Diazotrophic endophytes of native black cottonwood and willow
Diazotrophic endophytes of native black cottonwood and willow
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DOI：
10.1007/bf03179967
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发表时间：
2009-01-01
期刊：
影响因子：
2.5
通讯作者：
Staley, James T.
中科院分区：
文献类型：
--
作者：
Doty, Sharon L.;Oakley, Brian;Staley, James T.
杨树和柳树是经济上重要的、生长快速的树种，能够在营养贫乏的环境中定居。为了研究内生菌对这种能力的可能贡献，我们从华盛顿州西部河岸系统的本地杨树（Populus trichocarpa）和柳树（Salix satchensis）的表面灭菌茎中分离出细菌。一些分离株在限氮培养基中生长良好。 nifH（一种编码固氮酶亚基之一的基因）的存在已在包括伯克霍尔德氏菌、雷氏菌、鞘氨醇单胞菌和不动杆菌等多种分离株中得到证实。一些分离株也证实了固氮酶活性（通过乙炔还原测定测定）。这些固氮微生物的存在可能有助于解释这些开创性树种在氮限制下生长的能力。
Poplar and willow are economically-important, fast-growing tree species with the ability to colonize nutrient-poor environments. To initiate a study on the possible contribution of endophytes to this ability, we isolated bacteria from within surface-sterilized stems of native poplar (Populus trichocarpa) and willow (Salix sitchensis) in a riparian system in western Washington state. Several of the isolates grew well in nitrogen-limited medium. The presence of nifH, a gene encoding one of the subunits of nitrogenase, was confirmed in several of the isolates including species of Burkholderia, Rahnella, Sphingomonas, and Acinetobacter. Nitrogenase activity (as measured by the acetylene reduction assay) was also confirmed in some of the isolates. The presence of these diazotrophic microorganisms may help explain the ability of these pioneering tree species to grow under nitrogen limitation.