Zinc-finger protein MdBBX7/MdCOL9, a target of MdMIEL1 E3 ligase, confers drought tolerance in apple.

Water deficit is one of the main challenges for apple (Malus × domestica) growth and productivity. Breeding drought-tolerant cultivars depends on a thorough understanding of the drought responses of apple trees. Here, we identified the zinc-finger protein B-BOX 7/CONSTANS-LIKE 9 (MdBBX7/MdCOL9), which plays a positive role in apple drought tolerance. The overexpression of MdBBX7 enhanced drought tolerance, whereas knocking down MdBBX7 expression reduced it. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis identified one cis-element of MdBBX7, CCTTG, as well as its known binding motif, the T/G box. ChIP-seq and RNA-seq identified 1,197 direct targets of MdBBX7, including ETHYLENE RESPONSE FACTOR (ERF1), EARLY RESPONSIVE TO DEHYDRATION 15 (ERD15), and GOLDEN2-LIKE 1 (GLK1) and these were further verified by ChIP-qPCR and electronic mobility shift assays. Yeast two-hybrid screen identified an interacting protein of MdBBX7, RING-type E3 ligase MYB30-INTERACTING E3 LIGASE 1 (MIEL1). Further examination revealed that MdMIEL1 could mediate the ubiquitination and degradation of MdBBX7 by the 26S proteasome pathway. Genetic interaction analysis suggested that MdMIEL1 acts as an upstream factor of MdBBX7. In addition, MdMIEL1 was a negative regulator of the apple drought stress response. Taken together, our results illustrate the molecular mechanisms by which the MdMIEL1-MdBBX7 module influences the response of apple to drought stress.

Fine-tuning of SUMOylation modulates drought tolerance of apple.

SUMOylation is involved in various aspects of plant biology, including drought stress. However, the relationship between SUMOylation and drought stress tolerance is complex; whether SUMOylation has a crosstalk with ubiquitination in response to drought stress remains largely unclear. In this study, we found that both increased and decreased SUMOylation led to increased survival of apple (Malus × domestica) under drought stress: both transgenic MdSUMO2A overexpressing (OE) plants and MdSUMO2 RNAi plants exhibited enhanced drought tolerance. We further confirmed that MdDREB2A is one of the MdSUMO2 targets. Both transgenic MdDREB2A OE and MdDREB2AK192R OE plants (which lacked the key site of SUMOylation by MdSUMO2A) were more drought tolerant than wild-type plants. However, MdDREB2AK192R OE plants had a much higher survival rate than MdDREB2A OE plants. We further showed SUMOylated MdDREB2A was conjugated with ubiquitin by MdRNF4 under drought stress, thereby triggering its protein degradation. In addition, MdRNF4 RNAi plants were more tolerant to drought stress. These results revealed the molecular mechanisms that underlie the relationship of SUMOylation with drought tolerance and provided evidence for the tight control of MdDREB2A accumulation under drought stress mediated by SUMOylation and ubiquitination.

Testing the limits of plant drought stress and subsequent recovery in four provenances of a widely distributed subtropical tree species.

Drought-induced tree mortality may increase with ongoing climate change. Unraveling the links between stem hydraulics and mortality thresholds, and the effects of intraspecific variation, remain important unresolved issues. We conducted a water manipulation experiment in a rain-out shelter, using four provenances of Schima superba originating from a gradient of annual precipitation (1124-1796 mm) and temperature (16.4-22.4°C). Seedlings were droughted to three levels of percentage loss of hydraulic conductivity (i.e., P50 , P88  and P99) and subsequently rewatered to field capacity for 30 days; traits related to water and carbon relations were measured. The lethal water potential associated with incipient mortality was between P50 and P88 . Seedlings exhibited similar drought responses in xylem water potential, hydraulic conductivity and gas exchange. Upon rehydration, patterns of gas exchange differed among provenances but were not related to the climate at the origin. The four provenances exhibited a similar degree of stem hydraulic recovery, which was correlated with the magnitude of antecedent drought and stem soluble sugar at the end of the drought. Results suggest that there were intraspecific differences in the capacity of S. superba seedlings for carbon assimilation during recovery, indicating a decoupling between gas exchange recovery and stem hydraulics across provenances.

Abscisic acid homeostasis is mediated by feedback regulation of MdMYB88 and MdMYB124.

The phytohormone abscisic acid (ABA) is involved in various plant processes. In response to drought stress, plants quickly accumulate ABA, but the regulatory mechanism of ABA accumulation is largely unknown, especially in woody plants. In this study, we report that MdMYB88 and MdMYB124 are myeloblastosis (MYB) transcription factors critical for ABA accumulation in apple trees (Malus x domestica) following drought, and this regulation is negatively controlled by ABA. MdMYB88 and MdMYB124 positively regulate leaf water transpiration, photosynthetic capacity, and stress endurance in apple trees under drought conditions. MdMYB88 and MdMYB124 regulate the expression of biosynthetic and catabolic genes of ABA, as well as drought- and ABA- responsive genes. MdMYB88 associates with promoter regions of the ABA biosynthetic gene 9-cis-epoxycarotenoid dioxygenase 3 (NCED3). Finally, expression of MdMYB88 and MdMYB124 is repressed by ABA. Our results identify a feedback regulation of MdMYB88 and MdMYB124 in modulating ABA homeostasis in apple trees.

Global photosynthetic capacity is optimized to the environment.

Earth system models (ESMs) use photosynthetic capacity, indexed by the maximum Rubisco carboxylation rate (Vcmax ), to simulate carbon assimilation and typically rely on empirical estimates, including an assumed dependence on leaf nitrogen determined from soil fertility. In contrast, new theory, based on biochemical coordination and co-optimization of carboxylation and water costs for photosynthesis, suggests that optimal Vcmax can be predicted from climate alone, irrespective of soil fertility. Here, we develop this theory and find it captures 64% of observed variability in a global, field-measured Vcmax dataset for C3 plants. Soil fertility indices explained substantially less variation (32%). These results indicate that environmentally regulated biophysical constraints and light availability are the first-order drivers of global photosynthetic capacity. Through acclimation and adaptation, plants efficiently utilize resources at the leaf level, thus maximizing potential resource use for growth and reproduction. Our theory offers a robust strategy for dynamically predicting photosynthetic capacity in ESMs.

The China Plant Trait Database: toward a comprehensive regional compilation of functional traits for land plants.

Plant functional traits provide information about adaptations to climate and environmental conditions, and can be used to explore the existence of alternative plant strategies within ecosystems. Trait data are also increasingly being used to provide parameter estimates for vegetation models. Here we present a new database of plant functional traits from China. Most global climate and vegetation types can be found in China, and thus the database is relevant for global modeling. The China Plant Trait Database contains information on morphometric, physical, chemical, and photosynthetic traits from 122 sites spanning the range from boreal to tropical, and from deserts and steppes through woodlands and forests, including montane vegetation. Data collection at each site was based either on sampling the dominant species or on a stratified sampling of each ecosystem layer. The database contains information on 1,215 unique species, though many species have been sampled at multiple sites. The original field identifications have been taxonomically standardized to the Flora of China. Similarly, derived photosynthetic traits, such as electron-transport and carboxylation capacities, were calculated using a standardized method. To facilitate trait-environment analyses, the database also contains detailed climate and vegetation information for each site. The data set is released under a Creative Commons BY license. When using the data set, we kindly request that you cite this article, recognizing the hard work that went into collecting the data and the authors' willingness to make it publicly available.

A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring.

In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

Novel Concrete Temperature Monitoring Method Based on an Embedded Passive RFID Sensor Tag.

This paper firstly introduces the importance of temperature control in concrete measurement, then a passive radio frequency identification (RFID) sensor tag embedded for concrete temperature monitoring is presented. In order to reduce the influences of concrete electromagnetic parameters during the drying process, a T-type antenna is proposed to measure the concrete temperature at the required depth. The proposed RFID sensor tag is based on the EPC generation-2 ultra-high frequency (UHF) communication protocol and operates in passive mode. The temperature sensor can convert the sensor signals to corresponding digital signals without an external reference clock due to the adoption of phase-locked loop (PLL)-based architecture. Laboratory experimentation and on-site testing demonstrate that our sensor tag embedded in concrete can provide reliable communication performance in passive mode. The maximum communicating distance between reader and tag is 7 m at the operating frequency of 915 MHz and the tested results show high consistency with the results tested by a thermocouple.

Long-term water stress leads to acclimation of drought sensitivity of photosynthetic capacity in xeric but not riparian Eucalyptus species.

BACKGROUND AND AIMS: Experimental drought is well documented to induce a decline in photosynthetic capacity. However, if given time to acclimate to low water availability, the photosynthetic responses of plants to low soil moisture content may differ from those found in short-term experiments. This study aims to test whether plants acclimate to long-term water stress by modifying the functional relationships between photosynthetic traits and water stress, and whether species of contrasting habitat differ in their degree of acclimation. METHODS: Three Eucalyptus taxa from xeric and riparian habitats were compared with regard to their gas exchange responses under short- and long-term drought. Photosynthetic parameters were measured after 2 and 4 months of watering treatments, namely field capacity or partial drought. At 4 months, all plants were watered to field capacity, then watering was stopped. Further measurements were made during the subsequent 'drying-down', continuing until stomata were closed. KEY RESULTS: Two months of partial drought consistently reduced assimilation rate, stomatal sensitivity parameters (g1), apparent maximum Rubisco activity (V'(cmax)) and maximum electron transport rate (J'(max)). Eucalyptus occidentalis from the xeric habitat showed the smallest decline in V'(cmax) and J'(max); however, after 4 months, V'(cmax) and J'(max) had recovered. Species differed in their degree of V'(cmax) acclimation. Eucalyptus occidentalis showed significant acclimation of the pre-dawn leaf water potential at which the V'(cmax) and 'true' V(cmax) (accounting for mesophyll conductance) declined most steeply during drying-down. CONCLUSIONS: The findings indicate carbon loss under prolonged drought could be over-estimated without accounting for acclimation. In particular, (1) species from contrasting habitats differed in the magnitude of V'(cmax) reduction in short-term drought; (2) long-term drought allowed the possibility of acclimation, such that V'(cmax) reduction was mitigated; (3) xeric species showed a greater degree of V'(cmax) acclimation; and (4) photosynthetic acclimation involves hydraulic adjustments to reduce water loss while maintaining photosynthesis.

A Novel Passive Wireless Sensor for Concrete Humidity Monitoring.

This paper presents a passive wireless humidity sensor for concrete monitoring. After discussing the transmission of electromagnetic wave in concrete, a novel architecture of wireless humidity sensor, based on Ultra-High Frequency (UHF) Radio Frequency Identification (RFID) technology, is proposed for low-power application. The humidity sensor utilizes the top metal layer to form the interdigitated electrodes, which were then filled with polyimide as the humidity sensing layer. The sensor interface converts the humidity capacitance into a digital signal in the frequency domain. A two-stage rectifier adopts a dynamic bias-voltage generator to boost the effective gate-source voltage of the switches in differential-drive architecture. The clock generator employs a novel structure to reduce the internal voltage swing. The measurement results show that our proposed wireless humidity can achieve a high linearity with a normalized sensitivity of 0.55% %RH at 20 °C. Despite the high losses of concrete, the proposed wireless humidity sensor achieves reliable communication performances in passive mode. The maximum operating distance is 0.52 m when the proposed wireless sensor is embedded into the concrete at the depth of 8 cm. The measured results are highly consistent with the results measured by traditional methods.

Impact of inhibitor loaded with pigments content on properties of inorganic zinc rich coatings.

In order to overcome the poor dispersion of traditional inorganic zinc-rich coating, addressing the sedimentation and the agglomeration caused by high zinc powder content and improve the anti-corrosion performance of coatings. In this paper, the molybdate intercalated hydrotalcite flake zinc layer double hydroxide (ZnAl-NO3-/LDH) was synthesized by hydrothermal synthesis method at first, and the KH560 modified the Mo/LDH flake zinc powder was further obtained by ion exchange method. The results show that the samples have a layered structure of hydrotalcite with good crystal structure through X-ray diffraction (XRD) and Fourier transform infrared (FT-IR), and the molybdate corrosion inhibiting ions inserted successfully into the interlayer structure of hydrotalcite. Meanwhile, different contents of pigments and fillers were added into the inorganic zinc-rich coatings. It was found that the Nyquist radius of curvature and modulus value of the coating were the largest with a pigment and filler content of 40 %, the maximum corrosion potential was -0.017V, and the minimum corrosion current density was 3.377 × 10-7 A-cm-2. The result indicates that the coating has the best corrosion resistance with 40 % pigment content, which has good application prospects in the fields of cross-sea bridges, natural gas and oil pipelines et al.

Removal of typical PFAS from water by covalent organic frameworks with different pore sizes.

Adsorption is highly effective and desirable for the removal of per- and polyfluoroalkyl substances (PFAS) from water, and suitable pore size of porous adsorbents is important for efficient removal of PFAS, but the relationship between adsorbent pore size and PFAS adsorption remains unclear. In this study, five regular covalent organic frameworks (COFs) with distinct pore sizes were successfully synthesized, and the correlation between the pore size of COFs and PFAS length for efficient PFAS adsorption was investigated. Both excessively small and large pore sizes of COFs are not conducive to the efficient adsorption of PFAS due to the diffusion hindrance and weak binding forces. The COFs with a pore size ranging from 2.5 to 4.0 times of the PFAS molecular size demonstrated the most suitable for PFAS adsorption. This study also investigated the potential impact of nanobubbles on PFAS adsorption on orderly porous COFs through aeration and degassing treatment of the adsorption system. The bubbles on hydrophobic COFs were verified to be responsible for PFAS adsorption, another important adsorption mechanism of PFAS on COFs. The long-chain PFAS have stronger enrichment at the gas-liquid interface than the short-chain PFAS, resulting in higher adsorption capacity for long-chain PFAS.

Multidimensional Transport Experiment and Simulation of Chloride Ions in Concrete Subject to Simulated Dry and Wet Cycles in a Marine Environment.

Chloride ion erosion is an important factor affecting the durability of marine engineering concrete. In particular, concrete structures in wave splash and tidal zones are subjected to dry and wet cycles and multidimensional diffusion of chloride ions. To investigate the intricate diffusion of chloride ions within concrete under these dynamic conditions, we devised a comprehensive experiment. This experiment encompasses multiple dimensions, involving dry and wet cycles, as well as static immersion. The experiment intends to reveal how chloride ions are distributed in the concrete and clarify the changes that occur in its microstructure. Based on Fick's second law, the multidimensional diffusion model of chloride ions in concrete under the dry and wet cycles and static immersion was established by comprehensively considering the effects of chloride ion exposure time, environment temperature, relative humidity, and the action of dry and wet cycles. The results show that, under the same conditions, the chloride content in concrete decreases with the increase in penetration depth but increases with the increase in the chloride diffusion dimension and exposure time. Dry and wet cycles and multidimensional diffusion of chloride ions increase the development of cracks and pores in the concrete structure and generate large quantities of C3A·CaCl2·10H2O, which will exacerbate the chloride ion transport rate and penetration depth of concrete. Under the same exposure time and penetration depth, the chloride ion content in concrete under two-dimensional (2D) and three-dimensional (3D) diffusion under dry and wet cycles was 1.09~4.08 times higher than that under one-dimensional (1D) diffusion. The correlation coefficients between the simulation results of the multidimensional transport model of chloride ions in concrete under multi-factor coupling and the experimental results were all greater than 0.95, and the model can be utilized to predict the distribution of chloride ion concentration in concrete.

Efficient adsorption and degradation of dyes from water using magnetic covalent organic frameworks with a pyridinic structure.

Covalent organic frameworks (COFs) have promising applications in environmental remediation owing to their precise directional synthesis and superior adsorption ability. However, magnetic COFs with pyridinic N have not been studied as bifunctional materials for the adsorption and catalytic degradation of dyes. Therefore, in this study, a magnetic COF with a pyridinic structure (BiPy-MCOF) was successfully synthesized using a solvothermal method, which exhibited higher methyl orange (MO) removal than other common adsorbents. The best degradation efficiency via the Fenton-like reaction was obtained by pre-adsorbing MO for 3 h at pH 3.1. Both adsorption and catalytic degradation resulted in better removal of MO under acidic conditions. The introduction of pyridinic N improved MO adsorption and degradation on BiPy-MCOF. The electrostatic potential (ESP) showed that pyridinic N had a strong affinity for MO adsorption. Density functional theory calculations confirmed the potential sites on MO molecules that may be attacked by free radicals. Possible degradation pathways were proposed based on the experimental results. Moreover, BiPy-MCOF could effectively degrade MO at least four times, and a high degradation efficiency was obtained in other dyes applications. The coupling of adsorption and degradation demonstrated that the as-prepared BiPy-MCOF was an effective material for organic dyes removal from water.

Post-synthetic thiol modification of covalent organic frameworks for mercury(II) removal from water.

Various materials have been developed for environmental remediation of mercury ion pollution. Among these materials, covalent organic frameworks (COFs) can efficiently adsorb Hg(II) from water. Herein, two thiol-modified COFs (COF-S-SH and COF-OH-SH) were prepared, through the reaction between 2,5-divinylterephthalaldehyde and 1,3,5-tris-(4-aminophenyl)benzene, followed by post-synthetic modification using bis(2-mercaptoethyl) sulfide and dithiothreitol, respectively. The modified COFs showed excellent Hg(II) adsorption abilities with maximum adsorption capacities of 586.3 and 535.5 mg g-1 for COF-S-SH and COF-OH-SH, respectively. The prepared materials showed excellent selective absorbability for Hg(II) against multiple cationic metals in water. Unexpectedly, the experimental data showed that both co-existing toxic anionic diclofenac sodium (DCF) and Hg(II) performed positive effect for capturing another pollutant by these two modified COFs. Thus, a synergistic adsorption mechanism between Hg(II) and DCF on COFs was proposed. Moreover, density functional theory calculations revealed that synergistic adsorption occurred between Hg(II) and DCF, which resulted in a significant reduction in the adsorption system's energy. This work highlights a new direction for application of COFs to simultaneous removal of heavy metals and co-existing organic pollutants from water.

Evolution Law of Structural Form and Heat Transfer Performance of Thermal Insulation System.

Building thermal insulation and energy conservation have become urgent problems in the field of civil engineering because they are important for achieving the goal of carbon neutralization. Thermal conductivity is an important index for evaluating the thermal insulation of materials. To study the influence of different porosity levels on the thermal conductivity of materials, this paper established a random distribution model using MATLAB and conducted a comparative analysis using COMSOL finite element software and classical theoretical numerical calculation formulas. The thermal conductivity of composite materials was determined based on a theoretical calculation formula and COMSOL software simulations, and the theoretical calculation results and simulation results were compared with the measured thermal conductivity of the composites. Furthermore, the influence of the width of the gaps between the materials on the heat transfer process was simulated in the fabricated roof structure. The results showed the following: (1) The thermal conductivity values calculated using the Zimmerman model were quite different from those calculated using the Campbell-Allen model and those calculated using the COMSOL software; (2) The thermal conductivity values calculated using the theoretical calculation formula were lower than the measured data, and the maximum relative error was more than 29%. The COMSOL simulation results were in good agreement with the measured data, and the relative error was less than 5%; (3) When the gap width was less than 60 mm, it increased linearly with the heat transfer coefficient. The heat transfer coefficient increased slowly when the gap width was greater than 60 mm. This was mainly due to the thermal bridge effect inside the insulation system. Based on these research results, a thermal insulation system was prepared in a factory.

Insights into the molecular mechanisms underlying responses of apple trees to abiotic stresses.

Apple (Malus[Formula: see text]domestica) is a popular temperate fruit crop worldwide. However, its growth, productivity, and quality are often adversely affected by abiotic stresses such as drought, extreme temperature, and high salinity. Due to the long juvenile phase and highly heterozygous genome, the conventional breeding approaches for stress-tolerant cultivars are time-consuming and resource-intensive. These issues may be resolved by feasible molecular breeding techniques for apples, such as gene editing and marker-assisted selection. Therefore, it is necessary to acquire a more comprehensive comprehension of the molecular mechanisms underpinning apples' response to abiotic stress. In this review, we summarize the latest research progress in the molecular response of apples to abiotic stressors, including the gene expression regulation, protein modifications, and epigenetic modifications. We also provide updates on new approaches for improving apple abiotic stress tolerance, while discussing current challenges and future perspectives for apple molecular breeding.

Crack Texture Feature Identification of Fiber Reinforced Concrete Based on Deep Learning.

Structural cracks in concrete have a significant influence on structural safety, so it is necessary to detect and monitor concrete cracks. Deep learning is a powerful tool for detecting cracks in concrete structures. However, it requires a large quantity of training samples and is costly in terms of computational time. In order to solve these difficulties, a deep learning target detection framework combining texture features with concrete crack data is proposed. Texture features and pre-processed concrete data are merged to increase the number of feature channels in order to reduce the demand of training samples for the model and improve training speed. With this framework, concrete crack detection can be realized even with a limited number of samples. To accomplish this aim, self-made steel fiber reinforced concrete crack data is used for comparison between our framework and those without texture feature mergence or pre-processed concrete data. The experimental results show that the number of parameters that need to be fitted in the model training and training time can be correspondingly reduced and the detection accuracy can also be improved.

Towards a unified theory of plant photosynthesis and hydraulics.

The global carbon and water cycles are governed by the coupling of CO2 and water vapour exchanges through the leaves of terrestrial plants, controlled by plant adaptations to balance carbon gains and hydraulic risks. We introduce a trait-based optimality theory that unifies the treatment of stomatal responses and biochemical acclimation of plants to environments changing on multiple timescales. Tested with experimental data from 18 species, our model successfully predicts the simultaneous decline in carbon assimilation rate, stomatal conductance and photosynthetic capacity during progressive soil drought. It also correctly predicts the dependencies of gas exchange on atmospheric vapour pressure deficit, temperature and CO2. Model predictions are also consistent with widely observed empirical patterns, such as the distribution of hydraulic strategies. Our unified theory opens new avenues for reliably modelling the interactive effects of drying soil and rising atmospheric CO2 on global photosynthesis and transpiration.

Intercalating negatively charged pillars into graphene oxide sheets to enhance sulfonamide pharmaceutical removal from water.

Herein, novel composite materials were prepared by intercalating functional pillars, i.e., pentafluorobenzene (PFB) and sodium 2,3,4,5,6-pentafluorobenzoate (PFBS), into graphene oxide (GO) sheets. It led to forming size hives and increased availability of intrinsic area of GO. The synthesized materials (GO-PFB and GO-PFBS) were investigated as adsorbents to eliminate sulfadiazine (SD) from aqueous solutions. The adsorption capacities of GO-PFBS (1002.21 µmol/g) and GO-PFB (564.17 µmol/g) were 6.37 and 3.59 times higher than that of GO (157.21 µmol/g), respectively. The adsorption of SD onto GO-PFBS decreased with increasing solution pH. Density functional theory (DFT) results revealed that the SD adsorption onto the adsorbents was exothermic, and the introduction of the carboxylate groups showed lower binding energy. It was found that hydrophobic interaction fully participates in the adsorption process, and the electrostatic complementation of hydrogen bonding further enhances the SD adsorption. Obtained results showed that intercalating functional rigid molecules as pillars to support GO sheets could improve its adsorption behavior.