|
PLANT PHYSIOLOGY , Vol 114, Issue 4 1385-1395, Copyright © 1997 by American Society of Plant Biologists
|
BIOCHEMISTRY AND ENZYMOLOGY |
Temperature-Sensitive Plant Cells with Shunted Indole-3-Acetic Acid Conjugation
J. H. Oetiker and G. Aeschbacher
Friedrich Miescher-Institut, Postfach 2543, Basel, Switzerland
Cells of henbane (Hyoscyamus muticus L.) grow indefinitely in culture
without exogenous auxin. Cells of its temperature-sensitive variant XIIB2
grow like the wild type at 26[deg]C but die rapidly at 33[deg]C unless
auxin is added to the medium. Despite this temperature-sensitive auxin
auxotrophy, XIIB2 produces wild-type amounts of indole-3-acetic acid (IAA).
IAA is the predominant auxin and is important for plant growth and
development. Since the IAA production of the variant is functional, we
investigated whether the synthesis or degradation of IAA metabolites,
possibly active auxins themselves, is altered. The IAA metabolites were
IAA-aspartate (IAAsp) and IAA-glucose. The wild type converted IAA mainly
to IAAsp, whereas the variant produced mainly IAA-glucose. Exogenous auxin
corrected the shunted IAA metabolism of the variant. The half-life of
labeled IAAsp in the variant was reduced 21-fold, but in the presence of
exogenous auxin it was not different from the wild type. The temperature
sensitivity of XIIB2 was also corrected by supplying IAAsp. Pulse-chase
experiments revealed that henbane rapidly metabolizes IAAsp to compounds
not identical to IAA. The data show that the variant XIIB2 is a useful tool
to study the function of IAA conjugates to challenge the popular hypothesis
that IAA conjugates are merely slow-release storage forms of IAA.
This article has been cited by other articles:
|
|
|
|
 
J.-E. Park, J.-Y. Park, Y.-S. Kim, P. E. Staswick, J. Jeon, J. Yun, S.-Y. Kim, J. Kim, Y.-H. Lee, and C.-M. Park
GH3-mediated Auxin Homeostasis Links Growth Regulation with Stress Adaptation Response in Arabidopsis
J. Biol. Chem.,
March 30, 2007;
282(13):
10036 - 10046.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J.-C. Chou, W. H. Welch, and J. D. Cohen
His-404 and His-405 are Essential for Enzyme Catalytic Activities of a Bacterial Indole-3-Acetyl-L-Aspartic Acid Hydrolase
Plant Cell Physiol.,
September 15, 2004;
45(9):
1335 - 1341.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Jakubowska and S. Kowalczyk
The auxin conjugate 1-O-indole-3-acetyl-{beta}-D-glucose is synthesized in immature legume seeds by IAGlc synthase and may be used for modification of some high molecular weight compounds
J. Exp. Bot.,
April 1, 2004;
55(398):
791 - 801.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Walz, S. Park, J. P. Slovin, J. Ludwig-Muller, Y. S. Momonoki, and J. D. Cohen
A gene encoding a protein modified by the phytohormone indoleacetic acid
PNAS,
February 5, 2002;
99(3):
1718 - 1723.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Kowalczyk and G. Sandberg
Quantitative Analysis of Indole-3-Acetic Acid Metabolites in Arabidopsis
Plant Physiology,
December 1, 2001;
127(4):
1845 - 1853.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Y. Tam, E. Epstein, and J. Normanly
Characterization of Auxin Conjugates in Arabidopsis. Low Steady-State Levels of Indole-3-Acetyl-Aspartate, Indole-3-Acetyl-Glutamate, and Indole-3-Acetyl-Glucose
Plant Physiology,
June 1, 2000;
123(2):
589 - 596.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
A. Ester Sztein, J. D. Cohen, I. G. de la Fuente, and T. J. Cooke
Auxin metabolism in mosses and liverworts
Am. J. Botany,
November 1, 1999;
86(11):
1544 - 1555.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
