Abstract: Using Jimai 22 with high sensitivity to pre⁃harvest sprouting（PHS）as the control，the PHS resistance and α⁃amylase activities of the new white⁃grain wheat variety Wan 1329 and its parent Lianmai 2 were analyzed. During the critical period when α⁃amylase activity changed，transcriptome sequencing，KEGG and GO enrichment analysis were employed to identify differentially expressed amylase genes，and real⁃time fluorescence quantitative PCR（qRT⁃PCR）was used for verification their expression patterns.In addition，AlphaFold was employed to analyze the effects of coding sequence variations on protein structure. The results showed that both Wan 1329 and Lianmai 2 exhibited moderate resistance to PHS，while Wan 1329 had a lower relative germination index，indicating stronger resistance. At 24 h after seed imbibition，the α⁃amylase activities of Wan 1329 and Lianmai 2 were markedly lower than that of Jimai 22，and α⁃amylase activities at 20 h，24 h，and 72 h were highly positively correlated with the relative germination index. Transcriptome sequencing，KEGG and GO enrichment analysis revealed that two α⁃amylase genes located on the long arm of chromosome 6D， TraesCS6D02G313300 and TraesCS6D02G313500，were candidate α⁃amylase genes. The third exon of TraesCS6D02G313500 in Wan 1329 was elongated by 138 bp，extending into the 3´UTR region.qRT⁃PCR validation confirmed that the expression patterns of both genes were consistent with transcriptome analysis，and the cumulative relative expression level of TraesCS6D02G313500 in Wan 1329 was significantly lower than that in Lianmai 2.AlphaFold prediction suggested that this variation caused a C⁃terminal extension of α⁃amylase，resulting in decreased structural stability and increased conformational flexibility.Collectively，TraesCS6D02G313300 and TraesCS6D02G313500 are key genes related to PHS resistance in Wan 1329，among which the structural variation of TraesCS6D02G313500 may further enhance resistance to PHS.

Key words: Wheat, Pre?harvest sprouting resistance, Amylase, Transcriptome, Differential expressed genes

摘要： 以高感穗发芽品种济麦22为对照，分析白粒小麦新品种宛1329及其父本连麦2号的穗发芽抗性和α-淀粉酶活性，在α-淀粉酶活性转变关键时期利用转录组测序、KEGG和GO富集分析等挖掘差异表达淀粉酶基因，并利用实时荧光定量PCR（qRT-PCR）进行验证。同时，采用AlphaFold分析候选基因编码区变异对蛋白质结构的影响。结果表明，宛1329和连麦2号均表现为中抗穗发芽，而宛1329相对发芽指数更低，抗性更强。籽粒吸胀后24 h，宛1329和连麦2号的α-淀粉酶活性明显低于济麦22，且α-淀粉酶活性在20 h、24 h和72 h与相对发芽指数呈极显著正相关。转录组测序及KEGG、GO富集分析结果表明，位于6D染色体长臂的TraesCS6D02G313300和TraesCS6D02G313500为α-淀粉酶候选基因。其中，宛1329的TraesCS6D02G313500基因第3外显子多转录138 bp，侵入3´UTR区。qRT-PCR验证结果表明，2个候选基因的相对表达量变化趋势与转录组分析结果一致，且TraesCS6D02G313500基因累计相对表达量表现为宛1329显著低于连麦2号。Alphafold预测结果表明，该变异导致α-淀粉酶C端延伸并降低蛋白质结构的稳定性，增加构象的可变性。综上，α-淀粉酶基因TraesCS6D02G313300和TraesCS6D02G313500是宛1329抗穗发芽的重要基因，其中TraesCS6D02G313500的结构变异可能进一步增强穗发芽抗性。

关键词: 小麦, 抗穗发芽, 淀粉酶, 转录组, 差异表达基因