Identification of genes for enzymes involved in betalain biosynthesis and expression analysis in non-Dianthus plants.

为了阐明包括β蛋白酶合成在内的未识别酶，我们利用RNA-seq对4点钟的萼片进行了分析。鉴定了酪氨酸合成L-DOPA酶的9个候选cdna，该酶是甜菜蛋白酶合成的第一步关键酶。其中CYP76AD3的基因组结构与来源于红甜菜的CYP76AD1同源。在带有红色区或黄色背景点的杂色萼片CYP76AD3基因中，CACTA转座元件dTmj1插入到CYP76AD3基因的内含子中，干扰其转录，从而阻止CYP76AD3活性的表达或红β青素的合成，而合成黄色β青素。dTmj1在这种杂色萼片中的运动导致基因活性恢复，β花青素的合成恢复，在黄色背景上产生红色区域或点。

In order to elucidate the unidentified enzymes including betalain synthesis, the sepals of four o'clock were analyzed by RNA-seq. Nine candidate cDNAs for the enzyme catalyzing tyrosine to L-DOPA, which was the first key step enzyme of betalain synthesis, were identified. The genomic structure of one of them, CYP76AD3, which was homolog of CYP76AD1 derived from red beet, was revealed. In the CYP76AD3 gene of variegated sepals with red sectors or dots on a yellow background, CACTA transposable element, dTmj1, was inserted in the intron of CYP76AD3 gene to disturb its transcription, resulting to prevent the expression of CYP76AD3 activity or red betacyanin synthesis, but to synthesize yellow betaxanthins. The movement of dTmj1 in this variegated sepals caused to revert the gene activity and the synthesis of betacyanin revived to generate red sectors or dots on a yellow background.