Effects of insoluble Zn,Cd,and EDTA on the growth,activities of antioxidant enzymes and uptake of Zn and Cd in Vetiveria zizanioides

A root-bag experiment was conducted to study the effects of insoluble Zn, Cd, and ethylenediaminetetraacetic acid （EDTA） on the plant growth, activities of antioxidant enzymes, proline, glutathione （GSH）, water-soluble proteins and malondialdehyde （MDA） of Vetiveria zizanioides. The V. zizanioides uptake capacity of Zn and Cd also determined. The results showed that plant growth of V. zizanioides was inhibited by Zn and Cd. The shoot dry weight （SDW） and root dry weight （RDW） decrease by 14.2%, 14.1%, 17.0% and 17.3%, 32.5%, 35.7%, respectively, compared to the control without EDTA addition. After adding EDTA, shoot and root dry weight decreased over 10% and 15%, respectively. The toxicity from insoluble Zn and Cd in soil on SDW and RDW of V. zizanioides was in order： Zn＋Cd 〉 Cd 〉 Zn. The activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT）, and contents of MDA and proline increased significantly, while the contents of GSH and water-soluble proteins decreased markedly with increasing Zn and Cd toxicity. With EDTA, shoot and root Zn concentrations increased in the Zn treatment by 7.3% and 37.4%, and Cd concentrations in the combined Zn and Cd treatment increased by 18.6% and 391.9% compared to the treatment without EDTA. However, Zn and Cd concentrations in shoot and roots decreased in the Cd treatment compared to the plants grown in absence of EDTA, with exception of root Cd concentration in the presence of EDTA.

Valencene-rich fraction from Vetiveria zizanioides exerts immunostimulatory effects in vitro and in mice

Objective:To decipher the responsible compound present in the aqueous root extract of Vetiveria zizanioides which has tremendous immunomodulatory activity.Methods:Different fractions of the water extract were collected and analyzed for immunomodulatory activity by analyzing in vitro phagocytic activity and nitric oxide production.One fraction VF3 was selected and further analyzed for possible compounds by high performance liquid chromatography and gas chromatography coupled with a mass spectrometer.The in vitro immunomodulatory parameters such as phagocytic index,nitrite content,and tumor necrosis factor-α production in murine macrophages were analyzed.In vivo studies,sheep red blood cell induced haemagglutination titer,the number of antibody-producing cells,and sheep red blood cell induced delayed-type hypersensitivity were analyzed.Cytotoxic studies in L929 normal fibroblasts were also performed.Results:One of the fractions,VF3,was selected and confirmed the presence of an active compound valencene.The in vitro immunomodulatory parameters were significantly(P<0.05)increased by valencene treatment.In vivo studies in Swiss albino mice showed that valencene could significantly(P<0.05)increase haemagglutination titer,the number of antibody-producing cells,and delayed-type hypersensitivity.Cytotoxic studies also showed that valencene did not cause any morphological changes and DNA damage in normal fibroblasts.Conclusions:Valencene possesses immunomodulatory activities and can be commercially exploited for its immunostimulatory potentials.

Leaf Growth of Different Populations of Vetiveria zizanioides

Large sample sampling was adopted in this paper for the statistical analysis of leaves of four populations of Vetiveria zizanioides （ introduced, local wild, domesticated wild populations of different years）. The results showed that four populations varied in different degrees in terms of tiller height, leaf biomass, and leaf biomass ratio. Leaf length, leaf width, and ratio of leaf width to length of different populations also varied, but had similar power-function change regularity, and showed converging leaf biomass growth pattern and leaf growth process.

Accumulation of heavy metals in four grasses grown on lead and zinc mine tailings

A field experiment was conducted to compare the growth and metal accumulation of Vetiveria zizanioides, Paspalum notatum, Cynodon dactylon and Imperata cylindraca var. major on the tailings, amended with 10 cm domestic refuse + complex NPK fertilizer(Treatment A), 10 cm domestic refuse(Treatment B) and complex NPK fertilizer(Treatment C) respectively, and without any amendment used as control(Treatment D). The results indicated that V. zizanioides was a typical heavy metal excluder, because the concentrations in shoots of the plants were the lowest among the four plants tested. The most of metal accumulated in V. zizanioides distributed in its root, and transportation of metal in this plant from root to shoot was restricted. Therefore, V. zizanioides was more suitable for phytostabilization of toxic mined lands than P. notatum and C. dactylon, which accumulated a relatively high level of metals in their shoots and roots. It was also found that I. cylindraca var. major accumulated lower amounts of Pb, Zn and Cu than C. dactylon and P. notatum, and could also be considered for phytostalilisaton of tailings. Although the metal(Pb, Zn and Cu) concentrations in shoots and roots of V. zizanioides were the lowest, the total amounts of heavy metals accumulated in shoots of V. zizanioides were the highest among the four tested plants due to the highest dry weight yield of it. The results indicated that V. zizanioides was the best choice among the four species used for phytoremediation(for both phytostabilization and phytoextraction) of metal contaminated soils.

香根草在流域治理中的应用

香根草[Vetiveria zizanioides(L.)Nash]是治理水土流失问题常用的植物,其根系发达,有较强耐受性和涵水固土作用,同时对水体污染物有富集作用。通过分析香根草生态学特性及流域治理存在的问题,探讨香根草技术在流域治理中的作用,以期为流域治理提供思路。