Toward the amyloplast engineering in rice

在用MNU处理受精卵细胞时，90%以上的突变是GC向AT的转变。MNU处理的突变频率为每1kb 6~9个碱基，因此，如果建立约3000个突变系，预计它们至少涵盖水稻基因组中每个基因的4个突变，即它们是饱和突变体库。建立了TILLING结合MNU突变体文库和改良提取缓冲液的SDS-PAGE筛选方法，分离并鉴定了PHO1和FlO2等与淀粉生物合成和淀粉质工程相关的关键新基因。利用MNU处理产生的突变体进行遗传图谱分析，对于系统开发水稻淀粉新遗传资源，建立水稻淀粉新性状育种方法具有重要意义。

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.