Differences of Cu uptake and acid phosphatase activities of two Elsholtzia haichowensis Sun populations

Two Elsholtzia haichowensis Sun populations, one from Cu mine sites (Tonglushan) and the other from uncontaminated sites (Hong'an) in Hubei Province, China, were investigated in hydroponic experiments for the differences of Cu accumulation and ecophysiological responses to Cu under Cu treatment. The results showed that a significant increase in malondialdehyde (MDA) concentration in roots was observed in Hong'an population, whereas no significant change was observed in Tonglushan population. The root pressure exudates (ml) decreased significantly in Hong'an population, but increased significantly in Tonglushan population at high Cu concentration (≥ 20 μ mol/L) treatment. Cu concentration in roots of Hong'an population was significantly higher than that in Tonglushan population. For example, Cu concentration in Hong'an population was 3 times and 4 times higher than that in Tonglushan population after 20 μ mol/L Cu treatment for one day and three days, respectively. Cu concentration in Hong'an population was 20 times and 5 times higher than that in Tonglushan population after 80 μ mol/L Cu treatment for one day and three days, respectively. The intracellular and secreted acid phosphatase (APase) activities in roots were significantly higher in Tonglushan population than in Hong'an one. The intracellular APase activities in Tonglushan population were 3 times higher than those in Hong'an population after 80 μ mol/L Cu treatment for three days and five days, respectively. The root-secreted APase activities in Tonglushan population were 1.6 times and 1.8 times higher than those in Hong'an population after 80 μ mol/L Cu treatment for three days and five days, respectively. In conclusion, excessive Cu caused serious oxidative damage in roots of Hong'an population, but not in Tonglushan population. The high intracellular and root-excreted APase activities in Tonglushan population might play an important role in reducing Cu accumulation in roots and maintaining normal phosphorus physiological metabolism in root cells under Cu stress.     

Genetic diversity analysis among and within populations of Pogostemon cablin from China with ISSR and SRAP markers

The diversity and genetic relationship among and within 16 populations of Pogostemon cablin from China were analyzed using ISSR and SRAP markers. High percentage of polymorphism observed by these two markers indicated a high level of genetic diversity existed among P. cablin populations. The percentage of polymorphic bands revealed by these two markers showed genetic variations were much higher between populations of P. cablin than within. The UPGMA clustering results using ISSR, SRAP or ISSR + SRAP combination showed most accessions from the same or adjacent regions were classified together. However, cluster results based on the absolute contents of patchouli alcohol and pogostone did not keep in good accordance with their geographic distributions, which revealed that the forming of patchouli alcohol and pogostone were relevant to the cultivation conditions except for genetic factors and environmental conditions. Finally, an appropriate strategy for conserving the patchouli germplasm was proposed.     

海州香薷挥发油成份研究

香薷属(Elsholtzta)植物约40种,我国有33种,15变种及5变型,分布极广。香薷为常用中药,以全草入药。中医用于发表解暑、行水利湿,治疗暑湿感冒等。其挥发油具有广谱抗菌     

Adaptive Copper Tolerance in <Emphasis Type="Italic">Elsholtzia haichowensis</Emphasis> Involves Production of Cu-induced Thiol Peptides

Copper (Cu) accumulation and tolerance mechanisms in Elsholtzia haichowensis, an indicator plant of Cu mines, were investigated under hydroponics supplied with different concentrations (0.32, 50.0, 100.0 and 200.0 μM) of Cu for 8 days. Cu at 100 and 200 μM significantly decreased the root dry weight, but had no significant effect on shoot dry weight. The plants grown in the presence of 200 μM Cu accumulated 288 and 7626 μg g⁻¹ DW total Cu in the shoots and roots, respectively. A greater proportion of accumulated Cu was water-soluble accounting for 42–93% of the total Cu content in the shoots. The concentrations of reduced glutathione (GSH) and protein thiols were significantly enhanced under excess Cu supply. However, the concentrations of these compounds, particularly protein thiols, were much higher in the leaves than that in the roots. Three UV-absorbing peaks could be eluted out through gel filtration chromatography on Sephadex G-50. A large amount of Cu was detected in the UV-absorbing peaks in 40–50 and 70–90 ml elution fractions of the root extract, and in 40–50 and 120–140 ml elution fractions of the leaf extract. The results suggested that the adaptive Cu tolerance mechanism in E. haichowensis might involve the active participation of protein thiols which had a more important role in the leaves than in the roots.     

The Tolerance and Accumulation of Miscanthus Sacchariflorus (maxim.) Benth., an Energy Plant Species,to Cadmium

Miscanthus sacchariflorus (Maxim.) Benth. is a metallophyte suitable for the phytoremediation of mine wastes. The tolerance and accumulation of M. sacchariflorus to cadmium was studied by pot experiments. The results showed that O₂·^? generation rate, plasma membrane permeability and MDA content of M. sacchariflorus leaves increased with increasing Cd concentrations in soil, but significant effect was only observed when Cd concentrations were ≥ 50 mg·kg^?1. SOD and POD activities increased initially but decreased later on, whereas CAT activity only increased significantly at higher Cd concentrations, 50–100 mg·kg^?1. The content of photosynthetic pigment and growth of M. sacchariflorus were both not significantly affected when Cd concentration was ≤ 25 mg·kg^?1. In contrast, both parameters were significantly affected when Cd concentration was ≥ 50 mg·kg^?1. M. sacchariflorus could accumulate much Cd, but most of the Cd assimilated was retained in the belowground part, suggesting that M. sacchariflorus has poor ability to translocate Cd to the aboveground part. Our results suggested that although M. sacchariflorus was not a hyper-accumulator, it has a strong capacity to tolerate and stabilize the Cd. Therefore, M. sacchariflorus has a certain potential in the phytostabilization of Cd-contaminated soils.     

Effects of Cadmium Stress on Leaf Chlorophyll Fluorescence and Photosynthesis of Elsholtzia argyi—A Cadmium Accumulating Plant

A hydroponic experiment was conducted to investigate the effects of cadmium (Cd) on chlorophyll fluorescence and photosynthetic parameters on a Cd accumulating plant of Elsholtzia argyi. Four weeks-seedlings of E. argyi were treated with 0 (CK) 5, 10, 15, 20, 25, 30, 40, 50 and 100 μmol L^?1 Cd for 21days. Fv/Fo, Fv/Fm, qP, ΦPSП, ETR and Fv′/Fm′ were significantly increased under low Cd (5–15 μmol L^?1 for Fv/Fo, Fv/Fm and qP, 5–10 μmol L^?1 for ΦPSП, ETR and Fv′/Fm′) stress, and these parameters were similar to control under Cd ≤ 50μmol L^?1. All above parameters were significantly decreased at 100 μmol L^?1 Cd. Compared with control, Pn was significantly (P < 0.05) increased under 5–30 μmol L^?1 Cd. However, 50 and 100 μmol L^?1 Cd significantly (P < 0.05) reduced it. Gs and Tr were substantially decreased at 50–100 and 40–100 μmol L^?1 Cd, respectively. Ci was significantly increased at 50 and 100 μmol L^?1 Cd. High Cd-induced decrease of Pn is not only connected to stomatal limitation but also to the inhibition of Fv/Fo, Fv/Fm, ΦPSП, qP, ETR and increase of NPQ. Maintain chlorophyll fluorescence and photosynthesis parameters under its Cd tolerance threshold were one of tolerance mechanisms in E. argyi.     

土壤理化性质与海州香薷(Elsholtzia splendens Nakai)铜锌积累的关系

土壤理化性质是决定重金属矿山废弃地植被恢复效率和成败的重要因素之一。选取芜湖市南陵县境内大工山-凤凰山古铜矿区的3处弃土场和两处对照点,调查了其植被覆盖度、物种组成,并分析了土壤性质与海州香薷铜、锌积累的相关性。结果显示,矿区土壤污染程度随废弃时间的增加和植物多样性的提高而降低,但仍未达到安全水平。海州香薷对铜、锌的积累主要发生在地下部分,地上部分的最高铜浓度为179.83mg/kg,远未达到铜超积累植物的标准,只是一种规避植物。海州香薷的铜、锌积累量主要取决于土壤铜、锌浓度水平,同时与土壤全磷、有效磷和pH值等因素显著相关,而与土壤有机质无相关性;并且海州香薷对铜、锌两种主要污染元素的积累可能存在某种协同作用。     

龙须藤的化学成分研究

本文旨在研究龙须藤Bauhinia championii(Benth.)Benth藤的化学成分.本实验运用硅胶、聚酰胺、SephadexLH-20等柱色谱手段进行分离纯化,并根据理化性质和波谱数据鉴定其结构.分离得到7个化合物,分别鉴定为β-谷甾醇、胡萝卜苷、正三十烷、正六十烷、槲皮素、杨梅素和oblongixanthone A.其中化合物oblongixanthone A为首次从该植物中分离得到.     

抗氧化系统在海州香薷耐铜机制中的作用

利用溶液培养的方法研究了铜胁迫下海州香薷根系和地上部分MDA含量,各种抗氧化酶及非酶抗氧化系统的变化。结果表明,不同浓度铜处理8d后,海州香薷根系中MDA含量显著增加,叶片中则无显著变化;根系中SOD、POD、CAT、APX、GR活性和叶片中POD、SOD的活性随铜处理浓度的增加而显著增加,而50-200μmol·L^-1。铜处理条件下叶片中CAT、APX、GR活性与对照相比无明显差异。除CAT外,根系中这些抗氧化酶的活性都远远大于叶片中的活力。另外,实验结果表明,50μmol·L^-1 Cu^2＋对海州香薷的生物量并没有显著影响,当铜浓度达到100和200μmol·L^-1。时,铜则可显著降低海州香薷根系的生物量,对地上部生物量仍无显著影响。