Root-secreted spermine binds to Bacillus amyloliquefaciens SQR9 histidine kinase KinD and modulates biofilm formation.
Root-secreted spermine binds to Bacillus amyloliquefaciens SQR9 histidine kinase KinD and modulates biofilm formation.
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根部分泌的精胺与解淀粉芽孢杆菌 SQR9 组氨酸激酶 KinD 结合并调节生物膜形成。
DOI：
10.1094/mpmi-07-19-0201-r
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发表时间：
2019-11
影响因子：
3.5
通讯作者：
Zhang Ruifu
中科院分区：
文献类型：
--
作者：
Liu Yunpeng;Feng Haichao;Chen Lin;Zhang Huihui;Dong Xiaoyan;Xiong Qin;Zhang Ruifu
根分泌物中的信号分子是根际促生细菌（PGPR）调控根际定殖的关键。磷酸化Spo 0A是芽孢杆菌属物种中控制定殖和孢子形成的重要全局转录调节因子。在这项研究中，我们发现，从PGPR菌株解淀粉芽孢杆菌SQR 9，编码Spo 0A的原始磷酸盐供体的kinD的缺失，导致减少生物膜形成的根分泌物相比，野生型菌株，表明KinD是负责感测根分泌物。B的配体。通过非靶向配体钓取法和靶向表面等离子体共振（SPR）检测法测定黄瓜根系分泌物中的解淀粉酶SQR 9 KinD。总之，我们筛选了根分泌物中与KinD结合的80种化合物，发现精胺和鸟苷可以分别以213 μM和51 μ M的KD值与KinD结合。此外，L-苏糖酸钙、N-乙酰-L-天冬氨酸、癸酸钠和对羟基苯甲酸也能与KinD弱结合。然后，构建了三维结合模型，以证明根分泌信号和KinD之间的相互作用。观察到当kinD缺陷时，外源精胺减少了生物膜的皱纹，这表明KinD可能参与感应根分泌的精胺并稳定生物膜以响应这种负效应物。本研究为根际细菌传感器与根系分泌信号的相互作用提供了新的视角。
The signal molecules in root exudates that are sensed by plant growth-promoting rhizobacteria (PGPRs) are critical to regulate their root colonization. Phosphorylated Spo0A is an important global transcriptional regulator that controls colonization and sporulation in Bacillus species. In this study, we found that deletion of kinD from PGPR strain Bacillus amyloliquefaciens SQR9, encoding an original phosphate donor of Spo0A, resulted in reduced biofilm formation in root exudates compared with the wild type strain, indicating that KinD is responsible for sensing root exudates. Ligands of B. amyloliquefaciens SQR9 KinD in cucumber root exudates were determined by both the non-targeted ligand fishing method and the targeted surface plasmon resonance (SPR) detection method. In total, we screened 80 compounds in root exudates for binding to KinD and found that spermine and guanosine could bind to KinD with KD values of 213 μM and 51 μΜ, respectively. In addition, calcium L-threonate, N-acetyl-L-aspartic acid, sodium decanoic acid and parabanic acid could also bind to KinD weakly. Then, the 3-dimensional binding models were constructed to demonstrate the interactions between the root secreted signals and KinD. It was observed that exogenous spermine reduced the wrinkles of biofilm when kinD was defected, indicating that KinD might be involved in sensing root-secreted spermine and stabilizing biofilm in response to this negative effector. This study provided a new insight of interaction between rhizobacterial sensor and root secreted signals.