JXB Advance Access originally published online on June 27, 2005
Journal of Experimental Botany 2005 56(418):2071-2083; doi:10.1093/jxb/eri206
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
RESEARCH PAPER |
A mutational analysis of the ABA1 gene of Arabidopsis thaliana highlights the involvement of ABA in vegetative development
1División de Genética and Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Alicante, Spain
2Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
* To whom correspondence should be addressed. Fax: +34 966 65 85 11. E-mail: jlmicol{at}umh.es
Much of the literature on the phytohormone abscisic acid (ABA) describes it as a mediator in triggering plant responses to environmental stimuli, as well as a growth inhibitor. ABA-deficient mutants, however, display a stunted phenotype even under well-watered conditions and high relative humidity, which suggests that growth promotion may also be one of the roles of endogenous ABA. Zeaxanthin epoxidase, the product of the ABA1 gene of Arabidopsis thaliana, catalyses the epoxidation of zeaxanthin to antheraxanthin and violaxanthin, generating the epoxycarotenoid precursor of the ABA biosynthetic pathway. This paper gives a description of the molecular and phenotypic characterization of a large series of mutant alleles of the ABA1 gene, which cause different degrees of ABA deficiency, four of them previously isolated (aba1-1, aba1-3, aba1-4, and aba1-6) and the remaining five novel (sañ1-1, sañ1-2, sañ1-3, sañ1-4, and sre3). Molecular analysis of these alleles provides insights into the domains in which they compromise zeaxanthin epoxidase function. The size of the leaves, inflorescences, and flowers of these mutants is reduced, and their rosettes have lower fresh and dry weights than their wild types, as a result of a diminished cell size. Low concentrations of exogenous ABA increase the fresh weight of mutant and wild-type plants, as well as the dry weight of the mutants. The leaves of aba1 mutants are abnormally shaped and fail to develop clearly distinct spongy and palisade mesophyll layers. Taken together, these phenotypic traits indicate, as suggested by previous authors, that ABA acts as a growth promoter during vegetative development. The abnormal shape and internal structure of the leaves of aba1 mutants suggests, in addition, a role for ABA in organogenesis.
Key words: ABA1, abscisic acid, Arabidopsis thaliana, growth promotion, vegetative development, zeaxanthin epoxidase
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  D. Huang, W. Wu, S. R. Abrams, and A. J. Cutler The relationship of drought-related gene expression in Arabidopsis thaliana to hormonal and environmental factors J. Exp. Bot., August 1, 2008; 59(11): 2991 - 3007. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Wasilewska, F. Vlad, C. Sirichandra, Y. Redko, F. Jammes, C. Valon, N. F. d. Frey, and J. Leung An Update on Abscisic Acid Signaling in Plants and More ... Mol Plant, March 1, 2008; 1(2): 198 - 217. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Hricova, V. Quesada, and J. L. Micol The SCABRA3 Nuclear Gene Encodes the Plastid RpoTp RNA Polymerase, Which Is Required for Chloroplast Biogenesis and Mesophyll Cell Proliferation in Arabidopsis Plant Physiology, July 1, 2006; 141(3): 942 - 956. [Abstract] [Full Text] [PDF]
|
|