High Rates Of Water Loss Research Articles

Amphibians Exhibit Extremely High Hydric Costs of Respiration.

Terrestrial environments pose many challenges to organisms, but perhaps one of the greatest is the need to breathe while maintaining water balance. Breathing air requires thin, moist respiratory surfaces, and thus the conditions necessary for gas exchange are also responsible for high rates of water loss that lead to desiccation. Across the diversity of terrestrial life, water loss acts as a universal cost of gas exchange and thus imposes limits on respiration. Amphibians are known for being vulnerable to rapid desiccation, in part because they rely on thin, permeable skin for cutaneous respiration. Yet, we have a limited understanding of the relationship between water loss and gas exchange within and among amphibian species. In this study, we evaluated the hydric costs of respiration in amphibians using the transpiration ratio, which is defined as the ratio of water loss (mol H2O d-1) to gas uptake (mol O2 d-1). A high ratio suggests greater hydric costs relative to the amount of gas uptake. We compared the transpiration ratio of amphibians with that of other terrestrial organisms to determine whether amphibians had greater hydric costs of gas uptake relative to plants, insects, birds, and mammals. We also evaluated the effects of temperature, humidity, and body mass on the transpiration ratio both within and among amphibian species. We found that hydric costs of respiration in amphibians were two to four orders of magnitude higher than the hydric costs of plants, insects, birds, and mammals. We also discovered that larger amphibians had lower hydric costs than smaller amphibians, at both the species- and individual-level. Amphibians also reduced the hydric costs of respiration at warm temperatures, potentially reflecting adaptive strategies to avoid dehydration while also meeting the demands of higher metabolic rates. Our results suggest that cutaneous respiration is an inefficient mode of respiration that produces the highest hydric costs of respiration yet to be measured in terrestrial plants and animals. Yet, amphibians largely avoid these costs by selecting aquatic or moist environments, which may facilitate more independent evolution of water loss and gas exchange.

Water restriction increases oxidation of endogenous amino acids in house sparrows (Passer domesticus).

Animals can cope with dehydration in a myriad of ways, both behaviorally and physiologically. The oxidation of protein produces more metabolic water per kilojoule than that of fat or carbohydrate, and it is well established that birds increase protein catabolism in response to high rates of water loss. However, the fate of amino acids mobilized in response to water restriction has not been explicitly determined. While protein catabolism releases bound water, we hypothesized that water-restricted birds would also oxidize the resulting amino acids, producing additional water as a product of oxidative phosphorylation. To test this, we fed captive house sparrows (Passer domesticus) 13C-labeled leucine for 9 weeks to label endogenous proteins. We conducted weekly trials during which we measured the physiological response to water restriction as changes in lean mass, fat mass, metabolism and the enrichment of 13C in exhaled CO2 (δ13Cbreath). If water-restricted birds catabolized proteins and oxidized the resulting amino acids, we expected to simultaneously observe greater lean mass loss and elevated δ13Cbreath relative to control birds. We found that water-restricted birds catabolized more lean tissue and also had enriched δ13Cbreath in response to water restriction, supporting our hypothesis. δ13Cbreath, however, varied with metabolic rate and the length of the water restriction period, suggesting that birds may spare protein when water balance can be achieved using other physiological strategies.

Evaluation of the Primary Pipe Network at Banua Anyar Booster Pump as an Effort to Reduce Water Loss in the Service area of Northern Banjarmasin, South Kalimantan

Recorded as the best PDAM in South Kalimantan in Banjarmasin City. PT. Bandarmasih Perseroda Drinking Water (PAM Bandarmasih) is still facing the problem of high water loss rates of 29.07% in 2022, which is still far above the National Medium Term Development Plan (RPJMN) target with a minimum water loss value of 20%. One of the ways PDAM can reduce water loss is by evaluating the pipe network in a District Meter Area (DMA). This research focuses on evaluating the primary pipe network in the area served by the Banua Anyar booster which serves 18 DMAs. Network evaluation using EPANET 2.0 software. The evaluation results show that the diameter of the primary pipe from the booster pump to the Banua Anyar pipe bridge has quite high unit-head loss and flow velocity values due to flow friction with the pipe surface. It is necessary to change the diameter of the primary pipe used in the Banua Anyar booster network from a diameter of 400 mm to 600 mm which can reduce the rate of water loss by 6.3%. In the future, it is hoped that the value of water loss at PDAM Banjarmasin City can be reduced and the affordability of drinking water services for the people of Banjarmasin City can increase.

Effect of DMA characteristics on risk and asset analysis of the Metropolitan Waterworks Authority pipe network

AbstractThis study examines the District Metering Area (DMA) characteristics in the pipe networks of Metropolitan Waterworks Authority (MWA), with a specific focus on risk and asset analysis, including water loss rate, water usage, and pipe density. The objective is to classify the DMA types based on these characteristics and to determine the influence of area characteristics on water distribution infrastructure. This is achieved by employing risk assessment and asset valuation techniques to identify pipes that require replacement. Initially, the Area Characteristic Index (ACI) for all 64 DMAs within the Ladprao service office branch was evaluated using a fuzzy inference system. Subsequently, six selected DMAs from three distinct area types were analyzed by the fuzzy logic model to figure out the Risk Index (RI) values. Concurrently, the Infrastructure Value Index (IVI) contributed to the asset valuation. These indices pinpointed both the high‐risk pipe routes and the poor‐condition infrastructure. Moreover, the Modified Risk‐Value Index (MRVI) was adopted to prioritize these pipe routes within a constrained budget. The main conclusion drawn is that while DMA characteristics do not directly influence the identification of deteriorated pipes through risk assessment and asset analysis methods, the characteristic of a high water loss rate does impact the number of pipe routes identified by the RI.

Hydric effects on thermal tolerances influence climate vulnerability in a high-latitude beetle.

Species' thermal tolerances are used to estimate climate vulnerability, but few studies consider the role of the hydric environment in shaping thermal tolerances. As environments become hotter and drier, organisms often respond by limiting water loss to lower the risk of desiccation; however, reducing water loss may produce trade-offs that lower thermal tolerances if respiration becomes inhibited. Here, we measured the sensitivity of water loss rate and critical thermal maximum (CTmax ) to precipitation in nature and laboratory experiments that exposed click beetles (Coleoptera: Elateridae) to acute- and long-term humidity treatments. We also took advantage of their unique clicking behavior to characterize subcritical thermal tolerances. We found higher water loss rates in the dry acclimation treatment compared to the humid, and water loss rates were 3.2-fold higher for individuals that had experienced a recent precipitation event compared to individuals that had not. Acute humidity treatments did not affect CTmax , but precipitation indirectly affected CTmax through its effect on water loss rates. Contrary to our prediction, we found that CTmax was negatively associated with water loss rate, such that individuals with high water loss rate exhibited a lower CTmax . We then incorporated the observed variation of CTmax into a mechanistic niche model that coupled leaf and click beetle temperatures to predict climate vulnerability. The simulations indicated that indices of climate vulnerability can be sensitive to the effects of water loss physiology on thermal tolerances; moreover, exposure to temperatures above subcritical thermal thresholds is expected to increase by as much as 3.3-fold under future warming scenarios. The correlation between water loss rate and CTmax identifies the need to study thermal tolerances from a "whole-organism" perspective that considers relationships between physiological traits, and the population-level variation in CTmax driven by water loss rate complicates using this metric as a straightforward proxy of climate vulnerability.

Model based predictive control strategy for water saving drip irrigation

Traditional irrigation control systems is characterized with inefficient management of water and often results in low water productivity index and reduced cultivation yield. In addition, insufficient water supply and high rate of water loss due to evapotranspiration increases plant stress which often affects its growth and development. Therefore, to address this issues, this paper is aimed at developing a model predictive control (MPC) strategy for water saving drip irrigation experiment that will regulate the soil moisture content within the desired field capacity and above the wilting point, while scheduling irrigation to replace the loss of water from soil and plant due to evapotranspiration in the greenhouse environment. The controller design involves a data driven predictive model identified and integrated with the MPC designer in MATLAB and thereafter exported in Simulink for simulation. The generate controller code was modified and deployed on a Raspberry Pi 4 controller to generate a pulse width modulated signal to drive the pump for the control water mixed with fertilizer. To achieve enhancement of controller an Internet of Things (IoT) integration was used for easy soil, weather, and plant monitoring which are used to update the MPC model for the irrigation control. The performance of the proposed MPC controller deployed drip irrigated Greenhouse(GH1) is benchmarked against an existing automatic evapotranspiration (ETo) model based controller in Greenhouse(GH2), with each greenhouse containing 80 poly bags of Cantaloupe plant with similar growth stage. The results obtained shows that, the proposed MPC-based irrigation system has higher water productivity index of 36.8 g/liters, good quality of fruit with average sweetness level of 13.5 Brix compared to automatic ETo-based irrigation system with 25.6 g/liters and 10.5 Brix, respectively. However, the total mass of harvested fruit for ETo-based irrigation system is higher than MPC-based irrigation system by 21.7%. The performance of the proposed MPC controller was achieved through the integration of event based scheduling with IoT monitoring as well as inclusion of evapotranspiration effect in the plant dynamics.

ANALISIS SISTEM DISTRIBUSI AIR BERSIH MENGGUNAKAN EPANET 2.0 DI PDAM TIRTA LANGKISAU UNIT PELAYANAN LUMPO

Lumpo Service Unit is one of the clean water service units in PDAM Tirta Langkisau, Pesisir Selatan Regency, which serves parts of IV Jurai District. The Lumpo Service Unit currently has a production capacity of 3 l/sec or still 24% of the total served population and a fairly high water loss rate (35% or 2,671 m 3 ). This study aims to analyze the clean water needs of the community in the Lumpo Unit area from 2021 and 2025 and analyze the condition of the clean water distribution network system in the Lumpo Service Unit in 2021 and 2025. Analysis of the water distribution system network was carried out using Epanet 2.0. It was found that the water demand in 2021 was 5.45 l/s (22.51 l/s at a service level of 100%) and there was an increase in 2025, namely 28.23 l/s. Analysis of the piping distribution network in 2025 shows that 27 out of a total of 49 junctions have water pressure below the minimum limit for distribution pipe criteria from PERMEN PU No. 18/PRT/M/2007, as well as 13 out of 50 total pipes with water flow rates below the minimum limit of the same criteria of 0.3 m/s.

Water loss performance indicators in peripheral areas of a metropolitan region in Amazonia

This paper aims to quantify and compare the losses of two isolated water supply systems with similar characteristics (Canarinho e Benjamin Sodré), located in the Metropolitan Region of Belém, state of Pará, Amazonia-Brazil. The methods included diagnosis of systems, technical documental and commercial surveys from the water supply utility, outflow measurements (ultrasound portable outflow measurer and pitometer type equipment with transductor and data logger), statistical treatment of data and determination of the loss indexes of the water supply systems. The high Distribution Network Loss Index recorded of Canarinho and Benjamin Sodré with 81.98% and 70.04% respectively, jointly observed with Connection Losses Index values ​(3.2 and 7.3 times higher, respectively, compared to the national average) increased the Water Meter Index of the studied systems (Canarinho with 84.66% and Benjamin Sodré with 70.93%). The high water loss rates are a characteristic of the northern region of Brazil and are reflected in the data obtained from the studied systems. Losses of this magnitude make systems economically unsustainable due to frauds, lack of maintenece and a poor quality or degradation of infrastructure.

The Effects of Storage Temperature, Light Illumination, and Low-Temperature Plasma on Fruit Rot and Change in Quality of Postharvest Gannan Navel Oranges.

Gannan navel orange (Citrus sinensis Osbeck cv. Newhall) is an economically important fruit, but postharvest loss occurs easily during storage. In this study, the effects of different temperatures, light illuminations, and low-temperature plasma treatments on the water loss and quality of the Gannan navel orange were investigated. The fruit began to rot after 90 d of storage at 5 °C and 20-45 d at 26 °C. Navel oranges stored at 26 °C had 7.2-fold and 3.1-fold higher rates of water loss at the early and late storage stages, respectively, as compared with those stored at 5 °C. Storage at 5 °C decreased the contents of total soluble solids at the early storage stage and the contents of titratable acids at the late storage stage, whereas storage at 26 °C decreased the contents of total soluble solids at the late storage stage and the contents of titratable acids at the early storage stage, respectively. Application of low-temperature plasma produced by air ionization for 6 min, or continuous blue or red light illumination significantly inhibited water loss within 7 and 21 d of storage at 22 °C, respectively, but exhibited no significant effect on fruit quality. Furthermore, the low-temperature plasma treatment protected against fruit rot. Thus, treatment with low-temperature plasma followed by storage at a low temperature under continuous red or blue light illumination was of potential value as a green technology for preserving Gannan navel orange during storage.

The Poisoned Chalice of Evolution in Water: Physiological Novelty Versus Morphological Simplification in Marsileaceae

The Marsileaceae is a small family of semi-aquatic ferns displaying numerous traits commonly observed in angiosperms, including heterospory, sophisticated hydraulic architecture, and high rates of atmospheric gas exchange. Despite these similar traits, Marsileaceae is comparatively ecologically limited. Most species are found in Marsilea which is sister to Regnellidium and Pilularia, together these two genera include only seven species. Here we studied the anatomy and physiology of Marsileaceae to better understand the potential constraints on ecological and species diversity in this family. We focused on epidermal anatomy and stomatal responses to changes in light and water availability, which are unique amongst ferns. We found two evolutionary strategies in Marsileaceae, one of morphological simplification, physiological inflexibility, and aquatic specialization in Pilularia; which contrasts with a strategy of maximizing photosynthetic carbon gain at the expense of high rates of water loss in Marsilea and Regnellidium. We conclude that aquatic environments provide evolutionary opportunities for physiological innovation with regard to stomatal function, as well as selective pressures that drive the canalized evolution of highly specialized aquatic forms.

Mutation of OsMYB60 reduces rice resilience to drought stress by attenuating cuticular wax biosynthesis.

The cuticular wax layer on leaf surfaces limits non-stomatal water loss to the atmosphere and protects against pathogen invasion. Although many genes associated with wax biosynthesis and wax transport in plants have been identified, their regulatory mechanisms remain largely unknown. Here, we show that the MYB transcription factor OsMYB60 positively regulates cuticular wax biosynthesis and this helps rice (Oryza sativa) plants tolerate drought stress. Compared with the wild type (japonica cultivar 'Dongjin'), osmyb60 null mutants (osmyb60-1 and osmyb60-2) exhibited increased drought sensitivity, with more chlorophyll leaching and higher rates of water loss. Quantitative reverse-transcription PCR showed that the loss of function of OsMYB60 led to downregulation of wax biosynthesis genes, leading to reduced amounts of total wax components on leaf surfaces under normal conditions. Yeast one-hybrid, luciferase transient transcriptional activity, and chromatin immunoprecipitation assays revealed that OsMYB60 directly binds to the promoter of OsCER1 (a key gene involved in very-long-chain alkane biosynthesis) and upregulates its expression. Taken together, these results demonstrate that OsMYB60 enhances rice resilience to drought stress by promoting cuticular wax biosynthesis on leaf surfaces.

THERMAL BIOLOGY OF A POPULATION OF Xenosaurus newmanorum (SQUAMATA: XENOSAURIDAE) FROM XILITLA, SAN LUIS POTOSÍ, MEXICO: DO THEY ACTIVELY THERMOREGULATE?

The knob-scaled lizards (family Xenosauridae) comprise a clade of crevice-dwelling North American lizards with a trend towards low body temperature and high rates of water loss, and are often regarded as thermoconformers. However, there are few studies on their thermal ecology, most of them limited to documenting the body temperatures and their relation with environmental temperatures. Here, we documented the field body temperatures (Tb), selected temperatures (Tset), operative temperatures (Te), thermoregulatory effectiveness, and thermal tolerances of 10 individuals of the Newman’s Knob-scaled Lizard, Xenosaurus newmanorum, collected in the fall of 2017 in La Huasteca region of Mexico. Mean Tb was 22.75 °C and mean Tset 25.08 °C (1.64 °C and 3.97 °C above mean Te, respectively). The species had a relatively narrow thermal tolerance range (25.89 °C). Furthermore, based on two different thermoregulatory indexes, we found direct evidence of active thermoregulation in X. newmanorum. This constitutes the first record of active thermoregulation in a xenosaurid from a low-elevation environment and the second record of thermal tolerances. We discuss on the thermal strategies of other species of the genus and pose that active thermoregulation might be more widespread in Xenosaurus than previously thought.

Overexpressing VvWRKY18 from grapevine reduces the drought tolerance in Arabidopsis by increasing leaf stomatal density

The growth of grapevine [Vitis vinifera L.] is commonly limited by drought stress. The mechanisms by which grapevine copes with drought stress have not yet been extensively clarified. In this study, the drought and abscisic acid (ABA)-induced gene VvWRKY18 was demonstrated to decreased drought tolerance of Arabidopsis thaliana overexpression (VvWRKY18-OE) lines. Compared to wild-type plants, VvWRKY18-OE lines showed increased levels of malonaldehyde (MDA) and the reactive oxygen species (ROS) H2O2 and O2− decreased levels of proline, weakened activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and decreased sensitivity to ABA with respect to stomatal closure.VvWRKY18-OE lines also showed an increase in stomatal density and a higher water loss rate. Negative regulators of stomatal development including SDD1, YDA, TMM, and MPK6, were downregulated in VvWRKY18-OE lines. Transcript levels of the stress-related genes DREB1A and CBF2 were significantly reduced in VvWRKY18-OE lines under drought stress. Taken together, these findings demonstrate that VvWRKY18 reduced drought tolerance in Arabidopsis. Our results contribute to understanding of the roles that WRKY genes play in drought stress and stomatal development.

Effect of water migration rate on the deformation characteristics of wheat starch/gluten extruded noodles

Excessive deformation destroys the structure of wheat flour-based noodles. Wheat starch/gluten extruded noodles with various starch contents were made by an extruder and dried under various relative humidities to control noodle deformation. The difference between water activity (aw) and relative humidity (RH) includes three models: decrease model [(aw-RH) 33%→6%], constant model [(aw-RH) 22%→23%], and increase model [(aw-RH) 22%→40%]. The water migration rate was high when the difference increased, or the starch content was relatively high. When the extruded noodles are in the glass state, the relatively high water loss rate, induced by the model of [(aw-RH) 22%→40%], causes a high change ratio of slice area, rough area ratio, and concavity percentage of extruded noodles. Therefore, the water loss rate and deformation degree of wheat starch/gluten extruded noodles can be controlled by the difference between the water activity of noodles and the relative humidity of the environment.

Upaya Penurunan Kehilangan Air Menggunakan Metode Water Balance (Teknik Step Test - Sounding) dan Analisis Finansial (Studi Kasus: Graha Indah, PDAM Tirta Manggar Kota Balikpapan)

Abstract. The most common problem that occurs in the distribution of drinking water supply caused by the high rate of water loss or Non-Revenue Water (NRW), no matter how much the water loss is, it is causing a lot of disadvantages for the PDAM and has greatly affects for the company's performance. One of the efforts of PDAM Balikpapan in improving the drinking water supply system is to establish the District Meter Area (DMA) to optimize of water loss controlling. This study is located in 2 (two) District Meter Areas (DMA) namely DMA Graha Indah 1 and DMA Graha Indah 2 where the selection of study locations is based on the largest water loss rate among DMA systems in Balikpapan City. The DMA system aims to divide a wide distribution system area and hydraulically isolate the system so that it only has 1 input system. The loss of water from the results of the Balikpapan City PDAM Report 2015 for Graha Indah residence amounted to 35.44%. This research using the Water Balance Method (WB) as the main method that consists of water meter reading, step test-sounding technique, pipe repair and also using ILI as an indicator of physical loss meanwhile for non-physical loss using water meter accuracy. This study also discusses the simulation of existing network hydraulics (using the WaterCAD software V8i) as an approach to indicate water loss based on pressure along the pipeline. In attempting to reduce water loss in the Graha Indah residence, 3 scenarios in which all scenarios left 5% non-physical loss results in increased accuracy of water meter reading using an Android-based application which is an effort to reduce non-physical loss from data component error handling sub-component, then for water meter inaccuracy and illegal connection sub-component entered into the calculation in the planned scenario 100% reduction in losses non-physical water with inaccurate efforts to renew water meters and control illegal connections. Then for the remaining physical losses of 10%, 7.5% and 5% in each scenario with efforts to reduce physical water loss is to repair leaks in service pipes in both DMA. The results of research at both DMA shows that the water loss rate is quite high, namely for DMA Graha Indah 1 46.94% or 163,012 m3 (127,159 3 physical loss; 35,853 m3 non-physical loss) and DMA Graha Indah 2 is 59, 2% or 211,017 m3 (184,596 m3 physical loss; 26,420 m3 non-physical loss). The results obtained after the pipe repair has decreased as much as 4% for DMA Graha Indah 1 and 41.16% for DMA Graha Indah 2. The selected scenario is based on financial feasibility with a 5-year analysis period (i = 4.98%). The results of financial feasibility proves that scenario 3 is a selected scenario for DMA Graha Indah 1 which NPV, BCR, and BEP values ​​respectively Rp. 9,430,810,135; 3.3295; 0.1086 and for DMA Graha Indah 2 the chosen scenario is scenario 3 which NPV, BCR, and BEP values respectively Rp 8,417,476,299; 2.767; 0.146. Keywords: Water loss, DMA, WB Method, Step test, Sounding, Simulation, Financial feasibility

Reducing Water Loss Based on Water Balance Method (By Using Step Test - Sounding Technique) and Financial Analysis (Case Study: Graha Indah Residence, PDAM Tirta Manggar In Balikpapan City)

Abstract. The most common problem that occurs in the distribution of drinking water supply caused by the high rate of water loss or Non-Revenue Water (NRW), no matter how much the water loss is, it is causing a lot of disadvantages for the PDAM and has greatly affects for the company's performance. One of the efforts of PDAM Balikpapan in improving the drinking water supply system is to establish the District Meter Area (DMA) to optimize of water loss controlling. This study is located in 2 (two) District Meter Areas (DMA) namely DMA Graha Indah 1 and DMA Graha Indah 2 where the selection of study locations is based on the largest water loss rate among DMA systems in Balikpapan City. The DMA system aims to divide a wide distribution system area and hydraulically isolate the system so that it only has 1 input system. The loss of water from the results of the Balikpapan City PDAM Report 2015 for Graha Indah residence amounted to 35.44%. This research using the Water Balance Method (WB) as the main method that consists of water meter reading, step test-sounding technique, pipe repair and also using ILI as an indicator of physical loss meanwhile for non-physical loss using water meter accuracy. This study also discusses the simulation of existing network hydraulics (using the WaterCAD software V8i) as an approach to indicate water loss based on pressure along the pipeline. In attempting to reduce water loss in the Graha Indah residence, 3 scenarios in which all scenarios left 5% non-physical loss results in increased accuracy of water meter reading using an Android-based application which is an effort to reduce non-physical loss from data component error handling sub-component, then for water meter inaccuracy and illegal connection sub-component entered into the calculation in the planned scenario 100% reduction in losses non-physical water with inaccurate efforts to renew water meters and control illegal connections. Then for the remaining physical losses of 10%, 7.5% and 5% in each scenario with efforts to reduce physical water loss is to repair leaks in service pipes in both DMA. The results of research at both DMA shows that the water loss rate is quite high, namely for DMA Graha Indah 1 46.94% or 163,012 m3 (127,159 3 physical loss; 35,853 m3 non-physical loss) and DMA Graha Indah 2 is 59, 2% or 211,017 m3 (184,596 m3 physical loss; 26,420 m3 non-physical loss). The results obtained after the pipe repair has decreased as much as 4% for DMA Graha Indah 1 and 41.16% for DMA Graha Indah 2. The selected scenario is based on financial feasibility with a 5-year analysis period (i = 4.98%). The results of financial feasibility proves that scenario 3 is a selected scenario for DMA Graha Indah 1 which NPV, BCR, and BEP values respectively Rp. 9,430,810,135; 3.3295; 0.1086 and for DMA Graha Indah 2 the chosen scenario is scenario 3 which NPV, BCR, and BEP values respectively Rp 8,417,476,299; 2.767; 0.146. Keywords: Water loss, DMA, WB Method, Step test, Sounding, Simulation, Financial feasibility

Potential Water and Energy Savings for Reducing Urban Water Supply Loss in China

The high water loss rate of the urban water supply system owing to the old and failing water supply pipe network may cause serious water leakage and consequently unnecessary energy waste. Taking water-scarce China as an example, we evaluated urban water loss and the accompanying electricity waste from the water supply network for 266 Chinese cities in 2015 and further designed different water loss control scenarios to assess the potential water and energy benefits in 2035. Results indicated that the quantity of water loss equaled the domestic water demand of 134.0 million urban residents, and the related electricity waste could meet the electricity demand of 4.4 million urban residents for a year. The potential water and energy savings in 2035 can reach up to 4.8–9.7 billion cubic meters and 1.7–3.3 TW·h in different scenarios, respectively. Cities with water scarcity show higher water loss rate, more electricity waste, and greater potential of water and energy savings compared with the others. For water-receiving cities along the South to North Water Transfer Project, the ratio of their total urban water loss to their total water transferred was as high as 70.9% in 2015, and potential water saving can be accounted for 0.2–44.1% of their total water transferred in 2035. We suggested that differentiated local water loss control can be an effective supplement to local water supply and water stress alleviation, as well as energy conservation.

Comprehensive analysis of MAPK cascade genes in sorghum (Sorghum bicolor L.) reveals SbMPK14 as a potential target for drought sensitivity regulation.

The mitogen-activated protein kinase (MAPK) cascade plays a crucial role in regulating many important biological processes in plants. Here, we identified and characterized eight MAPKK and 49 MAPKKK genes in sorghum and analyzed their differential expression under drought treatment; we also characterized 16 sorghum MAPK genes. RNA-seq analysis revealed that 10 MAPK cascade genes were involved in drought stress response at the transcriptome level in sorghum. Overexpression of SbMPK14 in Arabidopsis and maize resulted in hypersensitivity to drought by promoting water loss, indicating that SbMPK14 functions as a negative regulator of the drought response. Subsequent transcriptome analysis and qRT-PCR verification of maize SbMPK14 overexpression lines revealed that SbMPK14 likely increases plant drought sensitivity by suppressing the activity of specific ERF and WRKY transcription factors. This comprehensive study provides valuable insight into the mechanistic basis of MAPK cascade gene function and their responses to drought in sorghum.

The bHLH transcription factor AhbHLH112 improves the drought tolerance of peanut

BackgroundBasic helix-loop-helix (bHLH) transcription factors (TFs) are one of the largest gene families in plants. They regulate gene expression through interactions with specific motifs in target genes. bHLH TFs are not only universally involved in plant growth but also play an important role in plant responses to abiotic stress. However, most members of this family have not been functionally characterized.ResultsHere, we characterized the function of a bHLH TF in the peanut, AhHLH112, in response to drought stress. AhHLH112 is localized in the nucleus and it was induced by drought stress. The overexpression of this gene improves the drought tolerance of transgenic plants both in seedling and adult stages. Compared to wild-type plants, the transgenic plants accumulated less reactive oxygen species (ROS), accompanied by increased activity and transcript levels of antioxidant enzymes (superoxide dismutase, peroxidase and catalase). In addition, the WT plants demonstrated higher MDA concentration levels and higher water loss rate than the transgenic plants under drought treatment. The Yeast one-hybrid result also demonstrates that AhbHLH112 directly and specifically binds to and activates the promoter of the peroxidase (POD) gene. Besides, overexpression of AhHLH112 improved ABA level under drought condition, and elevated the expression of genes associated with ABA biosynthesis and ABA responding, including AtNCED3 and AtRD29A.ConclusionsDrawing on the results of our experiments, we propose that, by improving ROS-scavenging ability, at least in part through the regulation of POD -mediated H2O2 homeostasis, and possibly participates in ABA-dependent stress-responding pathway, AhbHLH112 acts as a positive factor in drought stress tolerance.

Genome-wide characterization of carotenoid oxygenase gene family in three cotton species and functional identification of GaNCED3 in drought and salt stress.

Cotton that serves natural fiber for the textile industry is an important industrial crop. However, abiotic stress imposed a significant negative impact on yield and quality of cotton fiber. Carotenoid cleavage oxygenases (CCOs) that specifically catalyze the cleavage of carotenoid are essential for plant growth and development and abiotic stress response. While information of cotton CCOs and their potential functions in abiotic stress is still far from satisfactory, which imposes restrictions on application in genetic breeding for stress resistance. In this study, 15, 15, and 30 CCOs were identified from Gossypium arboreum, Gossypium raimondii, and Gossypium hirsutum, respectively. Phylogenetic relationship indicated that CCO genes could be classified into two groups (NCEDs and CCDs). Cis-elements prediction showed that there were 18 types of stress-related cis-elements in promoter regions. Analysis with transcriptome data revealed tissue-specific expression pattern of cotton CCOs. qRT-PCR analysis revealed only that GhNCED3a_A/D and GhNCED3c_A/D had strong response to drought, salt, and cold stress, while GhCCD1_A/D and GhCCD4_A showed relatively slight expression changes. Virus-induced gene silencing of GaNCED3a, the ortholog gene of GhNCED3a_A/D, suggested that silenced plants exhibited decreased resistance not only to drought but also to salt, with significantly reduced proline content, and high malondialdehyde content and water loss rate. In addition, stress response genes RD29A, DREB1A, and SOS1 significantly downregulated under drought and salt stress in silenced plants compared to control plants, indicating that GaNCED3a played an important role in drought and salt response. The results provided valuable insights into function analysis of cotton CCOs in abiotic stress response, and suggested potential benefit genes for stress-resistant breeding.