近日,日本筑波大学科学家利用基因编辑技术创造了一种新的花色牵牛花新品种:黄色牵牛花。在自然界中经过多年的培育,牵牛花有红色、桃色、紫色和白色品种,唯独没有黄色品种。日本研究人员通过分析牵牛花的花瓣花色形成机理,利用CRISPR/Cas9系统在白色牵牛花AK77品种中敲除了InCCD4基因,增加类胡萝卜素、橙酮等能够形成黄色色素的物质,最终获得了使其白色花瓣变成了黄色花瓣的牵牛花。花色基因编辑牵牛花与非转基因植株相比,ccd4突变植株中类胡萝卜素的含量增加了20倍。
该研究解释了牵牛花没有黄色品种的原因,也表明了通过生物技术手段培育黄色牵牛花的可行性。同时,该研究也为其它在自然界中花卉品种花色改良提供思路。
对照(白色) 黄色牵牛花 黄色牵牛花
文章信息:
Kenta Watanabe, Chihiro Oda-Yamamizo, Kimiyo Sage-Ono, Akemi Ohmiya, Michiyuki Ono; Alteration of flower colour in Ipomoea nil through CRISPR/Cas9- mediated mutagenesis of carotenoid cleavage dioxygenase 4;Transgenic Research, 15 December 2017
Abstract
Japanese morning glory, Ipomoea nil, exhibits a variety of flower colours, except yellow, reflecting the accumulation of only trace amounts of carotenoids in the petals. In a previous study, we attributed this effect to the low expression levels of carotenogenic genes in the petals, but there may be other contributing factors. In the present study, we investigated the possible involvement of carotenoid cleavage dioxygenase (CCD), which cleaves specific double bonds of the polyene chains of carotenoids, in the regulation of carotenoid accumulation in the petals of I. nil. Using bioinformatics analysis, sevenInCCD genes were identified in the I. nil genome. Sequencing and expression analyses indicated potential involvement of InCCD4 in carotenoid degradation in the petals. Successful knockout ofInCCD4 using the CRISPR/Cas9 system in the white-flowered cultivar I. nil cv. AK77 caused the white petals to turn pale yellow. The total amount of carotenoids in the petals of ccd4 plants was increased 20-fold relative to non-transgenic plants. This result indicates that in the petals of I. nil, not only low carotenogenic gene expression but also carotenoid degradation leads to extremely low levels of carotenoids.