水稻着丝粒附近一个淡绿叶突变相关基因的定位分析

Identification and Fine Mapping of a Gene Related to Pale Green Leaf near Centromere Region in Rice(Oryza sativa L.)

在T-DNA插入水稻突变体库中,发现了一个以日本晴为遗传背景的温度钝感型淡绿叶突变体pgl2(palegreen leaf 2)。遗传学分析表明该突变性状由1对单隐性核基因控制。利用突变体与籼稻品种龙特甫杂交,构建F2群体对突变基因进行精细定位。初步定位结果显示目的基因与第8染色体上SSR标记RM331连锁,在该标记附近发展了14对INDEL标记,将突变基因进一步定位于着丝粒上2.37 Mb的区间,并对该区间候选基因进行了分析。突变体叶绿素的总量与对照相仿,但是叶绿素a/b比值趋于1,明显低于对照。推测突变基因可能与叶绿素a、b间的转化有关。还就着丝粒中基因定位的引物设计方法进行了讨论。

A thermo-insensitive pale green leaf mutant （pgl2） was isolated from T-DNA inserted transgenic lines of rice （Oryza sativa L. subsp, japonica cv. Nipponbare）. Genetic analysis indicated that the phenotype was controlled by a recessive mutation in a single nuclear-encoded gene. To map the PGL2 gene, an F2 population was constructed by crossing the mutant with Longtefu （Oryza sativa L. subsp, indica）. The PGL2 locus was roughly linked to SSR marker RM331 on chromosome 8. Therefore, 14 new INDEL markers were developed around the marker. PGL2 gene was further mapped to a 2.37 Mb centromeric region. There was no obvious difference between the mutant and wild type in total chlorophyll content of rice leaves, while the ratio of Chl a/Chl b in the mutant was only about 1, distinctly lower than that in the control, which suggested that the PGL2 gene was related to the transformation between Chl a and Chl b. Moreover, the method of primer design around the centromeric region was discussed, which would provide insight into fine mapping the functional genes in plant eentromeres.