The genome dynamics and function in higher plants

在I.尼勒岛Purpurea和I. tricolor分别显示红色的花，而它们的野生型花显示蓝色或深紫色的花。我们已经鉴定出这些突变体在编码类黄酮3 '-羟化酶的F3' H基因内携带点突变或转座子插入，所述类黄酮3 '-羟化酶在花青素苷色素生物合成中介导柚皮素和脱氢山奈酚的B环的3'位置的羟基化。野生型I的红紫色芽。没有变化为蓝色开放的花，并且花着色的转变与花表皮细胞的液泡pH的增加相关。在液泡Na+/H+逆向转运蛋白NHX 1基因缺陷的突变体中，液泡碱化仅部分发生，红紫色的芽变成紫色开放的花。我们已经确定了一个新的液泡Na+/H+逆向转运蛋白基因NHX 2，这是一个基因，负责转换红紫色芽紫色开放的花朵，部分增加液泡pH值的情况下，NHX 1的活动。我的黑暗变种人。发现显示红棕色或紫灰色花的Nil缺乏用于花青素苷生物合成的新型糖基化酶UDP-葡萄糖：花青素3-O-葡糖苷-2 ″-O-葡糖基转移酶（3GGT），其介导花青素3-O-葡糖苷的葡糖基化以产生3-O-槐糖苷。通过在3GGT基因的同一位置插入4个突变体，发现所有的dusky突变体都携带4个突变体，并且这些插入引起移码突变。通过同源重组修饰基因（称为基因打靶）是表征基因功能的最直接的方法，并且我们已经成功地通过使用强正负选择可重复地修饰了水稻的Written基因。我们还鉴定了一个新的水稻DNA转座子nDart，它可以用于水稻基因标签。

The spontaneous magenta, pink and fuchsia mutants in I. nil, I. purpurea and I. tricolor exhibit reddish flowers, respectively, while their wild-type flowers display blue or dark purple flowers. We have identified that these mutants carry either point mutations or transposon insertions within the F3'H gene encoding flavonoid 3'-hydroxylase that mediates hydroxylation of the 3' position of the B-ring of naringenin and dehydrokaempferol in anthocyanin pigment biosynthesis. The reddish-purple buds of the wild-type I. nil change into blue open flowers, and the shift in the flower coloration correlates with an increase in the vacuolar pH of the flower epidermal cell. In the mutant deficient in the NHX1 gene for the vacuolar Na+/H+ antiporter, the vacuolar alkalization occurs only partially, and reddish-purple buds become purple open flowers. We have identified a novel vacuolar Na+/H+ antiporter gene NHX2, which is one of the genes responsible for converting reddish-purple buds into purple open flowers by partially increasing vacuolar pH in the absence of the NHX1 activity. The dusky mutants of I. nil displaying reddish-brown or purplish-gray flowers were found to be deficient in a novel glycosylation enzyme for anthocyanin biosynthesis, UDP-glucose : anthocyanidin 3-O-glucoside-2"-O-glucosyltransferase (3GGT), which mediates the glucosylation of anthocyanidin 3-O-glucosides to yield 3-O-sophorosides. All of the dusky mutants examined were shown to carry 4 by insertions at the identical position in the 3GGT gene, and the insertions caused frameshift mutations.Modification of genes through homologousrecombination termed gene targeting is the most direct method to characterize gene function, and we have succeeded in modifying the rice genomic sequence of the Waxy gene reproducibly by using a strong positive-negative selection. We also identified a novel rice DNA transposon, nDart, which can be used for gene tagging in rice.