The complex chemical characteristics of leaves of the representative species Globularia punctata were studied. The plant leaves contained large amounts of phenolic compounds (31% of the total ...analyzed constituents) followed by water-soluble proteins, total lipids, amino acids (AAs), and water-soluble sugars. A total of 22 AAs and two amides were identified with asparagine, glutamine, and proline dominating. An analysis of the lipids showed high concentrations of mono- and digalactosyldiacylglycerols and phosphatidylcholine. The fatty acids were dominated by dienoic and trienoic acids. The main source of linolenic acid was the glycolipid fraction, especially the MGDG and DGDG classes. The phospholipid fraction was more enriched in oleic and linoleic acids. The neutral lipid fraction contained various amounts of linoleic and linolenic acids.
Effects of 1 M NaCl on the lipid profile of detergent-resistant membranes in chloroplasts and mitochondria of salt-accumulating halophyte plants of family Amaranthaceae,
Salicornia perennans
Willd. ...and
Suaeda salsa
(L.) Pall. were studied. The composition of lipids and fatty acids in detergent-resistant membranes differed from total lipids of chloroplast and mitochondrial membranes by the abundance of cerebrosides and sterols. Under the given salinity level, a manyfold increase in the relative content of cerebrosides was noted in the composition of detergent-resistant chloroplast membranes of
S. perennans
. A similar salinity-related increase in cerebroside content was detected in detergent-resistant mitochondrial membranes of
S. salsa
. The opposite effect was observed for sterols: their relative content decreased under the action of salt. The results indicate that the detergent-resistant membranes are involved in the interactions of chloroplasts and mitochondria in the cell response of halophytes to salinity.
Modern concepts on structural, physiological, and biochemical aspects of salt tolerance of higher plants were considered. Integral physiological processes, such as growth and photosynthesis of ...glycophytes and halophytes in the context of their ecological plasticity, variety of their adaptive strategies developed in the course of their evolution, and natural selection, were discussed. Analysis of the known anatomical and morphological adaptations of halophytes (succulence, special salt-excreting structures, features associated with special tissues growth, leaf kranz-anatomy and mesostructure) providing their salt tolerance was conducted. The most important physiological and biochemical adaptations of such plants to salinity related to uptake, accumulation and excretion of Na
+
and Cl
–
, peculiarities of membrane composition and the pigment system, and protection against osmotic and oxidative stresses were described. The association of physiological and biochemical peculiarities of halophytes with ecological salt tolerance strategy was discussed.
Abstract
The authors study the effect of NaCl and NaHCO
3
at concentrations of 1 M on the physiological and biochemical state
of Salicornia perennans
and
Artemisia santonica
for 24 hours. In our ...experiment, we evaluated: the accumulation of Na in the aerial part of plants, the stress index is lipid peroxidation (LPO); the state of membranes – by the composition and content of lipids and proteins, the level of photosynthetic pigments. The euhalophyte
S. perennans
accumulated Na on average 30% more than the glycohalophyte
A. santonica
. The addition of NaCl and NaHCO
3
to the root environment promoted an increase in LPO in S. perennans by 2.4 times as compared to the control. In the case of
A. santonica
, LPO concentration increased by 1.2 times, but only when NaHCO3 was added to the soil. In addition, NaCl and NaHCO
3
negatively affected plant lipids and proteins. Thus, in
S. perennans
plants, NaCl contributed to a decrease in phosphlipids by 34%, and NaHCO
3
in glycolipids by 22% in comparison with the control. The quantitative content of the sum of water-soluble and membrane-bound proteins in the studied plants decreased by 10–36%. Chloride and soda-dominated salinity caused a decrease in the proportion of chlorophyll
a
and carotenoids only in
S. perennans
. The authors concluded that the response of the photosynthetic system and membrane complexes to various types of salinity in euhalophyte and glycohalophyte was different.
The ecological, morphological, physiological, and biochemical characteristics of representatives of the genus
Galium
(Rubiaceae) have been studied. The objects of study are the hybrid (nothospecies)
...Galium
×
affrenum
(Klokov) Ostapko (=nothospecies) and its parental species
G. ruthenicum
Willd., and
G. octonarium
(Klokov) Pobed. s. l.
G.
×
affrenum
is habitually closer to
G. ruthenicum;
however, it differs from the latter in pale lemon flowers. Based on the method of artificial neural networks, it is shown that the nothospecies is closer to the parental species
G. octonarium
with respect to physiological and biochemical features. The leaf biomass of
G.
×
affrenum
is characterized by an increased content of photosynthetic pigments and a greater variability in the concentration of photosynthetic pigments and lipid metabolism, which may be key to its greater stability and viability.
The mesophyll structure and the lipid profile of membranes were examined in leaves of four Chenopodiaceae halophytes with different types of photosynthesis. The analyzed plants represented the annual ...species with photosynthesis of C
3
type (
Salicornia perennans
),C
3
–C
4
intermediate type (
Sedobassia sedoides
), and C
4
-NAD type (
Climacoptera crassa
) as well as a perennial half-shrub
Kochia prostrate
with photosynthesis of C
4
-NADP type; the chosen species inhabited biotopes with various salinity and soil moisture content. The annual species with succulent leaves accumulated 7–15 times larger amounts of Na
+
than the perennial half-shrub. A strong positive correlation was found between the leaf thickness and leaf water content (
r
= 0.98,
P
= 0.04) and the total amount of elements accumulated in leaves (
r
= 0.96,
P
= 0.04). Mesophyll cells of the C
3
species
S. perennans
were substantially larger than the mesophyll and bundle sheath cells of the C
4
species; the number of chloroplasts per cell in the C
3
species was 1.5–3.5 times higher than in the C
4
species. The species with Kranz anatomy differed between one another in terms of the size and the relative number of bundle sheath and mesophyll cells. The total surface area of chloroplasts per unit leaf area in plants with Kranz anatomy was higher in mesophyll cells than in the bundle sheath cells. The assimilating surface areas of mesophyll and chloroplasts in plants with the C
3
and C
3
–C
4
types of photosynthesis were similar, as was that in species with C
4
-NAD and C
4
-NADP types of photosynthesis. The total number of cells and the number of chloroplasts in mesophyll cells correlated positively with the content of total lipids per unit leaf area (
r
= 0.95,
P
= 0.04). The content of 18:2(n-6) fatty acid decreased, while the content of 18:1(n-9) increased in the series C
3
→ C
3
–C
4
→ C
4
-NAD → C
4
-NADP species. It is concluded that differences among the examined species in terms of the volume and surface area of cells and chloroplasts in mesophyll and bundle sheath tissues become larger, while the content of membrane lipids in cells, chloroplasts, and mitochondria per unit leaf area decreases along with the extent to which the C
4
syndrome is pronounced. The composition of lipids and fatty acids is suited to support the metabolic activity of chloroplasts and mitochondria according to the type of photosynthesis.
Multiblock (segmented) copoly(urethane–imides) were prepared using as monomers toluene 2,4-diisocyanate-terminated aliphatic polyether and polyester poly(propylene glycol), ...poly(1,6-hexanediol/neopentylene glycol-alt-adipic acid), aromatic diamines 1,4-bis(4'-aminophenoxy)biphenyl sulfone or 4,4'-bis(4''-aminophenoxy)biphenyl in a mixture with 3,5-diaminobenzoic acid, and 1,3-bis(3',4-dicarboxyphenoxy)benzene dianhydride. Each of the polymers contains two structurally different soft polyether/polyester segments and two identical hard imide segments, into one of which the reactive carboxy group is introduced. The covalent cross-linking of the copolymers was performed by the reactions of the carboxy groups with aromatic diisocyanates (toluene 2,4-diisocyanate, biphenylmethane 4,4'-diisocyanate) and 1,2,5,6-diepoxycyclooctane. The cross-linked polymer systems obtained were studied by thermal gravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The kind of cross-linking agent influences the properties of cross-linked copoly(urethane–imides). Variation of the mechanical loss tangent tan δ and width of the temperature interval of the transition from glassy to rubber-elastic state in relation to the chemical structure of copoly(urethane–imides) was analyzed. For the polymers under consideration, the maximal tan δ values exceed 0.3, which indicates that these polymers exhibit the damping ability.
Poly(urethane-imide) copolymers (PUICs) containing reactive carboxyl groups in hard imide segment were synthesized from poly(propylene glycol) with isocyanate end groups, 1,3-bis(3
′
,4
′
...-dicarboxyphenoxy)benzene dianhydride, aromatic diamines 4,4
′
-bis(4
″
-aminophenoxy)diphenyl sulfone or 4,4
′
-bis-(4
″
-aminophenoxy)biphenyl, and 3,5-diaminobenzoic acid. The PUICs were covalently cross-linked using reactions of carboxyl groups with aromatic diisocyanates and 1,2,5,6-diepoxycyclooctane. The polymers obtained were studied by thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. It was shown that the structure of the cross-linking agents influences the properties of cross-linked PUICs. Changes in the mechanical loss factor (tg δ) were analyzed
vs.
chemical structure of the PUICs. The maximum tg δ values of the copolymers studied are in the range of 0.3–0.4, which suggests good damping capacity of these systems.
Interrelation between the morphology, physiology, biochemistry, and productivity of potato plants was shown for the first time using the example of a mid-season-ripening variety (v.) Siversky and a ...mid-early Tretyakovka v. The yield of Siversky v. turned out to be 1.6 times higher than the yield of Tretyakovka. Aboveground biomass of Siversky v. was distinguished by an increased content of photosynthetic pigments, a greater variability of the protein and lipid metabolism indicators, and more intense oxidation processes and antioxidant protection, which can be the key to its greater productivity. Multivariate statistical analysis showed that the greatest relationship in the climatic conditions of central Russia in 2020 was found for productivity and such indicators as the stomata number per unit leaf area, the number of stems, and the content of pigments, phospholipids, neutral lipids, and water-soluble part of the protein. Thus, both morphological and physiological–biochemical properties can influence the course and direction of the production process, and, hence, the yield of a certain variety.
Introduction. The new reassortant of the swine flu virus A(H1N1)pdm09, which emerged in 2009, overcame the species barrier and caused the 2009-2010 pandemic. One of the key points required for the ...influenza virus to overcome the species barrier and adapt it to humans is its specific binding to the receptors on the epithelium of the human respiratory tract.Targets and goals. Studying the dynamics of changes in receptor specificity (RS) of the HA1 subunit of the hemagglutinin of the influenza A(H1N1)pdm09 virus strains isolated during the period 2009-2016 on the territory of the Russian Federation, and an analysis of the possible impact of these changes on the incidence rates of the population of the Russian Federation of pandemic influenza in certain epidemic seasons. Material and Methods. Standard methods of collecting clinical materials, isolation of influenza viruses, their typing and genome sequencing were used. For the study of RS of influenza A virus (H1N1)pdm09, the method of solid phase sialosidenzyme analysis was used. Results. It is shown that the change in the parameter W3/6 , which characterizes the degree of a2-3 receptor specificity (a2-3-RS) of the influenza virus A(H1N1)pdm09 over a2-6-RS, coincides with the change in the incidence rates of the Russian Federation’s pandemic flu in separate epidemic seasons. There is a tendency to increase the affinity of the virus A(H1N1)pdm09 to α2-3 analogs of the sialyl-glycan receptors of the human respiratory tract epithelium - α2-3-sialoglycopolymers (α2-3-SGP), and falls to α2-6-SGP, with the virus showing the greatest affinity for sulfated sialoglycopolymers. Discussion. Screening for RS strains of influenza A (H1N1)pdm09 virus isolated on the territory of the Russian Federation in 2009-2016 revealed a decrease in the affinity of viruses for a2-6-sialosides, especially for 6’SL-SGP, which is probably due to the presence of amino acid substitutions in the 222 and 223 positions of RBS HA1 viruses. Previous studies have shown that the presence of such substitutions correlates with an increase in the virulence of the influenza A virus (H1N1)pdm09 16, 23. Probably, the pandemic virus has evolved towards the selection of more virulent pneumotropic variants. Conclusion. Monitoring of the receptor specificity of a pandemic influenza virus makes it possible to identify strains with altered RS to the epithelium of the human respiratory tract and an increased ability to transfer from person to person. Change in the period 2009-2016 the W3/6 parameter characterizing the degree of α2-3-RS excess of the influenza A(H1N1)pdm09 virus over α2-6-RS, coincides with the change in the incidence rates of the pandemic influenza population of the Russian Federation in certain epidemic seasons.
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