Enhanced removal of nitrate in the maize rhizosphere by plant growth-promoting Bacillus megaterium NCT-2, and its colonization pattern in response to nitrate
Enhanced removal of nitrate in the maize rhizosphere by plant growth-promoting Bacillus megaterium NCT-2, and its colonization pattern in response to nitrate
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促进植物生长的巨大芽孢杆菌NCT-2增强玉米根际硝酸盐去除及其响应硝酸盐的定植模式
DOI：
10.1016/j.chemosphere.2018.05.189
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发表时间：
2018-10-01
期刊：
影响因子：
8.8
通讯作者：
Zhou, Pei
中科院分区：
文献类型：
--
作者：
Chu, Shaohua;Zhang, Dan;Zhou, Pei
高土壤硝酸盐浓度会导致土壤的次要盐水。 Megaterium nct-2是一种从二级盐水分离的野生型菌株，在减少硝酸盐方面非常有效。进行了实验室和温室实验，以研究其硝酸盐还原能力，定殖模式和植物生长促进对土壤中硝酸盐含量的促进反应。 B. Megaterium NCT-2用绿色荧光蛋白（GFP）基因标记，并成功地将玉米根和根际定居。用GFP标记的NCT-2接种可显着促进从土壤中去除硝酸盐并改善植物生长。共聚焦显微镜结果表明，NCT-2是一种内生菌，可以定居于根尖的分生和伸长区，以及根的中间部分。土壤硝酸盐浓度对NCT-2分布没有显着影响。根部和根际土壤中的GFP标记的NCT-2种群首先增加，但随后减少，在实验结束时，根际土壤中的定植水平在与5 x 10（4）CFU G（-1）的土壤相似。但是，根中的水平再次增加到不同处理中的1-3 x 10（4）cfu g（-1）。根中的NCT-2人群受硝酸盐含量的显着影响。 72 mg kg（-1）的硝酸盐氮浓度是玉米根NCT-2定殖的最佳浓度。这项研究将改善NCT-2作为硝酸盐去除和植物生长促进的农业应用。 （c）2018 Elsevier Ltd.保留所有权利。
High soil nitrate concentrations can lead to the secondary salinization of soils. Bacillus megaterium NCT-2 is a wild-type strain isolated from secondary salinized soil and is very effective in reducing nitrate. Laboratory and greenhouse experiments were carried out to investigate its nitrate reduction capabilities, colonization pattern, and plant growth promotion responses to nitrate content in the soil. B. megaterium NCT-2 was marked with a green fluorescent protein (gfp) gene and was left to successfully colonize maize roots and the rhizosphere. Inoculation with gfp-tagged NCT-2 significantly promoted nitrate removal from the soil and improved plant growth. Confocal microscopy results revealed that NCT-2 is an endophyte that can colonize the meristematic and elongation zones of the root tip, and the middle segment of the root. Soil nitrate concentration had no significant effect on NCT-2 distribution. The gfp-tagged NCT-2 populations in the roots and rhizosphere soil first increased, but then decreased, and at the end of the experiment, colonization levels in the rhizosphere soil stabilized at similar to 5 x 10(4) CFU g(-1) soil. However, the levels in the roots increased again to 1-3 x 10(4) CFU g(-1) root in the different treatments. The NCT-2 population in the roots was significantly affected by nitrate content. A nitrate-nitrogen concentration of 72 mg kg(-1) was the optimum concentration for NCT-2 colonization of maize roots. This study will improve the agricultural application of NCT-2 as a biofertilizer for nitrate removal and plant growth promotion. (C) 2018 Elsevier Ltd. All rights reserved.