Pseudomonas fluorescens 2P24 is a rhizosphere bacterium that produces 2,4-diacetyphloroglucinol (2,4-DAPG) as the decisive secondary metabolite to suppress soilborne plant diseases. The biosynthesis of 2,4-DAPG is strictly regulated by the RsmA family proteins RsmA and RsmE. However, mutation of both of rsmA and rsmE genes results in reduced bacterial growth. In this study, we showed that overproduction of 2,4-DAPG in the rsmA rsmE double mutant influenced the growth of strain 2P24. This delay of growth could be partially reversal when the phlD gene was deleted or overexpression of the phlG gene encoding the 2,4-DAPG hydrolase in the rsmA rsmE double mutant. RNA-seq analysis of the rsmA rsmE double mutant revealed that a substantial portion of the P. fluorescens genome was regulated by RsmA family proteins. These genes are involved in the regulation of 2,4-DAPG production, cell motility, carbon metabolism, and type six secretion system. These results suggest that RsmA and RsmE are the important regulators of genes involved in the plant-associated strain 2P24 ecologic fitness and operate a sophisticated mechanism for fine-tuning the concentration of 2,4-DAPG in the cells.

中文翻译：

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RsmA和RsmE蛋白在荧光假单胞菌2P24中的多效性效应。

荧光假单胞菌2P24是根际细菌，可产生2,4-二乙酰基间叶三酚（2,4-DAPG）作为抑制土壤植物病害的决定性次要代谢产物。RsmA家族蛋白RsmA和RsmE严格调节2,4-DAPG的生物合成。但是，rsmA和rsmE基因的突变都会导致细菌生长减少。在这项研究中，我们表明rsmA rsmE双突变体中2,4-DAPG的过量生产影响了菌株2P24的生长。当删除了phlD基因或在rsmA rsmE双突变体中编码2，4-DAPG水解酶的phlG基因过表达时，这种生长延迟可能会部分逆转。rsmA rsmE双重突变体的RNA-seq分析显示，荧光假单胞菌基因组的很大一部分受RsmA家族蛋白调控。这些基因参与了2,4-DAPG的产生，细胞运动，碳代谢和六型分泌系统的调控。这些结果表明，RsmA和RsmE是参与植物相关菌株2P24生态适应性的重要基因调节剂，并具有精细调节细胞中2,4-DAPG浓度的精密机制。