Search

Purpose: Training zones are generally assessed by gas-exchange thresholds (GET). Several mathematical analyses of heart rate variability (HRV) are proposed for indirect GET determination. Our study aimed to investigate the accordance of the detrend fluctuation analysis (DFA α1) for determining GET with first (VT1) and second ventilatory (VT2) thresholds in well-trained subjects. Methods: Eighteen female and 38 male sub-elite cyclists performed a maximal incremental cycling test of 2-min stage duration with continuous gas exchange and HR measurements. Power output (PO), Oxygen uptake ( V ˙ O2) and HR at VT1 and VT2 were compared with DFA α1 0.75 (HRVT1) and 0.50 (HRVT2). Agreements between PO, V ˙ O2 and HR values were analyzed using Bland–Altman analysis. Results: Large limits of agreement between VT1 and HRVT1 were observed for measures of V ˙ O2 expressed in mL.min−1.kg−1 [− 21.3; + 14.1], HR [ 39.2; + 26.9] bpm and PO [− 118; + 83] watts. Indeed, agreements were also low between VT2 and HRVT2 for measures of V ˙ O2 [− 26.7; + 4.3] mL.min−1.kg−1, HR [− 45.5; + 10.6] bpm and PO [− 157; + 35] watts. Our results also showed a sex effect: women obtained worst predictions based on DFA α1 than men for HR (p = 0.014), PO (p = 0.044) at VT1 and V ˙ O 2 (p = 0.045), HR (p = 0.003) and PO (p = 0.004) at VT2. Conclusion: There was unsatisfactory agreement between the GET and DFA α1 methods for VT1 and VT2 determination in both sex well-trained cyclists. Trial registration number 2233534 on 2024/03/05 retrospectively registered. [ABSTRACT FROM AUTHOR]

Extended Abstract Background: In contemporary times, the increasing population growth in large urban areas, industrial development in these cities, and the need for expanding urban green spaces and green belts have drawn the attention of managers to the use and cultivation of multipurpose tree species more than ever before. In many advanced countries, the use of chemical fertilizers has been discontinued in urban green spaces, parks, agriculture, and horticulture. The major reasons for this include undesirable environmental effects, disruption of soil chemical balance and structure, disruption of the ecology of plant and animal communities, and pollution of freshwater bodies. For this reason, the utilization of various organic fertilizers has been highlighted as one of the important strategies in improving horticultural and agricultural production and reducing the risk of environmental pollution, especially pollution of surface and groundwater resources. Humic acid (HA) is among the main types of organic fertilizers and a type of stabilized organic acid derived from the main compounds of humus, considered one of the most abundant organic compounds in nature. The use of HA for plants can directly and indirectly promote better plant growth, thereby increasing production levels and improving crop quality. Therefore, the present study aimed to assess the possibility of enhancing the growth and viability components of white mulberry seedlings as the most commonly used tree species for planting in the green belt of Mashhad using HA fertilizer and animal manure. Methods: For this research, two-year-old and uniform-sized mulberry seedlings were prepared as bare-root. Then, they were transferred to prepared beds in the green belt nursery of Mashhad for planting in pits with planting distances of 1.5 × 1.5 m in a completely randomized design. In five separate experimental plots, the nursery soil was thoroughly and uniformly mixed with animal manure. Subsequently, HA fertilizer in liquid form (at 50 and 300 mg/l) was mixed with the soil in two plots in addition to the animal manure. In the other two plots, foliar spraying at 50 and 300 mg l-1 on the leaf surfaces of the seedlings was carried out at the beginning of the growing season. Only animal manure treatment was considered for the seedlings in the fifth plot. Ten seedlings were selected for each treatment as replicates for examination. The seedlings were irrigated uniformly throughout a six-month growing period for measurement purposes. The growth and physiological characteristics of the seedlings, including plant height, collar diameter, root length, leaf and branch numbers, dry weight of aerial and root parts, gas exchange rates, photosynthesis rate, and seedling survival, were measured and statistically compared after 6 months of applying the treatments. To measure biomass, the seedlings were carefully removed from the soil, and the soil was washed from around the roots, followed by counting the number of branches and leaves. Each seedling was then divided into two parts of roots and stems, which were dried at 70 °C for 48 h and weighed using a digital scale. Finally, the data were analyzed in a completely randomized design, and their means were statistically compared using Tukey's test. The gas exchange rates (stomatal conductance) and photosynthesis rate in outdoors and under natural conditions of temperature, light, and relative humidity were measured using a portable device for gas exchange measurements. For this purpose, 3-6 mature leaves were selected from each replicate. All measurements were conducted between 9 am and 12 pm on a sunny day with a light intensity of 1400 µmol m-2 s-1. Results: The HA treatment added to the soil at a concentration of 300 mg/l resulted in the highest average values of the variables, namely the highest values of radial growth (3.2 mm), sapling height growth (35.1 cm), number of leaves (45), number of branches (16), dry root weight (31.3 g), and shoot weight (38.1 g). A comparison of physiological variables, such as photosynthesis intensity (14.5 μmol m-2 s-1) and stomatal conductance rate (0.23 mol m-2 s-1), revealed that the treatment with 300 mg/l of HA added to the soil led to the highest values. Subsequently, the treatment of 50 mg l-1 of HA added to the soil and then foliar spraying with an HA solution of 300 mg l-1 showed better effects than the other treatments. Overall, increasing HA in the soil resulted in better performance than foliar spraying on the leaf surface of white mulberry seedlings. Animal manure created the lowest averages in all evaluated variables. Conclusion: The positive effects of HA on plant growth and biomass are attributed to its ability to increase water and nutrient absorption by plants, as well as its pseudo-hormonal effects on plants. Based on the results of the present study, HA application positively influenced growth characteristics, photosynthesis intensity, and biomass increase (variables such as leaf number, branch number, sapling length growth, radial growth, root growth, and aerial parts growth). Therefore, adding HA fertilizers to the soil during mulberry planting is highly recommended in urban green spaces, horticulture, and urban green belts.

This research was undertaken to investigate the efficacy of dust stabilization by two-year-old seedlings of four green space trees within a controlled experimental setting. Following the calibration of the dust simulation apparatus to ensure uniform dust dispersion, gas exchange measurements were taken on the seedlings, and subsequently, they were introduced into the dusting device. Dusting operations were performed at 30 and 60 g per square meter concentrations, with treatments involving one, two, and three dusting episodes at 48-h intervals facilitated by a wind pump. After confirming dust settlement, the crown and trunk sections were segregated, washed and the weight of falling dust was measured. The results revealed that Eldar pine exhibited superior dust absorption per unit leaf area (0.0063 g/cm−2), potentially attributed to its densely covered leaf surface with regular excrescences and copious foliage. In contrast, no discernible distinctions were observed among the remaining three species. Examining fixed dust quantities per unit crown volume unveiled significant effects for all factors except for the interaction between species and dust concentration. Once again, Eldar pine exhibited the highest dust absorption. Comparative analyses of pre- and post-dusting gas exchange data indicated that dusting significantly reduced gas exchange for olive and River Red Gum. Conversely, no noteworthy variation was observed in the case of Eldar pine (6.83 mmol/g/s decrease) and Oriental Arbor-vitae (7.39 mmol/g/s decrease). The findings further indicated that increased crown void spaces and reduced foliage density substantially decreased stabilized dust quantities per unit crown volume. Augmented dust concentration and more frequent dusting operations were correlated with heightened total dust stabilization and increased dust accumulation per unit leaf area and volume in the seedlings. Eldar pine emerged as a robust species for dust absorption, demonstrating marked superiority over the other species investigated in this study. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of physiological changes involved in the acclimation responses of plants after their exposure to repeated cycles of water stress is crucial to selecting resilient genotypes for regions with recurrent drought episodes. Under such background, we tried to respond to questions as: (1) Are there differences in the stomatal-related and non-stomatal responses during water stress cycles in different clones of Coffea canephora Pierre ex A. Froehner? (2) Do these C. canephora clones show a different response in each of the two sequential water stress events? (3) Is one previous drought stress event sufficient to induce a kind of “memory” in C. canephora? Seven-month-old plants of two clones (’3V’ and ‘A1’, previously characterized as deeper and lesser deep root growth, respectively) were maintained well-watered (WW) or fully withholding the irrigation, inducing soil water stress (WS) until the soil matric water potential (Ψmsoil) reached ≅ −0.5 MPa (−500 kPa) at a soil depth of 500 mm. Two sequential drought events (drought-1 and drought-2) attained this Ψmsoil after 19 days and were followed by soil rewatering until a complete recovery of leaf net CO2 assimilation rate (Anet) during the recovery-1 and recovery-2 events. The leaf gas exchange, chlorophyll a fluorescence, and leaf reflectance parameters were measured in six-day frequency, while the leaf anatomy was examined only at the end of the second drought cycle. In both drought events, the WS plants showed reduction in stomatal conductance and leaf transpiration. The reduction in internal CO2 diffusion was observed in the second drought cycle, expressed by increased thickness of spongy parenchyma in both clones. Those stomatal and anatomical traits impacted decreasing the Anet in both drought events. The ‘3V’ was less influenced by water stress than the ‘A1’ genotype in Anet, effective quantum yield in PSII photochemistry, photochemical quenching, linear electron transport rate, and photochemical reflectance index during the drought-1, but during the drought-2 event such an advantage disappeared. Such physiological genotype differences were supported by the medium xylem vessel area diminished only in ‘3V’ under WS. In both drought cycles, the recovery of all observed stomatal and non-stomatal responses was usually complete after 12 days of rewatering. The absence of photochemical impacts, namely in the maximum quantum yield of primary photochemical reactions, photosynthetic performance index, and density of reaction centers capable of QA reduction during the drought-2 event, might result from an acclimation response of the clones to WS. In the second drought cycle, the plants showed some improved responses to stress, suggesting “memory” effects as drought acclimation at a recurrent drought.

Cyclamen (Cyclamen persicum Mill.) is an ornamental plant that is highly susceptible to pathogens, requiring high amounts of phytosanitary products. Therefore, the development of more sustainable alternatives has been required. The present study aimed to analyze the effect of C. canadensis root extract (aqueous and with dichloromethane) applied via foliar or soil, in C. persicum, on gas exchange and the SPAD index and on the biomass of cyclamen. The aqueous extract treatment increased net CO2 assimilation, the transpiration rates, and instantaneous carboxylation efficiency. The water use efficiency values were reduced in the treatments with both extracts. The greatest increases in the SPAD index were provided by the aqueous extract. The cyclamens that received the aqueous extract applied in soil or the dichloromethane extract applied in leaves showed an increase in total biomass and number of leaves. To identify the compounds present in the extracts, CG-MS and LC-MS/MS analyses were performed. The positive effects obtained indicated a high biostimulant effect of C. Canadensis. Thus, the root extracts of C. Canadensis, particularly the aqueous extracts, have the potential to be used to reduce the use of mineral fertilizers and pesticides, promoting agroecological practices and contributing to sustainable agriculture.

Cyclamen (Cyclamen persicum Mill.) is an ornamental plant that is highly susceptible to pathogens, requiring high amounts of phytosanitary products. Therefore, the development of more sustainable alternatives has been required. The present study aimed to analyze the effect of C. canadensis root extract (aqueous and with dichloromethane) applied via foliar or soil, in C. persicum, on gas exchange and the SPAD index and on the biomass of cyclamen. The aqueous extract treatment increased net CO2 assimilation, the transpiration rates, and instantaneous carboxylation efficiency. The water use efficiency values were reduced in the treatments with both extracts. The greatest increases in the SPAD index were provided by the aqueous extract. The cyclamens that received the aqueous extract applied in soil or the dichloromethane extract applied in leaves showed an increase in total biomass and number of leaves. To identify the compounds present in the extracts, CG-MS and LC-MS/MS analyses were performed. The positive effects obtained indicated a high biostimulant effect of C. Canadensis. Thus, the root extracts of C. Canadensis, particularly the aqueous extracts, have the potential to be used to reduce the use of mineral fertilizers and pesticides, promoting agroecological practices and contributing to sustainable agriculture. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of physiological changes involved in the acclimation responses of plants after their exposure to repeated cycles of water stress is crucial to selecting resilient genotypes for regions with recurrent drought episodes. Under such background, we tried to respond to questions as: (1) Are there differences in the stomatal-related and non-stomatal responses during water stress cycles in different clones of Coffea canephora Pierre ex A. Froehner? (2) Do these C. canephora clones show a different response in each of the two sequential water stress events? (3) Is one previous drought stress event sufficient to induce a kind of "memory" in C. canephora? Seven-month-old plants of two clones ('3V' and 'A1', previously characterized as deeper and lesser deep root growth, respectively) were maintained well-watered (WW) or fully withholding the irrigation, inducing soil water stress (WS) until the soil matric water potential (Ψmsoil) reached ≅ −0.5 MPa (−500 kPa) at a soil depth of 500 mm. Two sequential drought events (drought-1 and drought-2) attained this Ψmsoil after 19 days and were followed by soil rewatering until a complete recovery of leaf net CO2 assimilation rate (Anet) during the recovery-1 and recovery-2 events. The leaf gas exchange, chlorophyll a fluorescence, and leaf reflectance parameters were measured in six-day frequency, while the leaf anatomy was examined only at the end of the second drought cycle. In both drought events, the WS plants showed reduction in stomatal conductance and leaf transpiration. The reduction in internal CO2 diffusion was observed in the second drought cycle, expressed by increased thickness of spongy parenchyma in both clones. Those stomatal and anatomical traits impacted decreasing the Anet in both drought events. The '3V' was less influenced by water stress than the 'A1' genotype in Anet, effective quantum yield in PSII photochemistry, photochemical quenching, linear electron transport rate, and photochemical reflectance index during the drought-1, but during the drought-2 event such an advantage disappeared. Such physiological genotype differences were supported by the medium xylem vessel area diminished only in '3V' under WS. In both drought cycles, the recovery of all observed stomatal and non-stomatal responses was usually complete after 12 days of rewatering. The absence of photochemical impacts, namely in the maximum quantum yield of primary photochemical reactions, photosynthetic performance index, and density of reaction centers capable of QA reduction during the drought-2 event, might result from an acclimation response of the clones to WS. In the second drought cycle, the plants showed some improved responses to stress, suggesting "memory" effects as drought acclimation at a recurrent drought. [ABSTRACT FROM AUTHOR]

This is the first study to describe the daytime evolution of respiratory parameters in mechanically ventilated COVID-19 patients. The data base refers to patients hospitalised in the intensive care unit (ICU) at Arequipa Hospital (Peru, 2335 m) in 2021. In both survivors (S) and non-survivors (NS) patients, a remarkable decrease in respiratory compliance was observed, revealing a proportional decrease in inflatable alveolar units. The S and NS patients were all hyperventilated and their SatO2 was maintained at >90%. However, while S remained normocapnic, NS developed progressive hypercapnia. We compared the efficiency of O2 uptake and CO2 removal in the air blood barrier relying on a model allowing to partition between diffusion and perfusion limitations to gas exchange. The decrease in O2 uptake was interpreted as diffusion limitation, while the impairment in CO2 removal was modelled by progressive perfusion limitation. The latter correlated with the increase in positive end-expiratory pressure (PEEP) and plateau pressure (Pplat), leading to capillary compression, increased blood velocity, and considerable shortening of the air-blood contact time. [ABSTRACT FROM AUTHOR]

Background: In contemporary times, the increasing population growth in large urban areas, industrial development in these cities, and the need for expanding urban green spaces and green belts have drawn the attention of managers to the use and cultivation of multipurpose tree species more than ever before. In many advanced countries, the use of chemical fertilizers has been discontinued in urban green spaces, parks, agriculture, and horticulture. The major reasons for this include undesirable environmental effects, disruption of soil chemical balance and structure, disruption of the ecology of plant and animal communities, and pollution of freshwater bodies. For this reason, the utilization of various organic fertilizers has been highlighted as one of the important strategies in improving horticultural and agricultural production and reducing the risk of environmental pollution, especially pollution of surface and groundwater resources. Humic acid (HA) is among the main types of organic fertilizers and a type of stabilized organic acid derived from the main compounds of humus, considered one of the most abundant organic compounds in nature. The use of HA for plants can directly and indirectly promote better plant growth, thereby increasing production levels and improving crop quality. Therefore, the present study aimed to assess the possibility of enhancing the growth and viability components of white mulberry seedlings as the most commonly used tree species for planting in the green belt of Mashhad using HA fertilizer and animal manure. Methods: For this research, two-year-old and uniform-sized mulberry seedlings were prepared as bare-root. Then, they were transferred to prepared beds in the green belt nursery of Mashhad for planting in pits with planting distances of 1.5 × 1.5 m in a completely randomized design. In five separate experimental plots, the nursery soil was thoroughly and uniformly mixed with animal manure. Subsequently, HA fertilizer in liquid form (at 50 and 300 mg/l) was mixed with the soil in two plots in addition to the animal manure. In the other two plots, foliar spraying at 50 and 300 mg l-1 on the leaf surfaces of the seedlings was carried out at the beginning of the growing season. Only animal manure treatment was considered for the seedlings in the fifth plot. Ten seedlings were selected for each treatment as replicates for examination. The seedlings were irrigated uniformly throughout a six-month growing period for measurement purposes. The growth and physiological characteristics of the seedlings, including plant height, collar diameter, root length, leaf and branch numbers, dry weight of aerial and root parts, gas exchange rates, photosynthesis rate, and seedling survival, were measured and statistically compared after 6 months of applying the treatments. To measure biomass, the seedlings were carefully removed from the soil, and the soil was washed from around the roots, followed by counting the number of branches and leaves. Each seedling was then divided into two parts of roots and stems, which were dried at 70 °C for 48 h and weighed using a digital scale. Finally, the data were analyzed in a completely randomized design, and their means were statistically compared using Tukey's test. The gas exchange rates (stomatal conductance) and photosynthesis rate in outdoors and under natural conditions of temperature, light, and relative humidity were measured using a portable device for gas exchange measurements. For this purpose, 3-6 mature leaves were selected from each replicate. All measurements were conducted between 9 am and 12 pm on a sunny day with a light intensity of 1400 μmol m-2 s-1. Results: The HA treatment added to the soil at a concentration of 300 mg/l resulted in the highest average values of the variables, namely the highest values of radial growth (3.2 mm), sapling height growth (35.1 cm), number of leaves (45), number of branches (16), dry root weight (31.3 g), and shoot weight (38.1 g). A comparison of physiological variables, such as photosynthesis intensity (14.5 μmol m-2 s-1) and stomatal conductance rate (0.23 mol m-2 s-1), revealed that the treatment with 300 mg/l of HA added to the soil led to the highest values. Subsequently, the treatment of 50 mg l-1 of HA added to the soil and then foliar spraying with an HA solution of 300 mg l-1 showed better effects than the other treatments. Overall, increasing HA in the soil resulted in better performance than foliar spraying on the leaf surface of white mulberry seedlings. Animal manure created the lowest averages in all evaluated variables. Conclusion: The positive effects of HA on plant growth and biomass are attributed to its ability to increase water and nutrient absorption by plants, as well as its pseudo-hormonal effects on plants. Based on the results of the present study, HA application positively influenced growth characteristics, photosynthesis intensity, and biomass increase (variables such as leaf number, branch number, sapling length growth, radial growth, root growth, and aerial parts growth). Therefore, adding HA fertilizers to the soil during mulberry planting is highly recommended in urban green spaces, horticulture, and urban green belts. [ABSTRACT FROM AUTHOR]

This is the first study to describe the daytime evolution of respiratory parameters in mechanically ventilated COVID-19 patients. The data base refers to patients hospitalised in the intensive care unit (ICU) at Arequipa Hospital (Peru, 2335 m) in 2021. In both survivors (S) and non-survivors (NS) patients, a remarkable decrease in respiratory compliance was observed, revealing a proportional decrease in inflatable alveolar units. The S and NS patients were all hyperventilated and their SatO2 was maintained at >90%. However, while S remained normocapnic, NS developed progressive hypercapnia. We compared the efficiency of O2 uptake and CO2 removal in the air blood barrier relying on a model allowing to partition between diffusion and perfusion limitations to gas exchange. The decrease in O2 uptake was interpreted as diffusion limitation, while the impairment in CO2 removal was modelled by progressive perfusion limitation. The latter correlated with the increase in positive end-expiratory pressure (PEEP) and plateau pressure (Pplat), leading to capillary compression, increased blood velocity, and considerable shortening of the air-blood contact time.

Understanding the impact of drought stress on Arabica coffee physiology and metabolism is essential in the pursuit of developing drought-resistant varieties. In this study, we explored the physiological and metabolite changes in coffee genotypes exhibiting varying degrees of tolerance to drought—namely, the relatively tolerant Ca74110 and Ca74112, and the sensitive Ca754 and CaJ-19 genotypes—under well-watered conditions and during terminal drought stress periods at two time points (0 and 60 days following the onset of stress). The metabolite profiling uncovered significant associations between the growth and the physiological characteristics of coffee genotypes with distinct drought tolerance behaviors. Initially, no marked differences were observed among the genotypes or treatments. However, at the 60-day post-drought onset time point, notably higher shoot growth, biomass, CO2 assimilation, pigments, and various physiological parameters were evident, particularly in the relatively tolerant genotypes. The metabolite profiling revealed elevations in glucose, maltose, amino acids, and organic acids, and decreases in other metabolites. These alterations were more pronounced in the drought-tolerant genotypes, indicating a correlation between enhanced compatible solutes and energy-associated metabolites crucial for drought tolerance mechanisms. This research introduces GC-MS-based metabolome profiling to the study of Ethiopian coffee, shedding light on its intricate responses to drought stress and paving the way for the potential development of drought-resistant coffee seedlings in intensified agro-ecological zones. [ABSTRACT FROM AUTHOR]

The use of microalgae has been proeminent in agricultural scenario, because it is an alternative product considered extremelly productive, which contains essential elements for plants. Thus, this study aimed to evaluate the morphophysiology of Punica granatum L. seedlings treated with Spirulina platensis and Scenedesmus sp. nanoparticles in controlled environment. The research was carried out at the of Federal University of Campina Grande, Pombal-PB, using a completely randomized design with five replications. The factorial scheme (2 x 4) was adopted, represented by two types of microalgae (Spirulina platensis; Scenedesmus sp.) and four doses of application (0, 5, 10 and 15%). Growth evaluations happened at 135 days after planting, verifying the number of leaves and branches and shoot length. The physiological parameters evaluated were gas exchanges, chlorophyll 'a' fluorescence, electron transport rate, stationary fluorescence, maximum fluorescence yield after light adaptation and quantum efficiency of PSII. Shoot length and number of branches had rises at doses of 6 and 15%. Number of leaves was induced in seedlings at dose of 8% with Spirulina platensis. Stomatal conductance and internal CO2 concentration increased in seedlings sprayed with Spirulina platensis. extract of Scenedesmus sp. improved the stationary fluorescence and quantum efficiency of PSII in pomegranate seedlings. [ABSTRACT FROM AUTHOR]

Rainfed olive groves in arid Tunisia face severe water scarcity and a low abundance of native arbuscular mycorrhizal fungi (AMF). We investigated if a supplement of commercial AMF-product at transplantation would improve olive plant survival and ecophysiological performance in an arid region. The commercial AMF product was added to two olive tree cultivars, 'Meski' and 'Zarrazi'. There was an increase in the mycorrhizal intensity in the roots of 'Meski'. Mycorrhizal symbiosis seems to have improved the survival of 'Meski' and the growth rate of 'Zarrazi'. Plant water status and gas exchanges were enhanced in 'Meski'. Mycorrhization helped maintain a higher photosynthetic assimilation rate and stomatal conductance in 'Zarrazi'. AMF-symbiosis exhibited an inter-cultivar difference in the enhancement of the ecophysiological performance of olive trees under aridity. It also improved pre-existent indigenous defense strategies. It reinforced the avoidance strategy of 'Meski' but strengthened the tolerance strategy of 'Zarrazi'. [ABSTRACT FROM AUTHOR]

Rainfed olive groves in arid Tunisia face severe water scarcity and a low abundance of native arbuscular mycorrhizal fungi (AMF). We investigated if a supplement of commercial AMF-product at transplantation would improve olive plant survival and ecophysiological performance in an arid region. The commercial AMF product was added to two olive tree cultivars, ‘Meski’ and ‘Zarrazi’. There was an increase in the mycorrhizal intensity in the roots of ‘Meski’. Mycorrhizal symbiosis seems to have improved the survival of ‘Meski’ and the growth rate of ‘Zarrazi’. Plant water status and gas exchanges were enhanced in ‘Meski’. Mycorrhization helped maintain a higher photosynthetic assimilation rate and stomatal conductance in ‘Zarrazi’. AMF-symbiosis exhibited an inter-cultivar difference in the enhancement of the ecophysiological performance of olive trees under aridity. It also improved pre-existent indigenous defense strategies. It reinforced the avoidance strategy of ‘Meski’ but strengthened the tolerance strategy of ‘Zarrazi’.

The ozone layer (O3) is essential to the absorption and blocking of UV-B radiation, preventing a large portion from reaching the Earth's surface. The degradation of the ozone layer (O3) caused by increased pollution has led to climate change exerting significant influence on natural ecosystems and has resulted in severe stress on the environment, such as an increase in UV-B radiation, which has deleterious effects on plant physiology. UV-B influences the protection pathways that increase compound production, leading to metabolic adjustments and promoting plant acclimatization. This study evaluated whether UV-B application prior to sunlight exposure induces anthocyanin synthesis, photochemical change, and carbohydrate profile modification, contributing to acclimatization in Psidium guajava seedlings. A higher concentration of H2O2 may have stimulated anthocyanin synthesis. Furthermore, greater instantaneous water use efficiency (iWUE), the absence of trehalose—a stress marker, and lower concentrations of glucose, fructose, and sucrose indicate that these plants acclimatize when exposed to full sun (30 days). Seedlings exposed to increased UV-B may be more resistant to the climate. The radiation can aid in water resource management with elevated carbohydrate concentrations. These conditions may enhance the success of P. guajava in the field. Therefore, it is suggested that UV-B application to seedlings of P. guajava promotes effective acclimatization, as it activates anthocyanin synthesis, inhibits trehalose accumulation, and increases iWUE. UV-B radiation, depending on its radiance, can be used as a technique in seedling production that can be implanted in anthropic environments. [ABSTRACT FROM AUTHOR]

With the expansion of eucalyptus crops to areas with severe water limitations, physiological studies involving eucalyptus clones to identify those that are tolerant to water stress become important. The objective of this study was to assess morphological and physiological responses by eucalyptus clones subjected to drought stress and rehydration. The experiment consisted of three eucalyptus clones: VC865, I224 and I144 and two water regimes: control and water stress followed by rehydration, with six replicates. Leaf water potential, gas exchange, maximum quantum efficiency of photosystem II and plant height and stem diameter were evaluated under drought stress and rehydration. After 6 d of rehydration, the number of leaves, leaf area and dry mass of root, leaf, stem and their total were evaluated. All clones showed intense reduction of gas exchange during the drought stress period, and only VC865 and I144 showed rapid recovery with 3 d of rehydration. Clone I224 showed greater reduction in height, stem diameter, number of leaves, water potential at midday (Ψw Midday), and maximum quantum efficiency of photosystem II (Fv/Fm). Clones VC865 and I144 showed lower reductions in Ψw Midday and Fv/Fm under stress. VC865 had lower reductions in leaf number, leaf area and higher leaf dry mass, while clone I144 had higher height and lower reduction in root dry mass under. Both these clones showed higher water use efficiency with 3 d of rehydration. These different phenotypic plasticities gave the clones VC865 and I144 efficient mechanisms of acclimatization to stress and more drought tolerance, enhancing their greater capacity for recovery after stress, which allowed lower dry mass reduction. Clone I224, however, was more susceptible to drought stress, undergoing greater physiological damage with only partial recovery during rehydration. [ABSTRACT FROM AUTHOR]

This investigation was aimed to study the response of potato plants to water deficit and exogenous application of salicylic acid (SA) and glycine betaine (GB). Potato cultivars, Spirit, Born, Arinda and Banba were experienced under two irrigation regimes, 30 and 60 % depletion of available soil water, and two concentrations of both SA (0.5 and 1.0 mM) and GB (1.0 and 2.0 mM) additionally the control (0.0 mM SA and GB). Gas exchanges, proline content (Pro), root volume (RV), root/shoot ratio (R/S), plant dry mass (PDM), number tuber (NT) and yield of potato cultivars were measured. With the exception of R/S, water deficit led to notable decreases in gas exchanges, RV, PDM, NT and yield of potato cultivars and increases in Pro content. Foliar application of SA and GB resulted in significant increases in photosynthesis (Photo), carbon dioxide concentration in the sub-stomatal chamber (Ci), stomatal conductance (Gs), Pro, PDM and yield in some levels of SA and GB; the level of the increases appeared more when potato plants were grown under water deficit conditions. All the overhead effects supported PDM and yield of potato cultivars to increase by exogenous application of SA and GB and directed to the assumption that water deficit converted harmful effects on potato cultivars could be released by exogenous applied SA and GB.

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This investigation was aimed to study the response of potato plants to water deficit and exogenous application of salicylic acid (SA) and glycine betaine (GB). Potato cultivars, Spirit, Born, Arinda and Banba were experienced under two irrigation regimes, 30 and 60 % depletion of available soil water, and two concentrations of both SA (0.5 and 1.0 mM) and GB (1.0 and 2.0 mM) additionally the control (0.0 mM SA and GB). Gas exchanges, proline content (Pro), root volume (RV), root/shoot ratio (R/S), plant dry mass (PDM), number tuber (NT) and yield of potato cultivars were measured. With the exception of R/S, water deficit led to notable decreases in gas exchanges, RV, PDM, NT and yield of potato cultivars and increases in Pro content. Foliar application of SA and GB resulted in significant increases in photosynthesis (Photo), carbon dioxide concentration in the sub-stomatal chamber (Ci), stomatal conductance (Gs), Pro, PDM and yield in some levels of SA and GB; the level of the increases appeared more when potato plants were grown under water deficit conditions. All the overhead effects supported PDM and yield of potato cultivars to increase by exogenous application of SA and GB and directed to the assumption that water deficit converted harmful effects on potato cultivars could be released by exogenous applied SA and GB. [ABSTRACT FROM AUTHOR]

Understanding the impact of drought stress on Arabica coffee physiology and metabolism is essential in the pursuit of developing drought-resistant varieties. In this study, we explored the physiological and metabolite changes in coffee genotypes exhibiting varying degrees of tolerance to drought—namely, the relatively tolerant Ca74110 and Ca74112, and the sensitive Ca754 and CaJ-19 genotypes—under well-watered conditions and during terminal drought stress periods at two time points (0 and 60 days following the onset of stress). The metabolite profiling uncovered significant associations between the growth and the physiological characteristics of coffee genotypes with distinct drought tolerance behaviors. Initially, no marked differences were observed among the genotypes or treatments. However, at the 60-day post-drought onset time point, notably higher shoot growth, biomass, CO2 assimilation, pigments, and various physiological parameters were evident, particularly in the relatively tolerant genotypes. The metabolite profiling revealed elevations in glucose, maltose, amino acids, and organic acids, and decreases in other metabolites. These alterations were more pronounced in the drought-tolerant genotypes, indicating a correlation between enhanced compatible solutes and energy-associated metabolites crucial for drought tolerance mechanisms. This research introduces GC-MS-based metabolome profiling to the study of Ethiopian coffee, shedding light on its intricate responses to drought stress and paving the way for the potential development of drought-resistant coffee seedlings in intensified agro-ecological zones.

ABSTRACT This work aims at evaluating and discriminating crambe genotypes regarding tolerance to water deficit by means of morpho-agronomic and physiological traits. The trial was carried out in a greenhouse under a randomized complete block design with four blocks, in a 2 x 8 factorial scheme, being two environments (with and without stress) and eight genotypes (FMS CR 1101, FMS CR 1106, FMS CR 1203, FMS CR 1305, FMS CR 1307, FMS CR 1312 and FMS CR 1326 and cultivar FMS Brilhante). The genotypes were evaluated according to physiological and morpho-agronomic traits. The significance of the mean squares was tested by the F test (P < 0.05) and the genetic parameters were estimated as ratio b between the genetic (CVg) and experimental (CVe) coefficients of variation, broad-sense heritability at genotypic mean level ( h ^ m 2), intraclass correlation (r) and selective accuracy (Ac). In general, water deficit did not cause severe physiological limitations to the plants. Plant height (PH), total dry mass (TDM) and grain yield (GY) were the traits that stood out for presenting the highest estimates of ratio b, h ^ m 2), CVg and r, revealing the possibility of genetic gains with the selection. Nevertheless, after evaluating the performance of genotypes in terms of physiological and morpho-agronomic traits, it was concluded that cultivar FMS Brilhante and inbred lines FMS CR 1326 and FMS CR 1106 had the most favorable traits for the selection, therefore, presenting potential for water deficit tolerance.

Climate change and compostinS1g methods have an important junction on the phenological and ripening grapevine phases. Moreover, the optimization of these composting methods in closed-loop corporate chains can skillfully address the waste problem (pomace, stalks, and pruning residues) in viticultural areas. Owing to the ongoing global warming, in many wine-growing regions, there has been unbalanced ripening, with tricky harvests. Excessive temperatures in fact impoverish the anthocyanin amount of the must while the serious water deficits do not allow a correct development of the berry, stopping its growth processes. This experiment was created to improve the soil management and the quality of the grapes, through the application of a new land conditioner (Zeowine) to the soil, derived from the compost processes of industrial wine, waste, and zeolite. Three treatments on a Sangiovese vineyard were conducted: Zeowine (ZW) (30 tons per ha), Zeolite (Z) (10 tons per ha), and Compost (C) (20 tons per ha). During the two seasons (2021–2022), measurements were made of single-leaf gas exchange and leaf midday water potential, as well as chlorophyll fluorescence. In addition, the parameters of plant yield, yeast assimilable nitrogen, technological maturity, fractionation of anthocyanins (Cyanidin-3-glucoside, Delphinidin-3-glucoside, Malvidin-3-acetylglucoside, Malvidin-3-cumarylglucoside, Malvidin-3-glucoside, Peonidin-3-acetylglucoside, Peonidin-3-cumarylglucoside, Peonidin-3-glucoside, and Petunidin-3-glucoside), Caffeic Acid, Coumaric Acid, Gallic Acid, Ferulic Acid, Kaempferol-3-O-glucoside, Quercetin-3-O-rutinoside, Quercetin-3-O-glucoside, Quercetin-3-O-galactoside, and Quercetin-3-O-glucuronide were analyzed. The Zeowine and zeolite showed less negative water potential, higher photosynthesis, and lower leaf temperature. Furthermore, they showed higher levels of anthocyanin accumulation and a lower level of quercetin. Finally, the interaction of the beneficial results of Zeowine (soil and grapevines) was evidenced by the embellishment of the nutritional and water efficiency, the minimizing of the need for fertilizers, the closure of the production cycle of waste material from the supply chain, and the improvement of the quality of the wines. [ABSTRACT FROM AUTHOR]

Drought alters rice morphophysiology and reduces grain yield. This study hypothesized that the combined analysis of morphophysiological and agronomic traits enables a systemic approach to responses to water deficit, allowing the selection of resistance markers to upland rice. The objectives were to evaluate the effects of water deficit applied at the reproductive stage in plant water status, leaf gas exchanges, leaf non-structural carbohydrate contents, and agronomic traits in upland rice genotypes; and to verify if the analyzed variables may be applied to group the genotypes according to their tolerance level. Water deficit was induced by irrigation suppression in eight genotypes at R2-R3. Physiological and biochemical traits were evaluated at the end of the water deficit period, thenceforth irrigation was restored until grain maturation for the analysis of the agronomic traits. Water deficit reduced: Ψw (63.64%, average); gs (28–90%); transpiration rate (40.63–65.45%); RWC from Serra Dourada to Esmeralda (43.36–61.48%); net CO2 assimilation from Serra Dourada to Primavera (70.04–99.91%); iWUE from Esmeralda to Primavera (83.98–99.85%); iCE in Esmeralda (99.92%); 100-grain weight in CIRAD and Soberana (13.65–20.63%); and grain yield from Primavera to IAC 164 (34.60–78.85%). Water deficit increased Ci from Cambará to Early mutant (79.64–215.23%), and did not affect the tiller number, shoot dry biomass, fructose, and sucrose contents. The alterations in the variables distinguished groups according to the water regime. RWC, Ψw, leaf gas exchanges, and iCE were valuable traits to distinguish the water regime treatments, but not to group the genotypes according to the drought tolerance level. [ABSTRACT FROM AUTHOR]

This work aims at evaluating and discriminating crambe genotypes regarding tolerance to water deficit by means of morpho-agronomic and physiological traits. The trial was carried out in a greenhouse under a randomized complete block design with four blocks, in a 2 x 8 factorial scheme, being two environments (with and without stress) and eight genotypes (FMS CR 1101, FMS CR 1106, FMS CR 1203, FMS CR 1305, FMS CR 1307, FMS CR 1312 and FMS CR 1326 and cultivar FMS Brilhante). The genotypes were evaluated according to physiological and morpho-agronomic traits. The significance of the mean squares was tested by the F test (P < 0.05) and the genetic parameters were estimated as ratio b between the genetic (CVg) and experimental (CVe) coefficients of variation, broad-sense heritability at genotypic mean level (2mh), intraclass correlation (r) and selective accuracy (Ac). In general, water deficit did not cause severe physiological limitations to the plants. Plant height (PH), total dry mass (TDM) and grain yield (GY) were the traits that stood out for presenting the highest estimates of ratio b, 2mh, CVg and r, revealing the possibility of genetic gains with the selection. Nevertheless, after evaluating the performance of genotypes in terms of physiological and morpho-agronomic traits, it was concluded that cultivar FMS Brilhante and inbred lines FMS CR 1326 and FMS CR 1106 had the most favorable traits for the selection, therefore, presenting potential for water deficit tolerance. [ABSTRACT FROM AUTHOR]

Inundation, excessive precipitation, or inadequate field drainage can cause waterlogging of cultivated land. It is anticipated that climate change will increase the frequency, intensity, and unpredictability of flooding events. This stress affects 10–15 million hectares of wheat every year, resulting in 20–50% yield losses. Since this crop greatly sustains a population's food demands, providing ca. 20% of the world's energy and protein diets requirements, it is crucial to understand changes in soil and plant physiology under excess water conditions. Variations in redox potential, pH, nutrient availability, and electrical conductivity of waterlogged soil will be addressed, as well as their impacts in major plant responses, such as root system and plant development. Waterlogging effects at the leaf level will also be addressed, with a particular focus on gas exchanges, photosynthetic pigments, soluble sugars, membrane integrity, lipids, and oxidative stress. [ABSTRACT FROM AUTHOR]

Kumquat is one of the citrus fruits that has gradually become important in the world. The fruits of kumquat suffer from sunburn in intense sunlight. In order to reduce the adverse effects of solar radiation, in this experiment, treatments of kaolin (0, 3 and 5%) and salicylic acid (with concentrations of 0, 0.1 and 1 mM) were used as foliar spray on potted samples. The evaluated treatments included relative water content, gas exchange, biochemical characteristics of the leaves, antioxidant enzymes activity and concentrations of nutrients. The results showed that treatments had significant effects on the measured parameters. Kaolin increased stomatal conductance and net CO2 uptake by creating a thin coating on the plant and protecting it from environmental stresses and reducing plant temperature. Salicylic acid also had positive effects on the activities of antioxidant enzymes. The effects of treatments on the balance of plant nutrients were not very noticeable, although slight changes were observed in some cases. In general, the results of this experiment showed that the use of kaolin 5% and 1mM salicylic acid together can be considered as a cheap and effective treatment in kumquat and in order to protect the plant in high temperature and severe radiation conditions. [ABSTRACT FROM AUTHOR]

The ozone layer (O3) is essential to the absorption and blocking of UV-B radiation, preventing a large portion from reaching the Earth’s surface. The degradation of the ozone layer (O3) caused by increased pollution has led to climate change exerting significant influence on natural ecosystems and has resulted in severe stress on the environment, such as an increase in UV-B radiation, which has deleterious effects on plant physiology. UV-B influences the protection pathways that increase compound production, leading to metabolic adjustments and promoting plant acclimatization. This study evaluated whether UV-B application prior to sunlight exposure induces anthocyanin synthesis, photochemical change, and carbohydrate profile modification, contributing to acclimatization in Psidium guajava seedlings. A higher concentration of H2O2 may have stimulated anthocyanin synthesis. Furthermore, greater instantaneous water use efficiency (iWUE), the absence of trehalose—a stress marker, and lower concentrations of glucose, fructose, and sucrose indicate that these plants acclimatize when exposed to full sun (30 days). Seedlings exposed to increased UV-B may be more resistant to the climate. The radiation can aid in water resource management with elevated carbohydrate concentrations. These conditions may enhance the success of P. guajava in the field. Therefore, it is suggested that UV-B application to seedlings of P. guajava promotes effective acclimatization, as it activates anthocyanin synthesis, inhibits trehalose accumulation, and increases iWUE. UV-B radiation, depending on its radiance, can be used as a technique in seedling production that can be implanted in anthropic environments.

Mango cultivation in a protected environment is becoming widespread in the Mediterranean basin where the species has to face unfavorable weather conditions which do not occur in its native cultivation areas. Besides open-air cultivation, greenhouses—and other protection systems such as shading nets and partial covering of plastic films—have been tested recently. In this study, we focused on assessing the effect of a shading net, and a partially covering plastic film, on the development of "Kensington Pride" mango fruit skin-color, its final quality, and the plants' photosynthetic activity. A new method of measuring mango skin-color on different sides of the fruit is proposed. No difference was observed with regard to the observed parameters between the plants cultivated under the two different protection systems and those growing in the open air. It can, therefore, be stated that such cultivation techniques do not alter the development of the mango fruit and its appearance, nor the plant's photosynthetic activity. [ABSTRACT FROM AUTHOR]

Light quality plays an essential role in setting plant structural and functional traits, including antioxidant compounds. This paper aimed to assess how manipulating the light spectrum during growth may regulate the photosynthetic activity and fruit bioactive compound synthesis in Solanum lycopersicum L. cv. 'Microtom' to improve plant physiological performance and fruit nutritional value. Plants were cultivated under three light quality regimes: red-green-blue LEDs (RGB), red-blue LEDs (RB) and white fluorescent lamps (FL), from sowing to fruit ripening. Leaf functional traits, photosynthetic efficiency, Rubisco and D1 protein expression, and antioxidant production in fruits were analyzed. Compared to FL, RGB and RB regimes reduced height and increased leaf number and specific leaf area, enhancing plant dwarf growth. The RGB regime improved photosynthesis and stomatal conductance despite lower biomass, favoring Rubisco synthesis and carboxylation rate than RB and FL regimes. The RB light produced plants with fewer flowers and fruits with a lower ascorbic acid amount but the highest polyphenol content, antioxidant capacity and SOD and CAT activities. Our data indicate that the high percentage of the green wavelength in the RGB regime promoted photosynthesis and reduced plant reproductive capacity compared to FL and RB. Conversely, the RB regime was the best in favoring the production of health-promoting compounds in tomato berries. [ABSTRACT FROM AUTHOR]

Atriplex nummularia L. is one of the most studied halophytes in research on phytoremediation of salt-affected soils. However, the optimization of biomass requires studies that indicate the appropriate way to evaluate the photosynthesis. The objective of this study was to investigate the photosynthetic efficiency of A. nummularia irrigated with saline water in order to indicate the best range of photosynthetically active radiation (PAR) that should be used. Plants were subjected to daily irrigations (0, 50, 100, 200, 250 and 300 mmol L-1 of NaCl). The light curves were determined at 15 and 84 days applying twenty light intensities (2000, 1750, 1500, 1250, 1000, 750, 500, 250, 200,175, 150, 125, 100, 75, 50, 25, 15, 10, 5, 0 µmol m-2 s-1 PAR). The highest values of photosynthesis rate were observed at PAR of 2000 µmol m-2 s-1 and of 800 µmol m-2 s-1 to 15 and 84 days of evaluation, independent of the NaCl concentration. The present study provides data that support the choice of the ideal PAR in evaluations of gas exchange in A. nummularia. [ABSTRACT FROM AUTHOR]

Light quality plays an essential role in setting plant structural and functional traits, including antioxidant compounds. This paper aimed to assess how manipulating the light spectrum during growth may regulate the photosynthetic activity and fruit bioactive compound synthesis in Solanum lycopersicum L. cv. ‘Microtom’ to improve plant physiological performance and fruit nutritional value. Plants were cultivated under three light quality regimes: red-green-blue LEDs (RGB), red-blue LEDs (RB) and white fluorescent lamps (FL), from sowing to fruit ripening. Leaf functional traits, photosynthetic efficiency, Rubisco and D1 protein expression, and antioxidant production in fruits were analyzed. Compared to FL, RGB and RB regimes reduced height and increased leaf number and specific leaf area, enhancing plant dwarf growth. The RGB regime improved photosynthesis and stomatal conductance despite lower biomass, favoring Rubisco synthesis and carboxylation rate than RB and FL regimes. The RB light produced plants with fewer flowers and fruits with a lower ascorbic acid amount but the highest polyphenol content, antioxidant capacity and SOD and CAT activities. Our data indicate that the high percentage of the green wavelength in the RGB regime promoted photosynthesis and reduced plant reproductive capacity compared to FL and RB. Conversely, the RB regime was the best in favoring the production of health-promoting compounds in tomato berries.

Nickel-induced changes in photosynthetic activity were investigated in three Ni-hyperaccumulating Odontarrhena species with increasing Ni tolerance and accumulation capacity, O. muralis , O. moravensis, and O. chalcidica. Plantlets were grown in hydroponics at increasing NiSO 4 concentrations (0, 0.25, and 1 mM) for one week, and the effects of Ni on growth, metal accumulation, photosynthesis, and nitrogen (N) allocation to components of the photosynthetic apparatus were analysed. Nickel treatments in O. chalcidica , and O. moravensis to a lesser extent, increased not only the photochemical efficiency of photosystem II (PSII) and the CO 2 assimilation rate, but also CO 2 diffusion from the atmosphere to the carboxylation sites. These two species displayed a specific increase and/or rearrangement of the photosynthetic pigments and a higher leaf N allocation to the photosynthetic components in the presence of the metal. Odontarrhena muralis displayed a decrease in photosynthetic performance at the lowest Ni concentration due to a combination of both stomatal and non-stomatal limitations. Our data represent the first complete investigation of the effects of Ni on the photosynthetic machinery in Ni hyperaccumulating plants. Our findings clearly indicate a stimulatory, hormetic-like, effect of the metal on both biophysics and biochemistry of photosynthesis in the species with the highest hyperaccumulation capacity. • Photosynthesis was investigated in three different Ni hyperaccumulating Odontarrhena. • Ni-imposed limitations to photosynthesis were found only in weak hyperaccumulators. • Strong hyperaccumulators showed improved photosynthetic activity in presence of Ni. • Ni induced stomata opening and increased PNUE in strong hyperaccumulators. [ABSTRACT FROM AUTHOR]

Rising temperatures in most viticultural regions are associated with a higher incidence of drastic weather circumstances such as heatwaves. The consequences are reflected in qualitative and quantitative white grapes characteristics. In fact, there is an enhancement in alcohol content and a jeopardized reduction in the aromatic potential. We performed a scientific test to assuage the bump of heatwaves and exposure of grapes on Vitis vinifera cv. "Sauvignon Blanc" with exposed vines (untreated) or with kaolin foliar treatment or with partial fruit-zone shading (shading net 30 and 70%). This work aimed to evaluate the effects of shading net (SD-30% and SD-70%) and foliar kaolin (K) treatment on physiology, technological maturity, and thiolic precursors in Italy during the 2020–2021 seasons. For this purpose, four treatments were established: SD-30% (green artificial shading net at 30%), SD-70% (green artificial shading net at 70%), K (foliar kaolin), and CTRL (no application). During the two vintages, single-leaf gas exchange appraisal, leaf temperature, berry temperature, chlorophyll fluorescence, pre-dawn, and leaf water potential were measured. Moreover, berry weight, pH, °Brix, acidity (technological maturity specifications), and the following thiolic precursors were analyzed: 3-S-glutathionylhexan-1-ol (Glut-3MH), S-4-(4-methylpentan-2-one)-L-cysteine (Cys-4MMP), and 3-S-cysteinylhexan-1-ol (Cys-3MH). SD-70% and K denoted less negative water potential, a lower berry temperature, and a higher level of all precursors than the other treatments. Acidity and sugar parameters indicated significant differences among treatments. The lower berry weight and the lower tartaric acidity were found in the CTRL treatment. In comparison, SD-70% and K showed lower and more balanced sugar contents. As a result of global warming, color shading net and kaolin have been demonstrated to be good practices to counterpoise the divergence between aromatic and technological maturity in Sauvignon Blanc grapevines. [ABSTRACT FROM AUTHOR]

Abstract Post cardiac arrest syndrome is associated with high morbidity and mortality, which is related not only to a poor neurological outcome but also to respiratory and cardiovascular dysfunctions. The control of gas exchange, and in particular oxygenation and carbon dioxide levels, is fundamental in mechanically ventilated patients after resuscitation, as arterial blood gases derangement might have important effects on the cerebral blood flow and systemic physiology. In particular, the pathophysiological role of carbon dioxide (CO2) levels is strongly underestimated, as its alterations quickly affect also the changes of intracellular pH, and consequently influence metabolic energy and oxygen demand. Hypo/hypercapnia, as well as mechanical ventilation during and after resuscitation, can affect CO2 levels and trigger a dangerous pathophysiological vicious circle related to the relationship between pH, cellular demand, and catecholamine levels. The developing hypocapnia can nullify the beneficial effects of the hypothermia. The aim of this review was to describe the pathophysiology and clinical consequences of arterial blood gases and pH after cardiac arrest. According to our findings, the optimal ventilator strategies in post cardiac arrest patients are not fully understood, and oxygen and carbon dioxide targets should take in consideration a complex pattern of pathophysiological factors. Further studies are warranted to define the optimal settings of mechanical ventilation in patients after cardiac arrest.

Light is one of the main factors that influences the greatest phenomenon of nature, namely photosynthesis. In modern society, excessive artificial light at night (ALAN) in the conditions of the urban environment can be considered as an external polluting factor as well. The purpose of this study carried out on Taxus baccata L. (1-year old leaves - PYL and the current year - CYL ones) grown as a hedge in urban conditions was to explore the effects of ALAN on leaves morphology, gas exchanges and associated indicators, as well as on assimilatory pigments content. The results showed that: (1) The leaves length (LL)(mm) of CYL, as well as surface area (cm²) and leaf length to width ratio (LL/LW) were significantly lower under ALAN, than in normal (day/night cycle) light (NL). For PYL, no significant differences were noticed in the case of LL, while significantly lower values have been registered in the case of LW and leaf area to leaf fresh weight (AFWR); (2) Net photosynthesis (A) had significantly higher values during the springtime for PYL in NL as against ALAN, but opposite data have been noticed in June. The quantum yield (φCO2), water use efficiency (WUE) as well as transpiration rate (T) and stomatal conductance (gs) proved to be affected by the light conditions. (3) The values for the content of chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll (TC) and carotenoids (C) were generally as that known for plants in general, with a higher amount of Chl a for PYL-ALAN, as compared to those for CYL-ALAN, or CYL-NL. Further research should be applied by the scientific community to monitor the impact of different light systems during the night and counteract the ALAN impact on plants and ecosystem. [ABSTRACT FROM AUTHOR]

Climate change and compostinS1g methods have an important junction on the phenological and ripening grapevine phases. Moreover, the optimization of these composting methods in closed-loop corporate chains can skillfully address the waste problem (pomace, stalks, and pruning residues) in viticultural areas. Owing to the ongoing global warming, in many wine-growing regions, there has been unbalanced ripening, with tricky harvests. Excessive temperatures in fact impoverish the anthocyanin amount of the must while the serious water deficits do not allow a correct development of the berry, stopping its growth processes. This experiment was created to improve the soil management and the quality of the grapes, through the application of a new land conditioner (Zeowine) to the soil, derived from the compost processes of industrial wine, waste, and zeolite. Three treatments on a Sangiovese vineyard were conducted: Zeowine (ZW) (30 tons per ha), Zeolite (Z) (10 tons per ha), and Compost (C) (20 tons per ha). During the two seasons (2021–2022), measurements were made of single-leaf gas exchange and leaf midday water potential, as well as chlorophyll fluorescence. In addition, the parameters of plant yield, yeast assimilable nitrogen, technological maturity, fractionation of anthocyanins (Cyanidin-3-glucoside, Delphinidin-3-glucoside, Malvidin-3-acetylglucoside, Malvidin-3-cumarylglucoside, Malvidin-3-glucoside, Peonidin-3-acetylglucoside, Peonidin-3-cumarylglucoside, Peonidin-3-glucoside, and Petunidin-3-glucoside), Caffeic Acid, Coumaric Acid, Gallic Acid, Ferulic Acid, Kaempferol-3-O-glucoside, Quercetin-3-O-rutinoside, Quercetin-3-O-glucoside, Quercetin-3-O-galactoside, and Quercetin-3-O-glucuronide were analyzed. The Zeowine and zeolite showed less negative water potential, higher photosynthesis, and lower leaf temperature. Furthermore, they showed higher levels of anthocyanin accumulation and a lower level of quercetin. Finally, the interaction of the beneficial results of Zeowine (soil and grapevines) was evidenced by the embellishment of the nutritional and water efficiency, the minimizing of the need for fertilizers, the closure of the production cycle of waste material from the supply chain, and the improvement of the quality of the wines.

The COVID-19 pandemic changed the management of emergency medicine and those complications that needed interventional procedures, such as endoscopy or other radiological procedures. At the beginning of the outbreak, there were no exploitable recommendations regarding the proper policy to apply for limiting the virus spread during endoscopy. Between the first and the second wave, the approach regarding interventional procedures changed, due to higher awareness and newly defined protocols, even if different among the health centers. Patients with severe COVID-19 may develop major gastrointestinal complications or require nutritional support, so interventional procedures are required at bedside, even if patients are in isolated rooms. Our tertiary center admitted 95 patients with severe COVID-19 at our ICU-dedicated department until May 2021, and 56% of them died. Among them, 61 endoscopic procedures were performed, mainly gastroscopies (81.96%) followed by colonoscopies (11.47%) and other more advanced procedures (6.55%). Our approach aimed to adapt and create COVID-related protocols, dedicated itineraries, and rooms in a separate department with the prospect to easily organize complete and safe endoscopic theaters at the COVID-ICU department. [ABSTRACT FROM AUTHOR]

Toward improving reforestation of Brazilian pine (Araucaria angustifolia), two contrasting sapling sizes in either full sun or in the shade of a mixed plantation and the effect of opening the canopy were evaluated for survival, growth, gas exchange, photosynthetic pigments, and leaf anatomy 18 months after being planted. At 23 months after planting, a partial opening was made in the canopy in the mixed plantation, then the saplings were evaluated again after 2 months for the same morphophysiological traits. After 18 months, saplings planted in the full sun had higher survival, growth, pigments, and photosynthesis compared to the shaded saplings. Large saplings had higher survival and growth compared to the small ones. Shaded leaves were thinner and little differentiation of palisade parenchyma and hypodermis. After opening of the canopy, photosynthetically active radiation was 10 times higher, and the saplings quickly grew in height due to increased photosynthesis. Thus, although the species can tolerate shade, growth in the shade is limited. We recommend that for reforestation purposes of Brazilian pine, large saplings should be selected and planted in the open for better development. [ABSTRACT FROM AUTHOR]

Irrigation water salinity is a major limiting factor in arid and semi-arid environments. The use of rootstock is one of the appropriate agronomic techniques that attempt to support and limit the negative effect of salinity. The objective of this study was to evaluate the behavior of eight one-year-old rootstocks grown in pots under salt stress conditions (30 and 60 mM NaCl). Some genotypes, i.e. C35 citrange, Bitters, Carpenter and Furr citrandarins were recently released or spread and poor information on their behavior in saline conditions is available, while Carrizo citrange, Swingle Citrumelo, Citrus volkameriana and Citrus macrophylla are spread since long ago in the Mediterranean basin. The results clearly demonstrated that the most salt sensitive genotypes were Carrizo and C35 citrange, that reduced morphological and gas exchanges performances. Furr, Bitters and Carpenter citrandarins revealed good physiological and hormonal behavior. An intense antioxidant enzymatic activity was noted in C35 and Carrizo citranges, while Furr showed a decrease in malondialdehyde and antioxidant enzymatic activities at 60 mM NaCl. Its tolerance to saline water was also confirmed by transcriptomic analyses. • Citrus rootstocks limit the negative effect of salinity water irrigation. • Citranges confirmed to be salt-sensitive in multi-omics analyses. • Novel Bitters, Carpenter and Furr could be considered salt-tolerant rootstocks. • Furr showed positive antioxidant enzymatic activity and hormonal responses. • Transcriptomic analyses confirmed the tolerant behavior of Furr. [ABSTRACT FROM AUTHOR]

Abstract Background Ultraviolet-B (UV-B) radiation can affect several aspects ranging from plant growth to metabolic regulation. Maca is a Brassicaceae crop native to the Andes growing in above 3500 m of altitude. Although maca has been the focus mainly due to its nutraceutical properties, it remains unknown how maca plants tolerate to harsh environments, such as strong UV-B. Here, we present the first study that reports the physiological responses of maca plants to counteract and recover to repeated acute UV-B irradiation. Results In detail, plants were daily exposed to acute UV-B irradiation followed by a recovery period under controlled conditions. The results showed that repeated acute UV-B exposures reduced biomass and photosynthetic parameters, with gradual senescence induction in exposed leaves, reduction of young leaves expansion and root growth inhibition. Negative correlation between increased UV-B and recovery was observed, with marked production of new biomass in plants treated one week or more. Conclusions A differential UV-B response was observed: stress response was mainly controlled by a coordinated source-sink carbon allocation, while acclimation process may require UV-B-specific systemic defense response reflected on the phenotypic plasticity of maca plants. Moreover, these differential UV-B responses were also suggested by multifactorial analysis based on biometric and physiological data.

Mango cultivation in a protected environment is becoming widespread in the Mediterranean basin where the species has to face unfavorable weather conditions which do not occur in its native cultivation areas. Besides open-air cultivation, greenhouses—and other protection systems such as shading nets and partial covering of plastic films—have been tested recently. In this study, we focused on assessing the effect of a shading net, and a partially covering plastic film, on the development of “Kensington Pride” mango fruit skin-color, its final quality, and the plants’ photosynthetic activity. A new method of measuring mango skin-color on different sides of the fruit is proposed. No difference was observed with regard to the observed parameters between the plants cultivated under the two different protection systems and those growing in the open air. It can, therefore, be stated that such cultivation techniques do not alter the development of the mango fruit and its appearance, nor the plant’s photosynthetic activity.

Inundation, excessive precipitation, or inadequate field drainage can cause waterlogging of cultivated land. It is anticipated that climate change will increase the frequency, intensity, and unpredictability of flooding events. This stress affects 10–15 million hectares of wheat every year, resulting in 20–50% yield losses. Since this crop greatly sustains a population’s food demands, providing ca. 20% of the world’s energy and protein diets requirements, it is crucial to understand changes in soil and plant physiology under excess water conditions. Variations in redox potential, pH, nutrient availability, and electrical conductivity of waterlogged soil will be addressed, as well as their impacts in major plant responses, such as root system and plant development. Waterlogging effects at the leaf level will also be addressed, with a particular focus on gas exchanges, photosynthetic pigments, soluble sugars, membrane integrity, lipids, and oxidative stress.

Physiological information about native species, make it possible to know their potential for use in programs to recovery degraded areas. Nowadays climate changes are severe and factors as water and light are involved with plant development and growth. We hypothesized that shading may contribute to adjusting the characteristics of photosynthetic metabolism of Campomanesia xanthocarpa seedlings under flooding. Thus, this work aimed to evaluate the flooding times and shading levels for gas exchanges and the maximal photochemical efficiency of PSII (Fv/Fm) in C. xanthocarpa seedlings. Seedlings were grown under two water regimes (control and flooding), three levels of shading (0, 30, and 70%) and 4 evaluation periods (0, 15, 30, and 45 days). We verified damages to the photosynthetic apparatus and reductions in the efficiency of the photochemical process under flooding and at a high level of shading (70%) in a short period (15 days). However, seedlings showed favourable responses to the adjustment over the 45 days of exposure to those conditions. According to the multivariate analysis, it was possible to identify the relation between photosynthetic rate and stomatal conductance as the main factor of metabolic adjustments in the tolerance of C. xanthocarpa to flooding and high shading intensity. C. xanthocarpa was more sensitive to short periods of flooding conditions and full sun and high level of shading (70%), however, it presented better adjustment responses to flooding periods when associated with 30% shade.stas de ajuste aos períodos de alagamento quando associado ao 30% de sombra.

The contamination of environments by heavy metals has become an urgent issue causing undesirable accumulations and severe damages to agricultural crops, especially cadmium and lead which are among the most widespread and dangerous metal pollutants worldwide. The selection of proper species is a crucial step in many plant-based restoration approaches; therefore, the aim of the present work was to check for early morphophysiological responsive traits in three cultivars of Cynara cardunculus (Sardo, Siciliano, and Spagnolo), helping to select the best performing cultivar for phytoremediation. For all three tested cultivars, our results indicate that cardoon displays some morphophysiological traits to face Cd and Pb pollution, particularly at the root morphology level, element uptake ability, and photosynthetic pigment content. Other traits show instead a cultivar-specific behavior; in fact, stomata plasticity, photosynthetic pattern, and antioxidant power provide different responses, but only Spagnolo cv. achieves a successful strategy attaining a real resilience to metal stress. The capacity of Spagnolo plants to modify leaf structural and physiological traits under heavy metal contamination to maintain high photosynthetic efficiency should be considered an elective trait for its use in contaminated environments. [ABSTRACT FROM AUTHOR]

Climate change has an important impact on the phenological phases of the grapevine. The consequences are directly reflected in quantitative and qualitative characteristics of the grapes. In fact, there is a decrease in the skin-to-pulp ratio (therefore a decrease in production with an excess of alcohol) and a consequent reduction in the aromatic potential of white grapes (lowering of the quality of musts). Volatile tioles are important aromatic compounds found in various foods and drinks; in particular they contribute to forming the aroma of some types of white wines as they are characterized by extremely low perception thresholds. This work aimed to evaluate the effects of water stress on ecophysiology, technological maturity and on the thiol precursors of Vitis vinifera L. cv. Sauvignon Blanc vineyards in the Tuscan region (Italy) during two seasons. To this end, three treatments were established: WW (well watered), MW (medium watered), and WS (water stress with no irrigation). During the seasons, measurements were made of single-leaf gas exchange, pre-dawn and leaf midday water potential, leaf temperature, chlorophyll fluorescence, as well chlorophyll content. In addition, the parameters of plant yield, technological maturity (° Brix, acidity, pH and berries weight) and the precursors of 3-Mercaptohexanol (3MH) were analyzed: 3-S-cysteinylhexan-1-ol (Cys-3MH) and 3-S-glutathionylhexan-1-ol (GSH-3MH). Well watered treatments (WW) showed less negative water potential, a higher rate of photosynthesis, of stomatal conductance, a lower leaf temperature (°C). Furthermore, WW showed higher levels of precursors accumulation (Cys-3MH and GSH-3MH) than the other treatments during two seasons. Technological analyses (° Brix and acidity) showed significant differences between WW and WS treatments. The lower berry weight was found in the WS treatment. Finally as a result of climate change, precision irrigation has proved to be a good technique to rebalance the gap between technological and aromatic maturity in Sauvignon Blanc grapes. • The role of water potential as a stress assessment tool. • Precision irrigation reduces water stress due to climate change. • Precision irrigation increase ecophysiological performance of vines. • Irrigation plays a key role in re-establishing optimal levels of tiol precursors. [ABSTRACT FROM AUTHOR]