ABSTRACT

Here, we explored the genomic loci and genes responsible for differences in Cs accumulation in the seeds of two soybean (Glycine max (L.) Merr.) cultivars, namely ‘Enrei’ (high accumulator) and ‘Onihadaka’ (low accumulator), using quantitative trait loci (QTL)-seq. For analysis, F₃ and F₅ generations were generated by crossing the two cultivars followed by self-fertilization. In the putative QTL regions of the F₃ generation, Glyma.11G099100 annotated as the vacuolar sorting protein/ubiquitin receptor VPS23 was found. VPS23A regulates the salt overly sensitive (SOS) signaling cascade in Arabidopsis, and mutations in SOS2 reduce radiocesium accumulation in rice grains. In the putative QTL regions of the F₅ generation, Glyma.06G112200, which is a homolog of the usually multiple acids move in and out transporter (UMAMIT) proteins in Arabidopsis, was found. UMAMIT proteins are the exporters of amino acids, and the addition of cysteine or its derivative methyl cysteine to the growth medium increased Cs accumulation in A. thaliana. Both Glyma.11G099100 and Glyma.06G112200 carried polymorphisms – an amino acid substitution – between ‘Enrei’ and ‘Onihadaka.’ Yeast cells heterologously expressing the Onihadaka-type Glyma.06G112200 showed higher Cs accumulation than those expressing the Enrei-type. Yeast cells expressing the Enrei-type Glyma.06G112200 showed lower Cs accumulation than the vector controls; however, there was no significant difference between yeast cells expressing the Onihadaka-type and the vector controls. These results suggest that variations in the sequences of Glyma.11G099100 and Glyma.06G112200 in ‘Enrei’ and ‘Onihadaka’ are possibly responsible for differences in Cs uptake between these soybean cultivars.

摘要

在这里，我们探索了导致两种大豆（Glycine max (L.) Merr.）品种种子中 Cs 积累差异的基因组位点和基因，即“Enrei”（高蓄积者）和“Onihadaka”（低蓄积者），使用数量性状基因座（QTL）-seq。为了分析，F ₃和F ₅代是通过将两个栽培品种杂交然后自体受精而产生的。在F ₃代的推定QTL 区域中，发现了注释为液泡分选蛋白/泛素受体VPS23 的Glyma.11G099100。VPS23A 调节拟南芥中的盐过度敏感 (SOS) 信号级联和 SOS2 的突变减少了稻谷中放射性铯的积累。在 F ₅代的推定 QTL 区域中，发现了Glyma.06G112200，它是拟南芥中通常多种酸移入移出转运蛋白 (UMAMIT) 蛋白的同源物。UMAMIT 蛋白是氨基酸的输出者，向生长培养基中添加半胱氨酸或其衍生物甲基半胱氨酸会增加拟南芥中 Cs 的积累。Glyma.11G099100和Glyma.06G112200都在“Enrei”和“Onihadaka”之间携带多态性——一种氨基酸替代。异源表达 Onihadaka 型Glyma.06G112200 的酵母细胞表现出比表达 Enrei 型的那些更高的 Cs 积累。表达 Enrei 型Glyma.06G112200 的酵母细胞显示出比载体对照更低的 Cs 积累；然而，表达 Onihadaka 型的酵母细胞和载体对照之间没有显着差异。这些结果表明，'Enrei' 和'Onihadaka' 中Glyma.11G099100和Glyma.06G112200序列的变异可能是这些大豆品种之间 Cs 吸收差异的原因。