The bacterial lipopeptide iturins induce Verticillium dahliae cell death by affecting fungal signalling pathways and mediate plant defence responses involved in pathogen-associated molecular pattern-triggered immunity
The bacterial lipopeptide iturins induce Verticillium dahliae cell death by affecting fungal signalling pathways and mediate plant defence responses involved in pathogen-associated molecular pattern-triggered immunity
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DOI：
10.1111/1462-2920.12538
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发表时间：
2015-04-01
影响因子：
5.1
通讯作者：
Tang, Canming
中科院分区：
文献类型：
--
作者：
Han, Qin;Wu, Fengli;Tang, Canming
由大丽轮枝菌（Verticilliumdahliae）引起的棉花黄萎病是世界范围内最严重的棉花病害之一。由于没有已知的杀真菌剂或棉花栽培品种提供足够的保护，对这种病原体，大丽轮枝菌造成主要的作物产量损失。在此，分离的棉花内生细菌，命名为解淀粉芽孢杆菌41 B-1，在温室条件下对棉花植物中的大丽轮枝菌表现出大于50%的生物防治效力。通过高效液相色谱分析和滤液质量分析，发现41 B-1菌株培养滤液中的抗真菌化合物为伊枯草菌素的一系列异构体。纯化的伊枯草菌素在不存在或存在棉花的情况下抑制大丽轮枝菌微菌核萌发。伊枯草菌素处理诱导活性氧簇爆发，Hog 1丝裂原活化蛋白激酶（MAPK）激活和细胞壁完整性的缺陷。氧化应激反应和高渗透压甘油途径有助于伊枯草菌素抗性大丽葡萄球菌。与此相反，Slt 2 MAPK途径可能参与伊枯草菌素敏感性在这种真菌。除了拮抗作用外，伊枯草菌素还可以作为激活剂诱导植物防御反应，并介导病原相关分子模式触发的免疫。这些研究结果表明，iturins可能会影响真菌的信号转导途径和介导植物对大丽轮枝菌的防御反应。
Verticillium wilt in cotton caused by Verticillium dahliae is one of the most serious plant diseases worldwide. Because no known fungicides or cotton cultivars provide sufficient protection against this pathogen, V.dahliae causes major crop yield losses. Here, an isolated cotton endophytic bacterium, designated Bacillus amyloliquefaciens 41B-1, exhibited greater than 50% biocontrol efficacy against V.dahliae in cotton plants under greenhouse conditions. Through high-performance liquid chromatography and mass analysis of the filtrate, we found that the antifungal compounds present in the strain 41B-1 culture filtrate were a series of isoforms of iturins. The purified iturins suppressed V.dahliae microsclerotial germination in the absence or presence of cotton. Treatment with the iturins induced reactive oxygen species bursts, Hog1 mitogen-activated protein kinase (MAPK) activation and defects in cell wall integrity. The oxidative stress response and high-osmolarity glycerol pathway contribute to iturins resistance in V.dahliae. In contrast, the Slt2 MAPK pathway may be involved in iturins sensitivity in this fungus. In addition to antagonism, iturins could induce plant defence responses as activators and mediate pathogen-associated molecular pattern-triggered immunity. These findings suggest that iturins may affect fungal signalling pathways and mediate plant defence responses against V.dahliae.