Plant defensin antibacterial mode of action against Pseudomonas species
Plant defensin antibacterial mode of action against Pseudomonas species
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DOI：
10.1186/s12866-020-01852-1
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发表时间：
2020-06-19
期刊：
影响因子：
4.2
通讯作者：
Samac, Deborah A.
中科院分区：
文献类型：
--
作者：
Sathoff, Andrew E.;Lewenza, Shawn;Samac, Deborah A.
背景虽然许多植物防御素具有抗菌活性，但其抗菌作用模式（MOA）却知之甚少。具有特征性MOA的抗菌肽诱导多种细菌外膜修饰的表达，这是对这些膜靶向肽的抗性所必需的。对铜绿假单胞菌（Pseudomonasaerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosae.aerodynosa.a.aerodynosa.a.aerodynosa.a.aerodynosae.a.a.aerodynosa.a.a.a.aerodynosa.a.a.a.a.a.aerodynosa.a.a.a.a.a.aerodynosae.a.a.a.a.a.a.a.aerodynosae.a.a.还评估了这些转录lux报告菌株对亚致死植物防御素暴露的lux基因表达的响应。此外，通过转座子诱变修饰植物病原体假单胞菌（Pseudomonaseringaepv.eringae）以产生对体外MtDef4处理具有抗性的突变体。结果植物防御素对铜绿假单胞菌具有较强的特异性抗菌活性。铜绿。来自蒺藜苜蓿的防御素MtDef4诱导LPS的氨基阿拉伯糖修饰和表面聚阳离子亚精胺生产操纵子的剂量依赖性基因表达。还通过荧光显微镜在视觉上验证了MtDef4破坏细菌外膜的能力。另一种防御素。truncatula，MtDef5，不能诱导lux基因的表达，并通过荧光显微镜检测到有限的外膜损伤。MtDef4抗性P.对甜菜夜蛾突变体进行了测序，并鉴定了核糖体基因的修饰有助于增强对植物防御素处理的抗性。结论MtDef 4与多粘菌素B一样，可损伤植物外膜，从而激活植物对抗菌肽的抗性机制。MtDef5似乎具有不同的抗菌MOA。此外，MtDef4抗菌作用模式还可能涉及抑制翻译。
Background Though many plant defensins exhibit antibacterial activity, little is known about their antibacterial mode of action (MOA). Antimicrobial peptides with a characterized MOA induce the expression of multiple bacterial outer membrane modifications, which are required for resistance to these membrane-targeting peptides. Mini-Tn5-luxmutant strains ofPseudomonas aeruginosawith Tn insertions disrupting outer membrane protective modifications were assessed for sensitivity against plant defensin peptides. These transcriptionalluxreporter strains were also evaluated forluxgene expression in response to sublethal plant defensin exposure. Also, a plant pathogen,Pseudomonas syringaepv.syringaewas modified through transposon mutagenesis to create mutants that are resistant to in vitro MtDef4 treatments. Results Plant defensins displayed specific and potent antibacterial activity against strains ofP. aeruginosa. A defensin fromMedicago truncatula, MtDef4, induced dose-dependent gene expression of the aminoarabinose modification of LPS and surface polycation spermidine production operons. The ability for MtDef4 to damage bacterial outer membranes was also verified visually through fluorescent microscopy. Another defensin fromM. truncatula, MtDef5, failed to induceluxgene expression and limited outer membrane damage was detected with fluorescent microscopy. The transposon insertion site on MtDef4 resistantP. syringaepv.syringaemutants was sequenced, and modifications of ribosomal genes were identified to contribute to enhanced resistance to plant defensin treatments. Conclusions MtDef4 damages the outer membrane similar to polymyxin B, which stimulates antimicrobial peptide resistance mechanisms to plant defensins. MtDef5, appears to have a different antibacterial MOA. Additionally, the MtDef4 antibacterial mode of action may also involve inhibition of translation.