Posttranscriptional Regulation of 2,4-Diacetylphloroglucinol Production by GidA and TrmE in Pseudomonas fluorescens 2P24
Posttranscriptional Regulation of 2,4-Diacetylphloroglucinol Production by GidA and TrmE in Pseudomonas fluorescens 2P24
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DOI：
10.1128/aem.00455-14
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发表时间：
2014-04
影响因子：
4.4
通讯作者：
Wei Zhang;Zhao Zhao-Zhao;Bo Zhang;Xiaogang Wu;Z. Ren;Li-qun Zhang
中科院分区：
文献类型：
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作者：
Wei Zhang;Zhao Zhao-Zhao;Bo Zhang;Xiaogang Wu;Z. Ren;Li-qun Zhang
摘要荧光假单胞菌2P24是一种能合成和分泌多种抗菌代谢产物的土生细菌。由phlACBD基因座合成的聚酮类化合物2，4-二乙酰间苯三酚(2，4-DAPG)是其主要生防决定子。本研究对两株拮抗立枯丝核菌的突变体进行了研究。菌株2P24的gida(PM701)或trmE(PM702)基因的缺失完全抑制了2，4-DAPG及其前体单乙酰间苯三酚(MAPG)和间苯三酚(PG)的产生。Phla基因的转录没有受到影响，但Phla和phlD基因的翻译显著减少。Gac/RSM途径的两个组分RSMA和RSME受GIDA和trmE的调控，而其他组分RsmX、RsmY和RsmZ则不受调控。然而，GIDA和trmE对2，4-DAPG产生的调节不依赖于Gac/RSM途径。突变株gida和trmE均不能产生PG，但能将PG转化为MAPG，将MAPG转化为2，4-DAPG。在gida和trmE突变体中过表达PhlD可以恢复PG和2，4-DAPG的产生。综上所述，这些发现表明GIDA和TrmE是在转录后影响2，4-DAPG生物合成的正调控元件。
ABSTRACT Pseudomonas fluorescens 2P24 is a soilborne bacterium that synthesizes and excretes multiple antimicrobial metabolites. The polyketide compound 2,4-diacetylphloroglucinol (2,4-DAPG), synthesized by the phlACBD locus, is its major biocontrol determinant. This study investigated two mutants defective in antagonistic activity against Rhizoctonia solani. Deletion of the gidA (PM701) or trmE (PM702) gene from strain 2P24 completely inhibited the production of 2,4-DAPG and its precursors, monoacetylphloroglucinol (MAPG) and phloroglucinol (PG). The transcription of the phlA gene was not affected, but the translation of the phlA and phlD genes was reduced significantly. Two components of the Gac/Rsm pathway, RsmA and RsmE, were found to be regulated by gidA and trmE, whereas the other components, RsmX, RsmY, and RsmZ, were not. The regulation of 2,4-DAPG production by gidA and trmE, however, was independent of the Gac/Rsm pathway. Both the gidA and trmE mutants were unable to produce PG but could convert PG to MAPG and MAPG to 2,4-DAPG. Overexpression of PhlD in the gidA and trmE mutants could restore the production of PG and 2,4-DAPG. Taken together, these findings suggest that GidA and TrmE are positive regulatory elements that influence the biosynthesis of 2,4-DAPG posttranscriptionally.