粉质胚乳突变体3901l来源于美国种质中心，该突变体胚乳呈现完全不透明表型。生化分析发现，该突变体α-和β-醇溶蛋白剧烈下降，同时伴随着非醇溶蛋白的大幅度升高。通过玉米SNP3072芯片进行基因分型分析发现，3901l基因定位于7号染色体约33 M的区间。通过与o2突变体进行等位测试，确认3901l是o2的等位突变体。进一步研究表明，该突变体的O2转录本缺失了一个61-bp的外显子，造成开放阅读框移码和翻译提前终止。利用O2特异抗体检测子粒总蛋白，发现突变体中O2蛋白完全缺失，不能检测到提前终止的O2蛋白，说明错误翻译的O2蛋白被机体快速识别并降解。

An opaque mutant 3901 of maize, obtained from the Maize Genetics Cooperation Stock Center, USA, showed completely non-transparency endosperm. Biochemical analysis showed that the α- and β-zein in mutant 3901 was drastically decreased, while the non-zein significantly increased. Through the analysis of maize SNP3072 genotyping array, the mutant gene 3901l was mapped to a 33-Mb interval on chromosome 7. Further, the allelism test of opaque2(o2) and 3901l indicated that 3901l is a new mutant allele of o2, in the O2 transcript of which a 61-bp exon was lost, causing frame-shift of O2 open reading frame and an early termination of O2 protein translation. Also through the total protein detection using O2-specific antibody, we found that O2 protein is completely lost in the kernel of mutant 3901 and no early terminated O2 protein was detected, which indicated that the O2 protein was degraded rapidly in 3091. Thus, a new o2 mutant allele was indentified.

国家“十三五”重点研发项目（2016YFD0101003）