Julius Kühn Institute (JKI)-Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, 38104 Braunschweig, Germany.
Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
Plant Physiol. 2023 Mar 17;191(3):2027-2044. doi: 10.1093/plphys/kiad017.
N-acyl homoserine lactones (AHLs) are important players in plant-bacteria interactions. Different AHL-producing bacteria can improve plant growth and resistance against plant pathogens. In nature, plants may host a variety of AHL-producing bacteria and frequently experience numerous AHLs at the same time. Therefore, a coordinated response to combined AHL molecules is necessary. The purpose of this study was to explore the mechanism of AHL-priming using combined AHL molecules including N-(3-oxo-hexanoyl)-L-homoserine lactone, N-3-oxo-octanoyl-L-homoserine lactone, N-3-oxo-dodecanoyl-L-homoserine lactone, and N-3-oxo-tetradecanoyl-L-homoserine lactone and AHL-producing bacteria including Serratia plymuthica HRO-C48, Rhizobium etli CFN42, Burkholderia graminis DSM17151, and Ensifer meliloti (Sinorhizobium meliloti) Rm2011. We used transcriptome analysis, phytohormone measurements, as well as genetic and microbiological approaches to assess how the combination of structurally diverse AHL molecules influence Arabidopsis (Arabidopsis thaliana). Our findings revealed a particular response to a mixture of AHL molecules (AHL mix). Different expression patterns indicated that the reaction of plants exposed to AHL mix differs from that of plants exposed to single AHL molecules. In addition, different content of jasmonic acid (JA) and derivatives revealed that jasmonates play an important role in AHL mix-induced priming. The fast and stable decreased concentration of COOH-JA-Ile after challenge with the flagellin-derived peptide flg22 indicated that AHL mix modifies the metabolism of jasmonates. Study of various JA- and salicylic acid-related Arabidopsis mutants strengthened the notion that JA homeostasis is involved in AHL-priming. Understanding how the combination of AHLs primes plants for enhanced resistance has the potential to broaden our approaches in sustainable agriculture and will help to effectively protect plants against pathogens.
N-酰基高丝氨酸内酯（AHLs）是植物-细菌相互作用中的重要参与者。不同的 AHL 产生细菌可以促进植物生长并提高植物对病原体的抗性。在自然界中，植物可能会宿主多种 AHL 产生细菌，并同时频繁地接触多种 AHL。因此，对组合 AHL 分子进行协调响应是必要的。本研究旨在探索使用包括 N-（3-氧代-己酰基）-L-高丝氨酸内酯、N-3-氧代-辛酰基-L-高丝氨酸内酯、N-3-氧代-十二酰基-L-高丝氨酸内酯和 N-3-氧代-十四酰基-L-高丝氨酸内酯在内的组合 AHL 分子以及包括粘质沙雷氏菌 HRO-C48、根瘤菌 etli CFN42、革兰氏阴性菌和苜蓿中华根瘤菌（中华根瘤菌）Rm2011 在内的 AHL 产生细菌进行 AHL 诱导的机制。我们使用转录组分析、植物激素测量以及遗传和微生物学方法来评估结构不同的 AHL 分子组合如何影响拟南芥（拟南芥）。我们的研究结果揭示了对 AHL 分子混合物（AHL 混合物）的特定反应。不同的表达模式表明，暴露于 AHL 混合物的植物的反应与暴露于单一 AHL 分子的植物的反应不同。此外，不同含量的茉莉酸（JA）及其衍生物表明茉莉酸在 AHL 混合物诱导的诱导中起着重要作用。在受到鞭毛衍生肽 flg22 挑战后，COOH-JA-Ile 的快速且稳定的浓度降低表明 AHL 混合物修饰了茉莉酸的代谢。对各种 JA 和水杨酸相关的拟南芥突变体的研究加强了 JA 动态平衡参与 AHL 诱导的观点。了解 AHL 混合物如何为增强植物抗性进行诱导，有可能拓宽我们在可持续农业中的方法，并有助于有效地保护植物免受病原体侵害。
