Role of the GacS Sensor Kinase in the Regulation of Volatile Production by Plant Growth-Promoting Pseudomonas fluorescens SBW25
Role of the GacS Sensor Kinase in the Regulation of Volatile Production by Plant Growth-Promoting Pseudomonas fluorescens SBW25
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DOI：
10.3389/fpls.2016.01706
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发表时间：
2016-11-18
影响因子：
5.6
通讯作者：
Raaijmakers, Jos M.
中科院分区：
文献类型：
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作者：
Cheng, Xu;Cordovez, Viviane;Raaijmakers, Jos M.
在植物相关的假单胞菌物种中，几种次生代谢物和外酶的产生受GacS/GacA双组分调节系统（gac -系统）的调节。在这里，我们研究了GacS传感器激酶的突变是否会影响P荧光SBW25 （f.SBW25）中挥发性有机化合物（VOCs）的产生，以及这种突变如何影响VOCs介导的生长促进和诱导拟南芥和烟草的系统性抗性。pfsbw25和gacS突变体分别在两种不同培养基上培养3天和6天，通过气相色谱-质谱法共检测到205种挥发性有机化合物。分级聚类后的判别函数分析显示，pff . sbw25与gacs -突变体之间有24种VOCs丰度显著不同，其中包括3-壬烯、4-十一烯、1-十一烯3种无环烯烃。这些烯烃被gacS突变显著减少，与生长介质和孵育时间无关。对于拟南芥，pff . sbw25和gacs -突变体均通过挥发性有机化合物（VOCs）增强根和茎生物量，诱导其对紫丁香叶侵染和根际酸化的系统性抗性。而在烟草中，挥发性有机化合物（vocs）对烟草茎和根生长的影响在f. sbw25和gacs -突变体之间存在显著差异。与未处理对照植株相比，Pf.SBW25突变体抑制烟草根系生长，而gacs -突变体增加了根生物量和侧根形成。这些结果表明，传感器激酶GacS参与了P1中VOCs产生的调节。SBW25，以植物物种依赖的方式影响植物生长。
In plant-associated Pseudomonas species, the production of several secondary metabolites and exoenzymes is regulated by the GacS/GacA two-component regulatory system (the Gac-system). Here, we investigated if a mutation in the GacS sensor kinase affects the production of volatile organic compounds (VOCs) in P fluorescens SBW25 (Pf.SBW25) and how this impacts on VOCs-mediated growth promotion and induced systemic resistance of Arabidopsis and tobacco. A total of 205 VOCs were detected by Gas Chromatography Mass Spectrometry for Pf SBW25 and the gacS mutant grown on two different media for 3 and 6 days. Discriminant function analysis followed by hierarchical clustering revealed 24 VOCs that were significantly different in their abundance between Pf.SBW25 and the gacS-mutant, which included three acyclic alkenes (3-nonene, 4-undecyne, 1-undecene). These alkenes were significantly reduced by the gacS mutation independently of the growth media and of the incubation time. For Arabidopsis, both Pf.SBW25 and the gacS-mutant enhanced, via VOCs, root and shoot biomass, induced systemic resistance against leaf infections by P syringae and rhizosphere acidification to the same extent. For tobacco, however, VOCs-mediated effects on shoot and root growth were significantly different between Pf.SBW25 and the gacS-mutant. While Pf.SBW25 inhibited tobacco root growth, the gacS-mutant enhanced root biomass and lateral root formation relative to the non-treated control plants. Collectively these results indicate that the sensor kinase GacS is involved in the regulation of VOCs production in P1.SBW25, affecting plant growth in a plant species-dependent manner.