Flavonoid 3ʹ-hydroxylase (F3ʹH) catalyzes hydroxylation at the 3ʹ position of the B ring of flavonoids. F3ʹH is associated with the seed coat and pubescence color, antioxidant properties, and chilling stress tolerance of soybean [Glycine max (L.) Merr.]. In this study, we found that soybean F3ʹH increases the calcium (Ca) and magnesium (Mg) contents in pods and reduces the levels of these elements in seeds. Inductively coupled plasma mass spectrometry (ICP-MS) analysis using a near-isogenic line (NIL) derived from Japanese cultivars ‘Natto-shoryu’ and ‘Hyoukei-kuro 3’ for F3ʹH (Glyma.06g202300), also known as the T gene, indicated that the contents of Ca and Mg were higher in the pods but lower in the seed coats and cotyledons from soybean with active F3ʹH than from soybean with inactive F3ʹH. No such clear tendency was observed for other inorganic ions measured in this study. These data suggested that the transport of Ca and Mg from the pod to the seed was inhibited by flavonoid produced through F3ʹH activity. The hardness of cooked beans from soybean with active F3ʹH was lower than that from soybean with inactive F3ʹH, which was likely related to the increase in heat-labile pectin caused by fewer cross-linked divalent ions. These results were supported by ICP-MS analysis and the hardness of cooked beans of other NILs for the T gene. Our findings demonstrate a novel and unexpected effect of flavonoids on the processing quality of soybean.

中文翻译：

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黄酮3′-羟化酶降低大豆种子中的Ca和Mg含量，导致煮熟的豆子硬度降低

类黄酮 3′-羟化酶 (F3′H) 在类黄酮 B 环的 3′ 位催化羟基化。F3ʹH 与大豆 [ Glycine max (L.) Merr.]的种皮和柔毛颜色、抗氧化特性和耐寒性有关。在这项研究中，我们发现大豆 F3ʹH 增加了豆荚中的钙 (Ca) 和镁 (Mg) 含量，并降低了种子中这些元素的含量。使用源自日本栽培品种“Natto-shoryu”和“Hyoukei-kuro 3”的F3ʹH ( Glyma.06g202300 )的近等基因线 (NIL) 进行电感耦合等离子体质谱 (ICP-MS) 分析，也称为T基因，表明与非活性F3′H大豆相比，具有活性F3′H的大豆豆荚中Ca和Mg含量较高，而种皮和子叶中的Ca和Mg含量较低。对于本研究中测量的其他无机离子，没有观察到这种明显的趋势。这些数据表明，钙和镁从豆荚到种子的运输受到 F3ʹH 活性产生的黄酮类化合物的抑制。具有活性 F3ʹH 的大豆煮熟豆的硬度低于具有非活性 F3ʹH 的大豆，这可能与交联二价离子较少导致不耐热果胶增加有关。这些结果得到了 ICP-MS 分析和其他 NIL 煮熟豆的硬度的支持。基因。我们的研究结果证明了黄酮类化合物对大豆加工质量的一种新颖而出人意料的影响。