State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, National Center for Soybean Improvement, Key Laboratory for Biology and Genetic Improvement of Soybeans (General, Ministry of Agriculture), Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China.
Zhongshan Biological Breeding Laboratory, Nanjing, Jiangsu 210014, China.
J Exp Bot. 2024 Mar 27;75(7):1852-1871. doi: 10.1093/jxb/erad483.
Drought tolerance is a complex trait in soybean that is controlled by polygenetic quantitative trait loci (QTLs). In this study, wilting score, days-to-wilting, leaf relative water content, and leaf relative conductivity were used to identify QTLs associated with drought tolerance in recombinant inbred lines derived from a cross between a drought-sensitive variety, Lin, and a drought-tolerant variety, Meng. A total of 33 drought-tolerance QTLs were detected. Of these 17 were major QTLs. In addition, 15 were novel drought-tolerance QTLs. The most predominant QTL was on chromosome 11. This was detected in at least three environments. The overlapped mapping interval of the four measured traits was 0.2 cM in genetic distance (about 220 kb in physical length). Glyma.11g143500 (designated as GmUAA6), which encodes a UDP-N-acetylglucosamine transporter, was identified as the most likely candidate gene. The allele of GmUAA6 from Lin (GmUAA6Lin) was associated with improved soybean drought tolerance. Overexpression of GmUAA6Lin in Arabidopsis and soybean hairy roots enhanced drought tolerance. Furthermore, a 3-bp insertion/deletion (InDel) in the coding sequence of GmUAA6 explained up to 49.9% of the phenotypic variation in drought tolerance-related traits, suggesting that this InDel might be used in future marker-assisted selection of drought-tolerant lines in soybean breeding programs.
耐旱性是大豆的一个复杂性状，由多基因数量性状位点（QTLs）控制。在这项研究中，萎蔫评分、萎蔫天数、叶片相对水含量和叶片相对电导率被用来鉴定与重组自交系中耐旱性相关的 QTL，这些重组自交系是由一个耐旱品种 Meng 和一个敏感品种 Lin 杂交产生的。共检测到 33 个耐旱性 QTL。其中 17 个是主要 QTL。此外，还有 15 个是新的耐旱性 QTL。最主要的 QTL位于第 11 号染色体上。该 QTL至少在三个环境中被检测到。四个测量性状的重叠映射区间在遗传距离上为 0.2 cM（约 220 kb 物理长度）。Glyma.11g143500（命名为 GmUAA6），编码 UDP-N-乙酰葡萄糖胺转运蛋白，被鉴定为最可能的候选基因。来自 Lin 的 GmUAA6 等位基因（GmUAA6Lin）与提高大豆耐旱性有关。在拟南芥和大豆毛状根中过表达 GmUAA6Lin 增强了耐旱性。此外，GmUAA6 编码序列中的 3 个碱基插入/缺失（InDel）解释了耐旱性相关性状表型变异的 49.9%，表明该 InDel 可用于未来大豆耐旱性品种的标记辅助选择。
