The Estimation of the Stability of Plants Constituting the Photosynthesizing Unit of Bioregenerative Life Support Systems for Including Them into the Plant Waste Mass Exchange

One of the ways of increasing the closure of mass exchange processes in the bioregenerative life support systems (BLSS) may be the technology of plant cultivation on the so-called soil-like substrate (SLS) which is expected to utilize inedible plant biomass with the help of the SLS heterotrophic link. Earlier, based on the example of the radish inedible biomass, there was shown the principal possibility of its successful biological combustion (without decreasing the productivity of the plants cultivated) during their direct introduction into the SLS. The possibility of a direct plant waste introduction into the SLS could considerably simplify the technological processes of their biological combustion and increase their efficiency. However, there were no experiments carried out with respect to the other vegetables included into the BLSS photosynthesizing link. The aim of the given work is estimating the possible influence of the inedible biomass of different plant species introduced into the SLS, on the plant productivity. Several series of the test experiments were carried out. In the first experiment series, dried radish leafy tops making up 0.8 kg/m2 of the sown area, dried carrot leafy tops – 3.1 kg/m2 and dried beet leafy tops – 2.5 kg/m2 were introduced into the SLS makeup. As a test culture, there was taken the radish Raphanus sativus L of the Virovsky Beliy species. In the second experiment series, before the sowing of radish and wheat, there were introduced 1.2 kg/m2 and 3.1 kg/m2 of dry wheat straw into the SLS respectively. In the third series of the experiments, the wheat straw, before being introduced into the SLS, was subjected to the preliminary processing. In the fourth experiment series, there was studied the supposition about the possibility of decreasing the negative influence of introducing the vegetable tops into the SLS on the plant growth of the succeeding generation under the conditions of growing plants on a various-ages multi-species vegetable conveyor. According to the results of the research, the direct introduction of carrot and beet tops, as well as dry wheat straw, resulted in the considerable drop of the plant productivity. The vegetable cultivation in a conveyor mode done for three generations, also resulted in their productivity decrease. It was shown that the straw mineralization by using the method of “wet incineration” developed by Yu. A. Kudenko had completely removed the negative effect of the plant waste on the plant growth and could be the alternative way of the wheat waste utilization

Влияние условий обитания на активность ферментов и содержание метаболитов аскорбат-глутатионового цикла в листьях Plantago media

The ascorbate-glutathione cycle (AGC) is a metabolic pathway that detoxifies H2O2, which is a reactive oxygen species produced as a waste product in metabolism. The cycle involves the antioxidant metabolites – ascorbate, glutathione, and NADPH, as well as enzymes linking them. We studied the effect of habitat conditions on the activity of enzymes and contents of metabolites of the ascorbate-glutathione cycle in Plantago media leaves. The experimental plants grew on the floodplain meadow: on the sparsely vegetated coastal edge (Site 1) and in the grass stand in the central part of the meadow (Site 2). The hoary plantain plants growing in Site 1 received twice more light than the plants in Site 2. The ascorbate and glutathione concentrations in leaves of the well-lit plants were 2–3 times higher than in shaded plants. The maximal levels of these metabolites were observed at midday, when light intensity and air temperature were increased, and relative humidity was decreased. The activity of AGC enzymes was changing similarly to the metabolite contents. As a result, the leaves of hoary plantain plants from the sites with different light levels did not significantly differ in their hydrogen peroxide concentrations. Our data suggest that the environmental conditions and, above all, the light intensity fine-tune the operation of AGC in plant leavesАскорбат-глутатионовый цикл (АГЦ) представляет собой метаболический путь, осуществляющий детоксификацию H2O2 в растительных клетках. В цикле участвуют низкомолекулярные антиоксиданты аскорбат и глутатион, НАДФН и ряд ферментов (аскорбатпероксидаза, дегидроаскорбатредуктаза, глутатионредуктаза). Мы исследовали закономерности изменения активности ферментов и содержания метаболитов АГЦ в листьях Plantago media (подорожник средний) в зависимости от условий местообитания. Растения произрастали на пойменном лугу: на слабо покрытой растительностью песчаной бровке ближе к реке (участок 1) и в травостое в центре луга (участок 2). Растения участка 1 получали вдвое больше света, чем растения участка 2. Выявили, что листья хорошо освещаемых растений содержали в 2–3 раза больше аскорбата и глутатиона, чем листья затененных растений. Максимальное накопление фонда этих метаболитов наблюдалось в полдень, когда освещенность и температура среды повышались, а относительная влажность воздуха снижалась. Уровень активности ферментов в течение дня изменялся комплементарно содержанию метаболитов. В результате хорошо освещенные и затененные растения не различались существенно по содержанию пероксида водорода в листьях. В целом наши данные показывают, что функционирование метаболического пути, участвующего в поддержании редокс-состояния фотосинтезирующих клеток, зависит от условий среды и, прежде всего, интенсивности света, тонко регулирующего активность ферментов и накопление метаболитов АГ

Влияние УФ-B‑радиации на антиоксидантную систему лишайников Peltigera aphthosa и Peltigera rufescens

Ultraviolet (UV) radiation is the short wavelength region of the solar spectrum. The high-energy photons of UV-B (280–315 nm) are potentially dangerous for all living organisms. The effect of UV-B radiation on lichens has not been studied sufficiently. We conducted a comparative study of the effects of the long-term (10 d) exposure to the environmentally realistic dose of UV-B radiation on the accumulation of lipid peroxidation products (TBARS), H2O2 content, superoxide dismutase (SOD) activity, and respiration rate in Peltigera aphthosa from the forest community and Peltigera rufescens from the open spaces of floodplain meadow. The H2O2 content and the SOD activity were found to increase in the thalli of P. rufescens. The TBARS content in the UV-B treated thalli of P. rufescens did not differ from the control thalli and was 2.5 times higher than in P. aphthosa. In P. aphthosa thalli, SOD activity did not change after UV-B exposure, and TBARS content increased by 33 % with an increase in the total UV-B dose. Both lichens exhibited an increase in the alternative respiratory pathway (AP) activity and a decrease in the ratio of the main (cytochrome) pathway to the energy low efficient AP. The AP involvement was more pronounced in P. aphthosa. The results of our study indicate the species-specific response in lichens and differences in their resistance to oxidative stress, which were due to adaptation to the light conditions in the typical habitats of these speciesУльтрафиолетовая (УФ) радиация относится к коротковолновой части солнечного спектра. Высокоэнергетические фотоны УФ-B‑излучения (280–315 нм) потенциально опасны для всех живых клеток. Реакция лишайников на УФ-В‑излучение исследована недостаточно. Мы провели сравнительное изучение влияния длительного действия экологически обоснованной дозы УФ-B‑радиации на накопление продуктов перекисного окисления липидов (ПОЛ), содержание Н2О2, активность cупероксиддисмутазы (СОД) и дыхание талломов Peltigera aphthosa из лесного сообщества и Peltigera rufescens, обитающей на хорошо инсолируемых участках пойменного луга. Выявили повышение содержания Н2О2 и активности СОД в талломах P. rufescens, экспонированных к УФ-В. Содержание продуктов ПОЛ в импактных талломах P. rufescens не отличалось от контроля и было в 2,5 раза выше по сравнению с P. aphthosa. Уровень активности СОД в талломах P. aphthosa не изменялся, но содержание продуктов ПОЛ возрастало на 33 % с увеличением суммарной дозы УФ-В. У обоих видов лишайников отмечали повышение активности альтернативного пути (АП) дыхания, что приводило к изменению соотношения основного (цитохромного) и энергетически малоэффективного АП. Вовлечение АП было сильнее выражено у P. aphthosa. Результаты исследования свидетельствуют о видовой специфичности реакции лишайников на воздействие УФ-В‑излучения, а также указывают на различия в их устойчивости к окислительному стрессу, обусловленные приуроченностью видов к местообитаниям с разным режимом освещенност

The Estimation of the Stability of Plants Constituting the Photosynthesizing Unit of Bioregenerative Life Support Systems for Including Them into the Plant Waste Mass Exchange

One of the ways of increasing the closure of mass exchange processes in the bioregenerative life support systems (BLSS) may be the technology of plant cultivation on the so-called soil-like substrate (SLS) which is expected to utilize inedible plant biomass with the help of the SLS heterotrophic link. Earlier, based on the example of the radish inedible biomass, there was shown the principal possibility of its successful biological combustion (without decreasing the productivity of the plants cultivated) during their direct introduction into the SLS. The possibility of a direct plant waste introduction into the SLS could considerably simplify the technological processes of their biological combustion and increase their efficiency. However, there were no experiments carried out with respect to the other vegetables included into the BLSS photosynthesizing link. The aim of the given work is estimating the possible influence of the inedible biomass of different plant species introduced into the SLS, on the plant productivity. Several series of the test experiments were carried out. In the first experiment series, dried radish leafy tops making up 0.8 kg/m2 of the sown area, dried carrot leafy tops – 3.1 kg/m2 and dried beet leafy tops – 2.5 kg/m2 were introduced into the SLS makeup. As a test culture, there was taken the radish Raphanus sativus L of the Virovsky Beliy species. In the second experiment series, before the sowing of radish and wheat, there were introduced 1.2 kg/m2 and 3.1 kg/m2 of dry wheat straw into the SLS respectively. In the third series of the experiments, the wheat straw, before being introduced into the SLS, was subjected to the preliminary processing. In the fourth experiment series, there was studied the supposition about the possibility of decreasing the negative influence of introducing the vegetable tops into the SLS on the plant growth of the succeeding generation under the conditions of growing plants on a various-ages multi-species vegetable conveyor. According to the results of the research, the direct introduction of carrot and beet tops, as well as dry wheat straw, resulted in the considerable drop of the plant productivity. The vegetable cultivation in a conveyor mode done for three generations, also resulted in their productivity decrease. It was shown that the straw mineralization by using the method of “wet incineration” developed by Yu. A. Kudenko had completely removed the negative effect of the plant waste on the plant growth and could be the alternative way of the wheat waste utilization

Traits of Heracleum sosnowskyi Plants in Monostand on Invaded Area.

The ability of giant hogweeds to form monodominant communities and even pure monostands in invaded areas has been well documented. Understanding of the mechanisms leading to monostand formation can aid in determining the limitations of existing community ecology models and establishing an effective management plan for invasive species elimination. The aim of this observational study was to investigate traits of Heracleum sosnowskyi plants (demography, canopy structure, morphology and physiology) of the plants in a pure stand in an invaded area useful for understanding potential monostand formation mechanisms. All measurements were performed in one typical Heracleum sosnowskyi monostand located in an abandoned agriculture field located in Syktyvkar city suburb (North-east Russia). This monostand consisted of five main plant growth stages: seed, seedling, juvenile, vegetative adult, and generative adult. Plants of all stages began to grow simultaneously shortly after the snowmelt, at the same time as spring ephemeral plant species grew. The density of generative plants did not change during the vegetation period, but the density of the other plant stages rapidly decreased after the formation of a tall (up to 2-2.5 m) and dense (Leaf area index up to 6.5) canopy. The canopy captured approximately 97% of the light. H. sosnowskyi showed high (several orders of magnitude higher than average taiga zone grasses) photosynthetic water use efficiency (6-7 μM CO2/μM H2O). Formation of H. sosnowskyi monostands occurs primarily in disturbed areas with relatively rich and well-moistened soils. Early commencement of growth, rapid formation of a dense canopy, high efficiency of light and water use during photosynthesis, ability of young plants to survive in low light conditions, rapid recovery of above-ground plant parts after damage, and the high density of the soil seed bank are the most important traits of H. sosnowskyi plants for monostand formation in invaded areas

Specific leaf area (SLA) at different metameres stem of <i>Heracleum sosnowskyi</i>.

<p>Symbols “a”, “b”, “c” designate the same groups segregated by Duncan's new multiple range test with a significance level at 0.05.</p

<i>Heracleum sosnowskyi</i> soil seed bank dynamics over a 12-month period (September 2012 to September 2013).

<p><i>Heracleum sosnowskyi</i> soil seed bank dynamics over a 12-month period (September 2012 to September 2013).</p

(a) Leaf area index and (b) height of <i>Heracleum sosnowskyi</i> leaf layers.

<p>Plant groups and plant parts: s–seedlings (N = 10); j—juvenile plants (N = 14), v—vegetative adult plants (N = 15); m3–m6 are generative plant metameres (N = 38): m3—leaves of first three metameres, and m4, m5, and m6—leaves of 4^th, 5^th, and 6^th metameres, respectively.</p

Parameters of the Light Curve of Net Photosynthesis in <i>Heracleum sosnowskyi</i> Leaves.

<p>QY: photosynthetic quantum yield (calculated as the tangent of the slope ratio of the light curve at low light intensities: 0–100 μM photons m^-2c^-1), LCP: Light Compensation Point is the light intensity at which the total CO₂-exchange is equal to zero, P_MAX: maximum photosynthesis rate, P_max*—maximum photosynthesis rate calculated by SLA, IRA: intensity of radiation adaptation, P_IRA: photosynthesis rate at IRA. For the QY P-value < 0.0001. The mean and standard error of mean of samples is shown.</p