| RRC ID |
3965
|
| 著者 |
Michaelson LV, Zäuner S, Markham JE, Haslam RP, Desikan R, Mugford S, Albrecht S, Warnecke D, Sperling P, Heinz E, Napier JA.
|
| タイトル |
Functional characterization of a higher plant sphingolipid Delta4-desaturase: defining the role of sphingosine and sphingosine-1-phosphate in Arabidopsis.
|
| ジャーナル |
Plant Physiol
|
| Abstract |
The role of Delta4-unsaturated sphingolipid long-chain bases such as sphingosine was investigated in Arabidopsis (Arabidopsis thaliana). Identification and functional characterization of the sole Arabidopsis ortholog of the sphingolipid Delta4-desaturase was achieved by heterologous expression in Pichia pastoris. A P. pastoris mutant disrupted in the endogenous sphingolipid Delta4-desaturase gene was unable to synthesize glucosylceramides. Synthesis of glucosylceramides was restored by the expression of Arabidopsis gene At4g04930, and these sphingolipids were shown to contain Delta4-unsaturated long-chain bases, confirming that this open reading frame encodes the sphingolipid Delta4-desaturase. At4g04930 has a very restricted expression pattern, transcripts only being detected in pollen and floral tissues. Arabidopsis insertion mutants disrupted in the sphingolipid Delta4-desaturase At4g04930 were isolated and found to be phenotypically normal. Sphingolipidomic profiling of a T-DNA insertion mutant indicated the absence of Delta4-unsaturated sphingolipids in floral tissue, also resulting in the reduced accumulation of glucosylceramides. No difference in the response to drought or water loss was observed between wild-type plants and insertion mutants disrupted in the sphingolipid Delta4-desaturase At4g04930, nor was any difference observed in stomatal closure after treatment with abscisic acid. No differences in pollen viability between wild-type plants and insertion mutants were detected. Based on these observations, it seems unlikely that Delta4-unsaturated sphingolipids and their metabolites such as sphingosine-1-phosphate play a significant role in Arabidopsis growth and development. However, Delta4-unsaturated ceramides may play a previously unrecognized role in the channeling of substrates for the synthesis of glucosylceramides.
|
| 巻・号 |
149(1)
|
| ページ |
487-98
|
| 公開日 |
2009-1-1
|
| DOI |
10.1104/pp.108.129411
|
| PII |
pp.108.129411
|
| PMID |
18978071
|
| PMC |
PMC2613699
|
| MeSH |
Arabidopsis / enzymology*
Arabidopsis / genetics
Arabidopsis / growth & development
Arabidopsis Proteins / genetics
Arabidopsis Proteins / metabolism*
Cloning, Molecular
DNA, Bacterial / genetics
Gene Expression Regulation, Plant
Glucosylceramides / biosynthesis
Lysophospholipids / metabolism*
Mutagenesis, Insertional
Open Reading Frames
Oxidoreductases / genetics
Oxidoreductases / metabolism*
Phylogeny
Pichia / genetics
Sequence Deletion
Sphingosine / analogs & derivatives*
Sphingosine / metabolism
|
| IF |
6.902
|
| 引用数 |
79
|
|
WOS 分野
|
PLANT SCIENCES
|
| リソース情報 |
| シロイヌナズナ / 植物培養細胞・遺伝子 |
pst17972 |
