Synthetic Regulation Of Zeaxanthin In Marigold

Zeaxanthin is natural carotenoid,mainly used as health care product.It plays an important role in preventing age-related macular degeneration(the main cause of blindness),cataracts,cardio vascular diseases,and cancer.As zeaxanthin cannot be synthesized in human body,therefore,zeaxanthin meets great demand in the food industry.Zeaxanthin often coexists with lutein in plants,which makes it difficult to be separated from plant materials.At present,zeaxanthin production is still inefficient according to its low accumulation and high purification costs.Marigold is popular ornamental that could produce relative high amounts of zeaxanthin,which leads to marigold as a good resource for obtaining zeaxanthin.Firstly,zeaxanthin epoxidase(ZEP)in zeaxanthin biosynthetic pathways was investigated..Knockout or silencing of the ZEP gene may increase the accumulation level of zeaxanthin.In this study,sequence alignments were performed based on ZEP genes from different species,then conserved regions were found and degenerate primers were designed for ZEP fragment amplification.Total RNA from marigold petals were extracted for c DNA synthesis,and then marigold ZEP partial fragment(named Te ZEP)was successfully cloned.Results indicated that marigold Te ZEP fragment was 1058 bp in length and encoded 352 amino acid residues.The sequence was analyzed from multiple aspects,including phylogenetic tree analysis with other species,and prediction of the physicochemical properties of the amino acids encoded by the Te ZEP gene,possible protein functional domains,and protein tertiary structure prediction.These results would be helpful for further generating transgenic plants with silencing Te ZEP to promote the production of zeacanthin.Meanwhile,applying high quality and effective chemical mutagen ethylmethane sulfonate(EMS)in mutagenizing marigold seeds with different concentration and mutagenesis time has been carried out.The result shows that the most suitable condition for mutagenesis is 1% of EMS for 16 h treatment.The chemical mutagenesis for marigold by EMS provides a variety of mutant object,which providing a good material basis for screening mutant strains with high zeaxanthin accumulation,and develops a new method for possible improving production of zeaxanthin.For rapid examining zeaxanthin amounts from marigold mutants,an effective approach was successfully developed.In summary,we successfully cloned Te ZEP fragment in marigold,which provides sequence information for subsequent possible silencing to improve the accumulation of zeaxanthin.In addition,we established a marigold EMS mutagenesis population to provide plant materials for screening high-zeaxanthin producing mutants.At last,we optimized the conditions for zeaxanthin extraction and rapid amounts determination,which greatly accelerated screening efficiency for obtaining high-zeaxanthin producing mutants..