Identification and Expression Analysis of Anthocyanin Biosynthesis Genes in Zoysia japonica L

Zoysiagrass (Zoysia japonica L.) is commonly found in coastal areas or grasslands and widely used for lawns in temperate climate regions. Z. japonica ‘Greenzoa’ with green stolons and spikes was isolated as an isogenic line of purple colored Z. japonica ‘Jungji’. From HPLC analysis, high levels of cyanidin chloride and petunidin chloride were detected from ‘Jungji’ but not from ‘Greenzoa’, suggesting that a lack of such anthocyanin pigments results in the green color of ‘Greenzoa’. In efforts to elucidate the genetic mechanisms of such differential pigmentation between the two cultivars, we obtained the sequence information of anthocyanin biosynthesis genes from de novo assembled transcriptomes and compared the sequences in two cultivars. A total of 22 anthocyanin biosynthesis genes were identical at the nucleotide level between the two cultivars but several of them were differently expressed at various developmental stages of spike. Especially, ZjDFR1 and ZjANS2 in the later steps of the anthocyanin biosynthesis pathway were significantly downregulated in ‘Greenzoa’ consistent with the lack of anthocyanin. The data strongly suggest that different anthocyanin accumulation in ‘Jungji’ and ‘Greenzoa’ is caused by different expression of anthocyanin biosynthesis genes.