We investigated the molecular mechanisms underlying the pigmentation patterns of the dorsal petals in torenia (Torenia fournieri Lind. ex Fourn.) cultivars. ‘Piccolo Mix’ consists of lines exhibiting different pigmentation patterns in the limb of the dorsal petal, i.e., entirely pigmented (all-pigmented line), picotee with a pigmented margin (half-pigmented line), and entirely pale (pale line). In the all- and half-pigmented lines, expression of T. fournieri CYCLOIDEA2 (TfCYC2), which is involved in dorsal–ventral floral asymmetry, was inhibited by integration of Ty1/Copia-like LTR retrotransposon TORE2 into the exon of TfCYC2 (TfCYC2^TORE2). The all-pigmented line was homozygotic for TfCYC2^TORE2, while the pale line was homozygotic normal-type TfCYC2 (TfCYC2⁺). The half-pigmented line was heterozygotic TfCYC2^TORE2/TfCYC2⁺. Therefore, the extent of pigmentation of the dorsal petal is negatively correlated with the gene dosage of TfCYC2⁺. Further, ‘Crown Violet’, another torenia cultivar exhibiting the same pigmentation pattern as the all-pigmented line of ‘Piccolo Mix’, was also homozygotic for TfCYC2^TORE2. These results indicate that TfCYC2^TORE2 is responsible for the marked enrichment of flower pigmentation patterns seen in torenia cultivars.

我们调查了肾上腺（Torenia fournieri Lind。ex Fourn。）品种背花瓣色素沉着模式的分子机制。“ Piccolo混合物”由在背瓣的肢体中表现出不同色素沉着模式的线条组成，即完全着色（全色素线条），皮库特边缘有色素边缘（半色素线条）和完全苍白（苍白线条）。在全色素和半色素细胞系中，Ty1 / Copia样LTR反转录转座子TORE2整合到TfCYC2（TfCYC2）的外显子中抑制了T.fournieri CYCLOIDEA2（TfCYC2）的表达，该表达参与背-侧花不对称。^TORE2）。TfCYC2 ^TORE2的全色素系是纯合的，而淡色系是正常型的TfCYC2（TfCYC2 ⁺）纯合的。半色素系是杂合的TfCYC2 ^TORE2 / TfCYC2 ⁺。因此，背瓣的色素沉着程度与TfCYC2 ⁺的基因剂量呈负相关。此外，另一种表现出与“ Piccolo Mix”的全色素系相同的色素沉着模式的鸟^冠花品种“ Crown Violet”对于TfCYC2 ^TORE2也是纯合的。这些结果表明TfCYC2 ^TORE2 导致了在Torenia品种中看到的花朵色素沉着模式的显着富集。