Abstract
The β subunit gene of soybean β-conglicinin of has been shown to be upregulated by sulfur deficiency at the level of transcription. Insertion of the 235 bp-sulfur responsive promoter region of this gene into cauliflower mosaic virus 35S promoter enabled us to observe response to sulfur in non-seed tissues (Awazuhara et al. 2002). In transgenic Arabidopsis NOB plants carrying this chimeric promoter fused with GFP gene, GFP fluorescence was increased by sulfur deficiency (Ohkama et al. 2002). We screened mutants with altered GFP fluorescence from M2 plants of EMS-mutagenized NOB plants.
nbm1-1 (NOB mutant) shows higher GFP fluorescence than parental NOB plants irrespective of sulfur condition. Expression of Sultr2;2, APR1. SAT1, endogenous sulfur-responsive genes, were also upregulated. genetic mapping located the nbm1-1 locus in upper arm of Chromosome 5. Awazuhara et al. (2002) Plant Sci. 163: 75-82, Ohkama et al. (2002) Plant Cell Physiol. 43: 1266-1275
