword(s):

Acetic Acid ◽

Plant Hormone ◽

Spinacia Oleracea ◽

Surrounding Medium ◽

Compartmental Analysis ◽

Chloroplast Envelope ◽

Mesophyll Cells ◽

Subcellular Compartmentation ◽

Chloroplast Stroma ◽

Indole 3 Acetic Acid

Abstract A compartmental analysis of the distribution of the plant hormone indole-3-acetic acid (IAA) was performed with mesophyll cells of spinach leaves. The results indicated that up to about 45% of the total amount of free IAA in the laminae of spinach is localized within the chloroplasts, although these organelles occupy only about 7% of the tissue volume. This distribution is due to the dissociation properties of IAA which has a pK a of 4,7. The chloroplast envelope is easily permeable for the undissociated acid (IAAH) and less permeable for the anion (IAA"). The rate of uptake of LAA by chloroplasts was linearly dependent on the IAAH concentration gradient between medium and stroma. Uptake was increased by lowering the extraplastidic pH or by alkalization of the stroma during illumination. In illuminated chloroplasts, IAA was accumulated up to 4 fold compared to the surrounding medium owing to the pH gradient between the medium (pH 7.6) and the stroma (pH 8.0). The unexpectedly high plastidic IAA concentration observed in the dark (concentration ratio stroma/medium was about 2) suggested binding of IAA to chloroplast components. Due to this binding, the IAA distribution between medium and chloroplasts must not be used for calculating the stroma pH, as is possible with ABA. However, from the different distribution of IAA in light and darkness the light-induced alkalization of the chloroplast stroma can be calculated.

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Identification of an aromatic aldehyde synthase involved in indole-3-acetic acid biosynthesis in the galling sawfly (Pontania sp.) and screening of an inhibitor

Insect Biochemistry and Molecular Biology ◽

10.1016/j.ibmb.2021.103639 ◽

2021 ◽

pp. 103639

Author(s):

Umi Miyata ◽

Kenta Arakawa ◽

Mami Takei ◽

Tadao Asami ◽

Kazuya Asanbou ◽

...

Keyword(s):

Acetic Acid ◽

Aromatic Aldehyde ◽

Acid Biosynthesis ◽

Indole 3 Acetic Acid

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Growth and indole-3-acetic acid biosynthesis ofAzospirillum brasilenseSp245 is environmentally controlled

FEMS Microbiology Letters ◽

10.1016/j.femsle.2005.03.048 ◽

2005 ◽

Vol 246 (1) ◽

pp. 125-132 ◽

Cited By ~ 70

Author(s):

Ositadinma Ona ◽

Jan Impe ◽

Els Prinsen ◽

Jos Vanderleyden

Keyword(s):

Acetic Acid ◽

Acid Biosynthesis ◽

Indole 3 Acetic Acid

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Biosynthesis of abscisic acid

Biochemical Society Transactions ◽

10.1042/bst0110553 ◽

1983 ◽

Vol 11 (5) ◽

pp. 553-557 ◽

Cited By ~ 8

Author(s):

R. HORGAN ◽

S. J. NEILL ◽

D. C. WALTON ◽

D. GRIFFIN

Keyword(s):

Acetic Acid ◽

Abscisic Acid ◽

Model System ◽

Acid Biosynthesis ◽

Abscisic Acid Biosynthesis ◽

Preliminary Results ◽

Endogenous Compounds

The fungus Cercospora rosicola has been studied as a model system for abscisic acid biosynthesis. 1′-Deoxyabscisic acid and 4′-hydroxy-α-ionylidene acetic acid have been identified as endogenous compounds in this fungus. The results of feeding these and other putative intermediates suggest that abscisic acid biosynthesis proceeds via the successive oxidations of a 3 -methyl- 5 - (2′,6′,6′- trimethylcyclohex-2′-en-1′-yl)- 2,4-pentadienyl intermediate. Preliminary results suggest that a similar pathway may operate in plants.

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