Experimental control of flowering in Pistia stratiotes L.

GA₃, salicylic acid and EDDHA induced flowering in Pistia stratiotesin vitro under short days and conditions of continuous light.It has been hypothesized that EDDHA and salicylic acid bringabout the same effect on flowering in Pistia and the duckweedspecies Lemma gibba G3 whereas the effect of GA₃ on the floweringmechanism of these species is basically different. (Received March 14, 1978; )     

Removal of chlorpyrifos by water lettuce (Pistia stratiotes L.) and duckweed (Lemna minor L.)

The potential of water lettuce (Pistia stratiotes L.) and duckweed (Lemna minor L.) to remove chlorpyrifos in water was investigated under laboratory greenhouse conditions. At initial chlorpyrifos concentrations of 0.0, 0.1 and 0.5 mg/L, the relative growth rates (RGR) of L. minor and P. stratiotes were not significantly different. In contrast, in the presence of 1 mg/L chlorpyrifos the RGR was significantly inhibited, giving an observed fresh weight based RGR(FW) for P. stratiotes and L. minor from day 0 to 7 of -0.036 and -0.023 mg/g/day, respectively. The maximum removal of chlorpyrifos by P. stratiotes and L. minor, when chlorpyrifos was at an initial culture concentration of 0.5 mg/L, was 82% and 87%, respectively, with disappearance rate constants under these conditions of 2.94, 10.21 and 12.14 microg h(-1) for the control (no plants), and with P. stratiotes and L. minor, respectively, giving actual corrected plant removal rate constants of 7.27 and 9.20 microg h(-1) for P. stratiotes and L. minor, respectively. The bioconcentration factor (BCF) of L. minor was significantly greater than that for P. stratiotes and therefore, at least under these greenhouse-based conditions, L. minor was more efficient than P. stratiotes for the accelerated removal of chlorpyrifos from water.     

The phytogeography and genetic diversity of the weedy hydrophyte,Pistia stratiotes L.

Biological Invasions - Understanding the origins and genetic relationships of invasive, non-native species is critical to informing conservation and management practices. Pistia stratiotes is one...     

Some effects of water lettuce (Pistia stratiotes,L.) on its habitat

Field and laboratory observations show that the growth of Pistia alters markedly the physico-chemical condition of its substrate. The nature of this effect in the field is suggested to depend on the cover of the vegetation. A large and dense mat insulates the water below it against solar radiation and causes stratification and poor oxygenation. The effects of a thin vegetation are the opposite of these.     

Survival and expansion of Pistia stratiotes L. in a thermal stream in Slovenia

We report about successful winter survival of a tropical plant Pistia stratiotes in a natural thermal stream Topla in Slovenia in temperate climate zone in central Europe. Only 2 years after its first occurrence in 2001 P. stratiotes managed to cover most of the water body where the thermal springs cause an elevated temperature (>17 °C year round). Enhanced biomass production of this invasive species took place in spring and summer and new stolons were formed at the end of the vegetation season. Over the winter older rosettes decayed and only small rosettes survived besides new rosettes formed from stolons. Plants developed flowers in April through August. Observations in December revealed viable seed production and seed presence in the sediment.     

Study on the Decomposition of Pistia stratiotes L. (Araceae) in Cisne Reservoir,Uruguay

A study on the decomposition process of Pistia stratiotes L. was carried out in Cisne Reservoir, Uruguay. For this purpose, leaves and roots were considered separately, and the process was studied in the littoral and the pelagic zone. The litter bag technique was used to estimate dry weight losses at different times. Leaves decomposed faster than roots in both zones. Pistia decomposed faster in the pelagic zone due to better oxygen conditions and a more intensive water movement that removes material from within the bags. Phosphorus, potassium, sodium and magnesium were leached rapidly during the first week. Nitrogen content in the leaves initially increased, reaching its maximum in the littoral zone that coincided with that of bacterial numbers colonizing the litter. The number of macroinvertebrates, dominated by Chironomidae, was low. A rough estimation of the phosphorus impact on the littoral zone associated to the decomposition process shows that after 24 h between 13.9 and 16.8 μg-at.1⁻¹ have been released to the water.     

Trace element composition of Pistia stratiotes L. in a polluted lake in Nigeria

Pistia stratiotes L. in a Nigerian lake receiving organic and laboratory chemical wastes, accumulated trace elements from the lake water. Its possible use in the treatment of specific industrial wastes or in selective enrichment of specific elements is discussed.     

Amelioration of municipal sludge by Pistia stratiotes L.: role of antioxidant enzymes in detoxification of metals

Pistia stratiotes when exposed to mixture of municipal sludge and effluent accumulated substantial amount of metals in the fronds and roots. With the increase in the metal accumulation by the plants, a reduction in the concentration of metals was found in leachates. The treated plants showed reduced level in chlorophylls but enhanced level of carotenoids and protein. The plant showed a concomitant increase in the activities of antioxidant enzymes; superoxide dismutase, guiacol peroxidase and also an enhanced level of lipid peroxidation. The activities were more in the root tissues as compared to frond. Initially a reduced level of cysteine content in roots of sludge treated plant as compared to control was found, but with time duration it increased progressively. The level of non-protein thiols also increased gradually at all the durations in both fronds and roots. Thus, beside the reduction of metals from municipal sludge, the ability of P. stratiotes to combat metal generated damages by induced synthesis of antioxidant enzymes and other metal binding ligands shows its suitability for the phytoremediation of the waste.     

Effects of Adding Nitroprusside on Arsenic Stressed Response of Pistia stratiotes L. Under Hydroponic Conditions

Effect of nitric oxide (NO) in mitigating stress induced by arsenic (As) was assessed in Pistia stratiotes, with NO supplied as sodium nitroprusside (SNP). Plants were exposed to four treatments: control, SNP (0.1 mg L^?1), As (1.5 mg L^?1), As + SNP (1.5 and 0.1 mg L^?1), for seven days (analyses of growth, absorption of As and mineral nutrients) and for 24 h (analyses of concentration of reactive oxygen intermediates (ROIs), antioxidant capacity and photosynthesis). P. stratiotes accumulated high concentrations of As and this accumulation wasn't affected by the addition of SNP, but the tolerance index of the plant to As increased. SNP attenuated effects of As on the absorption of mineral nutrients (Ca, Fe, Mn, and Mg), but not for phosphorus, and maintained concentrations of ROIs to normal levels, probably due to the increase in antioxidant capacity. The As damaged the photosynthesis by the decrease in pigment contents and by disturbance the photochemical (loss of PSII efficiency and increases in non-photochemical quenching coefficient) and biochemical (reductions in carbon assimilation, increase in the C_i/C_a and Φ_PSII/Φ_CO2 ratios) steps. The addition of SNP restored these parameters to normal levels. Thus, NO was able to increasing the resistance of P. stratiotes to As.

Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.     

Treatment of textile effluents with Pistia stratiotes,Eichhornia crassipes and Oedogonium sp.

Abstract

Phytoremediation by aquatic macrophytes is a promising technology with higher efficiency and no energy consumption. For this purpose, two macrophytes (Pistia stratiotes, Eichhornia crassipes), and an alga (Oedogonium sp.) were used to treat textile effluents rich in COD, BOD, dyes, and heavy metals (Pb, Fe, Cd, Cu). The aim of the study was to focus on comparative phytoremediation potential of these species by their metal removal capability. During 7?days experiment (day 0–day 6), the results showed that Oedogonium sp. was the best for COD removal and decolorization. Eichhornia crassipes was the best for BOD and heavy metal removal and proves more efficient than Pistia stratiotes and Oedogonium sp. However, Pistia stratiotes was found to accumulate more concentrations of Pb and Fe than Eichhornia stratiotes.     

Bioaccumulation and rhizofiltration potential of Pistia stratiotes L. for mitigating water pollution in the Egyptian wetlands

The bioaccumulation and rhizofiltration potential of P. stratiotes for heavy metals were investigated to mitigate water pollution in the Egyptian wetlands. Plant and water samples were collected monthly through nine quadrats equally distributed along three sites at Al-Sero drain in Giza Province. The annual mean of the shoot biomass was 10 times that of the root. The concentrations of shoot heavy metals fell in the order: Fe < Mn < Cr < Pb < Cu < Zn < Ni < Co < Cd, while that of the roots were: Fe < Mn < Cr < Pb < Zn < Ni < Co < Cu < Cd. The bio-concentration factor (BCF) of most investigated heavy metals, except Cr and Pb, was greater than 1000, while the translocation factor (TF) of most investigated metals, except Pb and Cu, did not exceed one. The rhizofiltration potential (RP) of heavy metals was higher than 1000 for Fe, and 100 for Cr, Pb and Cu. Significant positive correlations between Fe and Cu in water with those in plant roots and leaves, respectively were recorded, which, in addition to the high BCF and RP, indicate the potential use of P. stratiotes in mitigating these toxic metals.     

水浮莲中-株西瓜枯萎病拮抗菌的分离、筛选及鉴定

从水浮莲(Pistia stratiotes L.)的叶中分离出1株对西瓜枯萎病有明显拮抗作用的内生细菌XJPL-YB-26,其发酵液上清在280 nm处有最大紫外吸收峰.利用软件Primer 6.0设计16S rDNA引物并对其基因组DNA进行扩增并测序得到XJPL-YB-26的部分16S rDNA序列.GenBank接收号为EU251191.经 Blastn调出与菌株16S rDNA同源的序列,并用软件MEGA 3.1按Neighbor-Joining方法构建16S rDNA系统发育树.菌株XJPL-YB-26与AB271744处于同一分支,相似性为99%,最终鉴定为枯草芽孢杆菌Bacillus subtilis.     

Iron plaque formation in the roots of Pistia stratiotes L.: importance in phytoremediation of cadmium

Aquatic macrophytes play an important role in the removal of toxic metals from wastewater. Therefore, the induction of Fe plaque on the roots, and its consequences on Cd tolerance investigated in an aquatic macrophyte Pistia stratiotes L. The presence of Fe²⁺ ion but not Fe³⁺ resulted in Fe plaque formation. Induction of Fe plaque decreased Ca and increased K and Fe accumulations in the root. Plaque formed plants had accumulated less Cd until 50.0?µM CdCl₂ treatments because plaque acted as a barrier to Cd exposure. However, at higher concentrations (500.0?µM CdCl₂), plaque formed plants contained more Cd in the roots. Cadmium inducible ion leakage in the root and lowering of the photosynthetic pigment content were less in plants with a plaque. Stretching of aromatic carbonyl groups and alkyl groups among plaque formed plants upon Cd treatments indicated the putative role of phenolics in Cd detoxification.     

水浮莲中一株西瓜枯萎病拮抗菌的分离、筛选及鉴定

从水浮莲(Pistia stratiotes L.)的叶中分离出1株对西瓜枯萎病有明显拮抗作用的内生细菌XJPL-YB-26, 其发酵液上清在280 nm处有最大紫外吸收峰。利用软件Primer 6.0 设计16S rDNA引物并对其基因组DNA进行扩增并测序得到XJPL-YB-26的部分16S rDNA序列, GenBank接收号为EU251191。经Blastn调出与菌株16S rDNA同源的序列, 并用软件MEGA 3.1按Neighbor- Joining方法构建16S rDNA系统发育树。菌株XJPL-YB-26与AB271744处于同一分支, 相似性为99%, 最终鉴定为枯草芽孢杆菌Bacillus subtilis。     

根际中硅,铁,锰和铝的状况与水稻生长

本文以根盒试验与盆栽试验相结合的方法,研究了红壤性水稻土、淀浆白土、第四纪红土和赤红壤植稻后根际微生态系统中Si、Fe、Mn和Al等元素的状况及其与水稻生长的关系。结果表明,新垦红壤植稻后根际中活性Fe和Al富集;活性Mn量降低,但亏缺率小;活性Si则亏缺不明显,有时甚至富集。而熟化水稻土植稻后根际中活性Fe和Al则出现亏缺;Mn的亏缺较大,且差值明显;活性Si的亏缺现象更为显著。由于新垦红壤植稻后Fe和Al在根际微生态系统中富集,根茎叶中累积量较高,从而使Si、P和Mn等元素的吸收受阻,导致新垦红壤上水稻生长明显比熟化水稻土上的水稻要差。     

Biological control of water lettuce,Pistia stratiotes L., facilitates macroinvertebrate biodiversity recovery: a mesocosm study

Hydrobiologia - Floating aquatic weed infestations have negative socio-economic and environmental consequences to the ecosystems they invade. Despite the long history of invasion by macrophytes,...     

Pistia stratiotes in the phytoremediation and post-treatment of domestic sewage

Abstract

This work aimed to evaluate the potential of phytoremediation using Pistia stratiotes as a plant for post-treatment of wastewater from domestic sewage. The experiment was conducted at Toledo-PR, Brazil, for 42 days, in a pilot scale model. In order to evaluate the efficiency of Pistia as a post-treatment of domestic sewage, parameters such temperature, pH, turbidity, total solids, COD, N_total and P_total contents were determined in the effluent, as well as the total contents of K, Ca, Mg, Cu, Zn, Fe, Mn, Cd, and Pb. The bioaccumulation of K, Ca, Mg, Cu, Zn, Fe, Mn, Cd, and Pb in the living tissues of P. stratiotes have also been detected. The results demonstrate efficiency removal of turbidity, N_total, P_total and COD of 98.5, 100, 100, and 79.18%, respectively. The effluent contents of nutrients and toxic metals fluctuated during the study. This can have occurred due to photosynthetic activities of microorganisms and the plant senescence. The evaluation of some parameters in the effluent, such as temperature, DO, and organic matter, influenced these facts. Low levels of DO were observed, in function to the physical barrier of macrophytes in water surface, preventing the entry of air and light. The use of P. stratiotes proved to be a good complement for post-treatment of wastewater from domestic sewage.     

根际中硅、铁、锰和铝的状况与水稻生长

本文以根盒试验与盆栽试验相结合的方法,研究了红壤性水稻土、淀浆白土、第四纪红土和赤红壤植稻后根际微生态系统中Si、Fe、Mn和Al等元素的状况及其与水稻生长的关系。结果表明,新垦红壤植稻后根际中活性Fe和Al富集;活性Mn量降低,但亏缺率小;活性Si则亏缺不明显,有时甚至富集。而熟化水稻土植稻后根际中活性Fe和Al则出现亏缺;Mn的亏缺较大,且差值明显;活性Si的亏缺现象更为显著。由于新垦红壤植稻后Fe和Al在根际微生态系统中富集,根茎叶中累积量较高,从而使Si、P和Mn等元素的吸收受阻,导致新垦红壤上水稻生长明显比熟化水稻土上的水稻要差。     

Calcium channels are involved in calcium oxalate crystal formation in specialized cells of Pistia stratiotes L

BACKGROUND AND AIMS: Pistia stratiotes produces large amounts of calcium (Ca) oxalate crystals in specialized cells called crystal idioblasts. The potential involvement of Ca(2+) channels in Ca oxalate crystal formation by crystal idioblasts was investigated. METHODS: Anatomical, ultrastructural and physiological analyses were used on plants, fresh or fixed tissues, or protoplasts. Ca(2+) uptake by protoplasts was measured with (45)Ca(2+), and the effect of Ca(2+) channel blockers studied in intact plants. Labelled Ca(2+) channel blockers and a channel protein antibody were used to determine if Ca(2+) channels were associated with crystal idioblasts. KEY RESULTS: (45)Ca(2+) uptake was more than two orders of magnitude greater for crystal idioblast protoplasts than mesophyll protoplasts, and idioblast number increased when medium Ca was increased. Plants grown on media containing 1-50 microM of the Ca(2+) channel blockers, isradipine, nifedipine or fluspirilene, showed almost complete inhibition of crystal formation. When fresh tissue sections were treated with the fluorescent dihydropyridine-type Ca(2+) channel blocker, DM-Bodipy-DHP, crystal idioblasts were intensely labelled compared with surrounding mesophyll, and the label appeared to be associated with the plasma membrane and the endoplasmic reticulum, which is shown to be abundant in idioblasts. An antibody to a mammalian Ca(2+) channel alpha1 subunit recognized a single band in a microsomal protein fraction but not soluble protein fraction on western blots, and it selectively and heavily labelled developing crystal idioblasts in tissue sections. CONCLUSIONS: The results demonstrate that Ca oxalate crystal idioblasts are enriched, relative to mesophyll cells, in dihydropyridine-type Ca(2+) channels and that the activity of these channels is important to transport and accumulation of Ca(2+) required for crystal formation.