Molecular Biotechnology of Plants and Micro-organisms, Department of Biology, KU Leuven, Leuven, Belgium and KU Leuven Plant Institute (LPI).
Applied Mycology and Phenomics, Department of Plants and Crops, Ghent University, Ghent, Belgium.
Physiol Plant. 2024 May-Jun;176(3):e14325. doi: 10.1111/ppl.14325.
Boosting plant immunity by priming agents can lower agrochemical dependency in plant production. Levan and levan-derived oligosaccharides (LOS) act as priming agents against biotic stress in several crops. Additionally, beneficial microbes can promote plant growth and protect against fungal diseases. This study assessed possible synergistic effects caused by levan, LOS and five levan- and LOS-metabolizing Bacillaceae (Bacillus and Priestia) strains in tomato and wheat. Leaf and seed defense priming assays were conducted in non-soil (semi-sterile substrate) and soil-based systems, focusing on tomato-Botrytis cinerea and wheat-Magnaporthe oryzae Triticum (MoT) pathosystems. In the non-soil system, seed defense priming with levan, the strains (especially Bacillus velezensis GA1), or their combination significantly promoted tomato growth and protection against B. cinerea. While no growth stimulatory effects were observed for wheat, disease protective effects were also observed in the wheat-MoT pathosystem. When grown in soil and subjected to leaf defense priming, tomato plants co-applied with levan and the bacterial strains showed increased resistance to B. cinerea compared with plants treated with levan or single strains, and these effects were synergistic in some cases. For seed defense priming in soil, more synergistic effects on disease tolerance were observed in a non-fertilized soil as compared to a fertilized soil, suggesting that potential prebiotic effects of levan are more prominent in poor soils. The potential of using combinations of Bacilliaceae and levan in sustainable agriculture is discussed.
通过引发剂来增强植物免疫力可以降低植物生产中对农用化学品的依赖。在几种作物中，低聚果糖（levan）和低聚果糖衍生的低聚糖（LOS）可以作为生物胁迫的引发剂。此外，有益微生物可以促进植物生长并防止真菌病害。本研究评估了低聚果糖、LOS 和 5 种低聚果糖和 LOS 代谢芽孢杆菌（芽孢杆菌属和 Priesia）菌株在番茄和小麦中的协同作用。在非土壤（半无菌基质）和土壤系统中进行了叶片和种子防御引发试验，重点研究番茄-灰葡萄孢和小麦-稻瘟病菌（MoT）病理系统。在非土壤系统中，低聚果糖、菌株（特别是 Bacillus velezensis GA1）或其组合的种子防御引发显著促进了番茄的生长和对灰葡萄孢的保护。虽然对小麦没有观察到生长刺激作用，但在小麦-MoT 病理系统中也观察到了对病害的保护作用。当在土壤中生长并进行叶片防御引发时，与单独用低聚果糖或单菌株处理的植物相比，同时施用低聚果糖和细菌菌株的番茄植物对灰葡萄孢的抗性增强，在某些情况下这些作用具有协同性。对于土壤中的种子防御引发，与施肥土壤相比，未施肥土壤中观察到对疾病耐受性的协同作用更为明显，这表明低聚果糖的潜在益生元作用在贫瘠土壤中更为显著。讨论了利用芽孢杆菌和低聚果糖组合进行可持续农业的潜力。
