Maize Center, Department of Crop Genetics and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
Planta. 2012 Jan;235(1):205-15. doi: 10.1007/s00425-011-1491-z. Epub 2011 Aug 26.
The recessive mutant allele of the opaque2 gene (o2) alters the endosperm protein pattern and increases the kernel lysine content of maize (Zea mays L.). In this study, sequencing results showed that the o2 mutant was successfully introgressed into 12 elite normal maize inbred lines by marker assisted selection (MAS). The average genetic similarity between these normal inbred lines and their o2 near-isogenic lines (NILs) was more than 95%. Kernel lysine content increased significantly in most of o2 NILs lines relative to normal elite inbreds, but remained unchanged in the genetic backgrounds Dan598o2 and Liao2345o2. Moreover, the kernel characteristics of these two o2 NILs did not differ from the other inbred lines. The results of lysine content analysis in the F1 hybrids between Liao2345o2 and Dan598o2 and other o2 NILs demonstrated that gene(s) other than opaque2 may control kernel lysine content in these two o2 NILs. The results of zein analysis showed that 22-kD α-zein synthesis was reduced or absent, and the 19-kD α-zein synthesis was greatly reduced compared with the recurrent parents in most o2 NILs except for Dan598o2 and Liao2345o2. Our results indicate that gene(s) other than opaque2 may play more important roles in zein synthesis and kernel lysine content in some maize genetic backgrounds.
隐性突变等位基因 opaque2（o2）改变了玉米胚乳蛋白模式，并增加了玉米（Zea mays L.）的籽粒赖氨酸含量。在这项研究中，测序结果表明，o2 突变体已通过标记辅助选择（MAS）成功导入 12 个优秀的普通玉米自交系。这些普通自交系与其 o2 近等基因系（NILs）之间的平均遗传相似性大于 95%。与普通优良自交系相比，大多数 o2 NILs 系的籽粒赖氨酸含量显著增加，但在遗传背景 Dan598o2 和 Liao2345o2 中没有变化。此外，这两个 o2 NILs 的籽粒特性与其他自交系没有区别。Liao2345o2 和 Dan598o2 与其他 o2 NILs 之间的 F1 杂种的赖氨酸含量分析结果表明，除了 opaque2 基因外，可能还有其他基因控制这两个 o2 NILs 的籽粒赖氨酸含量。醇溶蛋白分析结果表明，除了 Dan598o2 和 Liao2345o2 之外，大多数 o2 NILs 中 22-kD α-醇溶蛋白的合成减少或缺失，而 19-kD α-醇溶蛋白的合成与轮回亲本相比大大降低。我们的研究结果表明，在某些玉米遗传背景下，除 opaque2 基因外，其他基因可能在醇溶蛋白合成和籽粒赖氨酸含量中发挥更重要的作用。
