Synthesis and import of GDP-l-fucose into the Golgi affect plant-water relations.

Land plants evolved multiple adaptations to restrict transpiration. However, the underlying molecular mechanisms are not sufficiently understood. We used an ozone-sensitivity forward genetics approach to identify Arabidopsis thaliana mutants impaired in gas exchange regulation.

Ragweed plants grown under elevated CO levels produce pollen which elicit stronger allergic lung inflammation.

Background: Common ragweed has been spreading as a neophyte in Europe. Elevated CO levels, a hallmark of global climate change, have been shown to increase ragweed pollen production, but their effects on pollen allergenicity remain to be elucidated.

Methods: Ragweed was grown in climate-controlled chambers under normal (380 ppm, control) or elevated (700 ppm, based on RCP4.

Pollen of common ragweed (Ambrosia artemisiifolia L.): Illumina-based de novo sequencing and differential transcript expression upon elevated NO/O.

Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic annual ruderal plant and native to Northern America, but now also spreading across Europe. Air pollution and climate change will not only affect plant growth, pollen production and duration of the whole pollen season, but also the amount of allergenic encoding transcripts and proteins of the pollen.

Heteroplasmy and atrazine resistance in Chenopodium album and Senecio vulgaris.

Atrazine-resistant weeds are well known, and the resistance is primarily caused by a point mutation in the psbA chloroplast gene encoding the photosystem II D1 protein. Heteroplasmy, the presence of different types of chloroplasts in an individual plant, is also very common. Thus, atrazine-resistant weeds may also partly possess the atrazine-binding sequence and vice versa.

Effects of NO2 and Ozone on Pollen Allergenicity.

This mini-review summarizes the available data of the air pollutants NO2 and ozone on allergenic pollen from different plant species, focusing on potentially allergenic components of the pollen, such as allergen content, protein release, IgE-binding, or protein modification. Various in vivo and in vitro studies on allergenic pollen are shown and discussed.

Large-Scale Phenomics Identifies Primary and Fine-Tuning Roles for CRKs in Responses Related to Oxidative Stress.

Cysteine-rich receptor-like kinases (CRKs) are transmembrane proteins characterized by the presence of two domains of unknown function 26 (DUF26) in their ectodomain. The CRKs form one of the largest groups of receptor-like protein kinases in plants, but their biological functions have so far remained largely uncharacterized. We conducted a large-scale phenotyping approach of a nearly complete crk T-DNA insertion line collection showing that CRKs control important aspects of plant development and stress adaptation in response to biotic and abiotic stimuli in a non-redundant fashion.

Common ragweed (Ambrosia artemisiifolia L.): allergenicity and molecular characterization of pollen after plant exposure to elevated NO2.

Ragweed pollen is the main cause of allergenic diseases in Northern America, and the weed has become a spreading neophyte in Europe. Climate change and air pollution are speculated to affect the allergenic potential of pollen. The objective of this study was to investigate the effects of NO2 , a major air pollutant, under controlled conditions, on the allergenicity of ragweed pollen.

Ragweed (Ambrosia artemisiifolia) pollen allergenicity: SuperSAGE transcriptomic analysis upon elevated CO2 and drought stress.

Background: Pollen of common ragweed (Ambrosia artemisiifolia) is a main cause of allergic diseases in Northern America. The weed has recently become spreading as a neophyte in Europe, while climate change may also affect the growth of the plant and additionally may also influence pollen allergenicity. To gain better insight in the molecular mechanisms in the development of ragweed pollen and its allergenic proteins under global change scenarios, we generated SuperSAGE libraries to identify differentially expressed transcripts.

Large-scale protein analysis of European beech trees following four vegetation periods of twice ambient ozone exposure.

Unlabelled: In the present study, we performed a large-scale protein analysis based on 2-DE DIGE to examine the effects of ozone on the leaves of juvenile European beech (Fagus sylvatica L.), one of the most important deciduous tree species in Central Europe. To this end, beech trees were grown under field conditions and subjected to ambient and twice ambient ozone concentrations during the vegetation periods of four consecutive years.

Molecular and immunological characterization of ragweed (Ambrosia artemisiifolia L.) pollen after exposure of the plants to elevated ozone over a whole growing season.

Climate change and air pollution, including ozone is known to affect plants and might also influence the ragweed pollen, known to carry strong allergens. We compared the transcriptome of ragweed pollen produced under ambient and elevated ozone by 454-sequencing. An enzyme-linked immunosorbent assay (ELISA) was carried out for the major ragweed allergen Amb a 1.

Lack of glyphosate resistance gene transfer from Roundup Ready soybean to Bradyrhizobium japonicum under field and laboratory conditions.

A field study was conducted at the Russell E. Larson Agricultural Research Center to determine the effect of transgenic glyphosate-resistant soybean in combination with herbicide (Roundup) application on its endosymbiont Bradyrhizobium japonicum. DNA of bacteroids from isolated nodules was analysed for the presence of the transgenic 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSPS) DNA sequence using polymerase chain reaction (PCR).

Ethylenediurea (EDU): a research tool for assessment and verification of the effects of ground level ozone on plants under natural conditions.

Ethylenediurea (EDU) has been widely used to prevent ozone (O(3)) injury and crop losses in crop plants and growth reductions in forest trees. Successful use requires establishing a dose/response curve for EDU and the proposed plant in the absence of O(3) and in the presence of O(3) before initiating multiple applications to prevent O(3) injury. EDU can be used to verify foliar O(3) symptoms in the field, and to screen plants for sensitivity to O(3) under ambient conditions.

Comparison of two ecotypes of the metal hyperaccumulator Thlaspi caerulescens (J. & C. PRESL) at the transcriptional level.

This paper investigates differences in gene expression among the two Thlaspi caerulescens ecotypes La Calamine (LC) and Lellingen (LE) that have been shown to differ in metal tolerance and metal uptake. LC originates from a metalliferous soil and tolerates higher metal concentrations than LE which originates from a non-metalliferous soil. The two ecotypes were treated with different levels of zinc in solution culture, and differences in gene expression were assessed through application of a cDNA microarray consisting of 1,700 root and 2,700 shoot cDNAs.

Ozone fumigation (twice ambient) reduces leaf infestation following natural and artificial inoculation by the endophytic fungus Apiognomonia errabunda of adult European beech trees.

In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation.

Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting.

Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria).

PAR modulation of the UV-dependent levels of flavonoid metabolites in Arabidopsis thaliana (L.) Heynh. leaf rosettes: cumulative effects after a whole vegetative growth period.

Long-term effects of ultraviolet (UV) radiation on flavonoid biosynthesis were investigated in Arabidopsis thaliana using the sun simulators of the Helmholtz Zentrum München. The plants, which are widely used as a model system, were grown (1) at high photosynthetically active radiation (PAR; 1,310 micromol m(-2) s(-1)) and high biologically effective UV irradiation (UV-B(BE) 180 mW m(-2)) during a whole vegetative growth period. Under this irradiation regime, the levels of quercetin products were distinctively elevated with increasing UV-B irradiance.

Molecular investigations of the soil, rhizosphere and transgenic glufosinate-resistant rape and maize plants in combination with herbicide (Basta) application under field conditions.

A field study was conducted during 1994 to 1998 on the Experimental Farm Roggenstein, near Fürstenfeldbruck, Bavaria, Germany to determine the effect of transgenic glufosinate-resistant rape in combination with the herbicide Basta [glufosinate-ammonium, phosphinothricin, ammonium (2RS)-2-amino-4-(methylphosphinato) butyric acid] application on soil microorganisms and the behaviour of the synthetic transgenic DNA in response to normal agricultural practice. No influence of Basta on microbial biomass could be detected. The phospholipid fatty acid analysis of soil extracts showed no difference between Basta application and mechanical weed control, whereas conventional herbicide application revealed a different pattern.

Quantification of mRNAs and housekeeping gene selection for quantitative real-time RT-PCR normalization in European beech (Fagus sylvatica L.) during abiotic and biotic stress.

Analyses of different plant stressors are often based on gene expression studies. Quantitative real-time RT-PCR (qRT-PCR) is the most sensitive method for the detection of low abundance transcripts. However, a critical point to note is the selection of housekeeping genes as an internal control.

Transcriptional profiling of summer wheat, grown under different realistic UV-B irradiation regimes.

There is limited information on the impact of present-day ultraviolet-B (UV-B) radiation on a reprogramming of gene expression in crops. Summer wheat was cultivated in controlled environmental facilities under simulated realistic climatic conditions. We investigated the effect of different regimes of UV-B radiation on summer wheat (Triticum aestivum L.

Low-level radiocaesium exposure alters gene expression in roots of Arabidopsis.

Radiocaesium is one of the main anthropogenic sources of internal and external exposure to beta- and gamma-radiation (e.g. from global fallout of atmospheric atomic bomb testing and from the Chernobyl reactor accident).

Caesium-affected gene expression in Arabidopsis thaliana.

* Excessive caesium can be toxic to plants. Here we investigated Cs uptake and caesium-induced gene expression in Arabidopsis thaliana. * Accumulation was measured in plants grown for 5 wk on agar supplemented with nontoxic and up to toxic levels of Cs.

Crosstalk and differential response to abiotic and biotic stressors reflected at the transcriptional level of effector genes from secondary metabolism.

Plant secondary metabolism significantly contributes to defensive measures against adverse abiotic and biotic cues. To investigate stress-induced, transcriptional alterations of underlying effector gene families, which encode enzymes acting consecutively in secondary metabolism and defense reactions, a DNA array (MetArray) harboring gene-specific probes was established. It comprised complete sets of genes encoding 109 secondary product glycosyltransferases and 63 glutathione-utilizing enzymes along with 62 cytochrome P450 monooxygenases and 26 ABC transporters.

Ozone-induced gene expression occurs via ethylene-dependent and -independent signalling.

Recent studies suggest that ethylene is involved in signalling ozone-induced gene expression. We show here that application of ozone increased glucuronidase (GUS) expression of chimeric reporter genes regulated by the promoters of the tobacco class I beta-1,3-glucanases (GLB and Gln2) and the grapevine resveratrol synthase (Vst1) genes in transgenic tobacco leaves. 5'-deletion analysis of the class I beta-1,3-glucanase promoter revealed that ozone-induced gene regulation is mainly mediated by the distal enhancer region containing the positively acting ethylene-responsive element (ERE).