利用转录组测序鉴定玉米白色籽粒突变基因PDS

Identification of PDS for white kernels in maize via RNA-seq

为探讨转录组测序在玉米质量性状基因克隆上的应用,以玉米自交系B73籽粒表现为白色的EMS突变体为材料,对该突变体授粉后15 d的籽粒进行转录组分析。通过与玉米B73参考基因组序列的比对分析,共鉴定到138个突变位点,其中51个突变位点对基因的功能有显著影响。通过基因功能注释与分类,发现该突变体在类胡萝卜素合成途径中的八氢番茄红素去饱和酶基因(PDS)发生无义突变,导致PDS蛋白翻译提前终止,阻断类胡萝卜素代谢途径中有色体番茄红素的生物合成,造成玉米籽粒白化。这些结果表明利用转录组测序技术能够快速准确地鉴定玉米EMS突变体的突变基因。

To verify the possibilities of RNA-seq in cloning qualitative genes in maize,here,an ethyl methane sulfonate(EMS)-induced mutant for white kernels in maize with B73 background are taken as study material.A total of 138 mutant sites are identified in the developing kernels 15 d after pollination of the EMS mutant,and 36.96%(51/138)of these sites have high/moderate effects on these genes functions.Among which,a stop gained pds mutant was identified and confirmed by resequencing.PDS encodes a phytoene desaturase,which functions in the upstream of carotenoids biosynthesis.The results in the blocked biosynthesis of maize kernel carotenoids,which leads to the white kernels.The results indicate that RNA-seq is really an accurate and time saving way to identify the EMS-induced mutant genes in maize.