Pre-harvest sprouting (PHS) induced by the absence of seed dormancy causes a severe reduction in crop yield and flour quality. In this study, we isolated and characterized TaABI4, an ABA-responsive transcription factor that participates in regulating seed germination in wheat. Sequence analysis revealed that TaABI4 has three homologues, located on chromosomes 1A/1B/1D. TaABI4 contains a conserved AP2 domain, and AP2-associated, LRP and potential PEST motifs. Putative cis-acting regulatory elements (CE1-like box, W-box, ABRE elements and RY elements) were identified in the TaABI4 promoter region that showed high conservation in 17 wheat cultivars and wheat-related species. Expression profiling of TaABI4 indicated that it is a seed-specific gene accumulating during the middle stages of seed development. Transcript accumulation of TaABI4 in wheat cultivar Chuanmai 32 (CM32, PHS susceptible) was 5.07-fold and 1.39-fold higher than that in synthetic hexaploidy wheat SHW-L1 (PHS resistant) at 15 and 20 DPA, respectively. Six expression quantitative trait loci (eQTL) of TaABI4 on chromosomes 2A, 2D, 3B and 4A were characterized based on the accumulated transcripts of TaABI4 in SHW-L1 and CM32-derived recombinant inbred lines. These QTLs explained 10.7 to 46.1% of the trait variation with 4.53–10.59 of LOD scores, which contain genes that may affect the expression of TaABI4.

中文翻译：

---

小麦收获前发芽相关基因TaABI4的表征及表达数量性状位点分析

因缺乏种子休眠而引起的收获前发芽 (PHS) 会导致作物产量和面粉质量严重下降。在这项研究中，我们分离并表征TaABI4，一种参与调节小麦种子萌发的 ABA 反应转录因子。序列分析表明TaABI4具有三个同源物，位于染色体 1A/1B/1D。TaABI4包含一个保守的 AP2 结构域和 AP2 相关的 LRP 和潜在的 PEST 基序。推定顺式-作用调节元件（CE1-like box、W-box、ABRE 元件和 RY 元件）在TaABI4在 17 个小麦品种和小麦相关物种中显示出高度保守的启动子区域。表达谱TaABI4表明它是种子发育中期积累的种子特异性基因。成绩单积累TaABI4小麦品种川麦 32（CM32，PHS 敏感）在 15 和 20 DPA 时分别比合成六倍体小麦 SHW-L1（抗 PHS）高 5.07 倍和 1.39 倍。六个表达数量性状基因座（eQTL）的TaABI4在染色体 2A、2D、3B 和 4A 上的特征是基于积累的转录本TaABI4在 SHW-L1 和 CM32 衍生的重组近交系中。这些 QTL 解释了 10.7 到 46.1% 的性状变异，LOD 得分为 4.53-10.59，其中包含可能影响基因表达的基因。TaABI4.