Methane in sulfate-rich and sulfate-poor wetland sediments

Wetlands of northern Belize provide a unique opportunity to study methane production and emissions from marshes dominated by identical species (Typha domingensis, Cladium jamaicense) and genus (Eleocharis spp.), but differing substantially in the amount of sulfates present in the sediments. Some marshes occur on limestone marls rich in gypsum (CaSO₄) while others are underlain by alluvial sands poor in sulfates. Concentrations of methane and sulfates in the sediment interstitial water are one or more orders of magnitude different for these two geological substrata averaging 139.2 and 14.9 M of CH₄, and 0.08 and 11.53 mM of SO₄ ^–2 2 on alluvial sands and limestone respectively. The amount of methane found in the internal atmosphere of plants from alluvial sands is significantly higher (6.3 M) than in plants from limestone (0.19 M). The average methane emissions measured in wetlands located on alluvial sands were 25.2 mg m^–2 h^–1 while emissions from marshes on limestone were only 2.4 mg m^–2 h^–1. These values extrapolated for the entire year and the respective wetland areas resulted in the estimate of total CH4 emissions from northern Belize of 0.066 Tg per year.     

The Chemical Principles from the Female lnftorescences of Typha angustata

Seven crystalline compounds have been isolated from the female inflorescences of Typha angustata Bory et Chaub. They were identified as vanillic acid (Ⅰ), E-p-hydroxy- cinnamic acid (Ⅱ), Protocatechuic acid (Ⅲ), E-Pro-penoic acid-3- (4-hydroxyphenyl)- 2,3-dihydrohypropyl ester (Ⅳ), Succinic acid (Ⅴ), p-hydroxybenzaldehyde (Ⅵ) and D-mannitol (Ⅶ). (Ⅳ) is a new compound. (Ⅰ), (Ⅱ), (Ⅲ) and (Ⅶ) were attained for the first time from Typhaceae.     

The effects of moisture and temperature on the ageing kinetics of pollen: interpretation based on cytoplasmic mobility

This study shows that characterization of the molecular mobility in the cytoplasm of pollen provides a new understanding of the effects of moisture and temperature on ageing rates. Using EPR spectroscopy, we determined the rotational motion of the polar spin probe, 3-carboxy-proxyl, in the cytoplasm of Typha latifolia pollen, under different temperature and moisture content conditions. Increasing the temperature resulted in faster rotational motion, analogous to faster ageing rates. With decreasing moisture content, rotational motion first decreased until a minimum was reached, after which rotational motion slightly increased again. The moisture content at which this minimal rotational motion was observed increased with decreasing temperature, comparable to the pattern of ageing rate. A significant linear relationship was found between ageing rates and rotational motion in the cytoplasm, suggesting that these parameters are causally linked. Upon melting of the intracellular glass, a twofold increase in activation energy of rotational motion and ageing rate was observed. In contrast, melting of the sucrose glass resulted in an increase in rotational motion of five orders of magnitude. The difference in rotational motion upon melting glasses of pollen or sucrose suggests that other molecules beside sugars play a role in intracellular glass formation in pollen.     

A Study of Pollen Morphology of Sparganium from China

Pollen morphology of 8 species in genus Sparganium from China has been studied. All of them were examined under the light microscope and SEM. It may draw the following conclusions: The characteristics of pollen grains in genus Sparganium are very similar. They are spheroidal, subspheroidal or sometimes slightly angular in shape, 21.8–38.3μm in diameter, monoporate. Porus is slightly sunken, its margin distinct or indistinct, and some granules on the porus membrane. The thickness of exine is 1.7–2.6μ m. The sexine is about as thick as nexine, sometimes thinner than nexine. It is difficult to distinguish one another under the light microscope, but may be seperated under SEM on the basis of the shape or size of lumina and width or height of muff. In some species small excrescenses can be observed under SEM. Some taxonomists (Rendle, 1953) considered that Sparganium is closely related to Pandanus, but others (Hutchison 1934, Takhtajan 1969) to Typha. According to the data of pollen morphology, Sparganium is more close to Typhaceae than to Pandanaceae, thus we agree to put it into family Typhaceae.     

Studies on the Constltuents of the Flavonoids from the Leaves of Typha angustifolia L.

Six flavonoids were isolated from the leaves of Typha angustifolia L. On the basis of spectroscopic (IR, UV, MS, 1HNMR and 13CNMR) analysis, they were identified as quercetin-3,3'-dimethyl ether (TF-Ⅰ), isorhamnetin (TF-Ⅱ), quercetin (TF-Ⅲ), quercetin-3,3' dimethyl ether-4'-O-β-D-glucoside (TF-Ⅳ), isorhamnetin-3-O-β-galactoside (TF-Ⅴ), and isorhamnetin-3-O-neohesperidoside (TF-Ⅵ). Compounds TF-Ⅰ and TF-Ⅴ were found in the genus of Typha for the first time.     

Plants for waste water treatment--effects of heavy metals on the detoxification system of Typha latifolia

Upon treatment with Cd and As cattail (Typha latifolia) showed induced catalase, monodehydroascorbate reductase and ascorbate peroxidase activities in leaves but strong inhibition in rhizomes. Peroxidase activity in leaves of the same plants was inhibited whereas linear increase was detected after Cd treatment in rhizomes.Glutathione S-transferase measurements resulted in identical effects of the trace elements on the substrates CDNB, DCNB, NBC, NBoC, fluorodifen. When GST was assayed with the model substrate DCNB, a different pattern of activity was observed, with strongly increasing activities at increasing HM concentrations. Consequently, to improve the success rates, future phytoremediation plans need to preselect plant species with high antioxidative enzyme activities and an alert GST pattern capable of detoxifying an array of organic xenobiotics.     

Effects of Amendments on Growth and Uptake of Cd and Zn by Wetland Plants,Typha angustifolia and Colocasia esculenta from Contaminated Sediments

A pot study was conducted to compare the effects of amendments (CaHPO₄ and cow manure) on growth and uptake of Cd and Zn from contaminated sediments by two wetland plant species, Typha angustifolia and Colocasia esculenta. Contaminated sediments (Cd 33.2 mg kg^–1 and Zn 363 mg kg^–1) were collected from Mae Tao basin, Mae Sot district, Tak province, Thailand. The experiment consisted of 4 treatments: control (uncontaminated sediment), Cd/Zn, Cd/Zn + 5% CaHPO₄, and Cd/Zn + 10% cow manure. Plants were grown for 3 months in the greenhouse. The addition of CaHPO₄ resulted in the highest relative growth rate (RGR) and highest Cd accumulation in both T. angustifolia and C. esculenta while the lowest RGR was found in C. esculenta grown in the cow manure treatment. Both plant species had higher concentrations of metals (Cd, Zn) in their belowground parts. None of the amendments affected Zn accumulation. C. esculenta exhibited the highest uptake of both Cd and Zn. The results clearly demonstrated the phytoremediation potential of C. esculenta and the enhancement of this potential by CaHPO₄ amendment.     

Endophytic colonization of Typha australis by a plant growth-promoting bacterium Klebsiella oxytoca strain GR-3

AIMS: To isolate and characterize endophytic diazotrophic bacteria from a semi-aquatic grass (Typha australis) which grows luxuriantly with no addition of any nitrogen source. METHODS AND RESULTS: Ten endophytic diazotrophic bacteria from surface-sterilized roots and culm of T. australis were isolated and screened for plant growth-promoting activities employing standard methods. Based on the rate of nitrogenase activity, indole acetic acid (IAA) production and phosphate (P) solubilization, one root isolate namely GR-3 was found to be the most efficient one. This isolate was identified as Klebsiella oxytoca on the basis of 16S rDNA sequence analysis. Amplification of nifH by polymerase chain reaction (PCR) and detection of dinitrogenase reductase by western blot confirmed the diazotrophic nature of GR-3. It was tagged with gusA fused to a constitutive promoter and the resulting transconjugant was inoculated onto endophyte-free rice variety Malviya dhan-36 seedlings to express cross-infection ability which resulted in a significant increase in root/shoot length and chlorophyll a content. CONCLUSIONS: Roots and culm of T. australis harbour several endophytic diazotrophic bacteria. One root isolate, identified as K. oxytoca GR-3, seems to be an efficient plant growth-promoting bacterium. SIGNIFICANCE AND IMPACT OF THE STUDY: Plant growth-promoting properties of GR-3 suggest that this promising isolate merits further investigations for potential application in agriculture.