DegQ regulates the production of fengycins and biofilm formation of the biocontrol agent Bacillus subtilis NCD-2
DegQ regulates the production of fengycins and biofilm formation of the biocontrol agent Bacillus subtilis NCD-2
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DegQ 调节风霉素的产生和生物防治剂枯草芽孢杆菌 NCD-2 的生物膜形成
DOI：
10.1016/j.micres.2015.06.006
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发表时间：
2015-01-01
影响因子：
6.7
通讯作者：
Ma, Ping
中科院分区：
文献类型：
--
作者：
Wang, Peipei;Guo, Qinggang;Ma, Ping
枯草芽孢杆菌NCD-2是番茄灰霉病和棉花土传病害的优良生防菌。丰霉素脂肽在其生物防治能力中起主要作用。先前的研究表明，插入带有mini-Tn 10转座子的degQ降低了菌株NCD-2对葡萄孢生长的抗真菌活性。为了阐明degQ对丰霉素生产的调节，我们通过框内突变删除了degQ。与野生型菌株NCD-2相比，degQ-null突变株的胞外蛋白酶和纤维素酶活性降低，对B的抑菌能力也有所下降。离体灰霉病来自degQ无效突变体的脂肽对B的抗真菌活性也显著降低。灰霉病的体外和体内研究。通过快速蛋白质液相色谱分析检测到的degQ无效突变体中芬枯草菌素产量的降低证实了这一结果。定量逆转录PCR进一步证明，degQ正调控丰霉素合成酶基因的表达。此外，相对于野生型菌株，degQ无效突变体还具有更平坦的菌落表型和显著降低的生物膜形成能力。通过在突变体中互补完整的degQ，可以将来自degQ无效突变体的所有这些特征恢复到菌株NCD-2野生型水平。因此，DegQ可能是B中丰霉素产生和生物膜形成的重要调节剂。枯草杆菌NCD-2。(C)2015 Elsevier GmbH. All rights reserved.
Bacillus subtilis NCD-2 is an excellent biocontrol agent for tomato gray mold and cotton soil-borne diseases. The fengycin lipopeptides serve as a major role in its biocontrol ability. A previous study revealed that insertion of degQwith the mini-Tn10 transposon decreased the antifungal activity of strain NCD-2 against the growth of Botrytis dnerea. To clarify the regulation of degQ on the production of fengycin, we deleted degQ by in-frame mutagenesis. Compared with the wild-type strain NCD-2, the degQ-null mutant had decreased extracellular protease and cellulase activities as well as antifungal ability against the growth of B. cinerea in vitro. The lipopeptides from the degQ-null mutant also had significantly decreased antifungal activity against B. cinerea in vitro and in vivo. This result was confirmed by the decreased fengycin production in the degQ-null mutant that was detected by fast protein liquid chromatography analysis. Quantitative reverse transcription PCR further demonstrated that degQ positively regulated the expression of the fengycin synthetase gene. In addition, the degQ-null mutant also had a flatter colony phenotype and significantly decreased biofilm formation ability relative to the wild-type strain. All of those characteristics from degQ-null mutant could be restored to the strain NCD-2 wild-type level by complementation of intact degQ in the mutant. Therefore, DegQ may be an important regulator of fengycin production and biofilm formation in B. subtilis NCD-2. (C) 2015 Elsevier GmbH. All rights reserved.