Calderón Claudia E, Carrión Víctor J, de Vicente Antonio, Cazorla Francisco M
Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas. Departamento de Microbiología, Facultad de Ciencias, Campus de Teatinos s/n, 29071 Málaga, Spain.
Microbiology (Reading). 2014 Dec;160(Pt 12):2670-2680. doi: 10.1099/mic.0.082677-0. Epub 2014 Sep 17.
Pseudomonas chlororaphis PCL1606 synthesizes the antifungal antibiotic 2-hexyl, 5-propyl resorcinol (HPR), which is crucial for the biocontrol of fungal soil-borne pathogens. The genetic basis for HPR production lies in the dar genes, which are directly involved in the biosynthesis of HPR. In the present study, we elucidated the genetic features of the dar genes. Reverse transcription PCR experiments revealed an independent organization of the dar genes, except for darBC, which was transcribed as a polycistronic mRNA. In silico analysis of each gene revealed putative promoters and terminator sequences, validating the proposed gene arrangement. Moreover, experiments utilizing 5' rapid amplification of cDNA ends were used to determine the transcriptional initiation sites for the darA, darBC, darS and darR gene promoters, and subsequently to confirm the functionality of these regions. The results of quantitative real-time PCR experiments indicated that biosynthetic dar genes were not only modulated through the global regulator gacS, but also through darS and darR. The interplay between darS and darR revealed transcriptional cross-inhibition. However, these results also showed that other regulatory parameters play a role in HPR production, such as the environmental conditions and additional regulatory genes.
绿针假单胞菌PCL1606合成抗真菌抗生素2-己基-5-丙基间苯二酚（HPR），这对于土壤传播的真菌病原体的生物防治至关重要。HPR产生的遗传基础在于dar基因，其直接参与HPR的生物合成。在本研究中，我们阐明了dar基因的遗传特征。逆转录PCR实验揭示了dar基因的独立组织，但darBC除外，它被转录为多顺反子mRNA。对每个基因的电子分析揭示了推定的启动子和终止子序列，验证了所提出的基因排列。此外，利用5' cDNA末端快速扩增实验来确定darA、darBC、darS和darR基因启动子的转录起始位点，并随后确认这些区域的功能。定量实时PCR实验结果表明，生物合成dar基因不仅通过全局调节因子gacS进行调节，还通过darS和darR进行调节。darS和darR之间的相互作用揭示了转录交叉抑制。然而，这些结果还表明，其他调节参数在HPR产生中起作用，如环境条件和其他调节基因。
