Expression analysis of different β-carotenoid hydroxylase gene families in stress response in Dunaliella viridis

: β-carotenoid hydroxylase (CHYB) is an important rate-limiting enzyme in the biosynthesis of plant carotenoid. In this study, chyb1 and chyb2, two gene families in Dunaliella viridis were obtained by RNA-seq. The fragment of promoters of CHYB family genes, 1 080 bp for chyb1 (GenBank No. KY012338) and 1 155 bp for chyb2 (GenBank No. KY012339) were cloned by the Genome Walking Technology, respectively. Cis-acting elements of two promoters were analyzed by Plantcare soft. The results show that the chyb1 gene promoter contains more cis-acting elements in responses to abiotic stresses, such as methyl jasmonate, arachidonic acid, acetylsalicylic acid, and so on. On the other hand, the chyb2 promoter contains more cis-acting elements in response to light stress. qRT-PCR results show that the mRNA expression levels of CHYBs are modulated by their promoters, and different CHYB gene families response to distinct stresses.