The PhoR/PhoP two-component system regulates fengycin production in Bacillus subtilis NCD-2 under low-phosphate conditions
The PhoR/PhoP two-component system regulates fengycin production in Bacillus subtilis NCD-2 under low-phosphate conditions
复制标题
PhoR/PhoP 双组分系统在低磷酸盐条件下调节枯草芽孢杆菌 NCD-2 中风霉素的产生
DOI：
10.1016/s2095-3119(17)61669-1
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发表时间：
2018-01-01
影响因子：
4.8
通讯作者：
Ma Ping
中科院分区：
文献类型：
--
作者：
Guo Qing-gang;Dong Li-hong;Ma Ping
枯草芽孢杆菌NCD-2菌株是防治植物土传病害的优良生防剂，脂肽风霉素是NCD-2菌株中具有抗真菌活性的化合物之一。在枯草杆菌中，调节因子Phop和它的传感器激酶phor组成了一个双组分系统。本研究通过框内缺失的方法构建了phor和Phop基因敲除突变体，并研究了phor/Phop基因在风霉素合成中的作用。与菌株NCD-2野生型相比，枯草杆菌中Phor或Phop的失活降低了其在体外对灰霉病菌生长的抑制能力。用盐酸沉淀法从菌株NCD-2野生型及其突变株中提取脂肽，与菌株NCD-2野生型脂肽相比，phor缺失突变株和Phop缺失突变株的脂肽几乎失去了对灰霉病菌生长的抑制作用。脂肽的快速蛋白质液相色谱(FPLC)分析表明，phor或Phop基因的失活降低了菌株NCD-2的风霉素产量。比较了细菌在低磷和高磷条件下的产毒能力。结果表明，Phor/Phop双组分体系对凤霉素产生的调节作用发生在LPM中，而不是HPM中。逆转录-聚合酶链式反应证实，在LPM培养条件下，峰霉素合成酶基因fenC受Phop正向调控。通过在突变体中补充完整的phor或Phop基因，所有这些特征都可以部分恢复。这些数据表明，Phor/Phop双组分系统主要在低磷条件下对枯草芽孢杆菌NCD-2的峰霉素产量和抗真菌能力起到很大的调节作用。
Bacillus subtilis strain NCD-2 is an excellent biocontrol agent for plant soil-borne diseases, and the lipopeptide fengycin is one of the active antifungal compounds in strain NCD-2. The regulator PhoP and its sensor kinase PhoR compose a two-component system in B. subtilis. In this study, the phoR-and phoP-knockout mutants were constructed by in-frame deletion and the role of PhoR/PhoP on the production of fengycin was determined. Inactivation of phoR or phoP in B. subtilis decreased its inhibition ability against Botrytis cinerea growth in vitro compared to the strain NCD-2 wild type. The lipopeptides were extracted from strain NCD-2 wild type and its mutant strains by hydrochloric acid precipitate, and the lipopeptides from phoR-null mutant or phoP-null mutant almost lost the inhibition ability against B. cinerea growth compared to the lipopeptides from strain NCD-2 wild type. Fast protein liquid chromatography (FPLC) analysis of the lipopeptides showed that inactivation of phoR or phoP genes reduced the production of fengycin by strain NCD-2. The fengycin production abilities were compared for bacteria under low-phosphate medium (LPM) and high-phosphate medium (HPM), respectively. Results indicated that the regulation of fengycin production by the PhoR/PhoP two-component system occurred in LPM but not in HPM. Reverse transcriptional-PCR confirmed that the fengycin synthetase gene fenC was positively regulated by phoP when cultured in LPM. All of these characteristics could be partially restored by complementation of intact phoR or phoP gene in the mutant. These data indicated that the PhoR/PhoP two-component system greatly regulated fengycin production and antifungal ability in B. subtilis NCD-2 mainly under low-phosphate conditions.