Cold pretreatment to enhance green plant regeneration from rye anther culture

Cold pretreatment of detached tillers of rye, Secale cereale, was tested under two light regimes. The ryes included two spring and two winter cultivars. Significant increases in green plant regeneration were recorded in each experiment when cold pretreatments of two to four weeks were applied. Dim light during the stress period improved green plant regeneration for two of the four cultivars tested. The highest regeneration rate, 30.6 green plants per 100 plated anthers, was reached following three weeks at +4 °C under dim light, for spring rye Jo02. Starvation stress applied to plated anthers in mannitol medium suppressed anther response. This revised version was published online in June 2006 with corrections to the Cover Date.     

Molecular interactions position Mso1p, a novel PTB domain homologue, in the interface of the exocyst complex and the exocytic SNARE machinery in yeast

In this study, we have analyzed the association of the Sec1p interacting protein Mso1p with the membrane fusion machinery in yeast. We show that Mso1p is essential for vesicle fusion during prospore membrane formation. Green fluorescent protein-tagged Mso1p localizes to the sites of exocytosis and at the site of prospore membrane formation. In vivo and in vitro experiments identified a short amino-terminal sequence in Mso1p that mediates its interaction with Sec1p and is needed for vesicle fusion. A point mutation, T47A, within the Sec1p-binding domain abolishes Mso1p functionality in vivo, and mso1T47A mutant cells display specific genetic interactions with sec1 mutants. Mso1p coimmunoprecipitates with Sec1p, Sso1/2p, Snc1/2p, Sec9p, and the exocyst complex subunit Sec15p. In sec4-8 and SEC4I133 mutant cells, association of Mso1p with Sso1/2p, Snc1/2p, and Sec9p is affected, whereas interaction with Sec1p persists. Furthermore, in SEC4I133 cells the dominant negative Sec4I133p coimmunoprecipitates with Mso1p-Sec1p complex. Finally, we identify Mso1p as a homologue of the PTB binding domain of the mammalian Sec1p binding Mint proteins. These results position Mso1p in the interface of the exocyst complex, Sec4p, and the SNARE machinery, and reveal a novel layer of molecular conservation in the exocytosis machinery.     

The uptake of and structural changes induced by trichloroacetic acid in the needles of Scots pine seedlings

The uptake of trichloroacetic acid (TCA) and structural changesinduced in the needles of Scots pine (Pinus sylvestris L.) seedlingswere studied. Two exposure set-ups, a root route and an atmosphericroute through the surfaces simulating the wet deposition offog, were used. Both set-ups included two dose levels and correspondingcontrol treatments. The temperature and the relative humidityin the climate chambers were adjusted to represent the conditionsof June–July in a subarctic area in central Finland. Theseedlings were exposed three times a week for two months. Theresults showed that the uptake of TCA in needles occurred bothvia roots and via needle surface. However, most of the TCA viathe atmospheric route was absorbed on the surface of the needles.The structural responses in pine needles depended partly onthe treatment method: TCA applied via the atmospheric routedisintegrated the structures of the epicuticular waxes and thatof the stomatal cells, which was not seen in the exposures viaroots. A common feature was the decrease in size of the chloroplastsin concert with the increasing TCA concentrations inside theneedles. Key words: Pinus sylvestris L., climate chamber, effects, microscopic structure, secondary pollutant, TCA, trichloroacetic acid     

Combined effect of elevated UVB,elevated temperature and fertilization on growth,needle structure and phytochemistry of young Norway spruce (Picea abies) seedlings

Simultaneously with warming climate, other climatic and environmental factors are also changing. Here, we investigated for the first time the effects of elevated temperature, increased ultraviolet‐B (UVB) radiation, fertilization and all combinations of these on the growth, secondary chemistry and needle structure of 1‐year‐old Norway spruce (Picea abies (L.) Karst.) seedlings in an outdoor experiment. After one growing season, elevated temperature increased root : shoot ratio and concentrations of needle piperidine alkaloids, while concentrations of needle catechins and acetophenones and bark flavonoids decreased compared with ambient temperature seedlings. UVB‐radiation increased concentrations of bark condensed tannins, while fertilization increased total biomass and concentrations of needle catechins. In addition to the main effects, concentrations of some individual phenolic compounds showed UV × temperature or UV × temperature × fertilization interactions, and fertilization modified temperature response on root : shoot ratio. All the treatments described here affected the defence chemistry profiles of the seedlings, which may imply some changes in plant‐herbivore interactions in connection with changing climate. The interactions between treatments indicate a need for further experiments involving several simultaneously affecting environmental changes.     

Specified species in gingival crevicular fluid predict bacterial diversity

Background

Analysis of gingival crevicular fluid (GCF) samples may give information of unattached (planktonic) subgingival bacteria. Our study represents the first one targeting the identity of bacteria in GCF.

Methodology/Principal Findings

We determined bacterial species diversity in GCF samples of a group of periodontitis patients and delineated contributing bacterial and host-associated factors. Subgingival paper point (PP) samples from the same sites were taken for comparison. After DNA extraction, 16S rRNA genes were PCR amplified and DNA-DNA hybridization was performed using a microarray for over 300 bacterial species or groups. Altogether 133 species from 41 genera and 8 phyla were detected with 9 to 62 and 18 to 64 species in GCF and PP samples, respectively, per patient. Projection to latent structures by means of partial least squares (PLS) was applied to the multivariate data analysis. PLS regression analysis showed that species of genera including Campylobacter, Selenomonas, Porphyromonas, Catonella, Tannerella, Dialister, Peptostreptococcus, Streptococcus and Eubacterium had significant positive correlations and the number of teeth with low-grade attachment loss a significant negative correlation to species diversity in GCF samples. OPLS/O2PLS discriminant analysis revealed significant positive correlations to GCF sample group membership for species of genera Campylobacter, Leptotrichia, Prevotella, Dialister, Tannerella, Haemophilus, Fusobacterium, Eubacterium, and Actinomyces.

Conclusions/Significance

Among a variety of detected species those traditionally classified as Gram-negative anaerobes growing in mature subgingival biofilms were the main predictors for species diversity in GCF samples as well as responsible for distinguishing GCF samples from PP samples. GCF bacteria may provide new prospects for studying dynamic properties of subgingival biofilms.     

Comparison of different normalised LCIA results and their feasibility in communication

Purpose

The purpose of this study was to answer the following three questions: (1) What are the reference values of normalisation for Finnish production and Finnish consumption and how do they differ from the European reference values?, (2) How do these differences influence the interpretation of normalised LCIA results?, and (3) How can normalised LCIA results be made more comprehensible to non-LCA experts with the help of communication material?

Methods

Finnish reference values for normalisation were calculated on the basis of the Finnish environmentally extended input–output model and ReCiPe LCIA method. The influence of different normalised results on the interpretation of LCIA was assessed based on an LCA study of print products. LCA communication material (product-specific fact sheets) was developed by organising workshops and interviews with stakeholders in the paper and printing industry.

Results and discussion

A comparison of the production based Finnish reference values to the European reference values shows that Finland contributes roughly 1 % to the European values in all impact categories except in the fossil depletion category where the contribution is 3 %. The order of magnitude of the impact categories varies depending on the reference system used for normalisation, which influences the interpretation of LCIA results. The normalised results were made more comprehensible by developing fact sheets including background information and guidance for interpretation of the LCIA results.

Conclusions

The interpreter of normalised LCIA results does not usually have the information to estimate how the chosen reference system influences the results. A sensitivity analysis with different reference values may help to highlight this effect. When communicating to non-LCA-practitioners, LCIA results need to be connected to a wider context, which can be achieved by using normalisation to give an idea of the order of magnitude of the results. However, the harmfulness of the impact categories in relation to each other cannot be judged on the basis of the normalised results, which seems to be a difficult concept for non-LCA-practitioners to understand.