Imamura Tomohiro, Takagi Hiroki, Miyazato Akio, Ohki Shinya, Mizukoshi Hiroharu, Mori Masashi
Ishikawa Prefectural University, Nonoichi, Ishikawa, 921-8836, Japan.
Ishikawa Prefectural University, Nonoichi, Ishikawa, 921-8836, Japan.
Biochem Biophys Res Commun. 2018 Feb 5;496(2):280-286. doi: 10.1016/j.bbrc.2018.01.041. Epub 2018 Jan 6.
In quinoa seedlings, the pigment betalain accumulates in the hypocotyl. To isolate the genes involved in betalain biosynthesis in the hypocotyl, we performed ethyl methanesulfonate (EMS) mutagenesis on the CQ127 variety of quinoa seedlings. While putative amaranthin and celosianin II primarily accumulate in the hypocotyls, this process produced a green hypocotyl mutant (ghy). This MutMap+ method using the quinoa draft genome revealed that the causative gene of the mutant is CqCYP76AD1-1. Our results indicated that the expression of CqCYP76AD1-1 was light-dependent. In addition, the transient expression of CqCYP76AD1-1 in Nicotiana benthamiana leaves resulted in the accumulation of betanin but not isobetanin, and the presence of a polymorphism in CqCYP76A1-2 in the CQ127 variety was shown to have resulted in its loss of function. These findings suggested that CqCYP76AD1-1 is involved in betalain biosynthesis during the hypocotyl pigmentation process in quinoa. To our knowledge, CqCYP76AD1-1 is the first quinoa gene identified by EMS mutagenesis using a draft gene sequence.
在藜麦幼苗中，色素甜菜红素积累于下胚轴。为了分离参与下胚轴中甜菜红素生物合成的基因，我们对CQ127品种的藜麦幼苗进行了甲磺酸乙酯（EMS）诱变。虽然假定的苋红素和鸡冠花色素II主要积累于下胚轴，但这一过程产生了一个绿色下胚轴突变体（ghy）。使用藜草图基因组的这种MutMap +方法表明，该突变体的致病基因是CqCYP76AD1-1。我们的结果表明，CqCYP76AD1-1的表达是光依赖性的。此外，CqCYP76AD1-1在本氏烟草叶片中的瞬时表达导致了甜菜红苷而非异甜菜红苷的积累，并且已证明CQ127品种中CqCYP76A1-2存在多态性导致其功能丧失。这些发现表明，CqCYP76AD1-1参与了藜麦下胚轴色素沉着过程中的甜菜红素生物合成。据我们所知，CqCYP76AD1-1是通过使用草图基因序列的EMS诱变鉴定出的第一个藜麦基因。
