Differential tissue-specific response to sulfate and methionine of a soybean seed storage protein promoter region in transgenic arabidopsis

Ohkama, N., Goto, D.B., Fujiwara, T. and Naito, S. (2002) Differential tissue-specific response to sulfate and methionine of a soybean seed storage protein promoter region in transgenic arabidopsis. Plant and Cell Physiology, 43 (11). pp. 1266-1275.

Abstract

Expression of the gene encoding the β subunit of β-conglycinin, a major soybean seed storage protein, is upregulated by sulfur deficiency and downregulated by methionine (Met). The tissue-specificity of these regulatory mechanisms was studied using a sulfate-responsive region (βSR) from the β subunit gene promoter. Transgenic Arabidopsis thaliana lines were generated carrying a green fluorescent protein (GFP) reporter gene under control of the cauliflower mosaic virus 35S RNA promoter with a tandem repeat of the βSR element, referred to as the P35S::βSRx3: GFP transgene. Upregulation of P35S::βSRx3:GFP by sulfur deficiency was strongest in leaf margins, where symptoms of sulfur deficiency first appear. P35S::βSRx3:GFP was also upregulated at 2 d after a medium shift from sulfur-sufficient to sulfur-deficient conditions, suggesting that the chimeric promoter is an efficient indicator of sulfur nutritional status. Analysis of transgene expression in a Met-overaccumulating mto1-1 mutation background revealed that the βSR region carries sufficient information for downregulation of promoter activity by Met in developing seeds, but not in young rosettes. Comparisons with another transgenic line, in which the full-length β promoter is active in non-seed tissues, also suggested that at least two separate tissue-specific mechanisms exist for the downregulation of the β promoter by Met.

Item Type:	Journal Article
Publisher:	Oxford University Press
Copyright:	JSPP © 2002
URI:	http://researchrepository.murdoch.edu.au/id/eprint/28511

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