Zhou Ping, Jiang Huiyan, Li Jingwen, He Xinrui, Jin Qijiang, Wang Yanjie, Xu Yingchun
Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China; Sanya Research Institute of Nanjing Agricultural University, Sanya 572000, China; College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China.
Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China; Sanya Research Institute of Nanjing Agricultural University, Sanya 572000, China.
Int J Biol Macromol. 2024 Dec;283(Pt 4):137724. doi: 10.1016/j.ijbiomac.2024.137724. Epub 2024 Nov 23.
Yellow tepal is a unique trait of the American lotus (Nelumbo lutea), and all yellow lotus cultivars in the market possess genetic material from the American lotus. However, the formation of yellow tepals in lotus and the genetic mechanism of their formation remain unclear. In this study, we identified a transposon DNA/hAT-Ac, located within the promoter region of an R2R3-MYB transcription factor, MYB12, by comparing the insertion patterns of transposons in the genomes of American and Asian lotus (Nelumbo nucifera). The transposon was found exclusively in yellow lotus cultivars and not in red or white lotus. The insertion of DNA/hAT-Ac facilitated the specific expression of MYB12 in the yellow lotus tepals. Transient expression in lotus tepals, dual-luciferase, and yeast one-hybrid assays demonstrated that MYB12 promotes the accumulation of carotenoids and flavonols by activating the expression of genes involved in carotenoid and flavonols biosynthesis, and it directly binds to the promoters of PSY and FLS. Our results indicated that the transposon DNA/hAT-Ac-mediated specific expression of MYB12 is crucial for the formation of yellow tepals in lotus, and the findings provide a theoretical basis for the breeding of yellow lotus cultivars.
黄色花瓣是美洲莲（Nelumbo lutea）的一个独特性状，市场上所有黄色莲花品种都含有来自美洲莲的遗传物质。然而，莲花中黄色花瓣的形成及其形成的遗传机制仍不清楚。在本研究中，我们通过比较美洲莲和亚洲莲（Nelumbo nucifera）基因组中转座子的插入模式，鉴定出一个位于R2R3-MYB转录因子MYB12启动子区域内的转座子DNA/hAT-Ac。该转座子仅在黄色莲花品种中发现，而在红色或白色莲花中未发现。DNA/hAT-Ac的插入促进了MYB12在黄色莲花花瓣中的特异性表达。莲花花瓣中的瞬时表达、双荧光素酶和酵母单杂交试验表明，MYB12通过激活参与类胡萝卜素和黄酮醇生物合成的基因的表达来促进类胡萝卜素和黄酮醇的积累，并且它直接与PSY和FLS的启动子结合。我们的结果表明，转座子DNA/hAT-Ac介导的MYB12特异性表达对于莲花黄色花瓣的形成至关重要，这些发现为黄色莲花品种的育种提供了理论基础。
