Institute of Botany ASCR, Zámek 1, 252 43, Průhonice, Czech Republic.
University of Chemistry and Technology Prague, Technická 5, 166 28, Praha 6, Czech Republic.
Microb Ecol. 2018 May;75(4):955-969. doi: 10.1007/s00248-017-1103-y. Epub 2017 Nov 10.
Numerous studies demonstrated that endophytic microbes can promote plant growth and increase plant stress resistance. We aimed at isolating poplar endophytes able to increase their hosts' fitness both in nutrient-limited and polluted environments. To achieve this goal, endophytic bacteria and fungi were isolated from roots and leaves of hybrid poplars (Populus nigra × P. maximowiczii clone Max-4) on an unpolluted and a risk element-polluted site in the Czech Republic and subsequently screened by a number of in vitro tests. Bacterial communities at the unpolluted site were dominated by Gammaproteobacteria with Pseudomonas sp. as the prominent member of the class, followed by Bacilli with prevailing Bacillus sp., whereas Alphaproteobacteria, mostly Rhizobium sp., prevailed at the polluted site. The fungal endophytic community was dominated by Ascomycetes and highly distinct on both sites. Dothideomycetes, mostly Cladosporium, prevailed at the non-polluted site while unclassified Sordariomycetous fungi dominated at the polluted site. Species diversity of endophytes was higher at the unpolluted site. Many tested endophytic strains solubilized phosphate and produced siderophores, phytohormones, and antioxidants. Some strains also exhibited ACC-deaminase activity. Selected bacteria showed high tolerance and the ability to accumulate risk elements, making them promising candidates for use in inocula promoting biomass production and phytoremediation. Graphical Abstract ᅟ.
许多研究表明，内生微生物可以促进植物生长并提高植物的抗逆性。我们的目的是从捷克共和国未受污染和受风险元素污染的地点的杂交杨树（黑杨×毛白杨克隆 Max-4）的根和叶中分离出能够提高其宿主在营养受限和污染环境中的适应性的杨树内生菌。为了实现这一目标，从捷克共和国未受污染和受风险元素污染的地点的杂交杨树（黑杨×毛白杨克隆 Max-4）的根和叶中分离出内生细菌和真菌，随后通过多项体外试验进行筛选。未受污染地点的细菌群落主要由γ变形菌门组成，假单胞菌属是该门的主要成员，其次是芽孢杆菌门，优势菌属为芽孢杆菌属，而受污染地点的细菌群落主要由α变形菌门，主要是根瘤菌属。内生真菌群落主要由子囊菌门组成，在两个地点都有很大的差异。未受污染地点以无性型的外囊菌属为主，而受污染地点以未分类的Sordariomycetes 真菌为主。内生菌的物种多样性在未受污染的地点更高。许多测试的内生菌株可以溶解磷酸盐并产生铁载体、植物激素和抗氧化剂。一些菌株还表现出 ACC 脱氨酶活性。一些选定的细菌表现出高耐受性和积累风险元素的能力，使它们成为促进生物量生产和植物修复的接种物的有前途的候选物。
