Cloning and Functional Analysis of a Zeaxanthin Epoxidase Gene in .

The xanthophyll cycle is a photoprotective mechanism in plants and algae, which protects the photosynthetic system from excess light damage under abiotic stress. Zeaxanthin is considered to play a pivotal role in this process. In this study, the relative content of xanthophylls was determined using HPLC-MS/MS in exposed to different salinities. The results showed that high-salt stress significantly increased the relative content of xanthophylls and led to the accumulation of zeaxanthin. It was speculated that the accumulated zeaxanthin may contribute to the response of to high-salt stress. Zeaxanthin epoxidase () is a key enzyme in the xanthophyll cycle and is also involved in the synthesis of abscisic acid and carotenoids. In order to explore the biological function of , a gene was cloned and identified from . The CDS of is 1122 bp and encodes 373 amino acids. Phylogenetic analysis showed that clusters within a clade of green algae. The results of qRT-PCR showed that high-salt stress induced the expression of . In addition, heterologous overexpression of the gene in yeast and improved the salt tolerance of transgenic organisms. In conclusion, the gene may be involved in the response of to high-salt stress and can improve the high-salt tolerance of transgenic organisms.