| Carotenois are a large group of natural products that are most formally built from isoprenic unit. Those kinds of compounds are biosynthesized by some bacterium, fungi, and plants. Carotenois mainly consist of two large groups: carotenes and its oxidative derivatives(xanthophylls). Many of these carotenois are closely related to human health, especially theβ-carotene and lycopene are very important to the development of eyes, prohibiting cancers and elevating immunity. They are synthesized through part of the isoprenoids pathway. In higher plant their biosynthesis pathway includes two :one is MVA pathway,the other is MEP pathway.ζ-catotene desaturase(ZDS) is a importanr enzyme that controls the biosynthesis ofβ-carotene upstream. It catalyses the conversion of 9,9,-di-ζ-catotene to 7,9,7,9,-tetra-lycopene.In this work, reverse transcription-PCR (RT-PCR) and rapid amplification of cDNA ends (RACE) techniques had been applied to clone the total open reading frame of the zds gene using wheat (Triticum aestivum) leaves as the target material. The full-length of open reading frame is 1,707 bp and encodes a peptide containing 568 amino acid residues, with a theoretical molecular weight of 62.5 kDa, an isoelectric point of 6.80 and an amino oxidase domain at its N-terminal. Secondary structure prediction reveals thatα-helix and random coil are the main structural conformations in ZDS protein. Through sequence analysis by BlastN online, the wheat zds nucleiotide sequence showed highly homologous to the genes which are from other plant species. The homology that compared with Oryza sativa, Zea mays, Arabidopsis thaliana, Daucus carota were 92%, 93%, 83% and 88% respectively. The phylogenetic tree showed that wheat ZDS was closely related to rice ZDS and maize ZDS.The cloning and analysis of wheat zds gene has layed a good basis for research on functional expression and potential application in improving the nutrition value of wheat through genetic engeering.
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