Toward the amyloplast engineering in rice

在MNU处理的受精卵细胞中，90%以上的突变是GC到AT的转变。在MNU处理下，突变频率为每1kb 6 ~ 9个碱基，因此，如果建立约3000个突变系，预计它们将覆盖水稻基因组中每个基因至少4个突变，即它们是饱和突变文库。我们建立了TILLING结合MNU突变体文库和SDS-PAGE修饰萃取缓冲液的有效筛选方法，并通过这些方法分离和表征了PHO1和FLO2等参与淀粉生物合成和淀粉质体工程的关键新基因。利用MNU处理诱导的突变体进行基因分析，有利于淀粉新遗传资源的系统开发和水稻淀粉新性状设计育种方法的建立。

More than 90% of mutations were GC to AT transition in the treatment of fertilized egg cells with MNU. The mutation frequency on the MNU treatment was 6 to 9 bases per 1kb, and thus if about three thousand mutant line is established, it will be expected that they cover at least four mutations for each of genes in rice genome, that is, they are the saturation mutant library. We established the effective screening methods using TILLING combined with the MNU mutant library and SDS-PAGE with modified extraction buffer, and some of key novel genes involving in starch biosynthesis and amyloplast engineering like as PHO1 and FLO2 were isolated and characterized by these methods. The profiling using the mutants induced by MNU treatment is effective to the systematic development of the novel genetic resources for starch and to the establishment of designed breeding method for novel starch properties in rice.