Identification of the Regulatory Network Governing Cold Tolerance During Soybean Germination through the Transcriptomic Characterization of a Chromosome Segment Substitution Line

Low temperature is a key factor affecting the geographical distribution, growth, development and yield of soybean. Low temperature stress can lead to a large amount of productivity loss during seed germination. Soybean seed vitality is a key trait affecting planting and germination. In this study, three germination characters of 205 soybean materials were evaluated, and a soybean chromosome fragment substitute strain was identified, which had high seed viability at low temperature. A total of 5 quantitative trait loci (QTLS) on 5 chromosomes were associated with seed viability at low temperature. Integration of fragment import and transcriptome analysis revealed 6 candidate genes. qRT-PCR verification was performed, which showed the same trend as the transcriptome. In combination with KEGG enrichment analysis, transcription inhibitor KAN1 Glyma.20G108600 affected the expression of several hormone-related pathway genes in seed germination through its effect on target gene auxin.

低温是影响大豆地理分布、生长发育与产量的关键因素。低温胁迫会在种子萌发阶段造成严重的产量损失。大豆种子活力是影响种植与萌发的关键性状。本研究对205份大豆材料的3个萌发性状开展了表型评价，从中鉴定出1份在低温条件下具有高种子活力的大豆染色体片段代换系。共计在5条染色体上定位到5个与低温下种子活力相关的数量性状位点（quantitative trait loci, QTLs）。通过片段导入与转录组整合分析，共筛选得到6个候选基因。开展了qRT-PCR验证实验，结果显示其表达趋势与转录组分析结果一致。结合京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes, KEGG）富集分析结果，转录抑制剂KAN1（Glyma.20G108600）通过调控靶基因生长素的表达，影响种子萌发过程中多条激素相关通路基因的表达。