Phytochrome Control of Cellulase Activity in Datura ferox L. Seeds and its Relationship with Germination

The influence of phytochrome on endosperm softening and cellulaseactivity was studied on light-stimulated Datura ferox seeds.Endosperm softening preceded the earliest signs of radicle protrusion,and there was good correlation between the % of seeds with softendosperm at 48 h after R and germination at 96 h after R. Cellulaseactivity was stimulated by R and the increase in activity preceded,by more than 24h, radicle protrusion and endosperm softening.The effect of R was reversed by FR, but, by delaying the irradiationwith FR until cellulase activity had increased significantly,it was observed that removing Pfr did more than just stop anyfurther increase, the level of cellulase activity decreasedin about 24 h close to the dark controls. Cellulase activitywas decreased by a FR irradiation even when more than 60% germinationhad escaped from reversion. These results indicate that phytochromeinfluence on cellulase is not an indirect consequence of thestimulus of germination and that the continuous presence ofPfr is required for the cellulase activity to remain high. Thepossibility that cellulase and other degrading enzymes may bepart of the mechanism of light-induced germination is discussed. Key words: Phytochrome, germination, cellulase     

New chromosome counts in the subtribe Centaureinae (Asteraceae, Cardueae) from West Asia, II

Seventeen chromosome counts of nine species of Centaurea , two species of Serratula , one species each of the genera Aetheopappus, Amberboa, Hyalaea, Oligochaeta, Stizolophus and the type of the monospecific genus Callicephalus from Armenia are reported; three of them are new reports, four others are corrections of previous counts and ten are confirmations of very scarce previous data.     

Juvenile dispersal behaviour and natal philopatry of a long-lived raptor, the Spanish Imperial Eagle Aquila adalberti

The dispersal behaviour of 30 radio-tagged young Spanish Imperial Eagles Aquila adalberti was studied in southwestern Spain in 1986–1990. The dispersal process involved first departure from the natal population, exploratory movements, temporary settlements and returns to the natal population. The dispersal process lasted for the whole of the immature period studied, and behaviour was radically different from that displayed by territorial adults. Movements between temporary settling areas and the natal population occurred continually throughout the dispersal period. Return to the natal population could be used by the young to explore the possibilities for pair formation where a vacancy may have occurred in the breeding population.     

Production via good manufacturing practice of exofucosylated human mesenchymal stromal cells for clinical applications

Background

The regenerative and immunomodulatory properties of human mesenchymal stromal cells (hMSCs) have raised great hope for their use in cell therapy. However, when intravenously infused, hMSCs fail to reach sites of tissue injury. Fucose addition in α(1,3)-linkage to terminal sialyllactosamines on CD44 creates the molecule known as hematopoietic cell E-/L-selectin ligand (HCELL), programming hMSC binding to E-selectin that is expressed on microvascular endothelial cells of bone marrow (BM), skin and at all sites of inflammation. Here we describe how this modification on BM-derived hMSCs (BM-hMSCs) can be adapted to good manufacturing practice (GMP) standards.

Seasonal and spatial population loads of a tropical insect: the case of the coffee leaf-miner in Mexico

Abstract.

• 1 The effect of weather fluctuations in a tropical rain forest upon a leaf-miner (the coffee leaf-miner Leucoptera coffeella Guerin-Meneville (Lepidoptera: Lyonetiidae)) was studied in Veracruz, Mexico. The combined effect of temperature and precipitation upon the leaf-miner populations was investigated in coffee plantations located along an elevation transect and throughout the annual seasons. The effect of plant diversity, displayed by the presence or absence of shade trees in coffee plantations, upon the population loads of the leaf-miner was also investigated.
• 2 The leaf-miner population increased significantly during the period of intermediate temperature and low precipitation (spring season). Elevation also affected the population load of the insect: leaf-miner populations were larger at low elevations (where temperatures are high and precipitation low) than at high elevations.
• 3 Plant structural diversity did not affect the population loads of the leaf-miner.
• 4 The results indicate that the direct and indirect effects of temperature and precipitation are significant factors in the population dynamics of the coffee leafminer. It is suggested that even moderate fluctuations in climatic conditions in tropical and subtropical regions may also play an important role in the dynamics of tropical insect populations, similar to that found in temperate zones where climatic fluctuations are extreme.

     

Holcus azoricus M. Seq. & Castrov. (Poaceae), a new species from the Azores Islands

A new species of Holcus L. (Poaceae), endemic to the Azores archipelago (Portugal), is described. The vegetative and reproductive structures were studied. The diagnostic characters were compared with those of closely related species. New chromosome counts in Holcus azoricus M. Seq. & Castrov. (2 n  = 35) and H. rigidus Hochst. (2 n  = 28) are included. A possible hybrid origin is hypothesized; the potential parents are H. lanatus L. and H. rigidus .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 259–267.     

Another new species of Ceratozamia (Zamiaceae) from Chiapas, Mexico

Ceratozamia mirandai sp. nov. from the Sepultura Biosphere reserve of Chiapas, Mexico, is described and illustrated. Its closest affinities are with C. kuesteriana Regel from Tamaulipas of north-east Mexico, but differs in male and female cone and trunk morphology.     

Features of basal and race-specific defences in photosynthetic Arabidopsis thaliana suspension cultured cells

Plant suspension cell cultures display many features of the innate immune responses observed in planta and have been extensively applied to the study of basal and race-specific defences. However, no single model including photosynthetic cultured cells has been used for the exhaustive characterization of both basal and race-specific defences to date. In this article, we report the activation of basal and race-specific defences in green cultured cells from Arabidopsis thaliana . Inoculation of cultured cells with isogenic virulent or avirulent strains of Pseudomonas syringae pv. tomato DC3000 (Pst) was used to evaluate race-specific defences. The proliferation of avirulent Pst was found to be lower than that of virulent Pst in the inoculated cultures. Extracellular pH changes, sustained oxidative burst (5–13 h post-inoculation), enhancement of salicylic acid, and massive cell death were specifically stimulated by the avirulent bacterium. Neither avirulent nor virulent Pst induced markers of basal resistance, such as callose deposition or early oxidative burst (1–5 h post-inoculation). However, both basal defences were activated when cells were exposed to Pseudomonas syringae pv. phaseolicola or to the Pst mutant defective in the type III secretion system (TTSS), Pst-hrpL⁻. Thus, in these cells, basal defences may be inhibited by Pst in a TTSS-dependent manner. Recapitulation of classical defence features demonstrates the usefulness of this system for the fine characterization of plant innate immune components.     

Comparative use of bendiocarb and DDT to control Anopheles pseudopuncitpennis in a malarious area of Mexico

The state of Sinaloa has one of the highest and most persistent malaria transmission levels in Mexico. Due to this situation, with resistance of the vector Anopheles pseudopunctipennis Theobald to DDT, the carbamate insecticide bendiocarb was evaluated as an alternative to DDT for residual house-spraying in village-scale trials during 1985-87. Application rates of the active ingredient per square metre of sprayable surface (ai/m2) were 0.4 g bendiocarb 80% wettable powder (80WP) and 2 g DDT 75% WP. Both insecticides failed to control mosquito populations. Human-bait mosquito densities were not altered as a result of insecticide spraying and human-bait collected mosquito mortality rates were low, suggesting little pre-biting insecticide contact due to avoidance or insufficient resting time indoors. Lower densities of indoor-resting mosquitoes were observed with DDT as opposed to bendiocarb treated houses. Anopheline mortality was higher (98-100%) when exposed for 1 h to 1% bendiocarb in standard WHO susceptibility tests and wall bioassays. Mortality-rates of 15-48% due to 1 h exposure to 4% DDT indicated that this insecticide may continue to be partially effective. House curtain and mark-recapture mosquito studies indicated that DDT produced higher excito-repellency than bendiocarb, as reflected by more mosquito landings but lower feeding rates, shorter resting period and earlier exit time from DDT sprayed houses. In the absence of insecticide, more than 50% of blood-fed An.pseudopunctipennis females exited from houses within 2-4 h of release, showing exophilic behaviour. The outdoor/indoor density ratio indicated that the majority were exophagic. These behavioural characteristics limit the usefulness of any residual insecticide against An.pseudopunctipennis.