Effects of pH on ammonium uptake by Typha latifolia L.

The effects of solution pH on NH₄⁺ uptake kinetics and net H⁺ extrusion by Typha latifolia L. were studied during short-term (days) and long-term (weeks) exposure to pH in the range of pH 3.5–8.0. The NH₄⁺ uptake kinetics were estimated from depletion curves using a modified Michaelis-Menten model. T. latifolia was able to grow in solution culture with NH₄⁺ as the sole N source and to withstand a low medium pH for short periods (days). With prolonged exposure (weeks) to pH 3.5, however, the plants showed severe symptoms of stress and stopped growing. The solution pH affected NH₄⁺ uptake kinetics. The affinity for NH₄⁺, as quantified by the half saturation constant (K_1/2) and C_min (the NH₄⁺ concentration at which uptake ceases), decreased with pH. K_1/2 was increased from 7.1 to 19.2 mmol m^?3 and C_min from 2.0 to 5.7 mmol m^?3 by lowering the pH in steps from 8.0 to 3.5. V_max was, however, largely unaffected by pH (～22 μmol h^?1 g^?1 root dry weight). Under prolonged exposure to constant pH, growth rates were highest at PH 5.0 and 6.5. At pH 8.0 growth was slightly depressed and at pH 3.5 growth completely stopped. NH₄⁺ uptake kinetics were similar at pH 5.0, 6.5 and 8.0 whereas at pH 3.5 NH₄⁺ uptake almost completely stopped. The ratio between net H⁺ extrusion and NH₄⁺ uptake decreased significantly at low pH. The adverse effects of low pH on NH₄⁺ uptake kinetics are probably a consequence of a reduced H⁺-ATPase activity and/or an increased re-entry of H⁺ at low pH, and the associated decrease in the electrochemical gradient across the plasma membranes of the root cells.     

Epifluorescent and histochemical aspects of shoot anatomy of Typha latifolia L., Typha angustifolia L. and Typha glauca Godr

Using epifluorescent and histochemical techniques, we examined anatomical differences in the shoot organs of Typha latifolia, T. angustifolia and T. glauca. The leaf lamina of T. latifolia and T. glauca had enlarged epidermal cells and a thickened cuticle above the subepidermal vascular bundles; that of T. angustifolia lacked these characteristics. Leaf sheaths were similar among the species and all lacked the epidermal thickenings found in the lamina. The fertile stems had typical scattered vascular bundles with a band of fibres that was most prominent in T. glauca. The sterile stems were only 1 cm in length and contained a multiseriate hypodermis and a uniseriate endodermis over part of their length. The rhizomes were similar except for a pronounced band of fibres surrounding the central core in T. angustifolia. The rhizome was also characterized by an outer cortical region with a large multiseriate hypodermis/exodermis and a uniseriate endodermis with Casparian bands, suberin lamellae and secondarily thickened walls.     

Nitrogen utilization by Typha latifolia L. as affected by temperature and rate of nitrogen application

Greenhouse and growth chamber studies were conducted to evaluate growth and N utilization by Typha latifolia L. in flooded organic soil under varying temperatures and rates of N additions. Elevation of temperature from 10 to 25°C increased shoot biomass yields by 275%. Root biomass yields were lowest at 10°C and increased linearly as a function of temperature. Shoot/root ratios were low (0.72–0.82) at lower temperatures (10–15°C) and ratios increased by about three times at higher temperatures (20–30°C). Biomass yields were increased by addition of N fertilizers, while the shoot/root ratios were directly related to plant-available N present in the soil.Fertilizer ¹⁵N uptake (expressed as % of applied N) by the whole plant was 5.3% at 10°C, 37.5% at 20°C and at 30°C decreased to 20.8%. Fertilizer N accumulation in shoots was 2.1–29.8% of applied N, while roots accumulated 3.2–7.7%. Under greenhouse conditions, N uptake by T. latifolia was found to increase with increased rate of N application. Fertilizer N uptake by both shoots and roots was in the range of 61–77%. Plants cultured in growth chambers were affected by low light conditions resulting in poor growth and low fertilizer ¹⁵N uptake, as compared to plants grown under greenhouse conditions. Added fertilizer N was the major source of N during the early part of the growing season, while soil organic N was the major and perhaps the sole source of N during the latter part of the growing season.     

Yield and nitrogen uptake of rapessed (Brassica campestris L.) with ammonium and nitrate

Water culture, growth chamber, greenhouse and field experiments were conducted to compare the effect of NH₄−N and NO₃−N on yield and N uptake of rapeseed (Brassica campestris L.). In water culture, the yields of 28-day old rapeseed plants grown at 14 μg N ml⁻¹ were double with NO₃ compared to NH₄, but N uptake was little affected. There was no such effect when concentration was reduced to 3.5 or 7 μg N ml⁻¹. The yield and N uptake of 26-day old rapeseed grown on six soils (pH 4.6 to 6.5) in pots in a growth chamber were much greater with NO₃ than with NH₄, although N concentration was more in the NH₄- than the NO₃-grown plants. In a greenhouse experiment with rapeseed grown on 12 potted soils, the N uptake of applied N was greater with NO₃ than with NH₄ on all soils. Averages were 63% with NH₄ and 78% with NO₃. However, NH₄-fixation capacities of the soils were only weakly correlated with yield from the two sources of N (r=0.48) and the relation was similar with N uptake. In contrast to the behavior of water culture, growth chamber and greenhouse experiments, the 33 field experiments did not show consistent difference in seed yield with NH₄ and NO₃ applied at time of seeding. In nine field experiments where band application was used for Ca(NO₃)₂, (NH₄)₂ SO₄, NH₄ NO₃, yield tended to be greatest for (NH₄)₂SO₄. However, in 19 experiments on acid soils with and without lime, yields in most cases were similar with (NH₄)₂SO₄ and NH₄ NO₃. Nitrification inhibitors were added to spring banded NH₄-based fertilizers in five experiments, but the yields were not influenced. Scientific Paper No. 558, Lacombe Research Station, Agriculture Canada.     

The uptake and distribution of 15N2 into the various organs of Typha latifolia L.

Direct evidence of heterotrophic dinitrogen fixation associated with the emergent aquatic angiosperm, Typha latifolia L., was obtained through the exposure of actively growing plants to ¹⁵N₂ gas for 7 days in a gas-tight exposure vessel. Highest enrichments of ¹⁵N were found in roots/rhizomes and leaf bases. Slight enrichments were also found in the leaves due to translocation from the roots, rhizomes and leaf bases. Total fixed ¹⁵N values were 71.8 μg for the plant and 49.1 μg for the soil.Plants growing in silica sand, which received a nutrient solution containing combined nitrogen, exhibited higher enrichments and fixed 86% more ¹⁵N after exposure to ¹⁵N₂ gas than plants which received a nutrient solution lacking combined nitrogen. It is hypothesized that the concentration of combined nitrogen added was insufficient to repress nitrogen fixation and resulted in an increase in nitrogen fixation by associated microorganisms.Propane was used to trace the loss and movement of gases from the ¹⁵N₂ vessel and between the upper leaf chamber and the lower root chamber. Gas was rapidly exchanged between the upper and lower chambers through the leaves and roots of T. latifolia. Further investigations showed that propane moved at a rate of 1223 μmol day⁻¹ from the leaves to the roots and 2652 μmol day⁻¹ from the roots to the leaves. These data demonstrated that gases diffuse rapidly through the plant body of T. latifolia.     

The uptake of nitrate and ammonium nitrogen in Chara hispida L.: the contribution of the rhizoid

Abstract The uptake of ammonium and nitrate nitrogen by cultured plants of the green freshwater alga Chara hispida L. has been compared quantitatively with the contribution of its rhizoidal tissue. In the short-term, the rhizoid takes up 7–20% of the ammonium nitrogen, and about 15% of the nitrate that is taken up by whole plants under similar conditions. The uptake was studied over a range of both temperatures and external concentrations. The apparent activation energy for the uptake of NH₄⁺ and NO₃^? by the whole plant was found to be 50 kJ mol^?1 and 30 kJ mol^?1, respectively. For the rhizoid, the values were similar for both nitrogenous ions, 106 kJ mol^?1 and 70–100 kJ mol^?1. The rhizoidal uptake mechanism for ammonium nitrogen operates more efficiently compared to that in the whole plant. Nitrate is taken up by the rhizoid by a mechanism with a substrate affinity higher than in the plant taken as a whole. The possible ecological significance of the results is discussed.     

Growth strategy of an emergent macrophyte, Typha orientalis Presl, in comparison with Typha latifolia L. and Typha angustifolia L.

The growth strategy of an emergent plant, Typha orientalis Presl, was examined in experimental ponds in comparison with two other Typha species distributed in Japan, Typha latifolia L. and Typha angustifolia L. T. orientalis showed the greatest ability of vegetative reproduction at the expense of growth in height. T. orientalis started to produce new ramets earlier than T. latifolia and T. angustifolia. These results suggest that T. orientalis should be a rather pioneer-like species and would be restricted to disturbed habitats.     

Depth distribution of three Typha species, Typha orientalis Presl, Typha angustifolia L. and Typha latifolia L., in an artificial pond

The depth distribution of the aquatic macrophyte Typha orientalis Presl was examined in comparison with two other Typha species: Typha angustifolia L. and Typha latifolia L. Vegetation surveys mapping the depth distributions were conducted at Ushigafuchi Pond, Tokyo, Japan, in autumn 2004 and 2005. All vegetation had been cleared from this artificial pond in spring 2003. In 2004 T. orientalis was distributed in shallow to deep water habitats between T. latifolia (shallow water regions) and T. angustifolia (shallow to deep water regions). However, by 2005 T. orientalis had almost disappeared from the pond. It had been replaced by Leersia japonica Makino at depths of 0–30 cm, by Schoenoplectus validus (Vahl) at depths of 30–60 cm and by T. angustifolia at depths of 60–100 cm. It appears that T. orientalis is not a strong competitor, particularly with taller species, but rather a pioneer species.     

The kinetics of ammonium and nitrate uptake by young rice plants

Summary An important process which affects the fate of fertilizer nitrogen (N) applied to a rice crop is crop N uptake. This uptake rate is controlled by many factors including the N-ion species and its concentration. In this study the relation between N concentration at the root surface and N uptake was characterized using Michaelis-Menten kinetics. The equation considers two parameters, Vmax and Km, which are measures of the maximum rate of uptake and the affinity of the uptake sites for the nutrient, respectively. Uptake rates of intact rice plants growing in a continuously flowing nutrient solution system were fitted to the Michaelis-Menten model using a weighted regression analysis. For NH₄−N the Km values for 4- and 9-week-old rice plants indicated a high affinity for the ammonium ions relative to concentrations reported for rice soils after fertilization. The Vmax values expressed on a unit-root-mass basis decreased with plant age, indicating a reduction in the average density of uptake sites on the root surface. The kinetics of NO₃−N uptake was similar to that of NH₄−N when NO₃−N was the only N source. However, if NH₄−N and NO₃−N were present simultaneously in the solution the Vmax for the uptake of NO₃−N was severely reduced, while the Km was affected very little. This inhibition appears to be noncompetitive. Fertilization of young rice plants leading to concentration of N at the root surface above approximately 900 μM will not increase crop uptake and may contribute to inefficient N recovery by the crop. The existence of NH₄−N and NO₃−N simultaneously at the root surface may also lead to inefficient N recovery because of reduced uptake of NO₃−N.     

多花黑麦草对不同形态氮的吸收动力学特征研究

采用改进常规耗竭法,比较研究了多花黑麦草(Lolium multiflorum Lam.)对NH₄⁺和NO₃^-吸收动力学特征。结果表明多花黑麦草对NH₄⁺和NO₃^-吸收符合Miehaelis-Menten方程,它对NH₄⁺的亲和力显著大于对NO₃^-的亲和力,但对NH₄⁺和NO₃^-的最大吸收速率差异不显著,说明多花黑麦草偏爱吸收NH₄⁺,在实际污水净化过程中,多花黑麦草具有优先吸收NH₄⁺的趋势,若有足够的停留时间,其对NH₄⁺净化程度会更高些;当吸收系统微生物受抑制时,多花黑麦草对NO₃^-的吸收速率明显降低,亲和力明显提高,可见微生物对吸收体系中氮素的去除有一定促进作用。     

Differences in uptake kinetics of ammonium and nitrate in legumes and cereals

Influx isotherms were obtained for nitrate and ammonium from three legumes, Cajanus cajan (L.) Millsp., Cicer arietinum L. and Arachis hypogaea L. and three cereals, Sorghum bicolor (L.) Moench., Pennisetum glaucum L. and Zea mays L. The transition in influx isotherms for both nitrogen sources was found to be within the concentration range (0.05–2.5 mM) tested. There were significant differences in Km and Vmax for ammonium between legumes and cereals. The difference in the kinetic properties for nitrate uptake between the two groups of plants only became apparent at the higher concentration tested. Legumes translocated absorbed nitrate and ammonium to shoots more rapidly than cereals. Results show that there are significant differences in uptake and translocation of ammonium and nitrate between legumes and cereals.     

Thermal Inactivation Properties of Enzymes from Typha latifolia L. Ecotypes

Irreversible thermal denaturation experiments with 3 enzymes from Typha latifolia populations native to distinct thermal climates produced 3 different responses: (1) malate dehydrogenase was much more resistant to high temperature inactivation when obtained from plants native to a hot climate, (2) glutamate-oxaloacetate transaminase was quite resistant to thermal denaturation regardless of origin, and (3) aldolase was rapidly inactivated by heat regardless of origin.     

Nitrogen nutrition of Salvinia natans: Effects of inorganic nitrogen form on growth,morphology, nitrate reductase activity and uptake kinetics of ammonium and nitrate

In this study we assessed the growth, morphological responses, and N uptake kinetics of Salvinia natans when supplied with nitrogen as NO₃⁻, NH₄⁺, or both at equimolar concentrations (500 μM). Plants supplied with only NO₃⁻ had lower growth rates (0.17 ± 0.01 g g⁻¹ d⁻¹), shorter roots, smaller leaves with less chlorophyll than plants supplied with NH₄⁺ alone or in combination with NO₃⁻ (RGR = 0.28 ± 0.01 g g⁻¹ d⁻¹). Ammonium was the preferred form of N taken up. The maximal rate of NH₄⁺ uptake (V_max) was 6–14 times higher than the maximal uptake rate of NO₃⁻ and the minimum concentration for uptake (C_min) was lower for NH₄⁺ than for NO₃⁻. Plants supplied with NO₃⁻ had elevated nitrate reductase activity (NRA) particularly in the roots showing that NO₃⁻ was primarily reduced in the roots, but NRA levels were generally low (<4 μmol NO₂⁻ g⁻¹ DW h⁻¹). Under natural growth conditions NH₄⁺ is probably the main N source for S. natans, but plants probably also exploit NO₃⁻ when NH₄⁺ concentrations are low. This is suggested based on the observation that the plants maintain high NRA in the roots at relatively high NH₄⁺ levels in the water, even though the uptake capacity for NO₃⁻ is reduced under these conditions.     

A New Type of Phytase from Pollen of Typha latifolia L.

A phytase was isolated and partially purified from pollen of cattail, Typha latifolia. Its maximum activity was at pH 8.0 and its Km value was 1.7 × 10^?5 m for phytic acid in the presence of Ca²⁺. Among divalent cations tested only Ca²⁺ affected the activity, increasing it by about 120%, but an excess was inhibitory. The enzyme was specific for phytic acid except for 6% activity for p-nitrophenylphosphate. It seems to be a new type of phytase because it cleaved almost 50% of the total phosphate esters in phytic acid and was product-specific, yielding an inositol triphosphate as a final product.     

Dynamics of Typha latifolia L. populations in treatment wetlands in Estonia

The aim of this paper is to evaluate and compare broadleaved cattail (Typha latifolia L.) biomass production and the nitrogen (N) and phosphorus (P) content in phytomass in three treatment wetland systems and to propose suitable areas for treatment wetlands in Estonia for raw material production. The biomass samples (roots/rhizomes, shoots with leaves and spadixes) and litter were collected from 1 m × 1 m plots—15 plots in the Tänassilma semi-natural wetland, 15 plots in the Põltsamaa free water surface (FWS) constructed wetland (CW), and 10 plots in the Häädemeeste FWS CW. The average aboveground biomass of T. latifolia varied from 0.37 to 1.76 kg DW m^?2 in autumn and from 0.33 to 1.38 kg DW m^?2 in winter. The greatest average nitrogen (22,950 mg N kg^?1) concentration was found in spadixes in 2002, and the phosphorus (6500 mg P kg^?1) concentration was measured in roots–rhizomes in 2003. Average standing stock of nitrogen and phosphorus was higher in aboveground than belowground phytomass. In FWS CWs with high hydraulic and nutrient loadings, however, the harvesting of aboveground biomass is not an effective means for the removal of nutrients. Cattail biomass is a valuable insulation material, whereas the fibre from spadixes mixed with clay gives elasticity to clay plasters. According to our estimates, about 5412 km² could be used for Typha cultivation in Estonia.     

Root exudation pattern of Typha latifolia L. plants after copper exposure

Aims

Typha latifolia L. is an aquatic plant that has been widely exploited for the aims of phytoremediation. The main reason why we have chosen this plant species for the current study is its capacity to accumulate and detoxify heavy metals. The main topic of the investigation focused on the root uptake of copper (II) nitrate and copper (II) sulfate and the impact of different chemical copper species on the excreted organic acids.

Methods

Oxalic, malic, acetic and lactic acids were determined using capillary electrophoresis; a comparison between the concentration and the time course during 7 days of treatment was performed.

Results

There is a correlation between the total copper (II) sulfate concentration in the roots and the total amount of the excreted organic acids. In addition to that organic acids are involved in the detoxification mechanisms of Typha latifolia for copper (II) nitrate and copper (II) sulfate.

Conclusions

Different from so far investigated plant species the highest amounts of organic acids are excreted from T. latifolia roots not in the first hours after treatment, but up to 7 days later.     

Evapotranspiration by Eichhornia crassipes (Mart.) Solms and Typha latifolia L.

Evapotranspiration (E) by Eichhornia crassipes (Mart.) Solms and Typha latifolia L. growing in 5.77-m² tanks and evaporation (E₀) from control tanks were measured over a 6-month period at Auburn, Alabama (32.5° N latitude). The E/E₀ ratios for E. crassipes and T. latifolia were 1.31–2.52 (mean = 1.75) and 1.05–2.50 (mean = 1.62), respectively. Evidence is presented which demonstrates that E/E₀ values were similar to those which occur in natural populations of the two species. Both plant characteristics and meteorological variables influenced evapotranspiration. Equations for estimating evapotranspiration were E_Ec = (4.19 + (7.32 × 10⁻⁸) S² + (0.00035 × 10⁻³)H²)D R² = 0.92E_Tl = (1.43 + (2.79 × 10⁻¹⁵)S⁴ + 1.44L)D R² = 0.93 where E_Ec and E_Tl are monthly water loss in mm/month for E. crassipes and T. latifolia, respectively; S is the average daily solar radiation in W m⁻² integrated over 24 h for the month; H is plant height in m; L is leaf area index (dimensionless); and D is the number of days in the month.