Dark septate endophytic(DSE) fungi are ubiquitous and cosmopolitan, and occur widely in association with plants in heavy metal stress environment. However, little is known about the effect of inoculation with DSE fung...Dark septate endophytic(DSE) fungi are ubiquitous and cosmopolitan, and occur widely in association with plants in heavy metal stress environment. However, little is known about the effect of inoculation with DSE fungi on the host plant under heavy metal stress.In this study, Gaeumannomyces cylindrosporus, which was isolated from Pb-Zn mine tailings in China and had been proven to have high Pb tolerance, was inoculated onto the roots of maize(Zea mays L.) seedlings to study the effect of DSE on plant growth, photosynthesis,and the translocation and accumulation of Pb in plant under stress of different Pb concentrations. The growth indicators(height, basal diameter, root length, and biomass) of maize were detected. Chlorophyll content, photosynthetic characteristics(net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO_2 concentration), and chlorophyll fluorescence parameters in leaves of the inoculated and non-inoculated maize were also determined. Inoculation with G. cylindrosporus significantly increased height,basal diameter, root length, and biomass of maize seedlings under Pb stress. Colonization of G. cylindrosporus improved the efficiency of photosynthesis and altered the translocation and accumulation of Pb in the plants. Although inoculation with G. cylindrosporus increased Pb accumulation in host plants in comparison to non-inoculated plants, the translocation factor of Pb in plant body was significantly decreased. The results indicated that Pb was accumulated mainly in the root system of maize and the phytotoxicity of Pb to the aerial part of the plant was alleviated. The improvement of efficiency of photosynthesis and the decrease of translocation factor of Pb, caused by DSE fungal colonization, were efficient strategies to improve Pb tolerance of host plants.展开更多
Over the last three decades, the presence and functional roles of arbuscular mycorrhizal(AM) fungi in wetland habitats have received increasing attention. This review summarized the mycorrhizal status in wetlands and ...Over the last three decades, the presence and functional roles of arbuscular mycorrhizal(AM) fungi in wetland habitats have received increasing attention. This review summarized the mycorrhizal status in wetlands and the effect of flooding on AM fungal colonization. Plants of 99 families living in 31 different habitats have been found to be associated with AM fungi, even including submerged aquatic plants and several plant species that were thought to be nonmycorrhizal(Cyperaceae, Chenopodiaceae, and Plumbaginaceae). The functions of AM fungi in wetland ecological systems could be concluded as their influences on the composition,succession, and diversity of the wetland plant community, and the growth and nutrition of wetland plants. Affecting the composition,succession, and diversity of the wetland plant community, AM fungi have positive, negative, or neutral effects on the performance of different wetland species under different conditions. The factors that affect the application effect of AM fungi in constructed wetland(CW) include flooding, phosphorus, plant species, aerenchyma, salinity, CW types, operation modes of CW, and wastewater quality.The generalist AM fungi strains can be established spontaneously, rapidly, and extensively in wastewater bioremediation technical installations; therefore, AM fungi can be considered ideal inhabitants of technical installations for the plant-based bioremediation of groundwater contaminated by organic pollutants or other contaminants. In the future, roles of AM fungi and factors that affect the purifying capacity of AM-CW system must be understood to optimize CW ecosystem.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 41671268, 31270639, and 31400435)the Program for Changjiang Scholars and Innovative Research Team in University of China (No. IRT1035)+1 种基金the Hubei Provincial Natural Science Foundation of China (No. 2015CFB596)the Shaanxi Provincial Science and Technology Innovation Project Plan of China (No. 2016KTCL02-07)
文摘Dark septate endophytic(DSE) fungi are ubiquitous and cosmopolitan, and occur widely in association with plants in heavy metal stress environment. However, little is known about the effect of inoculation with DSE fungi on the host plant under heavy metal stress.In this study, Gaeumannomyces cylindrosporus, which was isolated from Pb-Zn mine tailings in China and had been proven to have high Pb tolerance, was inoculated onto the roots of maize(Zea mays L.) seedlings to study the effect of DSE on plant growth, photosynthesis,and the translocation and accumulation of Pb in plant under stress of different Pb concentrations. The growth indicators(height, basal diameter, root length, and biomass) of maize were detected. Chlorophyll content, photosynthetic characteristics(net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO_2 concentration), and chlorophyll fluorescence parameters in leaves of the inoculated and non-inoculated maize were also determined. Inoculation with G. cylindrosporus significantly increased height,basal diameter, root length, and biomass of maize seedlings under Pb stress. Colonization of G. cylindrosporus improved the efficiency of photosynthesis and altered the translocation and accumulation of Pb in the plants. Although inoculation with G. cylindrosporus increased Pb accumulation in host plants in comparison to non-inoculated plants, the translocation factor of Pb in plant body was significantly decreased. The results indicated that Pb was accumulated mainly in the root system of maize and the phytotoxicity of Pb to the aerial part of the plant was alleviated. The improvement of efficiency of photosynthesis and the decrease of translocation factor of Pb, caused by DSE fungal colonization, were efficient strategies to improve Pb tolerance of host plants.
基金supported by the National Natural Science Foundation of China (Nos. 31400435 and 31270573)the Fundamental Research Funds for the Central Universities of China (No. WUT2014-IV-050)the Natural Science Foundation of Hubei Province, China (No. 2015CFB596)
文摘Over the last three decades, the presence and functional roles of arbuscular mycorrhizal(AM) fungi in wetland habitats have received increasing attention. This review summarized the mycorrhizal status in wetlands and the effect of flooding on AM fungal colonization. Plants of 99 families living in 31 different habitats have been found to be associated with AM fungi, even including submerged aquatic plants and several plant species that were thought to be nonmycorrhizal(Cyperaceae, Chenopodiaceae, and Plumbaginaceae). The functions of AM fungi in wetland ecological systems could be concluded as their influences on the composition,succession, and diversity of the wetland plant community, and the growth and nutrition of wetland plants. Affecting the composition,succession, and diversity of the wetland plant community, AM fungi have positive, negative, or neutral effects on the performance of different wetland species under different conditions. The factors that affect the application effect of AM fungi in constructed wetland(CW) include flooding, phosphorus, plant species, aerenchyma, salinity, CW types, operation modes of CW, and wastewater quality.The generalist AM fungi strains can be established spontaneously, rapidly, and extensively in wastewater bioremediation technical installations; therefore, AM fungi can be considered ideal inhabitants of technical installations for the plant-based bioremediation of groundwater contaminated by organic pollutants or other contaminants. In the future, roles of AM fungi and factors that affect the purifying capacity of AM-CW system must be understood to optimize CW ecosystem.
