ABSTRACT

Rhizospheric bacteria may induce resistance to plant diseases. However, the underlying plant resistance mechanisms are unclear. We demonstrated the potential ability of the rhizobacterial strain Bacillus subtilis IAGS174 to elicit systemic resistance in tomato plants against Fusarium wilt pathogens. Comparative biochemical, histological, and molecular analyses were conducted to screen the differential responses between non-inoculated and B. subtilis IAGS174-inoculated tomato plants followed by pathogen challenge. B. subtilis IAGS174 had a significant inhibitory effect on disease development and reduced the disease index. B. subtilis IAGS174-primed plants exhibited significantly improved synthesis of total phenolics, flavonoids, and plant defense enzymes. Furthermore, priming increased the production of physical defense barriers including lignin. Additionally, RT-qPCR analysis revealed that disease resistance in bacteria-treated tomato plants was associated with increased expression levels of lignin-related and phenylpropanoid biosynthetic genes. Our findings support a positive role of B. subtilis IAGS174 in triggering immunity of tomato plants against a soil-borne disease.

摘要

根际细菌可诱导对植物病害的抗性。然而，潜在的植物抗性机制尚不清楚。我们证明了根际细菌菌株枯草芽孢杆菌IAGS174 在番茄植物中引起对枯萎病病原体的系统抗性的潜在能力。进行了比较生化、组织学和分子分析，以筛选未接种和枯草芽孢杆菌IAGS174 接种的番茄植物之间的差异反应，然后进行病原体攻击。B. subtilis IAGS174对病害发展有显着抑制作用，降低病害指数。枯草芽孢杆菌IAGS174 引发的植物表现出显着改善的总酚类、黄酮类化合物和植物防御酶的合成。此外，引发增加了包括木质素在内的物理防御屏障的产生。此外，RT-qPCR 分析表明，细菌处理的番茄植株的抗病性与木质素相关和苯丙烷生物合成基因的表达水平增加有关。我们的研究结果支持枯草芽孢杆菌IAGS174 在触发番茄植物对土传疾病的免疫力方面的积极作用。