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The use of thermal-based crop water stress index (CWSI) has been studied in many crops in semi-arid regions and found as an effective method in detecting real-time crop water status of commercial fields remotely and non-destructively. However, to our knowledge, no previous studies have validated the usefulness of CWSI in a temperate crop like wild blueberries. Additionally, the temporal changes of the water status estimation model has not been well-studied. In this multi-year study, Unoccupied Aerial Vehicle (UAV)-borne thermal imageries were collected in 2019, 2020, and 2021 to test the temporal effects and the impact of different approach-based reference temperatures (Twet, wet reference temperature; Tdry, dry reference temperature) on leaf water potential (LWP) estimation models using CWSI in two large adjacent wild blueberry fields in Maine, United States. We found that different sampling dates have a significant impact on LWP estimation models using CWSISE (statistical Twet and empirical Tdry reference) and CWSISS (statistical Twet and statistical Tdry reference). Further, CWSIBB calculated with bio-indicator-based Twet and Tdry reference was found more effective (r² = 0.79) in estimating LWP in 2021, compared to the CWSISE and CWSISS approaches in 2019 (r² = 0.34 & r² = 0.36), 2020 (r² = 0.38 & r² = 0.44) and 2021 (r² = 0.43 & r² = 0.46). CWSIBB -LWP model-based crop water status maps show high variation in the crop water status of wild blueberries, even in an evenly irrigated field, suggesting the potential of UAV-borne thermal cameras to detect real-time crop water status within the field, with the CWSIBB calculated from bio-indicator-based references being more reliable. Our results could be used for precision irrigation to increase the overall water use efficiency and profitability of wild blueberry production. [ABSTRACT FROM AUTHOR]

Background: The analysis of changes in subcellular water distribution during mushroom fruiting is essential for elucidating the movement of water molecules within subcellular compartments. However, prior research on mushrooms has predominantly concentrated on alterations in water status during drying and postharvest processes in the food processing sector. Knowledge regarding subcellular water compartments throughout mushroom growth and fruiting remains limited. In the present study, the dynamics of subcellular water status across various growth stages of Agaricus bisporus were investigated using LF-NMR relaxometry. Results: Three components were resolved from transverse relaxation curves, assigned to cell wall, cytoplasmic and vacuolar water, in both whole mushroom and mushroom tissues (stalk and Pileus). As fruiting body developed, the proton degree of freedom of three water fractions determined by T2 measurement all increased. The T2 values of three water fractions in stalk were higher than those in pileus during the first three stages, whereas they became lower compared to those in pileus from somewhere between the two stages of 2–3 and 3–4. Apparently different patterns of change in three water contents were observed, indicating the variations in water distribution at subcellular level. Furthermore, relative humidities caused obvious changes in water status. In addition, highly significant correlations were observed between T2 and textural parameters, indicating that the dynamics of water status exert a substantial influence on the formation of mushroom quality. Conclusions: A consistent increase in the transverse proton degree of freedom of three distinct water fractions, accompanied by markedly divergent patterns in the variations of the three water contents, was observed across different growth stages of fruiting bodies. Subsequently, highly significant correlations between T2 and textural parameters were established. This study would contribute to reveal macroscopic water transport within mushroom tissues and provide theoretical insights for optimizing high-quality mushroom cultivation. [ABSTRACT FROM AUTHOR]

Introduction: Plant physiology response and adaptation to drought stress has become a hotspot in plant ecology and evolution. Cotoneaster multiflorus possesses high ecological, ornamental and economic benefits. It has large root system and tolerance to cold, drought and poor soil. Therefore, C. multiflorus is considered as one of the most important tree species for ecological restoration in arid and semi-arid areas. However, little is known about the physiological mechanisms, molecular mechanisms and drought strategies of how C. multiflorus responds to drought stress. Therefore, exploring the physiological response mechanisms, molecular mechanisms and adaptive strategies of C. multiflorus in response to drought is important for its growth in arid and semi-arid regions. Methods: We investigated the response and coupling mechanisms of water status, photosynthetic properties and chloroplast fluorescence parameters in C. multiflorus in response to drought and rehydrated after drought, especially the importance of nocturnal sap flow and nocturnal water refilling to maintain its own water balance in response to drought stress. In addition, we studied the stress response of C. multiflorus transcriptome factors, and we also discussed drought adaptation strategies of C. multiflorus. Results: C. multiflorus adapted to drought stress by a series of structural and physiological mechanisms, such as promoting closing stomata, increasing nocturnal sap flow. When rehydrated after undergoing severe drought stress, its physiological activities such as photosynthesis, water status, chlorophyll fluorescence parameters and other physiological activities have rapidly resumed. This showed C. multiflorus had strong tolerance to drought. In addition, water status, photosynthetic characteristics, and chloroplast fluorescence parameters of C. multiflorus were highly coupled. Nocturnal sap flow and nocturnal water refilling were very important for C. multiflorus to maintain its own water balance in response to drought stress. Finally, C. multiflorus will strengthen the drought defense mechanism by gene regulation of various metabolisms, such as promoting stomatal closure, reducing transpiration water loss, and vigorously regulating water balance. C. multiflorus responded to drought stress by avoiding or reducing water deficit in plant organs and tissues. Therefore, the shrub C. multiflorus is a drought-tolerant plant. Discussion: We explored the response mechanisms of water status, photosynthetic characteristics, and chloroplast fluorescence parameters of C. multiflorus in drought and rehydrated after drought stress, especially the response mechanisms of nocturnal sap flow and nocturnal water refilling in response to drought stress, and identified the physiological coupling mechanisms, molecular mechanisms and drought types of C. multiflorus in response to drought. [ABSTRACT FROM AUTHOR]

Salinity stress represents a significant challenge to agricultural productivity, adversely affecting plant photosynthesis, water and nutrient uptake, and cellular integrity. This study explores the efficacy of Arbuscular Mycorrhizal Fungi (AMF) in enhancing the salinity tolerance of pistachio plants, specifically focusing on the photosynthetic efficiency of Photosystem II. Our greenhouse experiment revealed that AMF symbiosis significantly bolstered plant growth and optimized ionic ratios, notably enhancing K, Ca, Mg, P, K/Na, and Ca/Na, while concurrently diminishing Na and Cl concentrations under saline conditions. AMF inoculation also reduced electrolyte leakage, malondialdehyde, and hydrogen peroxide levels, and elevated relative water content, water use efficiency, glycine betaine, soluble sugars, alpha-tocopherol, and carotenoid contents. Crucially, AMF treatment mitigated the decline in chlorophyll content and key photosynthetic efficiency metrics (Fv/Fm, Fv'/Fm', qP), and regulated non-photochemical quenching (NPQ) and the chlorophyll a/b ratio. Additionally, it improved net photosynthesis rate, stomatal conductance, and transpiration rate, while reducing intercellular CO2 concentration. Hierarchical clustering and heatmap analyses substantiated that AMF inoculation preserves physiological homeostasis akin to control conditions and modulates the stress response under NaCl stress, enhancing osmotic balance and reducing oxidative damage. Moreover, AMF inoculation favorably impacted nutrient assimilation and photosynthetic efficiency under saline stress, optimizing K/Na ratios and photochemical quenching parameters. Collectively, these findings demonstrate that AMF inoculation significantly enhances the photosynthetic capacity, water relations, and ion homeostasis of pistachio plants, thereby conferring improved salinity tolerance and plant vigor. [ABSTRACT FROM AUTHOR]

Sweet cherry is a high-value crop, and strategies to enhance production and sustainability are at the forefront of research linked to this crop. The improvement of plant status is key to achieving optimum yield. Biostimulants, such as glycine betaine (GB) or seaweed-based biostimulants [e.g., Ecklonia maxima (EM)], can represent a sustainable approach to improving plant conditions, even under adverse environmental circumstances. Despite their potential, few studies have focused on the effects of GB or EM exogenous application on sweet cherry tree physiology. To address this lack of research, a study was conducted in a Portuguese sweet cherry commercial orchard, using Lapins and Early Bigi cultivars. Trees were treated with products based on GB and EM at two different concentrations [GB 0.25% (v/v) and GB 0.40% (v/v); EM 0.30% (v/v) and EM 0.15% (v/v)], a combination of the lowest concentrations of both biostimulants (Mix —GB 0.25% and EM 0.15%), and a control group (C) treated with water. Applications were performed over three consecutive years (2019, 2020, and 2021) at three different phenological stages, according to the BBCH scale: 77, 81, and 86 BBCH. Results showed, in general, that the application of biostimulants led to improvements in water status as well as significantly lower values of electrolyte leakage and thiobarbituric acid reactive substances compared to C samples. Additionally, biostimulants reduced pigment loss in the leaves and enhanced their biosynthesis. The Chlorophylla/Chlorophyllb ratio, ranging from 2 to 4, indicated a greater capacity for light absorption and lower stress levels in treated leaves. Soluble sugar and starch content decreased during fruit development in both cultivars and years; however, biostimulants increased these contents, with increments of approximately 15% to 30% in leaves treated with EM. Soluble protein content also showed the same pattern for treated leaves. Biostimulants, especially EM, demonstrated a significant positive effect (p ≤ 0.001) on total phenolic content, with increases of approximately 25% to 50% in treated leaves. In conclusion, the application of biostimulants, especially algae-based, significantly improved tree performance by enhancing physiological parameters and stress resilience and could represent a novel approach in fruit production systems. [ABSTRACT FROM AUTHOR]

Introduction: Accurate diagnosis of the water status of fruit trees is a prerequisite for precise irrigation. Measurement of leaf turgor pressure provides a means to explore the water utilization mechanisms of fruit trees and their responses to water stress. However, there are few studies on the use of daily minimum leaf turgor pressure (Ppmax) to indicate water information in apple tree. Methods: We monitored Ppmax, stem flow rate (Vstem), leaf water potential, soil water, and the main meteorological factors under two drip irrigation levels (fully irrigated and under-irrigated) to elucidate the temporal dynamics of the daily leaf turgor minimum of apple trees and diagnose the water status of fruit trees. Results: The results showed that soil water deficiency could reduce leaf turgor pressure and increase Ppmax. In both years, the signal intensity and sensitivity of Ppmax were better than those of Vstem, and the sensitivity was 3.31 and 2.94 times of Vstem, respectively. Compared to Ppmax, Vstem had a higher correlation with meteorological factors and was more affected by meteorological conditions, independent of irrigation treatment. Ppmax was significantly negatively correlated with soil and leaf water potential, and its correlation coefficient was 2.58–4.89 times higher than that between Vstem and both. Discussion: These results not only enhance our understanding of the water regulation strategies employed by apple trees under drought conditions but also provide a theoretical foundation for developing efficient water-saving practices and precision irrigation strategies for fruit trees. [ABSTRACT FROM AUTHOR]

Background Results Conclusion Given the composition of rice and its lack of gluten proteins, rice flour fails to form a cohesive and elastic dough when mixed directly with water. Consequently, many rice products rely on rice sheets (RS) made by rolling cooked rice dough. Limited research exists on how the rolling process impacts the properties and structure of cooked indica rice dough.This study investigated the effect of the number of rolling passes on the eating quality, starch structure, and water distribution of cooked fermented indica RS formed by dough. When the number of rolling passes reached six, the RS (RP‐6) that was obtained exhibited the lowest cooking loss, the highest hardness, adhesiveness, and chewiness, and optimal stretchability. It also demonstrated the lowest water loss after freezing. Dense microstructures were observed on both the surface and cross‐section of RP‐6. More ordered starch crystal structures and double helix structures were formed. The relative peak area of tightly bound water significantly increased in RP‐6, indicating a stronger bonding status between the starch and water molecules. However, excessive rolling passes (more than six) led to a partial disruption of the internal RS structure, resulting in a decline in eating quality.The study demonstrated the importance of the rolling process in improving the performance of RS. It was found that a moderate number of rolling passes was conducive to producing excellent RS, providing a theoretical basis for the production of high‐quality rice‐based products such as rice noodles, dumplings, and cakes. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background: Salt stress (SS) has seriously threatened the productivity of pulses including black gram in modern input-intensive farming systems which necessitates finding biologically viable, pro-farmer and environmentally friendly SS ameliorating strategies. Methods: An experiment was conducted to assess three levels of both SS (0, 50 and 100 mM NaCl) and citric acid (CA, 0, 50 and 100 µM) applied as a foliar spray to ameliorate the deleterious effects of SS on black gram (cv. BARI Mash-3). The response variables included plant growth traits like plant height (PH), leaf number (BLPP) and root dry weight (RDW) along with chlorophyll contents (chl a, chl b and tchl), plant water status (relative water content RWC and water retention capacity WRC), grain yield (GY), stover yield (SY), biological yield (BY)) and harvest index (HI) along with nitrogen (N) and protein (P) content of black gram. Result: The results revealed that CA (100 µM) remained unmatched by increasing PH (76.25%), NLPP (37.52%), RDW (83.67%), Chl a (17.80%), Chl b (11.59%), tChl (15.51%), RWC (9.81%) and WRC (26.64%) under highest level of induced SS. The same treatment also surpassed the rest of the doses in terms of grains number per pod (23.89%), 100 grains weight (59.74%), GY (82.86%), SY (59.66%), BY (64.94%) and HI. Moreover, CA accumulated N and P content (29.9%) in the grain under SS conditions. These results indicated that application CA alleviated the adverse effects of SS by triggering the growth, yield and nutritional quality which might be developed as a potent strategy to cope with the declining productivity of black gram in saline environment. [ABSTRACT FROM AUTHOR]

The effects of ultrasound (US) pretreatment, heat pump drying temperature and drying time on the water status and viscoelastic properties as well as the correlation between them of scallop adductors were investigated. As drying progressed, the transverse relaxation time (T2) of tightly and loosely bound water maintained a relatively stable state, while the T2 of free and immobilized water shifted leftwards with US pretreatment and increasing drying temperature. The creep compliance was increased, but the relaxation modulus decreased with US pretreatment and an increase in drying temperature. However, the creep compliance exhibited a decreasing trend, but the relaxation modulus showed an increase tendency as drying proceeded, viz., decreasing moisture content. Burger's model and the three-element generalized Maxwell model achieved the best fit to describe the creep behavior and stress relaxation, respectively. The storage modulus (G′) and loss modulus (G″) were decreased with US pretreatment, increasing the drying temperature and moisture content. The T2 of all water components and peak area fraction of immobilized water were positively correlated with the creep compliance but significantly negatively correlated with the stress relaxation modulus, G′ and G″. Low-field nuclear magnetic resonance provided reliable viscoelastic properties of scallop adductors by monitoring the water status during the drying process, which can be used to accurately control the final product quality. [ABSTRACT FROM AUTHOR]

Sweet cherry (Prunus avium L.) is a highly valued fruit, and optimal nutrient management is crucial for enhancing yield and fruit quality. However, the over-application of chemical fertilizers in cherry cultivation leads to environmental issues such as soil degradation and nutrient runoff. To address this, foliar application, a more targeted and eco-friendly fertilization method, presents a promising alternative. This study evaluates the effects of pre-harvest foliar application of calcium (Ca) (150 and 300 g hL−1) and seaweed extracts (75 and 150 mL hL−1), both individually and in combination, on the physiological and biochemical responses of 'Burlat' sweet cherry trees. Key physiological parameters, including plant water status, photosynthetic performance, and leaf metabolites, were analyzed. Results show that trees treated with seaweed extracts or with combined Ca and seaweed application had improved water status, higher sugar, starch, and protein content, as well as enhanced antioxidant activity and phenolic content compared to those treated solely with calcium. However, the combined treatment did not significantly enhance overall tree performance compared to individual applications. This study highlights the potential of seaweed-based biostimulants in sustainable cherry production. [ABSTRACT FROM AUTHOR]

Chilli (Capsicum annuum) is an important spice crop in Bangladesh. This crop is very sensitive to waterlogging. Floating agriculture is an innovative system led by the local people of the southern region of Bangladesh, in which seedlings of vegetables are produced in low-lying areas using different aquatic macrophytes. An experiment was carried out to evaluate the viability of chilli cultivation in waterlogged areas, based on physiological and biochemical responses using floating agriculture. Eight different chilli varieties were subjected to floating agriculture in two different agronomic seasons. A soil-based chilli cultivation system was also trialled, to compare the utility of this method. To evaluate the performance of chilli in floating beds, plant water status, photosynthetic parameters, and leaf tissue concentrations of Na+, K+, NO3− and PO43−, chlorophyll, ascorbic acid and proline were assessed. This study shows that macrophytes utilised in floating beds provide favourable conditions for chilli cultivation under waterlogged conditions. Among the different varieties, Sakata 653 in summer and Jhilik in winter responded better than others. As the performance of chilli in the floating agriculture system was satisfactory in comparison with soil-based cultivation, floating agriculture can be an alternative agronomic method for chilli cultivation in waterlogged areas of Bangladesh. Floating agriculture is a promising way of crop cultivation under submergence. Production of chilli (Capsicum annuum), an important spice crop, is greatly affected by waterlogging. In submerged conditions, floating agriculture serves an alternative agronomic means of chilli cultivation. [ABSTRACT FROM AUTHOR]

BACKGROUND: The steam processing characteristics of chicken are a key factor in the simplicity and versatility of steamed chicken dishes. The aim of this study was to investigate in depth the changes in tenderness and water retention of marinated chicken at different slow steaming endpoint temperatures, and to further explore the effect of the evolution of protein conformations on the water status. RESULTS: The results showed that chicken samples' shear force peaked at 80 °C and decreased rapidly at 90 °C. As the steaming endpoint temperature increased between 50 and 90 °C, T21, T22, moisture content and centrifugal loss decreased, but P21, P22 and myofibril water‐holding capacity showed regular changes. The electrophoretic bands and protein conformation changes showed that protein in marinated chicken underwent different degrees of denaturation, degradation and aggregation. And at 70 °C, with an increase of hydrophobic groups and crosslinking of disulfide bonds as well as an increase in the number of denatured sarcoplasmic proteins, the intermolecular network was enhanced, thus affecting the water retention. CONCLUSION: Water status of chicken meat heated at different steaming temperatures is closely related to the evolution of protein conformations. The present study serves as a robust theoretical foundation for enhancing the quality of steamed chicken products at an industrial scale. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

IntroductionPlant physiology response and adaptation to drought stress has become a hotspot in plant ecology and evolution. Cotoneaster multiflorus possesses high ecological, ornamental and economic benefits. It has large root system and tolerance to cold, drought and poor soil. Therefore, C. multiflorus is considered as one of the most important tree species for ecological restoration in arid and semi-arid areas. However, little is known about the physiological mechanisms, molecular mechanisms and drought strategies of how C. multiflorus responds to drought stress. Therefore, exploring the physiological response mechanisms, molecular mechanisms and adaptive strategies of C. multiflorus in response to drought is important for its growth in arid and semi-arid regions.MethodsWe investigated the response and coupling mechanisms of water status, photosynthetic properties and chloroplast fluorescence parameters in C. multiflorus in response to drought and rehydrated after drought, especially the importance of nocturnal sap flow and nocturnal water refilling to maintain its own water balance in response to drought stress. In addition, we studied the stress response of C. multiflorus transcriptome factors, and we also discussed drought adaptation strategies of C. multiflorus.ResultsC. multiflorus adapted to drought stress by a series of structural and physiological mechanisms, such as promoting closing stomata, increasing nocturnal sap flow. When rehydrated after undergoing severe drought stress, its physiological activities such as photosynthesis, water status, chlorophyll fluorescence parameters and other physiological activities have rapidly resumed. This showed C. multiflorus had strong tolerance to drought. In addition, water status, photosynthetic characteristics, and chloroplast fluorescence parameters of C. multiflorus were highly coupled. Nocturnal sap flow and nocturnal water refilling were very important for C. multiflorus to maintain its own water balance in response to drought stress. Finally, C. multiflorus will strengthen the drought defense mechanism by gene regulation of various metabolisms, such as promoting stomatal closure, reducing transpiration water loss, and vigorously regulating water balance. C. multiflorus responded to drought stress by avoiding or reducing water deficit in plant organs and tissues. Therefore, the shrub C. multiflorus is a drought-tolerant plant.DiscussionWe explored the response mechanisms of water status, photosynthetic characteristics, and chloroplast fluorescence parameters of C. multiflorus in drought and rehydrated after drought stress, especially the response mechanisms of nocturnal sap flow and nocturnal water refilling in response to drought stress, and identified the physiological coupling mechanisms, molecular mechanisms and drought types of C. multiflorus in response to drought.

In certain winegrowing regions, it is a common practice to wrap canes very tightly around the cordon wire during the establishment of permanent cordon arms. This method of training may result in a constriction of the vascular system, leading to numerous deleterious impacts on vine growth, production, and longevity. This article summarises some of the key findings of previously published research regarding the use of this training method in South Australian vineyards.

IntroductionAccurate diagnosis of the water status of fruit trees is a prerequisite for precise irrigation. Measurement of leaf turgor pressure provides a means to explore the water utilization mechanisms of fruit trees and their responses to water stress. However, there are few studies on the use of daily minimum leaf turgor pressure (Ppmax) to indicate water information in apple tree.MethodsWe monitored Ppmax, stem flow rate (Vstem), leaf water potential, soil water, and the main meteorological factors under two drip irrigation levels (fully irrigated and under-irrigated) to elucidate the temporal dynamics of the daily leaf turgor minimum of apple trees and diagnose the water status of fruit trees.ResultsThe results showed that soil water deficiency could reduce leaf turgor pressure and increase Ppmax. In both years, the signal intensity and sensitivity of Ppmax were better than those of Vstem, and the sensitivity was 3.31 and 2.94 times of Vstem, respectively. Compared to Ppmax, Vstem had a higher correlation with meteorological factors and was more affected by meteorological conditions, independent of irrigation treatment. Ppmax was significantly negatively correlated with soil and leaf water potential, and its correlation coefficient was 2.58–4.89 times higher than that between Vstem and both.DiscussionThese results not only enhance our understanding of the water regulation strategies employed by apple trees under drought conditions but also provide a theoretical foundation for developing efficient water-saving practices and precision irrigation strategies for fruit trees.

Salinity poses a perpetual threat to agricultural lands, presenting an ongoing challenge to global food security. The present study aimed to explore the potential benefits of gibberellic acid (GA3) in enhancing stevia’s tolerance to salt stress. The experimental treatments comprised a control group (C) with 0 mM NaCl, salt stress (S) with 80 mM NaCl, 50 ppm of GA3 (G1), 100 ppm of GA3 (G2), as well as combinations of GA3 with salt stress (G1+S and G2+S). Exposure to saline water (80 mM NaCl) significantly decreased plant growth, water status, and photosynthetic attributes. However, it also led to notable increases in proline, glycine betaine, malondialdehyde (MDA), and antioxidant enzyme activities compared to the control treatment. Application of 100 ppm of GA3 effectively alleviated salt stress by enhancing plant performance under saline conditions, as evidenced by increased aerial (54%) and root (31%) dry weights compared to the control. Additionally, GA3 treatment resulted in elevated activities of polyphenol oxidase (24%), peroxidase (12%), superoxide dismutase (31%), and catalase (11%) while reducing MDA content by 41%, electrolyte leakage by 37%, and hydrogen peroxide by 34%. The use of phytohormones such as GA3 emerges as a promising strategy for mitigating salt stress-induced damage. It not only enhances plant performance but also reduces oxidative stress, offering protection against the detrimental effects of soil salinization.

The continuous and reliable assessment of crop water status through water indicators enables the sustainable management of water resources, especially in arid or semi-arid climate scenarios exacerbated by climate change. Therefore, the main objective of this study is to determine and compare the sensitivity of indices derived from trunk diameter fluctuations for the accurate and automatic detection of changes in the water status of cherry trees. The water stress indicators examined are maximum daily trunk shrinkage (MDS), trunk growth rate (TGR), early daily trunk shrinkage (EDS), and late daily trunk shrinkage (LDS). During two growing seasons, 'Lapins' sweet cherry trees were subjected to different water stress levels: (i) a control treatment irrigated at 115% of crop evapotranspiration demand to ensure non-limiting water conditions, and (ii) a deficit irrigation treatment, with two irrigation withholding cycles. Vegetative growth was affected by water stress. Trunk daily growth rate and late daily trunk shrinkage exhibited a high variability and did not clearly show differences in plant water status. Both EDS and MDS showed a third-degree polynomial relationship with Ψstem. MDS had a lineal relationship with Ψstem of up to −1.4 MPa; however, further decreases in Ψstem did not necessarily lead to increased MDS. In contrast, EDS became non-linear at −1.8 MPa, making it a more useful plant water indicator than MDS for 'Lapins' sweet cherry trees when detecting severe water stress conditions. The frequencies of both MDS and EDS decreased from 85% to 35% when water stress increased. Therefore, the information provided by MDS and EDS frequencies, along with their daily values, could be useful as irrigation management tools for sweet cherry trees. [ABSTRACT FROM AUTHOR]

One strategy to improve olive (Olea europaea) tree drought tolerance is through the symbiosis of arbuscular mycorrhizal fungi (AMF), which helps alleviate water deficit through a combination of morphophysiological effects. Cuttings of olive varieties Arbequina (A) and Barnea (B) were grown with (+AMF) or without (−AMF) inoculum in the olive grove rhizosphere soil. One year after establishment, pots were exposed to four different water regimes: (1) control (100% of crop evapotranspiration); (2) short-period drought (20 days); (3) long-period drought (25 days); and (4) rewatering (R). To evaluate the influence of AMF on tolerance to water stress, stem water potential, stomatal conductance and the biomarkers for water deficit malondialdehyde, proline, soluble sugars, phenols, and flavonoids were evaluated at the end of the irrigation regimes. Stem water potential showed higher values in A(+) and B(+) in all water conditions, and the opposite was true for stomatal conductance. For proline and soluble sugars, the stem water potential trend is repeated with some exceptions. AMF inoculum spore communities from A(+ and −) and B(+ and −) were characterised at the morphospecies level in terms of richness and abundance. Certain morphospecies were identified as potential drought indicators. These results highlight that the benefits of symbiotic relationships between olive and native AMF can help to mitigate the effects of abiotic stress in soils affected by drought. We evaluated different water regimes on young cuttings of olive (Olea europaea) cvs Arbequina and Barnea inoculated with or without arbuscular mycorrhizal fungi (AMF) in a central-western olive grove in Argentina. We measured AMF morphospecies richness and abundance in the soil, plant vegetative growth, plant adaptation to drought stress, and crop water status. We found that certain morphological, physiological and biochemicalindicators may be useful to identify new strategies to mitigate water stress and improve water use efficiency during transplantation. [ABSTRACT FROM AUTHOR]

Salinity poses a perpetual threat to agricultural lands, presenting an ongoing challenge to global food security. The present study aimed to explore the potential benefits of gibberellic acid (GA3) in enhancing stevia's tolerance to salt stress. The experimental treatments comprised a control group (C) with 0 mM NaCl, salt stress (S) with 80 mM NaCl, 50 ppm of GA3 (G1), 100 ppm of GA3 (G2), as well as combinations of GA3 with salt stress (G1+S and G2+S). Exposure to saline water (80 mM NaCl) significantly decreased plant growth, water status, and photosynthetic attributes. However, it also led to notable increases in proline, glycine betaine, malondialdehyde (MDA), and antioxidant enzyme activities compared to the control treatment. Application of 100 ppm of GA3 effectively alleviated salt stress by enhancing plant performance under saline conditions, as evidenced by increased aerial (54%) and root (31%) dry weights compared to the control. Additionally, GA3 treatment resulted in elevated activities of polyphenol oxidase (24%), peroxidase (12%), superoxide dismutase (31%), and catalase (11%) while reducing MDA content by 41%, electrolyte leakage by 37%, and hydrogen peroxide by 34%. The use of phytohormones such as GA3 emerges as a promising strategy for mitigating salt stress-induced damage. It not only enhances plant performance but also reduces oxidative stress, offering protection against the detrimental effects of soil salinization. [ABSTRACT FROM AUTHOR]

This study investigates the impact of vine training systems on water deficits in the Cognac region (France), through the application of a vine water balance model, taking into account different soil water holding capacities (SWHC) and soil management strategies, including grass cover. Using climate data from the SAFRAN gridded database, over 2 million simulations were performed for the period 1962 to 2021 to quantify the response of grapevine water status under varying training systems and environmental conditions. Indices based on simulated relative stomatal conductance were developed to characterise the intensity of grapevine water deficit during the critical flowering-to-maturity period. Results show a significant trend of increasing water deficit between 1962 and 2021, particularly in the north-western part of the region, affecting 23 % of the Cognac production area. Sensitivity analysis of the water balance model indicates that SWHC is the predominant factor influencing grapevine water status, explaining nearly 80 % of the variance in water deficit days. The simulations further suggest that adjustments in canopy width and grass cover have a significant effect on the duration and severity of water deficit. The methodology developed in this research allows quantifying the relative importance of major drivers of vine water deficits: SWHC, training system parameters and vineyard floor management, under different climatic conditions. It can be used as a basis for providing easy-to-implement vineyard management strategies to mitigate the effects of climate change in viticulture. It was applied to the Cognac region, but the workflow developed is applicable to any grape-growing region in the world.

Abstract Understanding the physiological and biochemical responses of tree seedlings under extreme drought stress, along with recovery during rewatering, and potential intra-species differences, will allow us to more accurately predict forest responses under future climate change. Here, we selected seedlings from four provenances (AH (Anhui), JX (Jiangxi), HN (Hunan) and GX (Guangxi)) of Schima superba and carried out a simulated drought-rewatering experiment in a field-based rain-out shelter. Seedlings were progressively dried until they reached 50% and 88% loss of xylem hydraulic conductivity (PLC) (i.e. P 50 and P 88), respectively, before they were rehydrated and maintained at field capacity for 30 days. Leaf photosynthesis (A sat), water status, activity of superoxide dismutase (SOD), and proline (Pro) concentration were monitored and their associations were determined. Increasing drought significantly reduced A sat, relative water content (RWC) and SOD activity in all provenances, and Pro concentration was increased to improve water retention; all four provenances exhibited similar response patterns, associated with similar leaf ultrastructure at pre-drought. Upon rewatering, physiological and biochemical traits were restored to well-watered control values in P 50-stressed seedlings. In P 88-stressed seedlings, Pro was restored to control values, while SOD was not fully recovered. The recovery pattern differed partially among provenances. There was a progression of recovery following watering, with RWC firstly recovered, followed by SOD and Pro, and then A sat, but with significant associations among these traits. Collectively, the intra-specific differences of S. superba seedlings in recovery of physiology and biochemistry following rewatering highlight the need to consider variations within a given tree species coping with future more frequent drought stress.

The aim of this work was to study the ability of 28-homobrassinolide (HBL) and 28-homocastasterone (HCS) to increase the resistance of barley (Hordeum vulgare L.) plants to drought and to alter their endogenous brassinosteroid status. Germinated barley seeds were treated with 0.1 nM HBL or HCS solutions for two hours. A water deficit was created by stopping the watering of 7-day-old plants for the next two weeks. Plants responded to drought through growth inhibition, impaired water status, increased lipid peroxidation, differential effects on antioxidant enzymes, intense proline accumulation, altered expression of genes involved in metabolism, and decreased endogenous contents of hormones (28-homobrassinolide, B-ketones, and B-lactones). Pretreatment of plants with HBL reduced the inhibitory effect of drought on fresh and dry biomass accumulation and relative water content, whereas HCS partially reversed the negative effect of drought on fresh biomass accumulation, reduced the intensity of lipid peroxidation, and increased the osmotic potential. Compared with drought stress alone, pretreatment of plants with HCS or HBL followed by drought increased superoxide dismutase activity sevenfold or threefold and catalase activity (by 36%). The short-term action of HBL and HCS in subsequent drought conditions partially restored the endogenous B-ketone and B-lactone contents. Thus, the steroidal phytohormones HBL and HCS increased barley plant resistance to subsequent drought, showing some specificity of action. [ABSTRACT FROM AUTHOR]

Understanding the physiological and biochemical responses of tree seedlings under extreme drought stress, along with recovery during rewatering, and potential intra-species differences, will allow us to more accurately predict forest responses under future climate change. Here, we selected seedlings from four provenances (AH (Anhui), JX (Jiangxi), HN (Hunan) and GX (Guangxi)) of Schima superba and carried out a simulated drought-rewatering experiment in a field-based rain-out shelter. Seedlings were progressively dried until they reached 50% and 88% loss of xylem hydraulic conductivity (PLC) (i.e. P50 and P88), respectively, before they were rehydrated and maintained at field capacity for 30 days. Leaf photosynthesis (Asat), water status, activity of superoxide dismutase (SOD), and proline (Pro) concentration were monitored and their associations were determined. Increasing drought significantly reduced Asat, relative water content (RWC) and SOD activity in all provenances, and Pro concentration was increased to improve water retention; all four provenances exhibited similar response patterns, associated with similar leaf ultrastructure at pre-drought. Upon rewatering, physiological and biochemical traits were restored to well-watered control values in P50-stressed seedlings. In P88-stressed seedlings, Pro was restored to control values, while SOD was not fully recovered. The recovery pattern differed partially among provenances. There was a progression of recovery following watering, with RWC firstly recovered, followed by SOD and Pro, and then Asat, but with significant associations among these traits. Collectively, the intra-specific differences of S. superba seedlings in recovery of physiology and biochemistry following rewatering highlight the need to consider variations within a given tree species coping with future more frequent drought stress. [ABSTRACT FROM AUTHOR]

The effect of drought stress on leaf physiology was studied in 10-month-old plants of Sindora siamensis. Plants were either placed in an open greenhouse (unhardening; UH) or in an open field (open field hardening; H) for 45 days. Both the UH and H plants stopped receiving water (D) until the initial drought injury and then rewatered (R) until complete recovery. Results showed necrosis in the leaves of UH + D, while H + D showed wilting at Day 7 after drought. A greater degree of necrosis was found in UH + D + R but made complete recovery in H + D + R at Day 4 after rewatering. Drought stress resulted in decreased leaf area in H, and reduced leaf and stem water status, PSII efficiency, net photosynthetic rate, stomatal conductance and transpiration rate in both UH and H. It also resulted in an increase in water use efficiency in both UH and H. Electrolyte leakage and malondialdehyde contents in UH were markedly increased due to drought stress. These results suggest that unhardened young plants of Sindora exposed to drought exhibited enhanced stomata behaviour by minimising open stomata and transpiration, resulting in high efficiency of water usage. However, there was still membrane damage from lipid peroxidation, which caused necrosis. Open field hardened plants exposed to drought demonstrated reduced open stomata and transpiration, thereby preserving leaf and soil water status and enhancing water use efficiency. This may be a reduction in lipid peroxidation though an oxidative scavenging mechanism that causes a slight alteration in membrane stability and a slight necrosis. [ABSTRACT FROM AUTHOR]

Extreme weather events, including drought, have occurred worldwide with increasing frequency and severity in recent years. Drought stress is the main limiting factor for agricultural development in many regions, including tobacco—an important economic crop and a model plant for scientific research. As it is adapted to the tropics, tobacco is highly susceptible to drought stress, with resultant decreases in yield and quality. Glycine betaine (GB) is an osmoregulatory substance that can enhance plant resistance to various abiotic stresses. Here, we investigate the protective mechanism of genetically engineered glycine betaine (GB) on tobacco photosynthesis under drought stress induced by 30% PEG-6000. This study used transgenic tobacco (T) accumulating GB and wild-type tobacco (WT) to investigate the protective effects conferred by the genetic engineering of GB synthesis on tobacco photosynthesis under drought stress (induced by 30% PEG-6000). The results showed that the net photosynthetic rate of the tobacco plants significantly decreased under drought stress, and the degree of decrease was significantly lower in the T line than in the WT line. GB accumulation improved the resistance of photosynthesis to drought stress. Furthermore, under drought stress, the photosynthesis improvement in the T line was related to the accumulation of GB, leading to maintenance of the water status, the promotion of osmotic regulation, and an enhancement in antioxidant enzyme activities, which reduced membrane peroxidation and thereby increased the thylakoid membrane's protein content and function, especially the photosystem II (PSII) function. The results provide a theoretical basis for further research on genetic engineering related to GB synthesis and the field application of exogenous GB. [ABSTRACT FROM AUTHOR]

In the context of climate change and the reduction of mineral nitrogen (N) inputs applied to the field, winter oilseed rape (WOSR) will have to cope with low-N conditions combined with water limitation periods. Since these stresses can significantly reduce seed yield and seed quality, maintaining WOSR productivity under a wide range of growth conditions represents a major goal for crop improvement. N metabolism plays a pivotal role during the metabolic acclimation to drought in Brassica species by supporting the accumulation of osmoprotective compounds and the source-to-sink remobilization of nutrients. Thus, N deficiency could have detrimental effects on the acclimation of WOSR to drought. Here, we took advantage of a previously established experiment to evaluate the metabolic acclimation of WOSR during 14 days of drought, followed by 8 days of rehydration under high- or low-N fertilization regimes. For this purpose, we selected three leaf ranks exhibiting contrasted sink/source status to perform absolute quantification of plant central metabolites. Besides the well-described accumulation of proline, we observed contrasted accumulations of some "respiratory" amino acids (branched-chain amino acids, lysineand tyrosine) in response to drought under high- and low-N conditions. Drought also induced an increase in sucrose content in sink leaves combined with a decrease in source leaves. N deficiency strongly decreased the levels of major amino acids and subsequently the metabolic response to drought. The drought-rehydration sequence identified proline, phenylalanine, and tryptophan as valuable metabolic indicators of WOSR water status for sink leaves. The results were discussed with respect to the metabolic origin of sucrose and some amino acids in sink leaves and the impact of drought on source-to-sink remobilization processes depending on N nutrition status. Overall, this study identified major metabolic signatures reflecting a similar response of oilseed rape to drought under low- and high-N conditions. [ABSTRACT FROM AUTHOR]

Key message: Hydraulic architecture and conductivity of current-year shoots of Japanese beech trees are closely related to the leaf area soon after full leaf expansion. To assess the impact of artificially reducing leaf area at two time points after full leaf expansion on the stem xylem hydraulic architecture and conductivity of current-year shoots in Fagus crenata, we manipulated leaf area by partially cutting the leaves in various proportions of potted beech trees at different times. The reduction in leaf area soon after full leaf expansion resulted in a decrease in the mean vessel diameter, number of vessels, and sapwood area of current-year shoots. Simultaneously, it increased vessel density, leading to a proportional decrease in hydraulic conductivity (Kh) and xylem-specific hydraulic conductivity (KS). However, the leaf-specific hydraulic conductivity (KL) of current-year shoots remained unchanged, irrespective of the reduction in leaf area. In contrast, the artificial reduction of leaf area one month after full leaf expansion increased KL but did not significantly affect the mean vessel diameter, number of vessels, vessel density, sapwood area, Kh, and KS. These results suggest that the stem xylem hydraulic architecture and conductivity of current-year shoots in Japanese beech are closely related to leaf area soon after full leaf expansion. [ABSTRACT FROM AUTHOR]

Key message: Repeated defoliation soon after full leaf expansion reduces xylem hydraulic transport safety in beech trees. Japanese beech trees undergo branch dieback and eventual mortality following years of repeated leaf loss due to leaf-feeding insects attacking immediately after full leaf expansion. To study the impact of recurrent defoliation on beech debilitation and mortality, we investigated xylem hydraulic transport safety and observed the xylem vessel architecture in field-grown medium-sized Japanese beech trees that had been artificially defoliated repeatedly for 4 years immediately after full leaf expansion. Multiple years of defoliation immediately after full leaf expansion increased the susceptibility to xylem cavitation (P50 value; − 4.46 ± 0.38 MPa (mean ± SD) for non-defoliated control beeches, and − 2.32 ± 0.20 MPa for defoliated beeches), despite a decrease in their vessel diameter and an increase in their vessel density. In defoliated beech, many irregularly shaped, axially wrinkled and partially cracked vessels, mountain-folded intervessel pits, and fibers with thin and less-lignified cell walls were observed. The intervessel double-wall thickness of the defoliated beech was thinner than that of the control beech. Furthermore, the size and shape of intervessel pits did not change in defoliated beech, but the density of intervessel pits and the total number and total area of intervessel pits per 1 mm of vessel length increased. We conclude that the increased susceptibility to xylem cavitation caused by repeated defoliation immediately after full leaf expansion may be due to an increased total area of intervessel pits with thin pit membranes per unit vessel wall area, in addition to cell wall alteration and vessel deformation and damage. [ABSTRACT FROM AUTHOR]

Water is a limiting factor and to adopt the most appropriate agronomic strategy it is necessary to know the water status. The objective is (i) analysing of the influence of different agronomic treatments on canopy temperature in vineyards with a thermal camera on an unmanned aerial vehicle (UAV), (ii) analysing of the influence of different agronomic treatments on vineyard water potentials with a pressure chamber, (iii) advanced technical feasibility analysis of vineyard crop monitoring. The control treatment (T07) in cv. Grenache consisted of applying 30% of reference evapotranspiration (ETo) with irrigation frequency every seven days and seven different treatments were proposed with different irrigation frequencies, pre-bud irrigation, and vine shoot distribution (T03, T15, T7A, T7V, T7P, T00, and T0P). As a result and in conclusion, the use of thermal cameras in UAVs and mid-day stem water potential allows differentiation between irrigated and unirrigated treatments, but no clear differences were shown between irrigation frequencies, pre-irrigation treatment, or vine shoot distribution. Comparing the thermal camera information in UAV and the stem water potential, certain patterns are identified with significant correlation values, the use of thermal cameras for the evaluation of plant water status is recommended, especially to obtain information in large areas. [ABSTRACT FROM AUTHOR]

This article aimed to monitor vegetation using C-band radar data at a subdaily time step. To this end, radar measurements using tower-mounted antennas with a 15-min time step, along with physiology-related information (sapflow and micrometric dendrometry), were acquired quasi-continuously from March 2020 to December 2021 in an olive orchard located near Marrakech, Morocco. The article focused on temporal coherence, whose clear diurnal cycle (highest at night and lowest at the end of the afternoon) had been highlighted over tropical and boreal forests in previous studies. The results showed that coherence was highly sensitive to: wind-induced movement of scatterers, since coherence was lowest when wind speed was highest in late afternoon, and vegetation activity, especially its water dynamics, since the morning coherence drop coincided with the onset of sapflow and the daily evapotranspiration cycle, as well as the good agreement between the temporal drop rate of coherence and the daily residual variation in trunk circumference (i.e., deviation from long-term trend). Finally, coherence remained high for temporal baselines of several days, showing that sentinel-1 data (when both satellites are operational) may be well suited for such studies, especially with acquisitions made during morning passes, when wind speed is low. These results open perspectives for monitoring tree crop physiology using high-revisit-time radar observations.

Sweet cherry (Prunus avium L.) is a highly valued fruit, and optimal nutrient management is crucial for enhancing yield and fruit quality. However, the over-application of chemical fertilizers in cherry cultivation leads to environmental issues such as soil degradation and nutrient runoff. To address this, foliar application, a more targeted and eco-friendly fertilization method, presents a promising alternative. This study evaluates the effects of pre-harvest foliar application of calcium (Ca) (150 and 300 g hL−1) and seaweed extracts (75 and 150 mL hL−1), both individually and in combination, on the physiological and biochemical responses of ‘Burlat’ sweet cherry trees. Key physiological parameters, including plant water status, photosynthetic performance, and leaf metabolites, were analyzed. Results show that trees treated with seaweed extracts or with combined Ca and seaweed application had improved water status, higher sugar, starch, and protein content, as well as enhanced antioxidant activity and phenolic content compared to those treated solely with calcium. However, the combined treatment did not significantly enhance overall tree performance compared to individual applications. This study highlights the potential of seaweed-based biostimulants in sustainable cherry production.

Asparagus (Asparagus officinalis L.) has short shelf-life due to the high metabolic activity of the apical meristems. Storage at low temperature and high relative humidity is used commercially to keep fresh asparagus spears. Techniques denominated “Hurdley technologies” (UV-C or gamma irradiation) have been tested in fruits and vegetables to extend postharvest life. These technologies were used to extend postharvest shelf life of asparagus spears by inhibition of meristematic activity. Spears were irradiated with UV-C at dosages of 2.46, and 4.93 kJ m-2 and gamma irradiation at 1 and 1.5 kGy, before storage at 2°C and 90% relative humidity (RH) for 20 days. Metabolic heat (Rq) was measured in apical meristems, as well as whole spear respiration, sugars content, water potential components and color descriptors. Metabolic heat and whole spears respiration rate did not show differences due to effect of UV-C treatments, while spears treated with gamma radiation showed a metabolic activity inhibition of 10 and 15% for 1 and 1.5 kGy, respectively, while whole spear respiration rate was not affected. Changes in color variables showed a slight reduction in gloss. Sugars content in UV-C remained unchanged, while gamma radiation induced a reduction in glucose. An increase in fresh weight loss was noticeable on those treated with gamma irradiation. No changes in water potential components were observed. It was concluded the treatments used did not reported positive benefits in extending asparagus spears shelf life.

(1) Background: Table grapes are often subjected to thermal stress during the growing season, affecting their production. Shading nets utilization has been proposed as an alternative to face this problem, but there is little available information about their effectiveness in hyperarid conditions. INIA-G2 vines were covered with kristall-colored mesh of 8% shade, and their ecophysiological responses were compared to uncovered vines during the daily cycle of two days with contrasting thermic conditions. (2) Methods: Net assimilation rate (AN), stomatal conductance (gs), transpiration (E), instantaneous water use efficiency (WUE: AN E−1), stem water potential (Ψs), air temperature (Ta) and vapor-pressure deficit (DPV) were determined in daily cycles (from 06:00 to 20:00 hrs) on two thermally contrasting days (330 DOY at 29.4 °C and 345 DOY at 22.6 °C) on grapevines without water restriction. (3) Results: The Ψs was not affected by treatment and day of measurement; nevertheless, AN and gs were statistically lower during 330 than 345 DOY (31% and 44% decrease, respectively). The covered vines presented less restrictive climatic conditions in terms of DPV in both DOY, reaching higher WUE values at 10, 12 and 14 h, which was associated with a decrease in E. (4) Conclusions: These results suggest that the use of shading nets can be an interesting alternative to cope with high temperatures in viticulture, improving the water use efficiency of vines. These are the first published results about the viticultural performance of the INIA-G2 variety. [ABSTRACT FROM AUTHOR]

Arid and semi-arid regions are characterised by extreme conditions including drought stress and salinity. These factors profoundly affect the agricultural sector. The objective of this work is to study the effect of drought and re-watering on leaf gas exchange, chlorophyll fluorescence and mineral nutrition in Pistacia vera and Pistacia atlantica. Water stress was applied to individuals of P. vera and P. atlantica for 23 days, followed by rehydration for 7 days. The results showed a clear reduction in water relations, leaf gas exchange and chlorophyll content in P. vera. Compared to P. vera, P. atlantica maintained less affected water status, total chlorophyll content, leaf gas exchange and chlorophyll fluorescence, stable Zn and Fe proportion, and even elevated K and Cu. The changes in the chlorophyll fluorescence parameter were manifested particularly at the maximal fluorescence (Fm). In contrast, no change was recorded at the minimal fluorescence (F0). After re-hydration, although water status was fully recovered in both species, stomatal conductance (gs), net photosynthesis (A) and transpiration rate (E) remain with lower values than the wellwatered seedlings. P. atlantica was better adapted to drought stress than P. vera. [ABSTRACT FROM AUTHOR]

Different soybean cultivars (Williams 82, Union, Jindou 21, Long Huang 1, Long Huang 2) were exposed to drying soil, to investigate whether endogenous abscisic acid (ABA) concentrations and leaf water relations regulated stomatal behaviour. We measured ABA concentrations in xylem and tissue of the first and second trifoliate leaves respectively; stomatal conductance (gs) and leaf water potential (Ψleaf) in both leaves; and water content in soil. Cultivar variation in leaf area and gs caused different rates of soil drying, but gs and Ψleaf declined similarly with soil drying in all cultivars. Variation in leaf xylem ABA concentration better explained stomatal responses than foliar ABA concentration in some cultivars, and was highly correlated with stomatal conductance. Xylem ABA concentration in well-watered soil was highest in Union, and in drying soil was lowest in Jindou 21 and Long Huang 2, although the latter had the highest foliar ABA concentrations. Jindou 21 accumulated lower xylem ABA concentrations than other cultivars as soil moisture or Ψleaf decreased, but its stomatal sensitivity to xylem ABA was greater. Because cultivars varied in both ABA accumulation and stomatal sensitivity to ABA, but had similar stomatal sensitivity to Ψleaf, leaf water relations seem more important in regulating stomatal closure of soybean. [ABSTRACT FROM AUTHOR]

Asparagus (Asparagus officinalis L.) has short shelflife due to the high metabolic activity of the apical meristems. Storage at low temperature and high relative humidity is used commercially to keep fresh asparagus spears. Techniques denominated "Hurdley technologies" (UVC or gamma irradiation) have been tested in fruits and vegetables to extend postharvest life. These technologies were used to extend postharvest shelf life of asparagus spears by inhibition of meristematic activity. Spears were irradiated with UVC at dosages of 2.46, and 4.93 kJ m2 and gamma irradiation at 1 and 1.5 kGy, before storage at 2°C and 90% relative humidity (RH) for 20 days. Metabolic heat (Rq) was measured in apical meristems, as well as whole spear respiration, sugars content, water potential components and color descriptors. Metabolic heat and whole spears respiration rate did not show differences due to effect of UVC treatments, while spears treated with gamma radiation showed a metabolic activity inhibition of 10 and 15% for 1 and 1.5 kGy, respectively, while whole spear respiration rate was not affected. Changes in color variables showed a slight reduction in gloss. Sugars content in UVC remained unchanged, while gamma radiation induced a reduction in glucose. An increase in fresh weight loss was noticeable on those treated with gamma irradiation. No changes in water potential components were observed. It was concluded the treatments used did not reported positive benefits in extending asparagus spears shelf life. [ABSTRACT FROM AUTHOR]

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Water stress can affect plant ecological distribution, crop growth and carbohydrate distribution, impacting berry quality. However, previous studies mainly focused on short-term water stress or osmotic stress and few studies paid attention to the responses of grape to long-term water stresses. Grapevines were subjected to no water stress (CK), mild water stress (T1) and moderate water stress (T2). Hundred-berry weight and malic acid content were reduced under T1 and T2; however, glucose and fructose content showed the opposite trend. Endogenous hormones and polyamines (PAs) can regulate plant growth and development as well as physiological metabolic processes. T1 and T2 could increase abscisic acid content, however, indole-3-acetic acid, jasmonate, gibberellins 3 and 4, cytokinin and trans -zeatin contents were slightly decreased. Three species of PAs (putrescine, spermidine and spermine) were detected, presenting obvious tissue specificity. Furthermore, there was a statistically positive correlation relating spermidine content in the pulp with glucose and fructose contents of grape berries; and a negative correlation with organic acid. In summary, water stress had a profound influence on hormonally-driven changes in physiology and berry quality, indicating that endogenous hormones and the PAs play a critical role in the development and ripening of grape berries under water stress. Grapevine (Vitis vinifera L.) is one of the most economically important fruit crops, with a high economic value worldwide. Most vine-growing areas globally are in temperate zones characterised by high temperatures and prolonged dry periods. Phytohormones and polyamines, as important endogenous signal mediators, regulate a plethora of metabolic processes and responses to water stress. Therefore, it is necessary to investigate the effects of water stress on hormones and free polyamines in various tissues. [ABSTRACT FROM AUTHOR]