Open dichotomous venation in the leaves ofUtricularia striatula (Lentibulariaceae)

The open dichotomous pattern of venation in the leaves ofUtricularia striatula is described in detail and compared withCircaeaster andKingdonia. Similar traits of dichotomous venation occur in other species ofUtricularia and may be due to reduction.Studies on IndianUtricularia, 3.     

The effect of copper on histidine biosynthesis inNeurospora crassa

The inhibition of growth of a wild strain ofNeurospora crassa by Cu²⁺ is counteracted by histidine, histidine methyl ester, histidinol and Mn²⁺. In the presence of Cu²⁺, the total free amino acid content decreased by 30%. The decreased free amino acid pools of arginine, histidine and tyrosine were restored on the addition of Mn²⁺. Histidinol phosphate phosphatase showed a decrease in activity in the presence of Cu²⁺. This inhibition was reversed on the addition of excess Mn²⁺. The data suggest that copper toxicity in the mould is due to suppression of histidine biosynthesis.     

Enhanced production of isoflavones by elicitation in hairy root cultures of Soybean

A combined treatment of sonication (2 min) and vacuum infiltration (2 min) stimulated isoflavones production of 75.26 mg g^?1 DW which was 15.11-fold higher than control hairy root line at optimal harvest time of 40 days. Addition of MeJ at 100 μM concentration with 72 h exposure time on 30 day-old hairy root culture further enhanced total isoflavones production of 53.16 mg g^?1 DW (10.67-fold) and SA at 200 μM concentration with 96 h exposure period enhanced the production of isoflavones (28.79 mg g^?1 DW; 5.78-fold). MeJ-treated hairy roots reduced biomass accumulation whereas sonication, vacuum infiltration and SA did not exhibit a negative effect on biomass growth.     

Anaerobiosis Induced State Transition: A Non Photochemical Reduction of PQ Pool Mediated by NDH in Arabidopsis thaliana

Background

Non photochemical reduction of PQ pool and mobilization of LHCII between PSII and PSI are found to be linked under abiotic stress conditions. The interaction of non photochemical reduction of PQ pool and state transitions associated physiological changes are critically important under anaerobic condition in higher plants.

Methodology/Findings

The present study focused on the effect of anaerobiosis on non-photochemical reduction of PQ pool which trigger state II transition in Arabidopsis thaliana. Upon exposure to dark-anaerobic condition the shape of the OJIP transient rise is completely altered where as in aerobic treated leaves the rise is unaltered. Rise in F _o and F _J was due to the loss of oxidized PQ pool as the PQ pool becomes more reduced. The increase in F_o′ was due to the non photochemical reduction of PQ pool which activated STN7 kinase and induced LHCII phosphorylation under anaerobic condition. Further, it was observed that the phosphorylated LHCII is migrated and associated with PSI supercomplex increasing its absorption cross-section. Furthermore, evidences from crr2-2 (NDH mutant) and pgr5 mutants (deficient in non NDH pathway of cyclic electron transport) have indicated that NDH is responsible for non photochemical reduction of the PQ pool. We propose that dark anaerobic condition accelerates production of reducing equivalents (such as NADPH by various metabolic pathways) which reduce PQ pool and is mediated by NDH leading to state II transition.

Conclusions/Significance

Anaerobic condition triggers non photochemical reduction of PQ pool mediated by NDH complex. The reduced PQ pool activates STN7 kinase leading to state II transition in A. thaliana.     

Stored-product insects associated with eight feed mills in the midwestern United States

Commercial food- and pheromone-baited pitfall traps and pheromone-baited sticky traps were used during 2003 to survey stored-product insect adults in eight participating feed mills in the midwestern United States. Across the eight feed mills, 27 species of beetles (Coleoptera) and three species of moths (Lepidoptera) were captured in commercial traps. The red flour beetle, Tribolium castaneum (Herbst), was the most abundant insect species captured inside the eight mills. The warehouse beetle, Trogoderma variabile (Ballion), was the most abundant insect species outside the mill and in the mill load-out area. The Indianmeal moth, Plodia interpunctella (Hübner), was the most abundant moth species inside the mill and in the mill receiving area. The Simpson's index of species diversity among mills ranged from 0.39 (low diversity) to 0.81 (high diversity). The types of species found among mills were different, as indicated by a Morisita's index of <0.7, for the majority of mills. The differences in the types and numbers of insect species captured inside, outside, in receiving, and in load-out areas could be related to differences in the types of animal feeds produced and the degree of sanitation and pest management practiced.     

Treatment of catechol bearing wastewater in an upflow anaerobic sludge blanket (UASB) reactor: sludge characteristics

This paper deals with the characteristics of anaerobic microbial granules grown in an UASB reactor treating catechol bearing synthetic wastewater (SWW). The specific methanogenic activity of the sludge showed an increase in trend with an increase in the organic loading rate and the catechol concentration in the SWW. The settling velocity of individual granules in the size range of 0.5-2.5mm was found to be in the range of 30-75mh(-1). The ash content in the sludge was 11.7% with a sludge volume index of 18-20mlg(-1). The inorganic elemental distribution within the granules showed a decrease except that for phosphorous and cobalt, which increased by approximately 12% and 18%, respectively, after the treatment of SWW. Scanning electron microscopy (SEM) coupled with electron disperse X-ray analysis showed an increase in the sulphur content by approximately 300% after the treatment of SWW. Surface mineral composition of the granules determined by XRD analysis indicated the existence of vuagnatite (CaAlSiO(4)(OH)). SEM observation of the granules showed the predominance of Methanosaeta and Methanobacterium type of species on the surface along with a variety of other species.     

X-ray crystal structure of the B component of Hemolysin BL from Bacillus cereus

Bacillus cereus Hemolysin BL enterotoxin, a ternary complex of three proteins, is the causative agent of food poisoning and requires all three components for virulence. The X-ray structure of the binding domain of HBL suggests that it may form a pore similar to other soluble channel forming proteins. A putative pathway of pore formation is discussed.     

Synthesis of peptides employing 9-fluorenylmethyl chloroformate as a coupling agent

Summary The synthesis of peptides employing 9-fluorenylmethyl chloroformate (Fmoc-Cl) as a coupling agent has been described. The method is simple, efficient and rapid. All the peptides have been obtained in good yield (70–95%). Furthermore, both the¹H NMR and the HPLC studies on Fmoc-Phg-Phe-OMe and Fmoc-D-Phg-Phe-OMe revealed that the coupling is free from racemization.     

Rho kinase and Ca2+ entry mediate increased pulmonary and systemic vascular resistance in L-NAME-treated rats

The small GTP-binding protein and its downstream effector Rho kinase play an important role in the regulation of vasoconstrictor tone. Rho kinase activation maintains increased pulmonary vascular tone and mediates the vasoconstrictor response to nitric oxide (NO) synthesis inhibition in chronically hypoxic rats and in the ovine fetal lung. However, the role of Rho kinase in mediating pulmonary vasoconstriction after NO synthesis inhibition has not been examined in the intact rat. To address this question, cardiovascular responses to the Rho kinase inhibitor fasudil were studied at baseline and after administration of an NO synthesis inhibitor. In the intact rat, intravenous injections of fasudil cause dose-dependent decreases in systemic arterial pressure, small decreases in pulmonary arterial pressure, and increases in cardiac output. L-NAME caused a significant increase in pulmonary and systemic arterial pressures and a decrease in cardiac output. The intravenous injections of fasudil after L-NAME caused dose-dependent decreases in pulmonary and systemic arterial pressure and increases in cardiac output, and the percent decreases in pulmonary arterial pressure in response to the lower doses of fasudil were greater than decreases in systemic arterial pressure. The Ca(++) entry blocker isradipine also decreased pulmonary and systemic arterial pressure in L-NAME-treated rats. Infusion of sodium nitroprusside restored pulmonary arterial pressure to baseline values after administration of L-NAME. These data provide evidence in support of the hypothesis that increases in pulmonary and systemic vascular resistance following L-NAME treatment are mediated by Rho kinase and Ca(++) entry through L-type channels, and that responses to L-NAME can be reversed by an NO donor.     

Light-induced trimer to monomer transition in the main light-harvesting antenna complex of plants: thermo-optic mechanism

The main chlorophyll a/b light-harvesting complex of photosystem II, LHCIIb, has earlier been shown to be capable of undergoing light-induced reversible structural changes and chlorophyll a fluorescence quenching in a way resembling those observed in granal thylakoids when exposed to excess light [Barzda, V., et al. (1996) Biochemistry 35, 8981-8985]. The nature and mechanism of this unexpected structural flexibility has not been elucidated. In this work, by using density gradient centrifugation and nondenaturing green gel electrophoresis, as well as absorbance and circular dichroic spectroscopy, we show that light induces a significant degree of monomerization, which is in contrast with the preferentially trimeric organization of the isolated complexes in the dark. Monomerization is accompanied by a reversible release of Mg ions, most likely from the outer loop of the complexes. These data, as well as the built-in thermal and light instability of the trimeric organization, are explained in terms of a simple theoretical model of thermo-optic mechanism, effect of fast thermal transients (local T-jumps) due to dissipated photon energies in the vicinity of the cation binding sites, which lead to thermally assisted elementary structural transitions. Disruption of trimers to monomers by excess light is not confined to isolated trimers and lamellar aggregates of LHCII but occurs in photosystem II-enriched grana membranes, intact thylakoid membranes, and whole plants. As indicated by differences in the quenching capability of trimers and monomers, the appearance of monomers could facilitate the nonphotochemical quenching of the singlet excited state of chlorophyll a. The light-induced formation of monomers may also be important in regulated proteolytic degradation of the complexes. Structural changes driven by thermo-optic mechanisms may therefore provide plants with a novel mechanism for regulation of light harvesting in excess light.