PDF(Pubmed)
Abstract：
Linolenic acid (LA) has poor oxidative stability since it is a polyunsaturated fatty acid. Soybean oil has a high LA content and thus has poor oxidative stability. To identify candidate genes that affect the linolenic acid (LA) content in soybean seeds, a genome-wide association study (GWAS) was performed with 1,060 soybean cultivars collected in China between 2019-2021 and which LA content was measured using matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF IMS). A candidate gene, GmWRI14, encoding an APETALA2 (AP2)-type transcription factor, was detected by GWAS in cultivars from all three study years. Multiple sequence alignments showed that GmWRI14 belongs to the plant WRI1 family. The fatty acid contents of different soybean lines were evaluated in transgenic lines with a copy of GmWRI14, control lines without GmWRI14, and the gmwri14 mutant. MALDI-TOF IMS revealed that GmWRI14 transgenic soybeans had a lower LA content with a significant effect on seed size and shape, whereas gmwri14 mutants had a higher LA content. compared to control. The RNA-seq results showed that GmWRI14 suppresses GmFAD3s (GmFAD3B and GmFAD3C) and GmbZIP54 expression in soybean seeds, leading to decreased LA content. Based on the RNA-seq data, yeast one-hybrid (Y1H) and qRT-PCR were performed to confirm the transcriptional regulation of FAD3s by GmWRI14. Our results suggest that FAD3 is indirectly regulated by GmWRI14, representing a new molecular mechanism of fatty acid biosynthesis, in which GmWRI14 regulates LA content in soybean seeds.
摘要：
亚麻酸(LA)具有差的氧化稳定性,因为它是多不饱和脂肪酸。大豆油具有高LA含量,因此具有差的氧化稳定性。为了确定影响大豆种子中亚麻酸（LA）含量的候选基因，对2019-2021年间在中国收集的1,060个大豆品种进行了全基因组关联研究(GWAS),并使用基质辅助激光解吸/电离飞行时间成像质谱(MALDI-TOFIMS)测量LA含量.一个候选基因,GmWRI14，编码APETALA2（AP2）型转录因子，GWAS在所有三个研究年的品种中都检测到了。多序列比对显示GmWRI14属于植物WRI1家族。在具有GmWRI14拷贝的转基因品系，不具有GmWRI14的对照品系和gmwri14突变体中评估了不同大豆品系的脂肪酸含量。MALDI-TOFIMS显示GmWRI14转基因大豆具有较低的LA含量，对种子大小和形状有显著影响。而gmwri14突变体具有较高的LA含量。与控制相比。RNA-seq结果表明,GmWRI14抑制大豆种子中GmFAD3s(GmFAD3B和GmFAD3C)和GmbZIP54的表达,导致LA含量下降。基于RNA-seq数据,进行酵母单杂交（Y1H）和qRT-PCR以确认GmWRI14对FAD3的转录调节。我们的研究结果表明，FAD3受到GmWRI14的间接调控，代表了脂肪酸生物合成的新分子机制，其中GmWRI14调节大豆种子中的LA含量。
