Aboudrar W, Schwartz C, Benizri E, Morel J L, Boularbah A
University Cadi Ayyad, Faculté des Sciences et Techniques Marrakech, Département de Biologie, Marrakech, Morocco.
Int J Phytoremediation. 2007 Jan-Feb;9(1):41-52. doi: 10.1080/15226510601139417.
It is hypothesized that metal hyperaccumulator plants have specific rhizosphere conditions, potentially modifying the bioavailability of soil metals. This article aims to further the knowledge about the rhizosphere of the hyperaccumulator Thlaspi caerulescens, focusing on its microflora isolated from metalliferous soils collected in situ where the plants grow naturally. We characterized the cultivable microbial communities isolated from the rhizosphere of one population of this Ni hyperaccumulator species grown on a serpentine soil. The rhizosphere soil harbored a wide variety of microorganisms, predominantly bacteria, confirming the stimulatory effect of the T. caerulescens rhizosphere on microbial growth and proliferation. We tested the hypothesis that the rhizosphere of T. caerulescens influences (1) the metabolic diversity of the bacterial community and (2) the bacterial resistance to metals. The principal component analysis of the Biolog plate's data confirmed a structural effect of the rhizosphere of T. caerulescens on bacterial communities. The percentage of Ni-resistant bacteria was higher in the rhizosphere than in the bulk soil, suggesting a direct effect of the rhizosphere on Ni tolerance, reflecting a greater bacterial tolerance to Ni in the rhizosphere.
据推测，金属超积累植物具有特定的根际条件，可能会改变土壤金属的生物有效性。本文旨在进一步了解超积累植物天蓝遏蓝菜的根际情况，重点关注从植物自然生长的原位金属土壤中分离出的微生物群落。我们对从生长在蛇纹石土壤上的该镍超积累植物种群的根际分离出可培养微生物群落进行了表征。根际土壤中含有各种各样的微生物，主要是细菌，这证实了天蓝遏蓝菜根际对微生物生长和繁殖的刺激作用。我们检验了以下假设：天蓝遏蓝菜的根际会影响（1）细菌群落的代谢多样性以及（2）细菌对金属的抗性。对Biolog平板数据的主成分分析证实了天蓝遏蓝菜根际对细菌群落的结构效应。根际中耐镍细菌的百分比高于非根际土壤，这表明根际对镍耐受性有直接影响，反映出根际中细菌对镍具有更高的耐受性。
