Involvement of nitric oxide in cerebroside-induced defense responses and taxol production in <Emphasis Type="Italic">Taxus yunnanensis</Emphasis> suspension cells

This work was to characterize the generation of nitric oxide (NO) in Taxus yunnanensis cells induced by a fungal-derived cerebroside and the signal role of NO in the elicitation of plant defense responses and taxol production. (2S,2′R,3R,3′E,4E,8E)-1-O-β-d-glucopyranosyl-2-N-(2′-hydroxy-3′-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine at 10 μg/ml induced a rapid and dose-dependent NO production in the Taxus cell culture, reaching a maximum within 5 h of the treatment. The NO donor sodium nitroprusside (SNP) potentiated cerebroside-induced H₂O₂ production and cell death. Inhibition of nitric oxide synthase activity by phenylene-1,3-bis(ethane-2-isothiourea) dihydrobromide or scavenging NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide partially blocked the cerebroside-induced H₂O₂ production and cell death. Moreover, NO enhanced cerebroside-induced activation of phenylalanine ammonium-lyase and accumulation of taxol in cell cultures. These results are suggestive of a role for NO as a new signal component for activating the cerebroside-induced defense responses and secondary metabolism activities of plant cells. Taxol is a trademark of Bristol-Myers Squibb, Madison, NJ.     

Cranial Morphology of a Pantolestid Eutherian Mammal from the Eocene Bridger Formation,Wyoming, USA: Implications for Relationships and Habitat

Pantolestinae is a eutherian subfamily of mammals whose members are known from the middle early Paleocene through at least the beginning of the Oligocene of North America. They are also known from Europe, and possibly Africa. A lack of information on pantolestine skulls has prevented the use of cranial anatomy in evaluation of this group’s enigmatic higher-level phylogenetic relationships. Conversely, postcranial skeletons are well known and locomotor interpretations based on them are robust. The most complete known skull of a pantolestine, Pantolestes longicaudus (YPM 13525), is described here and compared to potential close fossil relatives and extant mammals. Semicircular canal morphology is used to test locomotor hypotheses. YPM 13525 lacks an ossified bulla. It has a mediolaterally broad basioccipital, a large entoglenoid process, and a deeply incised glaserian fissure of the squamosal, caudal and rostral tympanic processes on the petrosal, a foramen for an internal carotid artery (ICA) that entered the tympanic cavity from a posteromedial position, bony tubes enclosing the main stem and transpromontorial branch of the ICA, a large anterior carotid foramen formed within the basisphenoid, evidence of a stapedial artery ramus superior, a groove on the dorsal aspect of the basisphenoid leading to the piriform fenestra possibly for drainage of the cavernous sinus to an extracranial inferior petrosal sinus, a dorsum sellae with well-developed posterior clinoid processes, a foramen rotundum within the alisphenoid, and a sphenorbital fissure between the alisphenoid and orbitosphenoid. Overall, the morphology is not strikingly similar to any potential close relative and the phylogenetic position of Pantolestinae cannot be estimated without cladistic analysis of a character matrix that includes this new morphology and broadly samples extant and extinct eutherian taxa. Semicircular canal morphology differs from that of two likely terrestrial Paleocene mammals, Aphronorus (another pantolestid) and Eoryctes (a palaeoryctid), suggesting a different, possibly semi-aquatic, lifestyle for Pantolestes.     

Cold responsive EARLI1 type HyPRPs improve freezing survival of yeast cells and form higher order complexes in plants

Plants have large families of proteins sharing a conserved eight-cysteine-motif (8CM) domain. The biological functions of these proteins are largely unknown. EARLI1 is a cold responsive Arabidopsis gene that encodes a hybrid proline-rich protein (HyPRP) with a three-domain architecture: a putative signal peptide at the N-terminus, a proline-rich domain (PRD) in the middle, and an 8CM domain at the C-terminus. We report here that yeast cells expressing different EARLI1 genes had significantly higher rates of freezing survival than empty-vector transformed controls. Arabidopsis plants with knocked down EARLI1 genes had an increased tendency for freezing-induced cellular damage. EARLI1-GFP fluorescence in transgenic plants and immunoblot analyses using protoplasts suggested cell wall localization for EARLI1 proteins. Immunoblot analyses showed that EARLI1 proteins form higher order complexes in plants, and that the PRD is a soluble and the 8CM an insoluble protein domain. We propose that EARLI1 proteins have a bimodular architecture in which the PRD may interact with the cell wall and the 8CM domain with the plasma membrane to protect the cells during freezing stress.     

Biodegradability of tannin-containing wastewater from leather industry

Tannins occur commonly in the wastewaters from forestry, plant medicine, paper and leather industries. The treatment of this kind of wastewaters, including settling and biodegradation, is usually difficult because tannins are highly soluble in water and would inhibit the growth of microorganisms in activated sludge. The objective of this study is to investigate biodegradability of tannin-containing wastewaters, so as to characterize the pollution properties of such wastewaters and provide a reference for their biological treatment in wastewater treatment plants. The research was typified by using the wastewater collected from vegetable tanning process in leather industry. A model was developed to describe the activated sludge process, and the biodegradation kinetics of vegetable tanning wastewater (VET wastewater) was studied. It was found that the biodegradability of tannin-containing wastewater varies heavily with the content of tannins in wastewater. The biodegradation of VET wastewater with tannin content around 4,900 mg/l occurred inefficiently due to the inhibition of tannins to the activated sludge process, and only 34.7% of biodegradation extent was reached in 14 days of incubation. The optimal biodegradability of VET wastewater was observed when its tannin content was diluted to 490 mg/l, where the COD and tannin removals reached 51.3% and 45.1% respectively in 6 days. Hence, it is suggested that a proper control of tannin content is necessary to achieve an effective biodegradation of tannin-containing wastewaters in wastewater treatment plants.     

Growth promoting effect of a transgenic <Emphasis Type="Italic">Bacillus mucilaginosus</Emphasis> on tobacco planting

In this study, we have investigated the plant growth promoting effect of Bacillus mucilaginosus strain D₄B₁, a rhizosphere soil organism, and its transgenic strain NKTS-3 on tobacco planting. The transgenic strain contains a phytase expression cassette that can express high active phytase extracellularly and hydrolyze phytate in the soil to liberate inorganic phosphorus for the growth of tobacco plants. Greenhouse study and field experiments showed that both wild-type B. mucilaginosus and the transgenic strain could promote tobacco plant growth. Moreover, the transgenic strain promoted tobacco plant growth (235% more than control in pot experiments and 125% more than control in field experiments) was higher than the wild-type B. mucilaginosus (183% more than control in pot experiments and 108% more than control in field experiments). In addition, the inoculation with transgenic rhizobacteria could significantly improve root acquisition of phosphorus and increase the phosphorus content of the plant.     

Effects of Selenium and Vitamin E,in Addıtıon to Melatonin,Against Oxidative Stress Caused by Cadmium in Rats

The present study was carried to evaluate the protective effects of melatonin alone and vitamin E with selenium combination against high dose cadmium-induced oxidative stress in rats. The control group received subcutanous physiological saline. The first study group administered cadmium chloride (CdCl₂) by subcutaneous injection of dose of 1 mg/kg. The second study group administered cadmium plus vitamin E with selenium (1 mg/kg sodium selenite with 60 mg/kg vitamin E); the third study group administered cadmium plus 10 mg/kg melatonin (MLT); the fourth study group administered CdCl₂ plus a combination of melatonin in addition to vitamin E and selenium for a month. Determination levels of plasma malondialdehyde (MDA), glutathione peroxidase (GSH-Px), blood superoxide dismutase (SOD), creatinine alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), blood urea nitrogen (BUN), and urea were measured in serum. In only CdCl₂ administered group, the MDA, creatinine, ALT, AST, ALP, and urea levels in the serum were significantly higher than the control group (p < 0.05). Whereas in all other groups, this values were significantly lower than the only CdCl₂ administered group (p < 0.05). Erythrocytes GSH-Px, serum SOD activities of only CdCl₂ received group were significantly lower than the control group (p < 0.05). In conclusion, vitamin E + Se, melatonin and vitamin E, and Se, in addition to MLT combinations, had protective effects against high dose cadmium-induced oxidative damage.     

Fusion of carbohydrate binding modules from <Emphasis Type="Italic">Thermotoga neapolitana</Emphasis> with a family 10 xylanase from <Emphasis Type="Italic">Bacillus halodurans</Emphasis> S7

Xylanase A of Thermotoga neapolitana contains binding domains both at the N- and C-terminal ends of the catalytic domain. In the N-terminal position it contains two carbohydrate-binding modules (CBM) which belong to family 22. These CBMs bind xylan but not to cellulose. The gene encoding the mature peptide of these CBMs was fused with an alkaline active GH10 xylanase from Bacillus halodurans S7 and expressed in Escherichia coli. The (His)₆ tagged hybrid protein was purified by immobilized metal affinity chromatography and characterized. Xylan binding by the chimeric protein was influenced by NaCl concentration and pH of the binding medium. Binding increased with increasing salt concentration up to 200 mM. Higher extent of binding was observed under acidic conditions. The fusion of the CBM structures enhanced the hydrolytic efficiency of the xylanase against insoluble xylan, but decreased the stability of the enzyme. The optimum temperature and pH for the activity of the xylanase did not change.