Siderophore Synthesis Ability of the Nitrogen-Fixing Bacterium (NFB) GXGL-4A is Regulated at the Transcriptional Level by a Transcriptional Factor (trX) and an Aminomethyltransferase-Encoding Gene (amt)
Siderophore Synthesis Ability of the Nitrogen-Fixing Bacterium (NFB) GXGL-4A is Regulated at the Transcriptional Level by a Transcriptional Factor (trX) and an Aminomethyltransferase-Encoding Gene (amt)
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固氮细菌 (NFB) GXGL-4A 的铁载体合成能力在转录水平上由转录因子 (trX) 和氨甲基转移酶编码基因 (amt) 调节
DOI：
10.1007/s00284-022-03080-4
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发表时间：
2022-10
影响因子：
2.6
通讯作者：
Yun-Peng Chen
中科院分区：
文献类型：
--
作者：
Bao-Yun Feng;Meng-Ting Zhang;Guo-Xun Su;Yu-Qing Bao;Yu Xu;Yun-Peng Chen
革兰氏阴性固氮菌Kosakonia radicitansGXGL-4A细胞壁表面被一层厚厚的荚膜，成为外源DNA进入细胞的物理屏障，遗传转化操作困难。本研究采用高渗HO-1培养基结合电穿孔技术，建立了一套优化的Tn 5转座子诱变体系。最终建立了一个包含1633个Tn 5插入突变体的突变体库。通过CAS琼脂平板法和分光光度法测定，发现突变株M81和M107合成铁载体的能力增强。将两个突变体的菌体应用于黄瓜促生试验。经M81和M107细胞处理的黄瓜幼苗的生物量（包括苗高、苗鲜重、根鲜重和根长）显著增加。对突变体M81和M107的全基因组测序结果表明，Tn 5转座子元件的整合位点分别位于GXGL-4A基因组中的MmyB类螺旋-转角-螺旋转录调控因子（locus tag：A3780_19720，trX）和氨甲基转移酶编码基因（locus tag：A3780_01680，amt）。Tn 5插入突变提高了目标突变体的铁载体合成能力，所获得的突变体在黄瓜幼苗上表现出良好的促生效果。结果表明，所鉴定的功能基因调控固氮菌GXGL-4A铁载体的生物合成，具体机制有待进一步研究。
Kosakonia radicincitansGXGL-4A, a gram-negative nitrogen-fixing (NF) bacterial strain is coated with a thick capsulatus on the surface of cell wall, which becomes a physical barrier for exogenous DNA to enter the cell, so the operation of genetic transformation is difficult. In this study, an optimized Tn5 transposon mutagenesis system was established by using a high osmotic HO-1 medium combined with the electroporation transformation. Eventually, a mutant library containing a total of 1633 Tn5 insertional mutants were established. Of these mutants, the mutants M81 and M107 were found to have an enhanced capability to synthesize siderophore through the CAS agar plate assay and the spectrophotometric determination. The bacterial cells of two mutants were applied in cucumber growth-promoting experiment. Cucumber seedlings treated with M81 and M107 cells had a significant increase in biomass including seedling height, seedling fresh weight, root fresh weight, and root length. The whole genome sequencing of the mutants M81 and M107 showed that the integration sites of Tn5 transposon element were located in MmyB-like helix-turn-helix transcription regulator (locus tag: A3780_19720,trX) and aminomethyltransferase-encoding genes (locus tag: A3780_01680,amt) in the genome of GXGL-4A, respectively. The ability of siderophore synthesis of the target mutants was improved by Tn5 insertion mutagenesis, and the mutants obtained showed a good plant growth-promoting effect when applied to the cucumber seedlings. The results suggest that the identified functional genes regulates the biosynthesis of siderophore in azotobacter GXGL-4A, and the specific mechanism needs to be further investigated.
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DOI：
10.3923/jm.2011.735.749
发表时间：
2011-10
期刊：
Research Journal of Microbiology
影响因子：
--
作者：
G. Sahu;S. Sindhu
通讯作者：
G. Sahu;S. Sindhu
影响因子：
--
作者：
I. Schalk;G. Mislin;K. Brillet
通讯作者：
I. Schalk;G. Mislin;K. Brillet
影响因子：
4.1
作者：
Chaiharn, Mathurot;Chunhaleuchanon, Somporn;Lumyong, Saisamorn
通讯作者：
Lumyong, Saisamorn
影响因子：
4.4
作者：
Meyer, JM;Geoffroy, VA;Palleroni, NJ
通讯作者：
Palleroni, NJ
Kosakonia radicincitans GXGL-4A（一种具有降解 TEX 能力的固氮细菌）的完整基因组序列
影响因子：
2.6
作者：
Chen, Yunpeng;Huang, Zhibo;Feng, Baoyun
通讯作者：
Feng, Baoyun