Faculty of Agriculture and Life Science, Hirosaki University , 3 Bunkyo, Hirosaki, Aomori 036-8561, Japan.
Breed Sci. 2012 Jan;61(5):523-30. doi: 10.1270/jsbbs.61.523. Epub 2012 Feb 4.
In soybean seeds, numerous variations in colors and pigmentation patterns exist, most of which are observed in the seed coat. Patterns of seed coat pigmentation are determined by four alleles (I, i(i), i(k) and i) of the classically defined I locus, which controls the spatial distribution of anthocyanins and proanthocyanidins in the seed coat. Most commercial soybean cultivars produce yellow seeds with yellow cotyledons and nonpigmented seed coats, which are important traits of high-quality seeds. Plants carrying the I or i(i) allele show complete inhibition of pigmentation in the seed coat or pigmentation only in the hilum, respectively, resulting in a yellow seed phenotype. Classical genetic analyses of the I locus were performed in the 1920s and 1930s but, until recently, the molecular mechanism by which the I locus regulated seed coat pigmentation remained unclear. In this review, we provide an overview of the molecular suppressive mechanism of seed coat pigmentation in yellow soybean, with the main focus on the effect of the I allele. In addition, we discuss seed coat pigmentation phenomena in yellow soybean and their relationship to inhibition of I allele action.
在大豆种子中，存在着众多颜色和色素模式的变化，其中大部分变化都发生在种皮中。种皮色素模式是由经典定义的 I 基因座的四个等位基因（I、i(i)、i(k)和 i）决定的，该基因座控制着种皮中花青素和原花青素的空间分布。大多数商业大豆品种产生黄色种子，具有黄色子叶和无色种皮，这是高质量种子的重要特征。携带 I 或 i(i)等位基因的植物分别表现出种皮完全抑制色素沉着或仅在种脐处出现色素沉着，从而导致黄色种子表型。I 基因座的经典遗传分析在 20 世纪 20 年代和 30 年代进行，但直到最近，I 基因座调控种皮色素沉着的分子机制仍不清楚。在这篇综述中，我们提供了一个关于黄色大豆种皮色素沉着的分子抑制机制的概述，主要集中在 I 等位基因的作用上。此外，我们还讨论了黄色大豆中的种皮色素沉着现象及其与 I 等位基因作用抑制的关系。
