AtMRD1 and AtMRU1, two novel genes with altered mRNA levels in the methionine over-accumulating mto1-1 mutant of Arabidopsis thaliana.
The mto1-1 mutant of Arabidopsis thaliana over-accumulates soluble methionine (Met) up to 40-fold higher than that in its Col-0 wild type. In order to identify genes regulated by altered Met concentrations, microarray analysis of gene expression in young rosettes and developing siliques of the mto1-1 mutant were performed. Expression of selected genes was then examined in detail in three developmental stages of the mto1-1 mutant using a combination of Northern hybridisation analysis and real-time PCR. Eight genes were identified that had altered mRNA accumulation levels in the mto1-1 mutant compared to that in wild-type plants. Three of the genes have known roles in plant development unrelated to amino acid biosynthesis. One other gene up-regulated specifically in mto1-1 rosettes shared similarity with the embryo-specific protein 3 (ATS3). Two novel genes, referred to as AtMRD1 and AtMRU1, were also identified that were expressed in a developmental manner in wild-type Col-0 and do not share sequence similarity with genes of known function. AtMRD1 was strongly down-regulated in both rosette and young silique tissues of the mto1-1 mutant. AtMRU1 was up-regulated approximately 3-fold in young mto1-1 rosettes and exhibited a developmental response to the mto1-1 mutation.
Laboratory of Molecular Biology, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan.
Derek B
DB
Goto
Satoshi
S
Naito
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D015152:Blotting, Northern; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D008715:Methionine / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D014995:Xylosidases / Q000235:genetics / Q000378:metabolism
C119827:ATS proteins, Arabidopsis; D029681:Arabidopsis Proteins; D012333:RNA, Messenger; D008715:Methionine; D014995:Xylosidases; C026579:exo-1,4-beta-D-xylosidase