Transcriptome profiling of sulfur-responsive genes in Arabidopsis reveals global effects of sulfur nutrition on multiple metabolic pathways.
Sulfate is a macronutrient required for cell growth and development. Arabidopsis has two high-affinity sulfate transporters (SULTR1;1 and SULTR1;2) that represent the sulfate uptake activities at the root surface. Sulfur limitation (-S) response relevant to the function of SULTR1;2 was elucidated in this study. We have isolated a novel T-DNA insertion allele defective in the SULTR1;2 sulfate transporter. This mutant, sel1-10, is allelic with the sel1 mutants identified previously in a screen for increased tolerance to selenate, a toxic analog of sulfate (Shibagaki et al., 2002). The abundance of SULTR1;1 mRNA was significantly increased in the sel1-10 mutant; however, this compensatory up-regulation of SULTR1;1 was not sufficient to restore the growth. The sulfate content of the mutant was 10% to 20% of the wild type, suggesting that induction of SULTR1;1 is not fully complementing the function of SULTR1;2 and that SULTR1;2 serves as the major facilitator for the acquisition of sulfate in Arabidopsis roots. Transcriptome analysis of approximately 8,000 Arabidopsis genes in the sel1-10 mutant suggested that dysfunction of the SULTR1;2 transporter can mimic general -S symptoms. Hierarchal clustering of sulfur responsive genes in the wild type and mutant indicated that sulfate uptake, reductive sulfur assimilation, and turnover of secondary sulfur metabolites are activated under -S. The profiles of -S-responsive genes further suggested induction of genes that may alleviate oxidative damage and generation of reactive oxygen species caused by shortage of glutathione.
Maruyama-Nakashita
Akiko
A
RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
Inoue
Eri
E
Watanabe-Takahashi
Akiko
A
Yamaya
Tomoyuki
T
Takahashi
Hideki
H
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D026901:Membrane Transport Proteins; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000076988:Sulfate Transporters; D013455:Sulfur / Q000378:metabolism*; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D026901:Membrane Transport Proteins; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D013455:Sulfur