Differential tissue-specific response to sulfate and methionine of a soybean seed storage protein promoter region in transgenic Arabidopsis.
Expression of the gene encoding the beta subunit of beta-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 (beta(SR)) from the beta 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 beta(SR) element, referred to as the P35S::beta(SR)x3: GFP transgene. Upregulation of P35S::beta(SR)x3:GFP by sulfur deficiency was strongest in leaf margins, where symptoms of sulfur deficiency first appear. P35S::beta(SR)x3: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 beta(SR) 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 beta promoter is active in non-seed tissues, also suggested that at least two separate tissue-specific mechanisms exist for the downregulation of the beta promoter by Met.
Ohkama
Naoko
N
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan.
Goto
Derek B
DB
Fujiwara
Toru
T
Naito
Satoshi
S
D052179:Antigens, Plant; D017360:Arabidopsis / Q000235:genetics*; D017796:Caulimovirus / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017930:Genes, Reporter / Q000187:drug effects / Q000235:genetics; D005916:Globulins / Q000187:drug effects / Q000235:genetics*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008715:Methionine / Q000494:pharmacology*; D009154:Mutation; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D055314:Seed Storage Proteins; D012639:Seeds / Q000187:drug effects / Q000235:genetics; D030262:Soybean Proteins / Q000187:drug effects / Q000235:genetics*; D013025:Glycine max / Q000187:drug effects / Q000235:genetics; D013379:Substrate Specificity; D013431:Sulfates / Q000494:pharmacology*
D052179:Antigens, Plant; D005916:Globulins; D008164:Luminescent Proteins; D055314:Seed Storage Proteins; D030262:Soybean Proteins; D013431:Sulfates; C013894:beta-conglycinin protein, Glycine max; D049452:Green Fluorescent Proteins; D008715:Methionine