Saturated and unsaturated fluorotelomer carboxylic acids have been identified as intermediates in the degradation of fluorotelomer alcohols to perfluorinated carboxylic acids (PFCAs). Although surface waters are the likely environmental sink for telomer acids, no fate or toxicity data exist for this matrix. We assessed the acute toxicity of the 4:2, 6:2, 8:2, and 10:2 saturated (FTCA) and unsat...

Pulses of a fluorinated analog of leucine, 5',5',5'-trifluoroleucine, reset the phase of the circadian rhythm of K(+) uptake in Lemna gibba G3 under continuous light conditions. The trifluoroleucine pulse caused the largest delay phase-shifts during the early subjective phase but it caused only small phase advances. The action of trifluoroleucine was investigated and the following results were ...

Utricularia gibba is an aquatic carnivorous plant with highly specialized morphology, featuring fibrous floating networks of branches and leaf-like organs, no recognizable roots, and bladder traps that capture and digest prey. We recently described the compressed genome of U. gibba as sufficient to control the development and reproduction of a complex organism. We hypothesized intense deletion ...

The Lhcb2*1 gene of Lemna gibba is regulated positively by phytochrome, and two separate, 10-bp regions of this promoter have been shown to be necessary for phytochrome regulation. We have now analyzed the effects of one and two base pair mutations to define exactly two cis elements within these regions that are necessary for phytochrome regulation. These elements, designated REalpha and REbeta...

Metals and polycyclic aromatic hydrocarbons (PAHs) are known to be toxic to plants. Because metals and PAHs often are cocontaminants in the environment, plants can be subjected to damage caused by their combined effects. We recently found that copper and an oxygenated PAH (1,2-dihydroxyanthraquinone [1,2-dhATQ]) synergistically are toxic to plants. This synergistic toxicity was linked indirectl...

Gene expression is a fundamental cellular process and expression dynamics are of great interest in life science. We succeeded in monitoring cellular gene expression in a duckweed plant, Lemna gibba, using bioluminescent reporters. Using particle bombardment, epidermal and mesophyll cells were transfected with the luciferase gene (luc+) under the control of a constitutive [Cauliflower mosaic vir...

We have studied the mechanism of UV protection in two duckweed species (Lemnaceae) by exploiting the UV sensitivity of photosystem II as an in situ sensor for radiation stress. A UV-tolerant Spirodela punctata G.F.W. Meyer ecotype had significantly higher indole-3-acetic acid (IAA) levels than a UV-sensitive ecotype. Parallel work on Lemna gibba mutants suggested that UV tolerance is linked to ...

The present paper is based on the results of taxonomic research work conducted in Dera Ismail Khan District of KPK, Pakistan, during 2005 - 2007. The area was extensively surveyed in order to collect floating aquatic weeds. From the study area 11 floating aquatic weed species belonging to 9 genera and 9 families were collected and identified in the light of available literature. These plants in...