Affiliation:
1. Department of Horticulture and Crop Science, The Ohio State University, Columbus, Ohio 43210
Abstract
Abstract
Glucose (Glc) signaling, along with abscisic acid (ABA) signaling, has been implicated in regulating early plant development in Arabidopsis. It is generally believed that high levels of exogenous Glc cause ABA accumulation, which results in a delay of germination and an inhibition of seedling development—a typical stress response. To test this hypothesis and decipher the complex interactions that occur in the signaling pathways, we determined the effects of sugar and ABA on one developmental event, germination. We show that levels of exogenous Glc lower than previously cited could delay the rate of seed germination in wild-ecotype seeds. Remarkably, this effect could not be mimicked by an osmotic effect, and ABA was still involved. With higher concentrations of Glc, previously known Glc-insensitive mutants gin2 and abi4 exhibited germination kinetics similar to wild type, indicating that Glc-insensitive phenotypes are not the same for all developmental stages of growth and that the signaling properties of Glc vary with concentration. Higher concentrations of Glc were more potent in delaying seed germination. However, Glc-delayed seed germination was not caused by increased cellular ABA concentration, rather Glc appeared to slow down the decline of endogenous ABA. Except for the ABA-insensitive mutants, all tested genotypes appeared to have similar ABA perception during germination, where germination was correlated with the timing of ABA drop to a threshold level. In addition, Glc was found to modulate the transcription of genes involved in ABA biosynthesis and perception only after germination, suggesting a critical role of the developmental program in sugar sensing. On the basis of an extensive phenotypic, biochemical, and molecular analysis, we suggest that exogenous Glc application creates specific signals that vary with concentration and the developmental stage of the plant and that Glc-induced fluctuations in endogenous ABA level generate a different set of signals than those generated by external ABA application.
Publisher
Oxford University Press (OUP)
Subject
Plant Science,Genetics,Physiology
Reference38 articles.
1. Arenas-Huertero F, Arroyo A, Zhou L, Sheen J, Leon P (2000) Analysis of Arabidopsis glucose insensitive mutants, gin5 and gin6, reveals a central role of the plant hormone ABA in the regulation of plant vegetative development by sugar. Genes Dev 14
: 2085–2096
2. Ausubel FM, Brent R, Kingston RE, Moore DD, Seidman JG, Smith JA, Struhl K, eds (1987) Current Protocols in Molecular Biology. Greene Publishing Associates and Wiley-Interscience, New York
3. Beaudoin N, Serizet C, Gosti F, Giraudat J (2000) Interactions between abscisic acid and ethylene signaling cascades. Plant Cell 12
: 1103–1115
4. Bockenhoff A, Prior DA, Grundler FM, Oparka KJ (1996) Induction of phloem unloading in Arabidopsis thaliana roots by the parasitic nematode Heterodera schachtii. Plant Physiol 112
: 1421–1427
5. Cheng WH, Endo A, Zhou L, Penney J, Chen HC, Arroyo A, Leon P, Nambara E, Asami T, Seo M et al. (2002) A unique short-chain dehydrogenase/reductase in Arabidopsis glucose signaling and abscisic acid biosynthesis and functions. Plant Cell 14
: 2723–2743
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