Lower Water Loss Research Articles

Indicators of adaptability of representatives of the genus Acer in an urban environment

A topical task has been set to assess the state of arboreal vegetation used in the landscaping of the city on the example of five species of the genus Acer. The main physiological and biochemical characteristics associated not only with the functionality of plants, but also involved in the formation of the plant's response to stress are involved for evaluation. It is shown that species differ in their physiological and biochemical characteristics and different reactions are observed in species to anthropogenic stressors. A significantly lower number of all groups of photosynthetic pigments was observed in species A. negundo and A. saccharinum, A. negundo it also differs in low indicators of the specific surface area of the sheet. In all five maple species in the urban environment, there was a significant increase in the total fund of green and yellow pigments compared to the background; there is an increase in the ratio Σchl / Σcar by 1.1-1.7 times, mainly due to a decrease in the level of chlorophylls and an increase in the proportion of carotenoids. A. negundo has significantly lower water deficiency and water loss by leaf tissues. The highest values of ascorbic acid were noted in the species A. saccharinum. To interpret the responses of species to the stressors of an urbanized area, cluster analysis was used, which divided the species into two clusters; at the same time, common mechanisms of responses were identified in maples that are introduced from different habitats.

Desempenho de cultivares de pimenta, baseado em caracteres de frutos, para consumo in natura

ABSTRACT Different studies report that pepper fruit cuticle and pericarp thickness vary among marked cultivars and these variations likely influence many fruit quality traits, especially water loss rates. Thus, the objectives of this work was to evaluate the fresh market performance of pepper cultivars based on fruit traits, and indicate the cultivars of Capsicum spp. with less probability of post harvest water loss. Pepper fruits, belonging to C. chinense, C. frutescens and C. baccatum species, were collected in an experimental area at Bonfim’s settlement, Alagoinha, Paraíba, Brazil. After harvest, fruits were taken to the laboratory of biotechnology at Centro de Ciências Agrárias of the Universidade Federal da Paraíba. Fruits were characterized according to pericarp thickness, fruit weight, and fruit length, larger and smaller fruit diameter. The experimental design was completely randomized with eight treatments and four repetitions. Analysis of variance, mean test, heritability, and ratio of coefficient of genetic variation by coefficient of environmental variation, genotypic and environmental correlation, and Tocher’s grouping method were performed. The cultivar habanero vermelha had better performance for fruit weight and larger and smaller fruit diameter. On the other hand ‘dedo de moça’ presented the longest fruits and major pericarp thickness. These two cultivars also belonged to different groups based on Tocher’s method. The genetic correlation between pericarp thickness and fruit weight was high (0.70) and highly significant. Fruit wall thickness also presented highly significant genotypic correlation with larger fruit diameter (0.93) and small fruit diameter. (0.93). Those finds indicate that indirect selection for pericarp thickness could be done based on larger fruit diameter. These correlations are trustworthy and important due to the high heritability values presented for these traits. Some authors suggest selecting fruits with higher cuticle thickness and fruit width values due to lower water loss. Thus, we suggest that small farmers cultivate ‘habanero vermelha’ and ‘dedo de moça’ in order to produce fruits with extended shelf life.

Responses of grapevines to planting density and training systems in semiarid environments

Aim. To investigate the physiological and agrobiological responses of grapevines on different systems of training systems in row plantations depending on the planting density and the possibility of adjusting plants for non-irri- gated crop cultivation under cold semiarid climate. Methods. The field two-way experiment of 2 × 4 was applied to study the effect of two planting density variants (3 × 1.5 m; 3 × 1 m) and four vine training systems (when the horizontal cordon is located at the height of 0.4 m, 0.8 m, 1.2 m, 1.6 m) on the parameters of the leaf area, leaf index, water loss through transpiration, activity of the photosynthetic apparatus of leaves and the yield of Zahrei wine grape cultivar (Vitis vinifera L.). The experiment data were processed using the analysis of variance. Results. The increase in the density of vine row plantations per area units from 3 × 1.5 m to 3 × 1 m enlarges the total leaf area, the exposed leaf area, water loss through transpiration, and yield weight, but these indices decrease in the evaluations per plant. The responses of grapevine to the training systems are similar and independent from the ex- perimental variants of planting density. At the height of the cordon of 0.4 and 0.8 m, the vertical shoot positioning enhances the potential of the photosynthetic capacity of the plantations, but this potential is realized only during the years with lower water deficit for plants. Free-growing shootings on the cordons, located at the height of 1.2 m, form the canopy architecture with relatively low water loss through transpiration which has a positive effect on the activity of the photosynthetic apparatus and yield, especially in dry years. The downward shoot positioning on the cordons of 1.6 m decreases the leaf area of the vines and creates the canopy architecture with increased transpiration which enhances the effect of the water deficit and has a negative effect on the productivity of plants. Conclusions. The agronomic methods of planting and training systems for grapevines ensure the management of the character of spatial shoot location, the formation of certain canopy architecture, and setting the parameters of the leaf area; their optimization mitigates the negative effect of water deficit and provides for adapting the plants for non-irrigated crops under semiarid climate. The positive effect of compacting plantations on crop yield was determined without irrigation in semiarid environments. The variant of planting density of 3 × 1 m decreases the yield on the vines on average by 12.1–31.0 %, as compared to the variant of 3 × 1.5 m. Yet, more dense plantations are remarkable for their yield, which is 18.5–61.3 % higher depending on the training system for vines. Under dry conditions, the most efficient system is the training system with the formation of the horizontal cordon at the height of 1.2 m and free-growing shoots. The system optimizes the leaf area density, and forms the canopy architecture with rather low water loss through transpiration which has a positive effect on the activity of the photosynthetic apparatus of leaves during droughts. Under free growth, the yield of the plantations increases by 4.3–12.3 % on average as compared to the vertical shoot positioning and by 21.3 % – under their downward positioning.

Evaluating the Mechanical Response of Agarose-Xanthan Mixture Gels Using Tensile Testing, Numerical Simulation, and a Large Amplitude Oscillatory Shear (LAOS) Approach.

Large deformation stress response characteristics of hydrocolloid mixture gel systems were investigated based on texture and rheological measurements. Agarose and xanthan mixtures at different ratios (1:0, 0.75:0.25, and 0.5:0.5) were chosen as the model systems. A decrease in failure stress from 2.65 to 1.82 MPa and an increase in failure strain from 0.08 to 0.13 with higher xanthan ratios were obtained based on the ring tensile test, indicating that xanthan molecules could improve the flexibility of the agarose network. The gels showed severe water loss by compression, particularly for the pure agarose gel (6.74%). Compared to the compression test, the gels presented low water loss after the ring tensile test (<1.3%) indicating that the ring tensile test could calculate the correct stress−strain relationship. Digital image correlation (DIC) and numerical simulation revealed that agarose-xanthan gel systems possess a deformation behavior with homogeneous strain distribution before failure. Elastic and viscous Lissajous−Bowditch curves from the large amplitude oscillatory shear (LAOS) measurement at different strains and frequencies elucidated that the agarose-xanthan gel was dominated by the agarose structure with a similar magnitude of elasticity at a low frequency. The large deformation approach from this study has great potential for elucidating and understanding the structure of food and biopolymer gels.

Addition of a Blend Based on Zinc Chloride and Lignans of Magnolia in the Diet of Broilers to Substitute for a Conventional Antibiotic: Effects on Intestinal Health, Meat Quality, and Performance.

This study aimed to determine whether adding a blend based on zinc chloride and lignans from magnolia to the diet of broilers could replace conventional performance enhancers. For this study, 360 chickens were divided into four groups, with six repetitions per group (n = 15), as follows: CN, without promoter; GPC, control, 50 mg/kg of enramycin growth promoter; T-50, additive blend at a dose of 50 g/ton; and T-100, additive blend at a dose of 100 g/ton. Chickens fed with the additive blend at 50 g/ton showed a production efficiency index equal to that in the GPC group (p < 0.05). At 42 days, the lowest total bacterial count (TBC) was found in the T-100 group, followed by that in the GPC group (p < 0.001). For E. coli, the lowest count was observed in the T-100 group, followed by that in the CP and T-50 groups (p < 0.001). Higher villus/crypt ratios were observed in birds belonging to the T-100 and T-50 groups than in the GPC and NC groups (p < 0.001). Greater water retention was found in the T-50 group than in NC and T-100 groups (p < 0.048). The lowest water loss during cooking was also noted in the T-50 group (p < 0.033). We concluded that adding the antimicrobial blend, primarily at 50 g/ton, maintains the efficiency of the index of production and improves the intestinal health and meat quality of the birds.

Effect of chitosan and hydroxypropyl starch complex polysaccharide on the physico-chemical properties of Tilapia fish (Oreochromis mossambicus) gel

The compound polysaccharide composed of chitosan and hydroxypropyl starch was aimed in this study to be used as a novel treatment to improve the quality of Tilapia fish surimi. Surimi gel properties, retention of oil, rate of water loss, colour changes, changes in protein content and gas composition were analysed. Compared with the control group, with the increase of hydroxypropyl starch content, the rate of water loss in all the groups (chitosan and hydroxypropyl starch) was improved, and 1.5% chitosan-treated samples showed significantly lower water losses. The protein content tended to increase at the beginning and then decrease. The whiteness index of surimi in both groups was significantly improved. The addition of 1.0% hydroxypropyl starch showed the highest oil retention in all treated groups (1.0% chitosan treated sample showed oil retention of 0.77 mL/g, while 1.5% chitosan treated samples showed maximum oil retention of 0.7 mL/g). Gas chromatography-mass spectroscopy (GC-MS) analysis detected two identical volatile organic compounds (VOCs) in both the control and compound polysaccharide groups. These results indicate that using complex polysaccharides can significantly improve the quality of fish surimi and, therefore, can be used as a practical basis for industries to improve freshwater fish surimi’s gel properties.

Multi‐objective optimization of drainage‐plates in wave‐plate mist eliminators using experiment and data‐driven modelling for lower water loss and energy requirement

AbstractWave‐plate mist eliminators are widely employed as gas–liquid separation devices to prevent the liquid escaping from thermal power plants or other cooling towers. In this study, the wave‐plate mist eliminator with drainage plates was numerically analyzed and the effects between geometrical variables on two objectives, namely, pressure drop (ΔP) and separation efficiency (η), were revealed. Plate spacing, width, and length, as well as the relative position of the drainage plate, were thoroughly investigated. A combined strategy was developed for multi‐objective optimization of the wave‐plate mist eliminator by integrating computational fluid dynamics (CFD) simulation, response surface methodology (RSM), non‐dominated sorting genetic algorithm‐II (NSGA‐II), and a technique for order of preference by similarity to ideal solution (TOPSIS) method. The results demonstrated that the relative position of drainage plates has a greater impact on the overall performance, whereas the width of drainage plates has the minimum effect. With the implementation of NSGA‐II and the TOPSIS method, an optimal solution for the design of the mist eliminator was obtained. After comparing with the baseline case, the optimized case presents promising characteristics with high separation efficiency (enhanced by 3.6%~9.06%) and a low energy consumption coefficient (reduced by 72.30% at η = 45%).

Improving the thermal characteristics of a cooling tower by replacing the operating fluid with functionalized and non-functionalized aqueous MWCNT nanofluids

In this study, the thermal properties of the operating fluid by replacing the fluid with better thermal properties and lower water loss in a cross-flow cooling tower (CFWCT) investigated. For this purpose, MWCNTs/H2O, MWCNTs-COOH/H2O, and MWCNTs-OH/H2O nanofluids were used instead of water, and the results were compared. The visual method and dynamic light scattering (DLS) were used to guarantee the stability of nanofluids and to determine the size distribution of the nanoparticles in the nanofluid. The influence of nanofluids concentration on cooling towers performance variables such as evaporation rate, performance characteristics, temperature drop, and tower efficiency were investigated. The results showed that the functionalized nanofluids with lower evaporation rates than water and the non-functionalized nanofluids with higher evaporation rates than water improved the thermal performance of CFWCT. For example, at a concentration of 0.1 wt% MWCNTs-COOH/H2O, MWCNTs-OH/H2O, and MWCNTs/H2O, the efficiency of the cooling tower was 46%, 45.3%, and 43.2%, and the performance characteristics were improved by 15.8%, 11.2%, and 6.1%, respectively, compared with water. Among the nanofluids, MWCNTs-COOH/H 2 O nanofluid had the best performance, in which the evaporation rate, performance characteristics, temperature drop, and efficiency were increased by about −4.3%, 15.8%, 15.9%, and 8.7%, respectively, compared to water.

An Assessment of Water and Soil Losses in Pastures of The Brazilian Savanna Using Simulated Rainfall

Pastures occupy a large part of Brazilian national territory, being of heterogeneous characteristics and varying in climate, fertility, and management. Water erosion, generated by the action of rainfall, is a principal source of soil depletion. These soils exhibit distinct behaviors spatially and temporally. Therefore, this research aims to evaluate the water and soil losses in a pasture of the Cerrado region during two periods of the year (winter and summer) with the aim of understanding the hydro-geomorphological dynamic of the pastures in question. A rainfall simulator was calibrated at 64.34 mm/h, to replicate similar intensities to those of the study region, for 30 minutes (32.17 mm) over four erosion plots. Overall, the plots presented low water and sediment losses, with the largest runoff volumes in the summer and the highest erosion rates in winter. These results are connected to seasonal climate variations expressed in the region, which are reflected in the plant growth habits, generating alterations in the structural quality of the pastures. It follows that the return of the rainy season (winter-summer transition) represents a critical phase for the triggering of the erosive process.

Overexpression of Myrothamnus flabellifolia MfWRKY41 confers drought and salinity tolerance by enhancing root system and antioxidation ability in Arabidopsis.

Myrothamnus flabellifolia is the only woody resurrection plant discovered so far and could recover from extreme desiccation condition. However, few genes related to its strong drought tolerance have been characterized, and the underlying molecular mechanisms remains mysterious. Members of WRKY transcription factor family are effective in regulating abiotic stress responses or tolerance in various plants. An early dehydration-induced gene encoding a WRKY transcription factor namely MfWRKY41 was isolated from M. flabellifolia, which is homologous to AtWRKY41 of Arabidopsis. It contains a typical WRKY domain and zinc finger motif, and is located in the nucleus. Comparing to wild type, the four transgenic lines overexpressing MfWRKY41 showed better growth performance under drought and salt treatments, and exhibited higher chlorophyll content, lower water loss rate and stomatal aperture and better osmotic adjustment capacity. These results indicated that MfWRKY41 of M. flabellifolia positively regulates drought as well as salinity responses. Interestingly, the root system architecture, including lateral root number and primary root length, of the transgenic lines was enhanced by MfWRKY41 under both normal and stressful conditions, and the antioxidation ability was also significantly improved. Therefore, MfWRKY41 may have potential application values in genetic improvement of plant tolerance to drought and salinity stresses. The molecular mechanism involving in the regulatory roles of MfWRKY41 is worthy being explored in the future.

Heterologous Expression of MfWRKY7 of Resurrection Plant Myrothamnus flabellifolia Enhances Salt and Drought Tolerance in Arabidopsis.

Drought and salinity have become major environmental problems that affect the production of agriculture, forestry and horticulture. The identification of stress-tolerant genes from plants adaptive to harsh environments might be a feasible strategy for plant genetic improvement to address the challenges brought by global climate changes. In this study, a dehydration-upregulated gene MfWRKY7 of resurrection Plant Myrothamnus flabellifolia, encoding a group IId WRKY transcription factor, was cloned and characterized. The overexpression of MfWRKY7 in Arabidopsis increased root length and tolerance to drought and NaCl at both seedling and adult stages. Further investigation indicated that MfWRKY7 transgenic plants had higher contents of chlorophyll, proline, soluble protein, and soluble sugar but a lower water loss rate and malondialdehyde content compared with wild-type plants under both drought and salinity stresses. Moreover, the higher activities of antioxidant enzymes and lower accumulation of O2− and H2O2 in MfWRKY7 transgenic plants were also found, indicating enhanced antioxidation capacity by MfWRKY7. These findings showed that MfWRKY7 may function in positive regulation of responses to drought and salinity stresses, and therefore, it has potential application value in genetic improvement of plant tolerance to abiotic stress.

NAC Transcription Factor TwNAC01 Positively Regulates Drought Stress Responses in Arabidopsis and Triticale.

The NAC transcription factors play important roles in regulating plant growth, development, and senescence, and responding to biotic and abiotic stressors in plants. A novel coding sequence (1,059 bp) was cloned from hexaploid triticale in this study. The putative protein (352 amino acids) encoded by this sequence was over 95% similar to the amino acid sequence of a NAC protein from Aegilops tauschii (XP020161331), and it formed a clade with Ae. tauschii, durum wheat, and barley. The putative protein contained a conserved nature actomyosin (NAM) domain (129 consecutive amino acids) between the 20th and 148th amino acids at the N-terminus and three transcription activation regions at the C-terminus. The novel gene was identified as a triticale NAC gene localized in the nucleus and designated as TwNAC01 (GenBank accession MG736919). The expression levels of TwNAC01 were the highest in roots, followed by leaves and stems when triticale lines were exposed to drought, polyethylene glycol 6,000 (PEG6000), NaCl, cold, methyl jasmonate (MeJA), and abscisic acid (ABA). Transgenic Arabidopsis thaliana overexpressing TwNAC01 had significantly lower leaf water loss rates and longer roots than wild-type (WT) A. thaliana. Virus-induced silencing of the TwNAC01 gene in triticale delayed root development and decreased length of primary root. Under drought stress, leaves of TwNAC01-silenced triticale had higher levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2), but lower relative water content (RWC), net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, and transpiration rate than the leaves of the WT. Gene overexpression and silencing experiments suggested that TwNAC01 improves plant stress tolerance by increasing root length, regulating the water content of plant leaves by reducing MDA and H2O2 content, and adjusting respiration rate. The results suggest that TwNAC01 is a novel NAC transcription factor gene that can be exploited for triticale and cereal improvement.

Role of Osmotic Regulation and Cryoprotectant Substances in the Freezing Tolerance of Alfalfa in Cold, Dry Conditions

Background: Freezing temperatures are a limiting factor hindering the survival of alfalfa (Medicago sativa L.) through winter. Soil drought also damages alfalfa crowns and can affect their regeneration. Therefore, it is important to determine the effects of cold, dry conditions on alfalfa to develop effective water management strategies in winter. Methods: Cold, dry conditions were established in the laboratory and the freezing tolerance of crowns was compared between the alfalfa cultivars ‘WL440HQ’ and ‘ZhaoDong’. The degree of freezing tolerance was estimated on the basis of relative electrolyte leakage and semi-lethal temperature. The effects of cold, dry conditions on alfalfa crowns were determined by investigating the rate of water loss and the concentrations of soluble sugars (which function as cryoprotectants) and betaine and proline (which function as osmoregulation substances). Result: Compared with crowns of ‘ZhaoDong’, those of ‘WL440HQ’ showed a higher water loss rate in cold, dry conditions and were irreversibly damaged and their freezing tolerance was severely affected. In comparison, crowns from ‘ZhaoDong’ showed a lower water loss rate and lower relative electrolyte leakage under cold, dry conditions and their freezing tolerance was not significantly affected. The higher water loss rate and lower freezing tolerance were the direct causes of death of ‘WL440HQ’, the cultivar with a higher fall dormancy score. In cold, dry conditions, the content of proline, an osmotic regulation substance, increased in response to soil water deficit and may have improved the ability to withstand freezing temperatures by preventing rapid water loss. In addition, sucrose, fructose, galactose and stachyose contents in the crown increased under cold, dry conditions and may have enhanced freezing tolerance because of their function as cryoprotectants. The results of this study indicate that maintaining soil moisture within the range suitable for the growth of crowns is important for the successful overwintering of alfalfa.

DNA Methylation Correlates with the Expression of Drought-Responsive Genes and Drought Resistance in Rice

The δ13C value is regarded as an important indicator for tolerance to drought stress (DS), which is a severe abiotic stress that influences rice productivity. However, exploration of drought-responsive genes (DRGs) related to δ13C regulation is less reported. In this study, we investigated the natural variation in δ13C values in 102 japonica rice accessions. Among them, two rice accessions with contrasting δ13C values, Longdao 10 (LD10, DS-tolerant) and Binxu (BX, DS-sensitive), were used for further analysis. LD10 possesses better drought resistance with 2% lower δ13C values, 35% lower stomatal length and density, 33% lower water loss, and 11% lower stomatal conductance in comparison to BX. Transcriptome analysis shows that there are 2325 and 1378 differentially expressed genes (DEGs) induced by DS in LD10 and BX at the tillering stage, respectively, while there are 1076 and 492 DEGs in LD10 and BX at the graining stage, respectively. In total, 21 overlapped DEGs (defined as DRGs) were identified due to DS effects across two rice accessions over two stages. Among them, the expression levels of six genes, including chloride transporter (CLT1) and photosystem II polypeptide (PSBP), were further tested using qRT-PCR. Furthermore, we found that four methyltransferase genes were upregulated in BX compared to LD10 under DS. Consistently, the methylation levels of CLT1 and PSBP were higher along both promoter and CDS regions for CG, CHG, and CHH types. This study highlights the importance of the expression of these DRGs in response to DS and provides deep insights into DNA methylation-driven gene expression conferring different drought responses in rice.

Ubiquitin ligase OsRINGzf1 regulates drought resistance by controlling the turnover of OsPIP2;1.

SummaryWater is crucial for plant growth and survival. The transcellular water movement is facilitated by aquaporins (AQPs) that rapidly and reversibly modify water permeability. The abundance of AQPs is regulated by its synthesis, redistribution and degradation. However, the molecular mechanism of proteasomal degradation of AQPs remains unclear. Here, we demonstrate that a novel E3 ligase, OsRINGzf1, mediated the degradation of AQPs in rice. OsRINGzf1 is the candidate gene from a drought‐related quantitative trait locus (QTL) on the long arm of chromosome 4 in rice (Oryza sativa) and encodes a Really Interesting New Gene (RING) zinc finger protein 1. OsRINGzf1 possesses the E3 ligase activity, ubiquitinates and mediates OsPIP2;1 degradation, thus reducing its protein abundance. The content of OsPIP2;1 protein was decreased in OsRINGzf1 overexpression (OE) plants. The degradation of OsPIP2;1 was inhibited by MG132. The OsRINGzf1 OE plants, with higher leaf‐related water content (LRWC) and lower leaf water loss rate (LWLR), exhibited enhanced drought resistance, whereas the RNAi and knockout plants of OsRINGzf1 were more sensitive to drought. Together, our data demonstrate that OsRINGzf1 positively regulates drought resistance through promoting the degradation of OsPIP2;1 to enhance water retention capacity in rice.

SUPPRESSOR of MAX2 1 (SMAX1) and SMAX1-LIKE2 (SMXL2) Negatively Regulate Drought Resistance in Arabidopsis thaliana.

Recent investigations in Arabidopsis thaliana suggest that SUPPRESSOR of MORE AXILLARY GROWTH 2 1 (SMAX1) and SMAX1-LIKE2 (SMXL2) are negative regulators of karrikin (KAR) and strigolactone (SL) signaling during plant growth and development, but their functions in drought resistance and related mechanisms of action remain unclear. To understand the roles and mechanisms of SMAX1 and SMXL2 in drought resistance, we investigated the drought-resistance phenotypes and transcriptome profiles of smax1 smxl2 (s1,2) double-mutant plants in response to drought stress. The s1,2 mutant plants showed enhanced drought-resistance and lower leaf water loss when compared with wild-type (WT) plants. Transcriptome comparison of rosette leaves from the s1,2 mutant and the WT under normal and dehydration conditions suggested that the mechanism related to cuticle formation was involved in drought resistance. This possibility was supported by enhanced cuticle formation in the rosette leaves of the s1,2 mutant. We also found that the s1,2 mutant plants were more sensitive to abscisic acid in assays of stomatal closure, cotyledon opening, chlorophyll degradation and growth inhibition, and they showed a higher reactive oxygen species detoxification capacity than WT plants. In addition, the s1,2 mutant plants had longer root hairs and a higher root-to-shoot ratio than the WT plants, suggesting that the mutant had a greater capacity for water absorption than the WT. Taken together, our results indicate that SMAX1 and SMXL2 negatively regulate drought resistance, and disruption of these KAR- and SL-signaling-related genes may therefore provide a novel means for improving crop drought resistance.

GmSAP5, a soybean A20/AN1 domain-containing stress-associated protein gene activated by GmAREB3, increases drought stress resistance in soybean by mediating ABA signaling

Drought stress impairs crop growth and productivity. Stress-associated proteins (SAPs), a class of zinc finger proteins containing the A20/AN1 domain, function in various stress responses in plants. However, little is known about the function of SAPs in drought-stress responses in soybean, an oil and protein crop. We report that a GmSAP5 protein confers drought tolerance by increasing sensitivity to abscisic acid (ABA) and reducing stomatal aperture. Overexpression and RNA interference of GmSAP5 in soybean hairy roots resulted in elevated resistance and sensitivity to drought stress, respectively. ABA and proline contents increased in GmSAP5-overexpressing plants under water-deficit conditions. Lower water loss rates and higher relative water contents were observed in GmSAP5-overexpressing plants, resulting in increased drought-stress resistance. A yeast one-hybrid assay and luciferase transient transcriptional activity assay showed that GmAREB3, an AREB/ABF transcription factor, could bind to the promoter of GmSAP5 and activate its expression. These results suggest that GmSAP5 acts downstream of GmAREB3 and improves drought-stress resistance by mediating ABA signaling.

Divergence and conservative of stomatal conductance in coexisting species in response to climatic stress in Tibetan Plateau

Convergence of eco-physiological function in harsh habitats due to environmental filtering is well-known, however, some evidence of eco-physiological divergence in coexisting species also exists. Experimental data to verify whether divergence of eco-physiological function in coexisting species increases with increasing environmental stress remain limited. Here, we measured bulk leaf oxygen isotope and functional traits along a climatic stress gradient in a grassland in Tibetan Plateau where drought, excess radiation, and temperature increased from east to west. Enrichment (Δ18O) in bulk leaf oxygen isotope was used as proxy for time-integrated gs. We found that the leaf water use (Δ18O and leaf area [LA]) spectrum was independent of the leaf economic spectrum, indicating that coexisting species shifted from high nitrogen use efficiency (high ratio of leaf carbon to nitrogen) and water loss (high LA) in low-stress habitats to high photosynthetic capacity (high leaf nitrogen) and low water loss (low gs) in high-stress habitats. As the stress intensity of climate increases, higher mean and maximum and lower skewness (varying from positive to negative values) of Δ18O in coexisting species confirmed that the abundance of water-saving species increased to cope with climatic stress, while the greater standard deviation and kurtosis further indicated that climatic stress drove the divergence in gs in coexisting species. This study revealed that coexisting species adopt more diversified water use strategies and the abundance of water-saving species increases to cope with climatic stress, regardless of decreases in overall species abundance.

Effects of washing step and salt-addition levels on textural and quality properties in the chicken-surimi products

The massive wastewater from surimi manufacture and salt addition is controversial. In our previous study, a chicken-surimi (CS) product can be successfully developed from the spent-hen breast via 3 times of washing steps and 2.5% salt addition in the recipe. Due to the characteristics of broiler breast (higher protein contents in muscle), this study was to optimize the washing step for CS batter recovered from broiler breast and the salt-addition level in the CS-product recipe. The step of washing once with 0.1% salt solution showed no (P > 0.05) differences in the texture profile and color parameters (expect a* value) in CS batters compared to initial washing steps (a 3-step washing procedure). The CS batter obtained by this washing step had higher amino-acid contents than boiler breast and large Grade A egg and even fit adults’ daily essential amino-acid requirement. Besides, the lower (P < 0.05) water loss of cooked CS products during the storage (4°C) was shown beyond 2.0% salt addition in CS products. For efficient/ecofriendly extraction and sodium-content reduction, the washing once with a 0.1% salt solution and 2% salt addition in the recipe is recommended in the CS batter recovered from broiler breast and its products, respectively.

Synergistic effect and disinfection mechanism of combined treatment with ultrasound and slightly acidic electrolyzed water and associated preservation of mirror carp (Cyprinus carpio L.) during refrigeration storage

This study evaluated the synergistic effects and disinfection mechanism of ultrasound (US, 200 W and 30 kHz) and slightly acidic electrolysed water (SAEW, 60 mg/L and pH of 6.2) treatment and the associated preservation of mirror carp during refrigeration storage (4 °C). US and SAEW alone and US combined with SAEW (US + SAEW) showed the lower water loss of fish. Fish treated with US + SAEW exhibited significantly lower degrees of lipid oxidation and protein degradation (P < 0.05). Microbiological results showed that US + SAEW inhibited the growth of Pseudomonas and activity of endogenous enzymes; also, US + SAEW decreased the relative activities of 2,3,5-triphenyl tetrazolium chloride-dehydrogenase (TTC-dehydrogenase) and ATP-ase in Pseudomonas by 65.89% and 10.26%, respectively. The combination of US + SAEW destroyed the cellular membrane and aggravated the leakage of nucleic acid and protein of Pseudomonas, and effectively inhibited the activity of antioxidant enzyme. This study reports a new industrial method for preserving refrigerated fish.