Rangel Wesley M, Thijs Sofie, Janssen Jolien, Oliveira Longatti Silvia M, Bonaldi Daiane S, Ribeiro Paula R A, Jambon Inge, Eevers Nele, Weyens Nele, Vangronsveld Jaco, Moreira Fatima M S
a Biology Department , Federal University of Lavras (UFLA) , Lavras , Minas Gerais , Brazil.
b Soil Science Department, Department , Federal University of Lavras (UFLA) , Lavras , Minas Gerais , Brazil.
Int J Phytoremediation. 2017 Feb;19(2):142-156. doi: 10.1080/15226514.2016.1207600.
Plants on contaminated mining soils often show a reduced growth due to nutrient depletion as well as trace elements (TEs) toxicity. Since those conditions threat plant's survival, plant growth-promoting rhizobacteria (PGPRs), such as rhizobia, might be of crucial importance for plant colonization on TE-contaminated soils. Native rhizobia from mining soils are promising candidates for bioaugmented phytoremediation of those soils as they are adapted to the specific conditions. In this work, rhizobia from Zn- and Cd-contaminated mining soils were in vitro screened for their PGP features [organic acids, indole-3-acetic acid (IAA), and siderophore (SID) production; 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity; and Ca(PO) solubilization] and Zn and Cd tolerance. In addition, some type and reference rhizobia strains were included in the study as well. The in vitro screening indicated that rhizobia and other native genera have great potential for phytoremediation purposes, by exerting, besides biological N fixation, other plant growth-promoting traits. Leucaena leucocephala-Mesorhizobium sp. (UFLA 01-765) showed multielement tolerance and an efficient symbiosis on contaminated soil, decreasing the activities of antioxidative enzymes in shoots. This symbiosis is a promising combination for phytostabilization.
受污染矿区土壤上的植物通常因养分耗尽以及微量元素（TEs）毒性而生长减缓。由于这些状况威胁到植物的生存，促进植物生长的根际细菌（PGPRs），如根瘤菌，对于植物在受TEs污染土壤上的定殖可能至关重要。来自矿区土壤的本地根瘤菌是这些土壤生物强化植物修复的有前景的候选者，因为它们适应特定条件。在这项工作中，对来自锌和镉污染矿区土壤的根瘤菌进行了体外筛选，以检测其植物生长促进特性[有机酸、吲哚-3-乙酸（IAA）和铁载体（SID）的产生；1-氨基环丙烷-1-羧酸（ACC）脱氨酶活性；以及Ca(PO)溶解]和对锌和镉的耐受性。此外，一些典型和参考根瘤菌菌株也被纳入研究。体外筛选表明，根瘤菌和其他本地属通过除生物固氮外发挥其他植物生长促进特性，在植物修复方面具有巨大潜力。银合欢-中生根瘤菌属（UFLA 01-765）在污染土壤上表现出多元素耐受性和高效共生，降低了地上部抗氧化酶的活性。这种共生关系是植物稳定化的一个有前景的组合。
