Soybean Research Institute, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
MARA National Center for Soybean Improvement, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
Theor Appl Genet. 2019 Oct;132(10):2793-2807. doi: 10.1007/s00122-019-03388-z. Epub 2019 Jul 6.
A wild soybean allele conferring 100-seed weight, protein content and oil content simultaneously was fine-mapped to a 329-kb region on Chromosome 15, in which Glyma.15g049200 was predicted a candidate gene. Annual wild soybean characterized with small 100-seed weight (100SW), high protein content (PRC), low oil content (OIC) may contain favourable alleles for broadening the genetic base of cultivated soybeans. To evaluate these alleles, a population composed of 195 chromosome segment substitution lines (SojaCSSLP4), with wild N24852 as donor and cultivated NN1138-2 as recurrent parent, was tested. In SojaCSSLP4, 10, 9 and 8 wild segments/QTL were detected for 100SW, PRC and OIC, respectively. Using a backcross-derived secondary population, one segment for the three traits (q100SW15, qPro15 and qOil15) and one for 100SW (q100SW18.2) were fine-mapped into a 329-kb region on chromosome 15 and a 286-kb region on chromosome 18, respectively. Integrated with the transcription data in SoyBase, 42 genes were predicted in the 329-kb region where Glyma.15g049200 showed significant expression differences at all seed development stages. Furthermore, the Glyma.15g049200 segments of the two parents were sequenced and compared, which showed two base insertions in CDS (coding sequence) in the wild N24852 comparing to the NN1138-2. Since only Glyma.15g049200 performed differential CDS between the two parents but related to the three traits, Glyma.15g049200 was predicted a pleiotropic candidate gene for 100SW, PRC and OIC. The functional annotation of Glyma.15g049200 indicated a bidirectional sucrose transporter belonging to MtN3/saliva family which might be the reason that this gene provides a same biochemical basis for 100SW, PRC and OIC, therefore, is responsible for the three traits. This result may facilitate isolation of the specific gene and provide prerequisite for understanding the other two pleiotropic QTL.
一个控制百粒重、蛋白质含量和油分含量的野生大豆等位基因被精细定位到 15 号染色体上的一个 329-kb 区域，其中 Glyma.15g049200 被预测为一个候选基因。具有小百粒重（100SW）、高蛋白含量（PRC）和低油分含量（OIC）的一年生野生大豆可能含有有利的等位基因，可拓宽栽培大豆的遗传基础。为了评估这些等位基因，利用以野生 N24852 为供体、NN1138-2 为轮回亲本的 195 个染色体片段代换系（SojaCSSLP4）群体进行了测试。在 SojaCSSLP4 中，检测到 10、9 和 8 个野生片段/QTL 分别控制 100SW、PRC 和 OIC。利用回交衍生的次级群体，将一个控制三个性状（q100SW15、qPro15 和 qOil15）和一个控制 100SW（q100SW18.2）的片段精细定位到 15 号染色体上的一个 329-kb 区域和 18 号染色体上的一个 286-kb 区域。综合 SoyBase 中的转录数据，在 329-kb 区域预测到 42 个基因，其中 Glyma.15g049200 在所有种子发育阶段的表达差异均有显著差异。此外，比较了两个亲本的 Glyma.15g049200 片段，发现野生 N24852 中的 CDS（编码序列）有两个碱基插入，而 NN1138-2 中则没有。由于只有 Glyma.15g049200 在两个亲本之间表现出不同的 CDS，但与三个性状相关，因此预测 Glyma.15g049200 是 100SW、PRC 和 OIC 的多效候选基因。Glyma.15g049200 的功能注释表明，它是一种双向蔗糖转运蛋白，属于 MtN3/saliva 家族，这可能是该基因为 100SW、PRC 和 OIC 提供相同生化基础的原因，因此，该基因负责这三个性状。这一结果可能有助于分离特定基因，并为理解其他两个多效性 QTL 提供前提条件。
