An Arabidopsis mutant resistant to thaxtomin A, a cellulose synthesis inhibitor from Streptomyces species.
Thaxtomin A is a phytotoxin produced by Streptomyces scabies and other Streptomyces species, the causative agents of common scab disease in potato and other taproot crops. At nanomolar concentrations, thaxtomin causes dramatic cell swelling, reduced seedling growth, and inhibition of cellulose synthesis in Arabidopsis. We identified a mutant of Arabidopsis, designated txr1, that exhibits increased resistance to thaxtomin as a result of a decrease in the rate of toxin uptake. The TXR1 gene was identified by map-based cloning and found to encode a novel, small protein with no apparent motifs or organelle-targeting signals. The protein, which has homologs in all fully sequenced eukaryotic genomes, is expressed in all tissues and during all developmental stages analyzed. Microarray transcript profiling of some 14,300 genes revealed two stomatin-like genes that were expressed differentially in the txr1 mutant and the wild type. We propose that TXR1 is a regulator of a transport mechanism.
Scheible
Wolf-Rüdiger
WR
Max Planck Institute of Molecular Plant Physiology, 14476 Golm, Germany. scheible@mpimp-golm.mpg.de
Fry
Barbara
B
Kochevenko
Andrej
A
Schindelasch
Dana
D
Zimmerli
Laurent
L
Somerville
Shauna
S
Loria
Rosemary
R
Somerville
Chris R
CR
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001693:Biological Transport, Active / Q000235:genetics; D002482:Cellulose / Q000096:biosynthesis; D018744:DNA, Plant / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007211:Indoles / Q000302:isolation & purification / Q000493:pharmacokinetics / Q000633:toxicity*; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D010879:Piperazines / Q000302:isolation & purification / Q000493:pharmacokinetics / Q000633:toxicity*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000737:chemistry / Q000472:pathogenicity
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D007211:Indoles; D010879:Piperazines; D011993:Recombinant Fusion Proteins; C406691:thaxtomine A; D002482:Cellulose