Transcriptomic consequence of the mutation in the response regulator gene gacA of the two-component regulatory system GacS/GacA in the rhizosphere biocontrol strain Pseudomonas aeruginosa M18. Pseudomonas aeruginosa M18

To investigate the influence of GacA on the genome-wide transcription of the rhizobacterium P. aeruginosa M18, DNA microarray experiments were carried out to compare the transcriptional profile of M18 with that of the gacA mutant grown to the early stationary phase (OD600 = 5.0 ~ 5.5) in KMB media. When compared with the M18 parental strain, the transcriptomic profile of gacA mutant revealed the significantly differential expression (increased or decreased by at least 2-fold as well as p-value < 0.05) of 839 genes, which represent approximately 15% of all 5696 annotated genes in the M18 genome. Of these 839 genes, 472 were downregulated and 367 genes were upregulated by the gacA mutation. Overall design: P. aeruginosa M18 and its gacA mutant were grown to OD600=5.0-5.5 (early stationary phase) in KMB medium at 28℃. Three independent experiments were performed at each time.

为探究GacA对根际细菌铜绿假单胞菌（P. aeruginosa）M18全基因组转录的影响，本研究开展DNA微阵列（DNA microarray）实验，比较M18亲本菌株与其gacA突变株在KMB培养基中生长至早期稳定期（OD600=5.0~5.5）的转录组谱。与M18亲本菌株相比，gacA突变株的转录组谱显示，共有839个基因出现显著差异表达（表达变化幅度至少为2倍，且p值<0.05），约占M18基因组中全部5696个注释基因的15%。其中472个基因在gacA突变后表达下调，367个基因表达上调。整体实验设计：将铜绿假单胞菌M18及其gacA突变株于28℃下在KMB培养基中培养至OD600=5.0~5.5（早期稳定期），每组设置3次独立实验。