Manipulating the light spectrum to increase the biomass production, physiological plasticity and nutritional quality of Eruca sativa L.

The extensive development in light-emitting diodes (LEDs) in recent years provides an opportunity to positively influence plant growth and biomass accumulation and to optimize biochemical composition and nutritional quality. This study aimed to assess how different light spectra affect the growth, photosynthesis and biochemical properties of Eruca sativa. Therefore two LED lighting modes - red:blue (RB, 1:1) and red:green:blue (RGB, 2:1:2) were compared to the conventional white light fluorescent tubes (WL).

Different reactions of wheat, maize, and rice plants to putrescine treatment.

Polyamines play an important role in growth and differentiation by regulating numerous physiological and biochemical processes at the cellular level. In addition to their roborative effect, their essential role in plant stress responses has been also reported. However, the positive effect may depend on the fine-tuning of polyamine metabolism, which influences the production of free radicals and/or signalling molecules.

Influence of a Mutation on Polyamine Metabolism in Depends on Light Spectral Conditions.

The aim of the study was to reveal the influence of mutations on polyamine metabolism in under different spectral compositions. Polyamine metabolism was also provoked with exogenous spermine. The polyamine metabolism-related gene expression of the wild type and plants responded similarly under white and far-red light conditions but not at blue light.

Changes in polyamine contents during Fusarium graminearum and Fusarium verticillioides inoculation in maize seedlings with or without seed-priming.

Maize (Zea mays L.) is the most produced field crop all over the world. One of its most critical diseases that results in economic loss is ear rot caused by various Fusarium species.

The role of methyl salicylate in plant growth under stress conditions.

Methyl salicylate is a volatile compound, the synthesis of which takes place via the salicylic acid pathway in plants. Both compounds can be involved in the development of systemic acquired resistance and they play their role partly independently. Salicylic acid transport has an important role in long-distance signalling, but methyl salicylate has also been suggested as a phloem-based mobile signal, which can be demethylated to form salicylic acid, inducing the de-novo synthesis of salicylic acid in distal tissue.

Improvement of Drought Tolerance by Exogenous Spermidine in Germinating Wheat ( L.) Plants Is Accompanied with Changes in Metabolite Composition.

Drought is one of the most important environmental factors reducing the yield and production of crops, including wheat. Polyamines are closely associated with plant stress tolerance. The present study investigated the mechanisms through seed germination with spermidine protecting wheat varieties from drought stress.

Light Spectral Composition Modifies Polyamine Metabolism in Young Wheat Plants.

Although light-emitting diode (LED) technology has extended the research on targeted photomorphogenic, physiological, and biochemical responses in plants, there is not enough direct information about how light affects polyamine metabolism. In this study, the effect of three spectral compositions (referred to by their most typical characteristic: blue, red, and the combination of blue and red [pink] lights) on polyamine metabolism was compared to those obtained under white light conditions at the same light intensity. Although light quality induced pronounced differences in plant morphology, pigment contents, and the expression of polyamine metabolism-related genes, endogenous polyamine levels did not differ substantially.

Mutations in Locus May Negatively Affect Frost Tolerance in Bread Wheat.

The wheat semi-dwarfing genes Rht (Reduced height) are widely distributed among the contemporary wheat varieties. These genes also exert pleiotropic effects on plant tolerance towards various abiotic stressors. In this work, frost tolerance was studied in three near-isogenic lines of the facultative variety ‘April Bearded’ (AB), carrying the wild type allele Rht-B1a (tall phenotype), and the mutant alleles Rht-B1b (semi-dwarf) and Rht-B1c (dwarf), and was further compared with the tolerance of a typical winter type variety, ‘Mv Beres’.

Methylglyoxal induces stress signaling and promotes the germination of maize at low temperature.

Maize is sensitive to cold injury, especially during germination. Since cold causes oxidative stress, compounds that promote the accumulation of free radical forms, such as the reactive aldehyde (RA) methylglyoxal (MG), may be suitable to trigger a systemic defense response. In this study, maize seeds were soaked in MG solution for one night at room temperature, before germination test at 13°C.

Polyamine Metabolism under Different Light Regimes in Wheat.

Although the relationship between polyamines and photosynthesis has been investigated at several levels, the main aim of this experiment was to test light-intensity-dependent influence of polyamine metabolism with or without exogenous polyamines. First, the effect of the duration of the daily illumination, then the effects of different light intensities (50, 250, and 500 μmol m s) on the polyamine metabolism at metabolite and gene expression levels were investigated. In the second experiment, polyamine treatments, namely putrescine, spermidine and spermine, were also applied.

Comparative study of salicylic acid contents in young wheat and rice plants and their anticancer activities in HepG2 and Caco-2 cells.

Some recent results reported that aspirin (acetylsalicylic acid) had a positive effect on the treatment of certain types of cancer. However, the results cannot be generalized and it is not always clear whether it is a direct anticancer effect or a general health effect. Since plants produce different amounts of salicylic acid, we have sought a relationship between the salicylic acid content of some plant extracts and their anticancer activity.

Validation of Reference Genes for Studying Different Abiotic Stresses in Oat ( L.) by RT-qPCR.

Oat ( L.) is a widely cultivated cereal with high nutritional value and it is grown mainly in temperate regions. The number of studies dealing with gene expression changes in oat continues to increase, and to obtain reliable RT-qPCR results it is essential to establish and use reference genes with the least possible influence caused by experimental conditions.

Unfinished story of polyamines: Role of conjugation, transport and light-related regulation in the polyamine metabolism in plants.

Polyamines play a fundamental role in the functioning of all cells. Their regulatory role in plant development, their function under stress conditions, and their metabolism have been well documented as regards both synthesis and catabolism in an increasing number of plant species. However, the majority of these studies concentrate on the levels of the most abundant polyamines, sometimes providing data on the enzyme activity or gene expression levels during polyamine synthesis, but generally making no mention of the fact that changes in the polyamine pool are very dynamic, and that other processes are also involved in the regulation of actual polyamine levels.

Abiotic Stress Response of Near-Isogenic Spring Durum Wheat Lines under Different Sowing Densities.

A detailed study was made of changes in the plant development, morphology, physiology and yield biology of near-isogenic lines of spring durum wheat sown in the field with different plant densities in two consecutive years (2013-2014). An analysis was made of the drought tolerance of isogenic lines selected for yield QTLs ( and ), and the presence of QTL effects was examined in spring sowings. Comparisons were made of the traits of the isogenic pairs and -- both within and between the pairs.

Acclimation of photosynthetic processes and metabolic responses to elevated temperatures in cereals.

The aim of the present work was to better understand the molecular mechanisms of heat acclimation processes in cereals. A large number of winter and spring wheat, barley and oat varieties were grown under either control conditions (22/20°C) or under a mild heat stress (30°C) that induce the acclimation processes. The temperature dependence of chlorophyll a fluorescence induction and gas exchange parameters showed that heat acclimation increased the thermotolerance of the photosynthetic apparatus, but these changes did not differ sharply in the winter-spring type cereals.

The effects of putrescine pre-treatment on osmotic stress responses in drought-tolerant and drought-sensitive wheat seedlings.

Recent studies have demonstrated that exogenous polyamines have protective effects under various stress condition. A broader understanding of the role of the polyamine pool fine regulation and the alterations of polyamine-related physiological processes could be obtained by comparing the stress effects in different genotypes. In this study, the impact of pre-treatment with putrescine in response to osmotic stress was investigated in the drought-tolerant Katya and drought-sensitive Zora wheat (Triticum aestivum) cultivars.

Molecular background of cadmium tolerance in Rht dwarf wheat mutant is related to a metabolic shift from proline and polyamine to phytochelatin synthesis.

Plant height is among the most important agronomic traits influencing crop yield. Wheat lines carrying Rht genes are important in plant breeding due to their both higher yield capacity and better tolerance to certain environmental stresses. However, the effects of dwarf-inducing genes on stress acclimation mechanisms are still poorly understood.

Salicylic Acid Signalling in Plants.

Ten articles published in the "Special Issue: Salicylic Acid Signalling in Plants" are summarized, in order to get a global picture about the mode of action of salicylic acid in plants, and about its interaction with other stress-signalling routes. Its ecological aspects and possible practical use are also discussed.

Involvement of Salicylic Acid and Other Phenolic Compounds in Light-Dependent Cold Acclimation in Maize.

The exposure of plants to non-lethal low temperatures may increase their tolerance to a subsequent severe chilling stress. To some extent, this is also true for cold-sensitive species, including maize. In the present work, based on our previous microarray experiment, the differentially expressed genes with phenylpropanoid pathways in the focus were further investigated in relation to changes in certain phenolic compounds and other plant growth regulators.

Interaction between elevated temperature and different types of Na-salicylate treatment in Brachypodium dystachion.

Salicylic acid (SA) plays a role in several physiological processes in plants. Exogenously applied SA is a promising tool to reduce stress sensitivity. However, the mode of action may depend on how the treatment was performed and environmental conditions may alter the effects of SA.

Metabolic responses of wheat seedlings to osmotic stress induced by various osmolytes under iso-osmotic conditions.

Many environmental stresses cause osmotic stress which induces several metabolic changes in plants. These changes often vary depending on the genotype, type and intensity of stress or the environmental conditions. In the current experiments, metabolic responses of wheat to osmotic stress induced by different kinds of osmolytes were studied under iso-osmotic stress conditions.

Polyamine-Induced Hormonal Changes in and Mutant Plants.

Polyamines are multifaceted compounds which play a role in regulating plant growth and stress tolerance in interactions with plant hormones. The aim of the present study was to reveal how exogenous polyamines influence the synthesis of salicylic acid, with a special emphasis on the effect of salicylic acid deficiency on the polyamine metabolism and polyamine-induced changes in other plant hormone contents. Our hypothesis was that the individual polyamines induced different changes in the polyamine and salicylic acid metabolism of the wild type and salicylic acid-deficient mutants, which in turn influenced other hormones.

Role of polyamines in plant growth regulation of Rht wheat mutants.

Besides their protective role, polyamines also serve as signalling molecules. However, further studies are needed to elucidate the polyamine signalling pathways, especially to identify polyamine-regulated mechanisms and their connections with other regulatory molecules. Reduced height (Rht) genes in wheat are often used in breeding programs to increase harvest index.

Identification of a redox-dependent regulatory network of miRNAs and their targets in wheat.

Reactive oxygen species and antioxidants have an important role in the regulation of plant growth and development under both optimal and stress conditions. In this study, we investigate a possible redox control of miRNAs in wheat (Triticum aestivum ssp. aestivum).