RRC ID 1866
Author Kurdyukov S, Faust A, Trenkamp S, Bär S, Franke R, Efremova N, Tietjen K, Schreiber L, Saedler H, Yephremov A.
Title Genetic and biochemical evidence for involvement of HOTHEAD in the biosynthesis of long-chain alpha-,omega-dicarboxylic fatty acids and formation of extracellular matrix.
Journal Planta
Abstract In plants, extracellular matrix polymers built from polysaccharides and cuticular lipids have structural and protective functions. The cuticle is found to be ten times thinner in Arabidopsis thaliana (L.) Heynh than in many other plants, and there is evidence that it is unusual in having a high content of alpha-,omega-dicarboxylic fatty acids (FAs) in its polyesters. We designated the new organ fusion mutant hth-12 after it appeared to be allelic to adhesion of calyx edges (ace) and hothead (hth), upon molecular cloning of the gene by transposon tagging. This mutant is deficient in its ability to oxidize long-chain omega-hydroxy FAs to omega-oxo FAs, which results in leaf polyesters in decreased alpha-,omega-dicarboxylic FAs and increased omega-hydroxy FAs. These chemical phenotypes lead to disorder of the cuticle membrane structure in hth-12. ACE/HTH is a single-domain protein showing sequence similarity to long-chain FA omega-alcohol dehydrogenases from Candida species, and we hypothesize that it may catalyze the next step after cytochrome P450 FA omega-hydroxylases in the omega-oxidation pathway. We show that ACE/HTH is specifically expressed in epidermal cells. It appears very likely therefore that the changes in the amount of alpha-,omega-dicarboxylic FAs in hth-12 reflect the different composition of cuticular polyesters. The ACE/HTH gene is also expressed in root epidermal cells which do not form a polyester membrane on the exterior surface, thereby making it possible that the end products of the pathway, alpha-,omega-dicarboxylic FAs, are generally required for the cross-linking that ensures the integrity of the outer epidermal cell wall.
Volume 224(2)
Pages 315-29
Published 2006-7
DOI 10.1007/s00425-005-0215-7
PMID 16404574
MeSH Alleles Amino Acid Sequence Arabidopsis / metabolism* Arabidopsis / ultrastructure Arabidopsis Proteins / chemistry Arabidopsis Proteins / genetics* Arabidopsis Proteins / metabolism* Base Sequence Cell Wall / metabolism Cloning, Molecular DNA Transposable Elements / genetics Dicarboxylic Acids / analysis Dicarboxylic Acids / chemistry Dicarboxylic Acids / metabolism* Extracellular Matrix / metabolism* Fatty Acids / analysis Fatty Acids / biosynthesis* Fatty Acids / chemistry Flowers / cytology Flowers / ultrastructure Lipids Molecular Sequence Data Mutation / genetics Oxidation-Reduction Phenotype Phylogeny Plant Epidermis / ultrastructure RNA, Messenger / genetics RNA, Messenger / metabolism
IF 3.06
Times Cited 85
Arabidopsis / Cultured plant cells, genes pda05706