Reducing shade avoidance responses in a cereal crop.

Several researchers have hypothesized that shade avoidance behaviour is favoured by natural selection because it increases the fitness of individuals. Shade avoidance can be disadvantageous for crops, however, because it reduces allocation of resources to reproductive yield, increases the risk of lodging and reduces weed suppression. One approach to develop varieties with reduced shade avoidance and enhanced agronomic performance is by inducing mutations followed by phenotypic screening.

QTLs and Potential Candidate Genes for Heat Stress Tolerance Identified from the Mapping Populations Specifically Segregating for / in Wheat.

Despite the fact that / (maximum quantum efficiency of photosystem II) is the most widely used parameter for a rapid non-destructive measure of stress detection in plants, there are barely any studies on the genetic understanding of this trait under heat stress. Our aim was to identify quantitative trait locus (QTL) and the potential candidate genes linked to / for improved photosynthesis under heat stress in wheat ( L.).

Association Mapping in Scandinavian Winter Wheat for Yield, Plant Height, and Traits Important for Second-Generation Bioethanol Production.

A collection of 100 wheat varieties representing more than 100 years of wheat-breeding history in Scandinavia was established in order to identify marker-trait associations for plant height (PH), grain yield (GY), and biomass potential for bioethanol production. The field-grown material showed variations in PH from 54 to 122 cm and in GY from 2 to 6.61 t ha(-1).

Identification and genome organization of saponin pathway genes from a wild crucifer, and their use for transient production of saponins in Nicotiana benthamiana.

The ability to evolve novel metabolites has been instrumental for the defence of plants against antagonists. A few species in the Barbarea genus are the only crucifers known to produce saponins, some of which make plants resistant to specialist herbivores, like Plutella xylostella, the diamondback moth. Genetic mapping in Barbarea vulgaris revealed that genes for saponin biosynthesis are not clustered but are located in different linkage groups.

Wheat cultivars selected for high Fv /Fm under heat stress maintain high photosynthesis, total chlorophyll, stomatal conductance, transpiration and dry matter.

The chlorophyll fluorescence parameter Fv /Fm reflects the maximum quantum efficiency of photosystem II (PSII) photochemistry and has been widely used for early stress detection in plants. Previously, we have used a three-tiered approach of phenotyping by Fv /Fm to identify naturally existing genetic variation for tolerance to severe heat stress (3 days at 40°C in controlled conditions) in wheat (Triticum aestivum L.).

Genotypic response of detached leaves versus intact plants for chlorophyll fluorescence parameters under high temperature stress in wheat.

The genotypic response of wheat cultivars as affected by two methods of heat stress treatment (treatment of intact plants in growth chambers versus treatment of detached leaves in test tubes) in a temperature controlled water bath were compared to investigate how such different methods of heat treatment affect chlorophyll fluorescence parameters. A set of 41 spring wheat cultivars differing in their maximum photochemical efficiency of photosystem (PS) II (Fv/Fm) under heat stress conditions was used. These cultivars were previously evaluated based on the heat treatment of intact plants.

Phenotyping of wheat cultivars for heat tolerance using chlorophyll a fluorescence.

In view of the global climate change, heat stress is an increasing constraint for the productivity of wheat (Triticum aestivum L.). Our aim was to identify contrasting cultivars in terms of heat tolerance by mass screening of 1274 wheat cultivars of diverse origin, based on a physiological trait, the maximum quantum efficiency of PSII (Fv/Fm).

Molecular activities, biosynthesis and evolution of triterpenoid saponins.

Saponins are bioactive compounds generally considered to be produced by plants to counteract pathogens and herbivores. Besides their role in plant defense, saponins are of growing interest for drug research as they are active constituents of several folk medicines and provide valuable pharmacological properties. Accordingly, much effort has been put into unraveling the modes of action of saponins, as well as in exploration of their potential for industrial processes and pharmacology.

Barbarea vulgaris linkage map and quantitative trait loci for saponins, glucosinolates, hairiness and resistance to the herbivore Phyllotreta nemorum.

Combined genomics and metabolomics approaches were used to unravel molecular mechanisms behind interactions between winter cress (Barbarea vulgaris) and flea beetle (Phyllotreta nemorum). B. vulgaris comprises two morphologically, biochemically and cytologically deviating types, which differ in flea beetle resistance, saponin and glucosinolate profiles, as well as leaf pubescence.

Evolutionary Agroecology: the potential for cooperative, high density, weed-suppressing cereals.

Evolutionary theory can be applied to improve agricultural yields and/or sustainability, an approach we call Evolutionary Agroecology. The basic idea is that plant breeding is unlikely to improve attributes already favored by millions of years of natural selection, whereas there may be unutilized potential in selecting for attributes that increase total crop yield but reduce plants' individual fitness. In other words, plant breeding should be based on group selection.

Identification of defense compounds in Barbarea vulgaris against the herbivore Phyllotreta nemorum by an ecometabolomic approach.

Winter cress (Barbarea vulgaris) is resistant to a range of insect species. Some B. vulgaris genotypes are resistant, whereas others are susceptible, to herbivory by flea beetle larvae (Phyllotreta nemorum).

The biological activity of a recombinantly expressed (His)(6)-tagged peanut allergen (rAra h 1) is unaffected by endotoxin removal.

The application of recombinant (His)(6)-tagged proteins in cell culture assays is associated with problems due to lipopolysaccharide (LPS) contamination. LPS stimulates cells of the immune system, thereby masking antigen-specific activation of T cells. Due to the affinity of LPS for histidine it is associated with difficulties to remove LPS from recombinant (His)(6)-tagged proteins.

Grain characteristics, chemical composition, and functional properties of rye (Secale cereale L.) as influenced by genotype and harvest year.

Grain characteristic, chemical composition, and functional properties of rye were measured in 19 different cultivars grown in one location in up to 3 years. The cultivars included 8 adapted hybrids, 7 adapted population cultivars, and 4 nonadapted population cultivars. The results showed a significant influence of both harvest year and genotype on grain characteristics, chemical composition, and functional properties of the grain.

A comparative study of the allergenic potency of wild-type and glyphosate-tolerant gene-modified soybean cultivars.

A large proportion of soybean cultivars grown in the USA are now genetically modified varieties and concern has been raised about the safety of these products for consumers. A study of the impact on allergenic potency in soybeans, comparable except for the newly introduced gene (CP4 EPSPS), was performed using soybean-sensitized patients. The allergenicity of 18 different (10 GM and 8 WT) soybean extracts was examined blindly by the following three methods: A) Sera from patients with specific IgE against soybean were used to determine concentrations inducing 50% RAST inhibition; B) Histamine release induced by the extracts was examined using blood from sensitized patients; C) SPT was performed on sensitized patients with all 18 extracts.