Department of Agronomy, Purdue University, West Lafayette, IN, USA.
Department of Plant Genetics and Breeding, China Agricultural University, Beijing, China.
Nat Plants. 2018 Jan;4(1):30-35. doi: 10.1038/s41477-017-0084-7. Epub 2018 Jan 1.
Many leguminous species have adapted their seed coat with a layer of powdery bloom that contains hazardous allergens and makes the seeds less visible, offering duel protection against potential predators . Nevertheless, a shiny seed surface without bloom is desirable for human consumption and health, and is targeted for selection under domestication. Here we show that seed coat bloom in wild soybeans is mainly controlled by Bloom1 (B1), which encodes a transmembrane transporter-like protein for biosynthesis of the bloom in pod endocarp. The transition from the 'bloom' to 'no-bloom' phenotypes is associated with artificial selection of a nucleotide mutation that naturally occurred in the coding region of B1 during soybean domestication. Interestingly, this mutation not only 'shined' the seed surface, but also elevated seed oil content in domesticated soybeans. Such an elevation of oil content in seeds appears to be achieved through b1-modulated upregulation of oil biosynthesis in pods. This study shows pleiotropy as a mechanism underlying the domestication syndrome , and may pave new strategies for development of soybean varieties with increased seed oil content and reduced seed dust.
许多豆科植物的种皮上都有一层粉状的花粉层，其中含有危险的过敏原，使种子不易被发现，从而为潜在的捕食者提供双重保护。然而，对于人类食用和健康来说，没有花粉的闪亮种子表面是理想的，因此在驯化过程中，这是选择的目标。在这里，我们表明，野生大豆的种皮花粉主要由 Bloom1（B1）控制，B1 编码一种跨膜转运蛋白样蛋白，用于荚果内种皮花粉的生物合成。从“有花粉”到“无花粉”表型的转变与 B1 编码区自然发生的核苷酸突变的人工选择有关，该突变在大豆驯化过程中发生。有趣的是，这种突变不仅“使”种子表面变亮，而且还提高了驯化大豆的种子含油量。这种在种子中提高油含量的现象似乎是通过 b1 调节荚果中油脂生物合成的上调来实现的。本研究表明，多效性是驯化综合征的一种机制，并可能为开发种子含油量增加、种子粉尘减少的大豆品种开辟新的策略。
