Grazing of protozoa on rhizosphere bacteria alters growth and reproduction of Arabidopsis thaliana
Grazing of protozoa on rhizosphere bacteria alters growth and reproduction of Arabidopsis thaliana
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根际细菌上原生动物的放牧改变了拟南芥的生长和繁殖
DOI：
10.1016/j.soilbio.2009.06.008
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发表时间：
2009
影响因子：
9.7
通讯作者：
S. Scheu
中科院分区：
文献类型：
--
作者：
K. Krome;K. Rosenberg;M. Bonkowski;S. Scheu
植物根际细菌是根际细菌食物网的基础，原生动物是最有效的捕食者。我们建立了一个定义明确的实验室系统，拟南芥为模式植物允许详细调查根际相互作用对植物性能的影响。我们用这个系统来分析自然根际细菌和原生动物卡氏阿米巴单独和联合对植物的影响。原生动物和细菌都能促进植物生长，其中原生动物的作用明显超过细菌。拟南芥立即响应原生动物的存在，增加碳，但不是氮的吸收。后来原生动物增强植物从有机物质中吸收氮，延长拟南芥的营养生长，导致种子产量大幅增加。它的结论是，植物的直接反应是基于根际信号的变化，诱导增加植物固碳，而不是原生动物介导的氮供应量的增加。随后增加的植物氮素吸收可能源于原生动物放牧，即土壤中的微生物循环提供的细菌生物量中固定的氮。这些结果表明，拟南芥通过增加碳固定和根碳分配为即将到来的氮动员做好了准备，这些碳分配后来通过增加养分捕获和强烈增加植物繁殖而得到回报。
Plant roots are densely colonized by bacteria which form the basis of the rhizosphere bacterial food web with protozoa as most effective predators. We established a well defined laboratory system with Arabidopsis thaliana as model plant allowing to investigate in detail the effect of rhizosphere interactions on plant performance. We used this system to analyse separate and combined effects of natural rhizobacteria and the protozoa Acanthamoeba castellanii on plants. Protozoa and bacteria increased plant growth with the effect of protozoa markedly exceeding that of bacteria only. Arabidopsis immediately responded to the presence of protozoa by increasing carbon but not nitrogen uptake. Later protozoa enhanced plant uptake of nitrogen from organic material and prolonged vegetative growth of Arabidopsis resulting in strongly increased seed production. It is concluded that the immediate plant response was based on changes in rhizosphere signalling inducing increased plant carbon fixation rather than on protozoa-mediated increase in nitrogen availability. The subsequently increased plant nitrogen uptake presumably originated from nitrogen fixed in bacterial biomass made available by protozoan grazing, i.e. the microbial loop in soil. The results suggest that Arabidopsis prepared for the upcoming mobilization of nitrogen by increasing carbon fixation and root carbon allocation which paid-off later by increased nutrient capture and strongly increased plant reproduction.
影响因子：
11.6
作者：
HENSEL, LL;GRBIC, V;BLEECKER, AB
通讯作者：
BLEECKER, AB