ISSN:
1573-5028
Keywords:
ASF-1
;
phytohormones
;
signal transduction
;
active oxygen species
;
glutathione S-transferase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The molecular mechanism of signal transduction pathways which mediate the action of phytohormones are poorly understood. Recently, we and others have shown that the as-1 type cis-acting elements can respond to auxin and salicylic acid, two well-characterized signaling molecules in plants. In the present work, we have examined a comprehensive set of physiological and abiotic agents and found that auxin, salicylic acid and methyl-jasmonate are three effective inducers of the as-1-type elements in transgenic tobacco. Using a cell suspension culture containing a synthetic promoter-GUS fusion, we demonstrated rapid and sensitive induction of the as-1-type element by these phytohormones. Furthermore, a tobacco glutathione S-transferase gene, GNT35, that contains an as-1-type binding site in its promoter is also inducible by auxin, salicylic acid and methyl-jasmonate with similar kinetics. As Ulmasov et al. have recently reported, we found that the as-1-type elements can also respond to weak/inactive analogues of auxin and salicylic acid. In addition, we show that hydrogen peroxide can also effectively activate the expression of GNT35 as well as the as-1-type element in a cell suspension culture, but not with whole seedlings. These results are discussed with respect to the possible mechanism(s) through which a single cis element may respond to a diverse array of molecules.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00019093
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