Regulation of developmental senescence is conserved between Arabidopsis and Brassica napus.
SAG12 is a developmentally controlled, senescence-specific gene from Arabidopsis which encodes a cysteine protease. Using SAG12 as a probe, we isolated two SAG12 homologues (BnSAG12-1 and BnSAG12-2) from Brassica napus. Structural comparisons and expression studies indicate that these two genes are orthologues of SAG12. The expression patterns of BnSAG12-1 and BnSAG12-2 in Arabidopsis demonstrate that the senescence-specific regulation of this class of cysteine proteases is conserved across these species. Gel-shift assays using the essential promoter regions of SAG12, BnSAG12-1, and BnSAG12-2 show that the extent of binding of a senescence-specific, DNA-binding protein from Arabidopsis is proportional to the expression levels of these genes in Arabidopsis. Therefore, the expression levels of these genes may reflect the affinities of the senescence-specific DNA-binding protein for the promoter element.
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Department of Biochemistry, University of Wisconsin, Madison 53706-1544, USA.
Amasino
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D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D001937:Brassica / Q000201:enzymology / Q000235:genetics*; D003546:Cysteine Endopeptidases / Q000235:genetics*; D018744:DNA, Plant; D004268:DNA-Binding Proteins / Q000378:metabolism; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D015698:Genomic Library; D008969:Molecular Sequence Data; D010940:Plant Proteins; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D010940:Plant Proteins; C402082:SAG12 protein, Arabidopsis; D003546:Cysteine Endopeptidases