小麦(Triticumaestivum)是世界上主要的主食作物,小麦白粉病(Blumeriagraminisf.sp.tritici)。增强小麦的抗病性对于满足全球粮食需求至关重要。这项研究调查了小麦的疾病反应,专注于生物活性小分子水杨酸(SA),哌啶酸(Pip),和N-羟基羧酸(NHP),为分子育种提供新的见解。我们发现SA的内源性水平,皮普,在受感染的植物中,NHP显著增加,Pip和NHP水平比SA的上升更早。值得注意的是,NHP的增长率明显高于SA。SARD1和CBP60g的基因表达水平,它们是SA的转录因子,皮普,和NHP生物合成,在感染的早期阶段显着增加。我们还发现在感染的后期,ALD1,SARD4和FMO1的表达,它们编码Pip和NHP生物合成的酶,急剧增加。此外,ICS1,它编码参与SA生物合成的关键酶,在感染后期也显示表达增加。ICS1转录的时间变化密切反映了内源性SA水平的行为,表明ICS途径是小麦SA生物合成的主要途径。总之,我们的结果表明,Pip和NHP的早期积累与SA在对抗小麦白粉病感染的疾病反应中协同作用。
Wheat (Triticum aestivum) is a major staple crop worldwide, and its yields are significantly threatened by wheat powdery mildew (Blumeria graminis f. sp. tritici). Enhancing disease resistance in wheat is crucial for meeting global food demand. This study investigated the disease response in wheat, focusing on the bioactive small molecules salicylic acid (SA), pipecolic acid (Pip), and N-hydroxypipecolic acid (NHP), to provide new insights for molecular breeding. We found that endogenous levels of SA, Pip, and NHP significantly increased in infected plants, with Pip and NHP levels rising earlier than those of SA. Notably, the rate of increase of NHP was substantially higher than that of SA. The gene expression levels of SARD1 and CBP60g, which are transcription factors for SA, Pip, and NHP biosynthesis, increased significantly during the early stages of infection. We also found that during the later stages of infection, the expression of ALD1, SARD4, and FMO1, which encode enzymes for Pip and NHP biosynthesis, dramatically increased. Additionally, ICS1, which encodes a key enzyme involved in SA biosynthesis, also showed increased expression during the later stages of infection. The temporal changes in ICS1 transcription closely mirrored the behavior of endogenous SA levels, suggesting that the ICS pathway is the primary route for SA biosynthesis in wheat. In conclusion, our results suggest that the early accumulation of Pip and NHP cooperates with SA in the disease response against wheat powdery mildew infection.