Interaction between Signal Pathways upon Formation of Plant Defense in Response to Environmental Stress Factors

Russian Journal of Plant Physiology - In the course of evolution, plants have developed numerous specific regulatory signal pathways, which are hormonal for the most part. Phytohormones comprise...     

IPSC-Derived Human Neurons with GCaMP6s Expression Allow In Vitro Study of Neurophysiological Responses to Neurochemicals

Neurochemical Research - The study of human neurons and their interaction with neurochemicals is difficult due to the inability to collect primary biomaterial. However, recent advances in the...     

Lectin involvement in the development of wheat tolerance to cadmium toxicity

In the roots of bread wheat (Triticum aestivum L.) seedlings, the effects of pretreatment with 28 nM wheat germ agglutinin (WGA) and successive action of 1 mM cadmium acetate on growth, phytohormone balance, lignin deposition, and also cadmium accumulation and distribution were studied. Priority data on cadmium-induced ABA-mediated reversible accumulation of WGA in the roots, which was accompanied by its excretion in the medium of seedling incubation, were obtained. Pretreatment with WGA exerted a clear protective effect on seedling growth in the presence of cadmium, which was based on a decrease in the amplitude of stress-induced shifts in the balance between IAA and ABA and preventing the reduction in the cytokinin level. Acceleration of lignification of the cell walls in the basal parts of roots of seedlings pretreated with WGA and subjected to stress is shown, and this limits cadmium entry into the plant.     

Cytokinin oxidase is key enzyme of cytokinin degradation

Cytokinin oxidase (EC 1.5.99.12) is an enzyme that catalyzes the irreversible degradation of cytokinin phytohormones that are extremely necessary for growth, development, and differentiation of plants. Cytokinin oxidase plays an important role in the regulation of quantitative level of cytokinins and their distribution in plant tissues. This review generalizes the available information on the structure, properties, and functional role of this enzyme in plant ontogeny under conditions of normal growth and under the influence of unfavorable environmental factors.     

Pathogenic properties of freshly isolated strains of the pertussis microbe

The serovar composition, toxicity, virulence and lymphocytosis stimulating activity (LSA) of B. pertussis strains circulating in the 1980-ies were studied in comparison with the strains circulating in previous years. The study revealed changes in the toxic properties of B. pertussis: their decrease in the years of the intensive immunization of children against whooping cough and rise at the period when the number of immunized children was reduced. The toxic properties and LSA in most B. pertussis strains were less pronounced in the 1980-ies than in the 1960-ies. The serovar composition of the circulating strains remained stable for 15 years with the prevalence of serovar 1.0.3.     

The surfactant system and structure of the respiratory portion of the lungs during de-adaptation following a single exposure to acute pressure chamber hypoxia

The effect of acute pressure chamber hypoxia on the surfactant system and respiratory segment structure of the lungs were studied in rats by physical, fluorescent microscopic and morphometric methods. Acute hypoxia decreases surface activity, induces changes in cellular and extracellular surfactant fluorescence and causes the development of diffuse vesicular emphysema. On the first day of adaptation atelectatic foci dominate over emphysema, and the pulmonary structure normalizes afterwards. During de-adaptation, surface activity and cellular surfactant fluorescence are higher than the control levels. Surface activity and extracellular surfactant fluorescence recover steadily by the fifth day of adaptation. The amount of phagocytized surfactant in alveolar macrophages is increased, with the changes being opposite to those characteristic of extracellular surfactant.     

Wheat germ agglutinin regulates cell division in wheat seedling roots

The mitogenic activity of wheat germ agglutinin (WGA) has been studied in roots of 4-day-old wheat seedlings. WGA had a more pronounced stimulating effect on cell division than the known mitogens concanavalin A and phytohemagglutinin whereas gliadin had no effect. Treatment of wheat seedling roots with exogenous WGA led to the accumulation of indoleacetic acid and cytokinins, hormones that play an important role in the activation of plant cell growth. The data on the combined effect of 24-epibrassinolide and WGA on cell division and accumulation of phytohormones in seedling roots support a possible link between the endogenous WGA level and hormonal regulation of cell division in the root meristem of wheat plants.