Plant Physiology 82:713-717 (1986)
© 1986 American Society of Plant Biologists
Articles
Insensitivity of the Diageotropica Tomato Mutant to Auxin 1
Maureen O. Kelly and
Kent J. Bradford
Department of Vegetable Crops, University of California, Davis, California 95616
The sensitivity of excised hypocotyl segments to indoleacetic acid (IAA) in two assays, ethylene production and elongation, was determined in the ethylene-requiring tomato (Lycopersicon esculentum Mill.) mutant, diageotropica (dgt), and its isogenic parent, cv VFN8. Endogenous (uninduced) ethylene synthesis rates were slightly lower in dgt hypocotyls than in VFN8 hypocotyls. Ethylene production was essentially unaffected by IAA in dgt, but was stimulated up to 10-fold by 10 micromolar IAA in VFN8. Elongation of dgt hypocotyls was also insensitive to concentrations of IAA as high as 100 micromolar, as compared to significant elongation of VFN8 hypocotyls in response to 0.1 micromolar IAA. A range of IAA analogs active in VFN8 was also ineffective in stimulating elongation of dgt hypocotyls, suggesting that the differences were not due to rapid metabolism of IAA by dgt tissues. Auxin-induced elongation of VFN8 hypocotyls was unaffected by 2,3,5-triiodobenzoic acid and naphthylphthalamic acid, indicating that polar auxin transport was not a factor in these experiments. Exogenous and auxin-induced ethylene had no effect on the elongation respone of either genotype, nor did exogenous ethylene restore the sensitivity of dgt hypocotyls to IAA. Despite their apparent insensitivity to auxin, dgt hypocotyls elongated dramatically and synthesized ethylene rapidly in response to 1.2 micromolar fusicoccin. These results suggest that the primary effect of the dgt mutation is to reduce the sensitivity of the tissue to auxin. As altered regulation of ethylene synthesis is only one symptom of this fundamental deficiency, dgt should more properly be considered to be the auxin-insensitive tomato mutant.
1 Supported in part by National Science Foundation Grant No. DMB-8408857.
This article has been cited by other articles:

|
 |

|
 |
 
M. de Jong, C. Mariani, and W. H. Vriezen
The role of auxin and gibberellin in tomato fruit set
J. Exp. Bot.,
April 1, 2009;
60(5):
1523 - 1532.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. A. Stieger, A. D. Meyer, P. Kathmann, C. Frundt, I. Niederhauser, M. Barone, and C. Kuhlemeier
The orf13 T-DNA Gene of Agrobacterium rhizogenes Confers Meristematic Competence to Differentiated Cells
Plant Physiology,
July 1, 2004;
135(3):
1798 - 1808.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. S.A. Al-Hammadi, Y. Sreelakshmi, S. Negi, I. Siddiqi, and R. Sharma
The polycotyledon Mutant of Tomato Shows Enhanced Polar Auxin Transport
Plant Physiology,
September 1, 2003;
133(1):
113 - 125.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Coenen, M. Christian, H. Luthen, and T. L. Lomax
Cytokinin Inhibits a Subset of Diageotropica-Dependent Primary Auxin Responses in Tomato
Plant Physiology,
April 1, 2003;
131(4):
1692 - 1704.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. Balbi and T. L. Lomax
Regulation of Early Tomato Fruit Development by the Diageotropica Gene
Plant Physiology,
January 1, 2003;
131(1):
186 - 197.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Catala, J. K.C. Rose, W. S. York, P. Albersheim, A. G. Darvill, and A. B. Bennett
Characterization of a Tomato Xyloglucan Endotransglycosylase Gene That Is Down-Regulated by Auxin in Etiolated Hypocotyls
Plant Physiology,
November 1, 2001;
127(3):
1180 - 1192.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. Caderas, M. Muster, H. Vogler, T. Mandel, J. K.C. Rose, S. McQueen-Mason, and C. Kuhlemeier
Limited Correlation between Expansin Gene Expression and Elongation Growth Rate
Plant Physiology,
August 1, 2000;
123(4):
1399 - 1414.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
C. Catalá, J. K.C. Rose, and A. B. Bennett
Auxin-Regulated Genes Encoding Cell Wall-Modifying Proteins Are Expressed during Early Tomato Fruit Growth
Plant Physiology,
February 1, 2000;
122(2):
527 - 534.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
C. V. Koka, R. E. Cerny, R. G. Gardner, T. Noguchi, S. Fujioka, S. Takatsuto, S. Yoshida, and S. D. Clouse
A Putative Role for the Tomato Genes DUMPY and CURL-3 in Brassinosteroid Biosynthesis and Response
Plant Physiology,
January 1, 2000;
122(1):
85 - 98.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Madlung, F. J. Behringer, and T. L. Lomax
Ethylene Plays Multiple Nonprimary Roles in Modulating the Gravitropic Response in Tomato
Plant Physiology,
July 1, 1999;
120(3):
897 - 906.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
R. C. Reed, S. R. Brady, and G. K. Muday
Inhibition of Auxin Movement from the Shoot into the Root Inhibits Lateral Root Development in Arabidopsis
Plant Physiology,
December 1, 1998;
118(4):
1369 - 1378.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
C. Coenen and T. L. Lomax
The Diageotropica Gene Differentially Affects Auxin and Cytokinin Responses throughout Development in Tomato
Plant Physiology,
May 1, 1998;
117(1):
63 - 72.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
T. Oyama, Y. Shimura, and K. Okada
The Arabidopsis HY5 gene encodes a bZIP protein that regulates stimulus-induced development of root and hypocotyl
Genes & Dev.,
November 15, 1997;
11(22):
2983 - 2995.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C P Romano, M B Hein, and H J Klee
Inactivation of auxin in tobacco transformed with the indoleacetic acid-lysine synthetase gene of Pseudomonas savastanoi.
Genes & Dev.,
March 1, 1991;
5(3):
438 - 446.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
G. R. HICKS, D. L. RAYLE, and T. L. LOMAX
The Diageotropica Mutant of Tomato Lacks High Specific Activity Auxin Binding Sites
Science,
July 7, 1989;
245(4913):
52 - 54.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
H. J. Klee, R. B. Horsch, M. A. Hinchee, M. B. Hein, and N. L. Hoffmann
The effects of overproduction of two Agrobacterium tumefaciens T-DNA auxin biosynthetic gene products in transgenic petunia plants
Genes & Dev.,
March 1, 1987;
1(1):
86 - 96.
[Abstract]
[PDF]
|
 |
|
|
|