Gas Exchange Characteristics Research Articles

Evaluating Sustainable Media Mixes Using Local Agricultural and Forestry Wastes for Enhancing the Early Establishment of Container-Grown Southern Highbush Blueberry in Subtropical Climates

Container-grown blueberry (Vaccinium spp.) production using soilless substrates has gained significant attention for offering better control over growing conditions. However, the reliance on peat moss as a primary substrate poses environmental concerns due to its non-renewable nature, emphasizing the need for sustainable alternatives. This study investigates the use of locally sourced agricultural and forestry wastes as alternative media mixes for container-grown ‘Biloxi’ southern highbush blueberry (V. corymbosum interspecific hybrids) in Taiwan. The media mixes tested included combinations of ultisols with rice husks, peanut shells, spent mushroom compost, or wood chips from longan (Dimocarpus longan Lam.) and sweetgum (Liquidambar formosana Hance) trees. Key growth parameters, such as pH, electrical conductivity (EC), shoot length, leaf area, gas exchange characteristics, plant dry weights, and fruit yield, were monitored during plant establishment. Our findings demonstrated that media mixes containing peanut shells [peanut shells: ultisols (v/v = 2:1, PSU)] effectively maintained optimal pH and EC levels, promoting vigorous growth and early fruit production, with total dry weights comparable to the peat-based control (PMP). These growth improvements were potentially linked to increased net CO2 assimilation rates. Conversely, the media mix with spent mushroom compost [spent mushroom compost: ultisols (v/v = 2:1, MCU)] resulted in elevated pH and EC levels, adversely impacting plant growth. The findings suggest that locally sourced materials can serve as sustainable and cost-effective alternatives to peat moss for blueberry production during the nursery or establishment phase, helping reduce costs and environmental impact. Further research is necessary to evaluate the long-term effects of these media mixes and their applicability across different blueberry cultivars and environmental conditions, focusing on their performance in later production cycles and larger container systems.

Extrato pirolenhoso como atenuador do déficit hídrico em plantas de pitanga

ABSTRACT In the semi-arid climate, the growth of fruit seedlings is challenged by the water stress characteristic of the region, which can restrict their development and, consequently, affect production. In this context, the aim was to assess the effect of pyroligneous extract on gas exchange characteristics, photosynthetic pigments, growth, and biomass of pitanga under different intensities of water deficit. The experiment was conducted using a randomized block design in a 3 × 2 factorial scheme, with four replicates, corresponding to water deficit periods (7 and 14 days) and control (daily irrigation), in substrates with and without pyroligneous extract. The plants were evaluated for gas exchange characteristics, chlorophyll indices, growth, and dry biomass. Application of pyroligneous extract after 7 days of water deficit increased the photosynthetic rate, carboxylation efficiency and Dickson quality index of pitanga seedlings by 40.04, 42.85 and 41.51%, respectively, compared to 14 days of water deficit. Pyroligneous extract was effective as a water stress attenuator in pitanga seedlings, especially during the first seven days of exposure to stress. Therefore, its application is recommended as a preventive and short-term measure to mitigate such effects on pitanga seedlings.

Nanoscale particles-induced mitigation of tannery wastewater chromium stress in rice: Implications for plant performance and human health risk assessment.

Due to the rapid increase in industrial and urban areas, environmental pollution is increasing worldwide, which is causing unwanted changes in air, water, and soil at biological, physical, as well as chemical levels that ultimately causing the negative effects in living things because of toxic level of chromium (Cr). However, nanotechnology is capturing great interest worldwide due to their stirring applications in various fields. For this purpose, a pot experiment was conducted to examine plant growth and exo-physiology in rice (Oryza sativa L.) under the different levels of wastewater 50% and 100% concentrations which were also primed with three nanoparticles (NPs)-copper oxide (nCuO), silicon (nSi), and zinc oxide (nZnO). The research outcomes indicated that elevated levels of wastewater in the soil (100%) notably reduced plant growth and biomass, photosynthetic pigments, and gas exchange attributes. However, increasing levels of Cr stress also induced oxidative stress in the plants by increasing malondialdehyde (MDA), hydrogen peroxide (H2O2), which also induced increased compounds of various enzymatic and non-enzymatic antioxidants and also the gene expression and sugar content. Furthermore, a significant increase in proline metabolism, the AsA-GSH cycle, and the pigmentation of cellular components was observed. Although, the application of nCuO, nSi, nZnO-NPs showed a significant increase in plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds, and their gene expression and also decreased oxidative stress. In addition, the application of nCuO, nSi, nZnO-NPs enhanced cellular fractionation and decreased the proline metabolism and AsA-GSH cycle in O. sativa plants. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils.

Selenium mitigates vanadium toxicity through enhanced nutrition, photosynthesis, and antioxidant defense in rice (Oryza sativa L.) seedlings

In the current industrial scenario, vanadium (V) as a metal is of great importance but poses a major threat to the ecosystem. In the present study, the effect of a toxic concentration of V, i.e., 10 µM in the soil on growth, photosynthetic pigments, gas exchange characteristics, oxidative stress biomarkers, antioxidants machinery (enzymatic and non-enzymatic antioxidants), ions uptake, proline metabolism, and V uptake in different parts of the plant was investigated with and without the exogenous application of selenium (Se) i.e., 5 µM in V-stressed rice (Oryza sativa L.). Our results depicted that V addition to the soil significantly (P < 0.05) decreased plant growth and biomass, gas exchange attributes, and minerals uptake by O. sativa as compared to the plants grown without the addition of V. However, V toxicity boosted the production of reactive oxygen species (ROS) by increasing the contents of malondialdehyde (MDA), which is the indication of oxidative stress in O. sativa and was also manifested by hydrogen peroxide (H2O2) contents to the membrane-bounded organelles. Although activities of various antioxidative enzymes like superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) and their gene expression Fe-SOD, POD, CAT, and APX and also non-enzymatic antioxidants like phenolic, flavonoid, and ascorbic acid, anthocyanin contents and also the proline metabolism i.e., proline, pyrroline5-carboxylate, pyrroline-5-carboxylate reductase, and pyrroline-5-carboxylate dehydrogenase were increased due to V stress. Although results also illustrated that the application of Se also decreased V toxicity in O. sativa seedlings by increasing antioxidant capacity and, thus, improved the plant growth and biomass, photosynthetic pigments, gas exchange characteristics, and decreased oxidative stress in the O. sativa seedlings, compared to those plants which were not artificially supplied by Se. Research findings, therefore, suggested that the Se application can ameliorate V toxicity in O. sativa seedlings and result in improved plant growth and composition under metal stress as depicted by balanced exudation of nutrient effluxes. This study provides novel insights into the role of selenium in mitigating vanadium-induced oxidative stress in rice, thereby offering a promising approach to enhancing crop resilience in metal-contaminated soils and advancing sustainable agricultural practices.

Water Relations and Physiological Traits Associated with the Yield Components of Winter Wheat (Triticum aestivum L.)

Water stress in agricultural systems may occur slowly or abruptly. Plant reactions to stress differ with regard to its level and duration. The level of plant susceptibility to water deprivation primarily depends on the management of the water content and metabolism adjustments. The aim of this study was to determine the correlation between water-based plant parameters and the yield components of 90 genotypes of winter wheat (Triticum aestivum L.). Since the loss of water is frequently used as a selection criterion to assess drought tolerance, the relationships between the yield and leaf water content, osmotic potential, and gas exchange characteristics were examined. Genotypes 1, 25, 34, 36, 42, 43, 46, 57, 66, 73, and 90 showed 33–45% larger numbers of grains/plant, 19–25% higher weights of grains/plant, and 4% higher thousand grain weights compared to other genotypes. The higher values of the yield components were accompanied by 20–30% lower leaf water content, 39–52% lower osmotic potential, and 4–39% lower water use efficiency. The principal component analysis revealed that the wheat genotypes had noticeable differences in a few physiological parameters that depended on the sowing date. Electrolyte leakage showed a substantial correlation with the sowing date, suggesting that it may not be a suitable factor for the prediction of drought tolerance. The factors that distinguished the examined genotypes the most were the leaf water content, osmotic potential, and water use efficiency. In addition, a significant correlation was observed between the mentioned parameters and yield components. As a result, these parameters may be helpful in genotype characterization in relation to water stress susceptibility, offering a trustworthy plant selection test.

Ameliorating arsenic and PVC microplastic stress in barley (Hordeum vulgare L.) using copper oxide nanoparticles: an environmental bioremediation approach

The present study investigates the impact of varying concentrations of PVC microplastics (PVC–MPs) – specifically 0 (no PVC–MPs), 2, and 4 mg L− 1 –alongside different arsenic (As) levels of 0 (no As), 150, and 300 mg kg− 1 in the soil, with the concurrent application of copper oxide–nanoparticles (CuO–NPs) at 0 (no CuO –NPs), 25 and 50 µg mL− 1 to barley (Hordeum vulgare L.) plants. This research primarily aims to assess plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, as well as the response of various antioxidants (both enzymatic and non-enzymatic) and their relevant genes expression, proline metabolism, the AsA–GSH cycle, and cellular fractionation within the plants. The findings showed that increased levels of PVC–MPs and As stress in the soil significantly reduced plant growth and biomass, photosynthetic pigments, and gas exchange characteristics. Additionally, PVC–MPs and As stress increased oxidative stress in the roots and shoots, as evidenced by elevated levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL), which in turn stimulated the production of various enzymatic and non-enzymatic antioxidants, gene expression, and sugar content. Furthermore, a notable increase in proline metabolism, the AsA–GSH cycle, and cellular pigmentation was observed. Conversely, the application of CuO–NPs resulted in a substantial improvement in plant growth and biomass, gas exchange characteristics, and the activity of enzymatic and non-enzymatic antioxidants, along with a reduction in oxidative stress. Additionally, CuO–NPs enhanced cellular fractionation while decreasing proline metabolism and the AsA-GSH cycle in H. vulgare plants. These outcomes provide new insights into sustainable agricultural practices and offer significant potential in addressing the critical challenges of heavy metal contamination in agricultural soils.

The role of selenium and biochar nanoparticles in alleviating cadmium stress in wheat (Triticum aestivum L.) examined via morphophysiological traits and organic acid exudation patterns

Nanotechnology is capturing great interest worldwide due to their stirring applications in various fields and also individual application of selenium (Se) and biochar nanoparticles (BC−NPs) have been studied in many literatures. However, the combined application of Se and BC−NPs is a novel approach and studied in only few studies. For this purpose, a pot experiment was conducted to examine various growth and biochemical parameters in wheat (Triticum aestivum L.) under the toxic concentration of cadmium (Cd) i.e., 50 mg kg−1 which were primed with combined application of Se and BC−NPs i.e., 10 mg L−1. Our results showed that the Cd toxicity in the soil showed a significant declined in the growth, gas exchange attributes and nutrient uptake in T. aestivum. However, Cd toxicity significantly increased oxidative stress biomarkers, organic acids, enzymatic and non-enzymatic antioxidants including their gene expression in T. aestivum. Although, the application of Se and BC−NPs showed a significant increase in the plant growth and biomass, gas exchange characteristics, nutrient uptake, enzymatic and non-enzymatic compounds and their gene expression and also decreased the oxidative stress and Cd uptake in different parts of the plant. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils.

Effect of fertilization in drill-holes on soil gas exchange, apple root, and fruit characteristics

Effect of fertilization in drill-holes on soil gas exchange, apple root, and fruit characteristics

Effect of seasonal variability on the physiological performance of selected cocoa (Theobroma cacao L) clones in Nigeria

Eleven cocoa clones namely AMAZ 15, ICS 95, IMC 47, MAN 15, PA 150, SCA 9, SPEC 54, UF 67, F3 AMAZON, N 38 and TC 2were hand pollinated and the seeds were raised for 6 months before being transplanted to the field at 6 months. Survival count of the clones was taken for 36 months starting from the first month of establishment. Data on the gas exchange characteristics of cocoa clones started when cocoa were 12 months and continued for the next 2 wet and 2 dry seasons. Majority of cocoa clones showed higher values of stomatal conductance, stomatal transpiration, photosynthetic rates, relative water content, cuticular transpiration and stomata density during wet season while eight of the eleven cocoa clones had higher water use efficiency performance in dry season. The regression analysis also showed a linear, positive and significant relationship between stomatal transpiration and stomatal density of all cocoa clones. The results showed significant differences in the abilities of cocoa clones to cope with water stress while majority of cocoa clones performances significantly differed between dry and wet seasons.

Light curve parametrization of three rice (Oryza sativa L.) cultivars based on mechanistic models.

This study aimed to assess variations in leaf gas-exchange characteristics, leaf pigment contents, and some intrinsic traits of photosynthetic pigment molecules in three rice cultivars (cv. JR3015, Wufengyou3015, and Jifengyou3015) using mechanistic models. The findings revealed that chlorophyll content varied significantly among the three cultivars, but not maximum electron transport rate. JR3015 had lower chlorophyll content but the highest eigen-absorption cross-section (σik) and the lowest minimum average life-time of photosynthetic pigment molecules in the excited state (τmin). Our results suggested that the highest σik and the lowest τmin in JR3015 facilitated its electron transport rate despite its lower leaf chlorophyll content. Furthermore, compared to Jifengyou3015 and Wufengyou3015, JR3015 had the lowest photosynthetic electron-use efficiency via PSII, which contributed to its lowest maximum net photosynthetic rate. These findings are important in selecting rice cultivars based on their differences in photosynthetic capacity.

Stomata Are Driving the Direction of CO2-Induced Water-Use Efficiency Gain in Selected Tropical Trees in Fiji.

Understanding plant physiological response to a rising atmospheric CO2 concentration (ca) is key in predicting Earth system plant-climate feedbacks; however, the effects of long-term rising ca on plant gas-exchange characteristics in the tropics are largely unknown. Studying this long-term trend using herbarium records is challenging due to specimen trait variation. We assessed the impact of a ca rise of ~95 ppm (1927-2015) on the intrinsic water-use efficiency (iWUE) and maximum stomatal conductance (gsmax) of five tropical tree species in Fiji using the isotopic composition and stomatal traits of herbarium leaves. Empirical results were compared with simulated values using models that uniquely incorporated the variation in the empirical gsmax responses and species-specific parameterisation. The magnitude of the empirical iWUE and gsmax response was species-specific, ranging from strong to negligible. Stomatal density was more influential than the pore size in determining the gsmax response to ca. While our simulation results indicated that photosynthesis is the main factor contributing to the iWUE gain, stomata were driving the iWUE trend across the tree species. Generally, a stronger increase in the iWUE was accompanied by a stronger decline in stomatal response. This study demonstrates that the incorporation of variation in the gsmax in simulations is necessary for assessing an individual species' iWUE response to changing ca.

Effects of titanium oxide nanoparticles and 24-epibrassinosteroid to mitigate the toxicity of cadmium (Cd) and improve physio-morphological traits of soybean (Glycine max L.) cultivated under Cd-contaminated soil

Cadmium (Cd) toxicity is a serious environmental threat to living organisms. Nanoparticles (NPs) and plant growth regulators are able to mitigate Cd toxicity and restore crop growth in heavy metals-contaminated soils. However, the synergistic potential of combining 24-epibrassinosteroid (24-epiBRs) and titanium oxide nanoparticles (TiO2-NPs) to alleviate Cd toxicity and restore soybean (Glycine max L.) production remains unexplored. Thus, a pot-based experimental trial was conducted to assess the effects of applying TiO2-NPs (15 mg L−1) and 24-epiBRs (10−7 M), individually and in combination, on soybean growth in soil cultivated with 30 ppm of Cd. The study revealed that Cd toxicity significantly inhibited soybean root length (11.0 %), root dry biomass (63.5 %), root fresh biomass (84.9 %), shoot length (11.7 %), shoot dry biomass (49.0 %), and shoot fresh biomass (27.3 %), compared to the control. Additionally, the toxicity of Cd enhanced the oxidative stress and lowered the photosynthetic efficiency, gas exchange characteristics, and antioxidant defense system of soybeans. Interestingly, the combined application of TiO2-NPs and 24-epiBRs ameliorated the Cd toxic effects and improved the agronomic traits, photosynthesis efficiency, and antioxidant activity in soybeans by lowering oxidative stress. Specifically, the dual application of 24-epiBRs and TiO2-NPs effectively lowered the Cd levels in roots, shoots, and leaves of soybean plants by 62.5, 162.7, and 87.1 %, respectively, relative to the control soybean plants grown under Cd stress. Overall, the combined treatment of TiO2-NPs and 24-epiBRs synergistically reduced Cd uptake and restored soybean physiology in Cd-contaminated soils. Moving forward, further research should include field trials to assess the effectiveness and economic viability of this novel method.

ОПРЕДЕЛЕНИЕ ИНТЕНСИВНОСТИ ВЕНТИЛЯЦИИ ИНКУБАТОРА ПО ДИНАМИКЕ РАСХОДА ВОДЫ В УВЛАЖНИТЕЛЕ

It is known that the air composition in the incubator chamber is critically important for the development of bird embryos, since the embryo consumes oxygen and produces carbon dioxide during development. High embryonic mortality is observed with insufficient ventilation of the incubator chamber, however, excessive ventilation leads to unreasonable costs of electricity and water in the humidification system. Gas analyzers that allow precise regulation of gas exchange between the incubator chamber and the surrounding air are not used in tabletop incubators, and the problem of determining the optimal ventilation parameters for tabletop incubators remains relevant at present. The possibility of interpreting data on water consumption by humidification systems of tabletop incubators in order to determine the characteristics of oxygen and carbon dioxide gas exchange between the air in the incubator chamber and the environment was studied. Grumbach tabletop incubators, a carbon dioxide detector based on the ZGm053UK IR sensor, and an AT-8100 electrochemical oxygen detector were used. It was established that the dynamics of water consumption of the incubator humidification system correlates with the volume of gas exchange between the incubator and the environment. The danger of stopping the respiratory activity of embryos occurs in sealed incubators, while the marker of the absence of gas exchange is a constant water level in the humidification system. With the rate of water evaporation by the evaporator of at least 3 cm3 / day per 1 chicken egg, the difference in relative humidity in the incubator room and the incubator chamber of at least 10% and the difference in temperatures in the incubator and the incubator room of at least 10 ° C, the gas exchange of the incubator with the room provides a carbon dioxide level of no more than 3000 ppm, and an oxygen level of at least 20.6%. The air composition in the incubator room has a direct effect on the air composition in the incubator, however, the required ventilation level of the incubator room, providing satisfactory air quality, can be determined organoleptically.

Silicon-Mediated Improvement in Drought and Salinity Stress Tolerance of Black Gram (Vigna mungo L.) by Modulating Growth, Physiological, Biochemical, and Root Attributes.

Water is a precious commodity for plant growth and metabolism; however, its scarcity and saline sand conditions have a drastic effect on plant growth and development. The main objective of the current study was to understand how silicon (Si) application might help Black gram (Vigna mungo L.) against the negative impacts of salt stress and drought. The treatments of this study were: no silicon = 0 mg/kg; silicon = 40 mg/kg; control = no stress; drought stress = 50% field capacity (FC); salinity = 10 dSm-1; drought + salinity = 10 dSm-1 + 50% field capacity (FC). The findings showed that the application of silicon in the sand significantly affected growth indices such as leaf area (LA), shoot fresh weight (SFW), shoot dry weight (SDW), and shoot length (SL). Root length (RL) increased significantly up to 55.9% in response to drought stress. Applying Si to the sand increased the root length (RL) by 53.9%. In comparison to the control, the turgor potential of leaves decreased by 10.3% under salinity, while it increased by 44.7% under drought stress. However, the application of silicon to the sand significantly improved the turgor potential of leaves by 98.7%. Under both drought and salt stress, gas exchange characteristics and photosynthetic pigments dramatically decreased. Applying 40 mg/kg silicon to sand improved the gas exchange characteristics, protein contents, and photosynthetic pigments of plants under drought and salt stress, such as levels of chlorophyll (a, and b) increased by 18% and 26%, respectively. Under control conditions, the hydrogen peroxide (H2O2) concentration was lower but increased during periods of drought and salinity stress. The concentrations of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) were decreased by salt and drought stress and increased by sand application of silicon at a rate of 40 mg/kg. Application of silicon at 40 mg/kg sand rate improved the growth and development under control and stress conditions. Overall, this study provides an extensive understanding of the physiological mechanisms underlying the black gram's ability to withstand under salt stress and drought stress by application of Si which will serve as a roadmap for future cellular research.

Mitigating Pb-induced oxidative stress in rice plants by cerium oxide and iron oxide nanoparticles

Nanotechnology offers creative and effective solutions for addressing various environmental issues, such as heavy metals (HM). The rapidly increasing HM concentrations in agricultural land have drawn considerable attention. Nanoparticles (NPs) have special physiochemical features that help reduce stress. This study assessed the viability of applying CeO2NPs and FeONPs to rice plants at a concentration of 25 mg/L to effectively remove the detrimental effects of lead (Pb) by using various concentrations (100 and 200 ppm) on plant development and growth. To achieve the desired concentrations, a Pb solution was prepared by dissolving lead nitrate in distilled water and added to the soil. Interestingly, the application of CeO2NPs and FeONPs resulted in a notable increase in plant growth, biomass, gas exchange characteristics, antioxidant enzymatic activity (SOD, POD, APX, and CAT), their gene expressions, as well as other antioxidants (phenols, prolines, amino acids, flavonoids, anthocyanins, and ascorbic acids) while simultaneously reducing oxidative stress (MDA, H2O2, and electrolyte leakage) and Pb uptake in rice. Conversely, Pb elevation in the soil increased oxidative damage and organic acid exudation pattern in the rice. At 200 ppm, a significant rise in Pb content (416.67 % and 380 %) was found in the roots and leaves of rice plants. According to our findings, rice growth can be bio-stimulated by CeO2NPs and FeONPs. Subsequent investigations should focus on the persistent ecological consequences and molecular mechanisms associated with the application of cerium oxide and iron oxide nanoparticles in agriculture to reduce Pb-induced oxidative stress.

Elucidating the role of rice straw biochar in modulating Helianthus annuus L. antioxidants, secondary metabolites and soil post-harvest characteristics in different types of microplastics

The emergence of microplastics (MPs) as pollutants in agricultural soils is increasingly alarming, presenting significant threats to soil ecosystems. Given the widespread contamination of ecosystems by various types of MPs, including polystyrene (PS), polyvinyl chloride (PVC), and polyethylene (PE), it is crucial to understand their effects on agricultural productivity. The present study was conducted to investigate the effects of different types of MPs (PS, PVC, and PE) on various aspects of sunflower (Helianthus annuus L.) growth with the addition of rice straw biochar (RSB). This study aimed to examine plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, and the response of various antioxidants (enzymatic and non-enzymatic) and their specific gene expression, proline metabolism, the AsA–GSH cycle, cellular fractionation in the plants and post-harvest soil properties. The research outcomes indicated that elevated levels of different types of MPs in the soil notably reduced plant growth and biomass, photosynthetic pigments, and gas exchange attributes. Different types of MPs also induced oxidative stress, which caused an increase in various enzymatic and non-enzymatic antioxidant compounds, gene expression and sugar content; notably, a significant increase in proline metabolism, AsA–GSH cycle, and pigmentation of cellular components was also observed. Favorably, the addition of RSB significantly increased plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds, and relevant gene expression while decreasing oxidative stress. In addition, RSB amendment decreased proline metabolism and AsA-GSH cycle in H. annuus plants, thereby enhancing cellular fractionation and improving post-harvest soil properties. These results open new avenues for sustainable agriculture practices and show great potential for resolving the urgent issues caused by microplastic contamination in agricultural soils.

Mitigating the effects of PVC microplastics and mercury stress on rye (Secale cereale L.) plants using zinc oxide−nanoparticles

AbstractIn present years, the use of zinc oxide nanoparticles (ZnO‐NPs) has received great attention due to increase in the nutrient accumulation by plants for improving the capability of agronomic Zn biofortification. Although, the emergence of polyvinyl chloride (PVC) microplastics (MPs) as pollutants in agricultural soils is increasingly alarming, presenting significant toxic threats to soil ecosystems. The present work studied the impact of different levels of PVC‐MPs, namely 0 (no PVC‐MPs), 2, and 4 mg L−1, along with mercury (Hg) levels of 0 (no Hg), 10, and 25 mg kg−1 in the soil, while concurrently applying with ZnO‐NPs at 0 (no ZnO‐NPs), 50, and 100 μg mL−1 to rye (Secale cereale L.) plants. This study aimed to examine plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, and the response of various antioxidants (enzymatic and non‐enzymatic) and their specific gene expression, proline metabolism, the ascorbic acid–dehydroascorbic acid (AsA–GSH) cycle, and cellular fractionation in the plants. The research outcomes indicated that elevated levels of PVC‐MPs and Hg stress in the soil notably reduced plant growth and biomass, photosynthetic pigments, and gas exchange attributes. However, PVC‐MPs and Hg stress also induced oxidative stress in the roots and shoots of the plants by increasing malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) which also induced increased compounds of various enzymatic and non‐enzymatic antioxidants, and also the gene expression and sugar content. Furthermore, a significant increase in proline metabolism, the AsA–GSH cycle, and the pigmentation of cellular components was observed. Although, the application of ZnO‐NPs showed a significant increase in plant growth and biomass, gas exchange characteristics, enzymatic and non‐enzymatic compounds, and their gene expression and also decreased oxidative stress. In addition, the application of ZnO‐NPs enhanced cellular fractionation and decreased the proline metabolism and AsA–GSH cycle in S. cereale plants. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils.

Enhancing drought tolerance in broccoli (Brassica oleracea L.) through melatonin application: Physiological and biochemical insights into growth, photosynthesis, and antioxidant defense mechanisms

Broccoli is a well-known and high-value vegetable crop for its abundance of antioxidants and minerals. Despite its popularity, its production faces significant challenges from various abiotic stressors, particularly drought stress. Melatonin a multifunctional molecule within plants modulates environmental stresses including drought stress. Therefore, the current study aimed to evaluate the effect of melatonin application (0 and 100 μM) on broccoli under 100% field capacity (FC) (well-watered) and drought stress (50% field capacity). Foliar application of melatonin helped overcome drought-induced losses and enhanced plant height (23.72%), root length (43.47%), total chlorophyll contents (46%), carotenoids (60%) and yield (34.23%), glycine betaine (GB) (77.7%), whereas reducing the oxidative activities of hydrogen peroxide (H2O2) (20%) and leaf water potential (LWP) (33.35%) in broccoli plants. Antioxidant activities, i.e., superoxide dismutase (SOD), peroxide (POD), catalase (CAT), and ascorbate (APX) were further enhanced under melatonin treatment with 28.53%, 26.10%, 35.26%, and 33.33% respectively. Melatonin application significantly increased gas exchange characteristics by increasing stomatal conductance. Pearson correlation matrix and biplot were developed for the determination of trait association and treatment performance. Exogenous melatonin application decreased the oxidative damage brought on by the drought and increased the yield of broccoli.

Exploring Bacillus mycoides PM35 efficacy in enhancing rice (Oryza sativa L.) response to different types of microplastics through gene regulation and cellular fractionation.

Soil contamination with microplastics (MPs) is a persistent threat to crop production worldwide. With a wide range of MP types, including polystyrene (PS), polyvinyl chloride (PVC) and polyethylene (PE), contaminating our environment, it is important to understand their impact on agricultural productivity. The present study was conducted to investigate the effects of different types of MPs (PS, PVC and PE) on various aspects of plant growth. Specifically, we examined growth and biomass, photosynthetic pigments, gas exchange attributes, oxidative stress responses, antioxidant compound activity (both enzymatic and non-enzymatic), gene expression, proline metabolism, the AsA-GSH cycle and cellular fractionation and nutritional status, in different parts of rice (Oryza sativa L.) seedlings, which were also exposed to plant growth promoting rhizobacteria (PGPR), i.e. Bacillus mycoides PM35, i.e. 20 μL. The research outcomes indicated that the different types of MPs in the soil notably reduced plant growth and biomass, photosynthetic pigments and gas exchange attributes. However, MP stress also induced oxidative stress in the roots and shoots of the plants by increasing malondialdehyde (MDA), hydrogen peroxide (H2O2) and electrolyte leakage (EL) which also induced increased compounds of various enzymatic and non-enzymatic antioxidants and also the gene expression. Furthermore, a significant increase in proline metabolism, the AsA-GSH cycle, and the fractionations of cellular components was observed. Although the application of B. mycoides PM35 showed a significant increase in plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds and their gene expression and also decreased oxidative stress. In addition, the application of B. mycoides PM35 enhanced cellular fractionation and decreased the proline metabolism and AsA-GSH cycle in O. sativa plants. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of MP contamination in agricultural soils.

Pulmonary Embolism in Donor Lungs—Incidence and Management

AbstractIn efforts to decrease the mortality on the waiting list for lung transplantation, alternatives to increase the donor pool have been explored. Caution must be used when accepting donor lungs with pulmonary embolism (PE), as prior evidence has shown mixed results after transplantation of donor lungs with PE. However, the mere diagnosis of PE on imaging should not be the sole reason for the exclusion of these donors for transplant, and they should be reviewed as any other donor. A comprehensive evaluation should be performed for every donor, with a special focus on abnormalities of gas exchange and gross pathologic characteristics during procurement.