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Salt solution pool boiling is of great significance in thermal engineering equipment, such as boilers and heat exchangers. Few researchers have been able to draw on systematic research into the impacts of salt concentration on boiling heat transfer coefficients. This experimental work is aimed to understand the role of dissolved salts on pool boiling performance, which is affected by surface wettability and bubble dynamics. Pool boiling experiment was conducted within a broad range of salt concentration. The results show two different tendencies for the two heating surfaces. The heat transfer coefficient is enhanced in the pin–fin heating surface while deteriorated in the bare heating surface as the salt concentration increased. It is indicated that salt solution promotes bubble diameter and nucleate density for ∼13% and 9%, respectively, by strengthening the hydrophobicity of the pin–fin heating surface. Hence, the boiling heat transfer is strengthened. [ABSTRACT FROM AUTHOR]

An image compression-encryption scheme utilizing the combination of fiber specklegram-based compressive sensing (CS) and double random phase encoding (DRPE) was demonstrated. The original image is compressed and encrypted by CS and then re-encrypted by DRPE. The measurement matrices for CS are constructed from multimode fiber specklegrams resulting from modes excitation and interference, which show better performance compared with those based on Gaussian random variables. Since fiber specklegrams have strong dependence on configuration, such measurement matrix can be constructed either by one specklegram or by specklegrams from different launched wavelengths. The double-encrypted image demonstrated good safety and reliability in several common attacks and presented high key sensitivity, which indicates good performance of the proposed scheme. [ABSTRACT FROM AUTHOR]

Mode excitations in D-shaped multimode fiber are analyzed in detail in terms of the effect of launch offset, polishing depth, and length of the D-shaped section. Based on the analysis, specklegrams from D-shaped multimode fiber structures are proposed to be applied in refractive index sensing. Glycerol solutions with different concentrations were used to study the relationship between the zero-mean normalized cross-correlation coefficient (ZNCC) of fiber output specklegrams and the surrounding refractive index. Responses of different D-shaped fiber structures are investigated and compared. For all of the structures, regular gradual changes of the ZNCC for each specklegram with the refractive index are found in a wide refractive index range of 1.352-1.444, which shows the feasibility of refractive index sensing. A high sensitivity being 10.47 RIU−1 is obtained by the structure with the polishing depth being $18~\mu \text{m}$ and length being 5cm. The proposed refractive sensing scheme is easy to realize with wide measurement range and high flexibility. [ABSTRACT FROM AUTHOR]

• Groundwater depth (GT) controlled transpiration dynamics of Populus tomentosa. • Diurnal (Q day) and nocturnal water use (Q night) had different seasonal trends. • Groundwater recharged Q night and reduced the water consumption from the stem. • Q night helped poplars refill the consumption of water stored in the stem (R e). • When GT < 170 cm of the surface, R e / Q night increased with increasing GT. For theories of forest water utilization over day-night cycles, it is important to have a reliable information on plant transpiration behaviors during daytime and nighttime and their environmental controls. With the help of thermal dissipation probes, our study investigated the seasonal variations in the diurnal (Q day) and nocturnal stand water use (Q night) of a Populus tomentosa plantation and explored their responses to groundwater table (GT) fluctuations and the meteorological factors. The results indicated that Q night occurred on most nights during the growing season in the P. tomentosa plantation, but with a different seasonal dynamic from Q day. A distinct increase in the ratio of nocturnal to daily water use appeared at the beginning and the end of the growing season. During the experimental period, stem refilling accounted for 61% of Q night , indicating that P. tomentosa was able to draw on stored water in the stem to support transpiration. The Q day and Q night were positively and negatively related to GT , respectively. When the GT varied within 170 cm of the surface, the proportion of stem refilling accounting for Q night increased with GT. The positive and negative correlations were found in meteorological factors with Q day and Q night , respectively. Among the single meteorological factors except for ET 0 , vapor pressure deficit (VPD) and photosynthetically active radiation (PAR) explained the highest variation in Q day in 2010 and 2011, respectively. In contrast, Q night was dominantly affected by VPD in 2011. Nocturnal stand water-use could help P. tomentosa to recharge the consumption of water stored in the stem and overcome the seasonal drought. The compensation effect of groundwater on the nocturnal stand water-use of P. tomentosa could reduce its consumption of water stored in the stem. As the stand age of P. tomentosa plantation varied, the key meteorological drivers of both Q day and Q night also changed. Our results enable better understanding of the water-use strategies of poplars in the North China Plain and can lead to refinement of current silvicultural techniques. [ABSTRACT FROM AUTHOR]

Highlights • Four different methods were applied to determine the optimal tensiometer placement. • The optimal tensiometer placement location should not change with stand age. • The tensiometer should best be placed 10 cm deep and 15 cm distant from the dripper. • This will optimize the schedule for drip irrigation in different aged Populus tomentosa forests. Abstract Determining the optimal tensiometer placement is crucial for scheduling irrigation based on soil water potential (SWP) in poplar plantations. However, such work has never been done. The stand-age effect on the tensiometer placement is still unknown, hindering the development of a dynamic irrigation regime. In a surface drip irrigated Populus tomentosa , short-rotation plantation on sandy loam soil, the variation of SWP at different positions [hereafter expressed in spatial coordinates (distance from dripper in cm, depth in cm)] within the soil wetting volume (WV), and the daily tree growth rates were continuously monitored in one growing season. Whereas, the transpiration and fine root distribution were measured in two growing seasons. The HYDRUS model was calibrated using soil water and transpiration data from one growing season and validated using data in another growing season. Then the model was applied to simulate sixty scenarios, which were combinations of different SWP measurement positions (ten scenarios), root distribution patterns (three scenarios; mainly using rooting depth as a proxy for trees at different ages), and irrigation thresholds (two scenarios). Based on the simulation results, we estimated the ratio of actual to potential transpiration (T a / T p) and irrigation efficiency (IE; calculated as (T a / T p)/irrigation amount) for each scenario. The absolute value of the mean relative difference of SWP was smaller at (15, 10) than at any other positions within the WV. The proportion of variation in growth (R2 = 0.294) and transpiration rates (R2 = 0.247) explained by root water-uptake was also highest at (15, 10). Fine roots concentrated on both sides of dripper as the trees grew bigger, with the maximal root density finally occurring at about (15, 10) and (−15, 10). Under the (−15, 10), (0, 10), (15, 10) and (0, 30) position scenarios, the T a / T p was at a high level relative to other scenarios, while the IE were at a middle level. As rooting depth increased, the ranks of different tensiometer positions in T a / T p and IE changed only a little, and T a / T p decreased slightly, implying the optimal placement should not vary with stand age. Therefore, tensiometer was recommended to place at 10 cm depth and about 15 cm distance from the dripper to schedule drip irrigation in different-aged P. tomentosa plantations on sandy loam soil. This will bring benefits to minimizing the use of irrigation water and maximizing production. Besides, the comprehensive approach used in this study can be adopted, when determining the optimal soil water measurement positions for scheduling irrigation for other plant species growing on other soil types. [ABSTRACT FROM AUTHOR]

The processing technology measures for the spinning of machine picked cotton with new blowing-carding unit were discussed. The technology performance of JWF1213 carding machine and the cotton assorting, processing configuration and processing parameters for Xinjiang machine picked cotton spinning were introduced. The indexes changing situation like neps and short fiber content of half finished product in each process together with the quality indexes of sliver and yarn were analyzed. The technology measures and matters needing attention for the spinning of Xinjiang machine picked cotton with blowing-carding unit were summarized. It is considered that picking process should focus on impurity removal, the drop gauge should be in larger control and the beater speed in each part should all be in smaller control according to the property of Xinjiang machine picked cotton with higher impurity rate. Carding should be moderated for carding machine and focusing on removing more short fibers and tiny impurities. The cotton feeding parameters of blowing-carding unit should be optimized and the function of auto-levelling should be well played to ensure the weight unevenness index of silver after blowing-car ding meeting the spinning requirement. [ABSTRACT FROM AUTHOR]

The accurate and fast calculation of circulating currents between strands for different transposition types is the important premise of the engineering design for stator bars in large turbo-generators. The air gap magnetic field partly enters into the stator slot, also generating circulating currents. However, there is a lack of fast simulation method for calculating the air gap magnetic field entering the stator slot in the existing calculation method for circulating currents. In this paper, the analytical algorithm of calculating circulating currents considering the air gap magnetic field entering stator slots is proposed, in which the equivalent circuit model of transposed strands in stator bars is established based on the superposition principle, the analytical algorithm of calculating the induced electromotive force is proposed based on the discrete integral method, and the analytical algorithm of calculating the air gap magnetic field entering stator slots is proposed based on the conformal mapping method. Then, a 1400-MW turbo-generator is taken as an example, circulating currents between transposed strands in stator bars under no-load and rated condition are calculated by the proposed analytical algorithm. Finally, the proposed analytical algorithm is validated by the two-dimensional finite element method. [ABSTRACT FROM AUTHOR]

Perfluorooctanoic acid (PFOA) is considered a persistent environmental pollutant. The aim of this study was to assess the potential toxicity of PFOA to earthworms ( Eisenia fetida) in artificial soil. The activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and glutathione S-transferase (GST) as well as the contents of malondialdehyde (MDA) were measured after exposure to 0, 5, 10, 20, and 40 mg kg PFOA in soils for 7, 14, 21, and 28 days. The results showed that SOD activity increased at 14 days and decreased from 21 to 28 days; MDA levels were highest in the treatment with 40 mg kg PFOA after 28 days of exposure. In contrast, CAT and POD activities increased after 14-21 days of exposure and significantly decreased with long-term exposure (28 days). GST activity increased significantly from 14 to 28 days. Our results indicate that PFOA has biochemical effects on E. fetida, thereby contributing to our understanding of the ecological toxicity of PFOA on soil invertebrates. [ABSTRACT FROM AUTHOR]

C/ZrC-SiC composites with a density of 3.09 g/cm 3 and a porosity of 4.8% were prepared by reactive melt infiltration and vapour silicon infiltration. The flexural strength and modulus were 235 MPa and 18.3 GPa, respectively, and the fracture toughness was 7.0 MPa m 1/2 . The formation of SiC and ZrSi 2 during vapour silicon infiltration, at the residual cracks and pores in the C/ZrC, enhanced the interface strength and its mechanical properties. The high flexural strength (223 MPa, c . 95% of the original value) after oxidation at 1600 °C for 10 min indicated the excellent oxidation resistance of the composites after vapour silicon infiltration. The mass loss and linear recession rate of the composites were 0.0071 g/s and 0.0047 mm/s, respectively and a fine ablation morphology was obtained. [ABSTRACT FROM AUTHOR]

Di- n-butyl phthalates (DBP) are recognized as ubiquitous contaminants in soil and adversely impact the health of organisms. Changes in the activity of antioxidant enzymes and levels of glutathione- S-transferase (GST), glutathione (GSH), and malondialdehyde (MDA) were used as biomarkers to evaluate the impact of DBP on earthworms ( Eisenia fetida) after exposure to DBP for 28 days. DBP was added to artificial soil in the amounts of 0, 5, 10, 50, and 100 mg kg of soil. Earthworm tissues exposed to each treatment were collected on the 7th, 14th, 21st, and 28th day of the treatment. We found that superoxide dismutase (SOD) and catalase (CAT) levels were significantly inhibited in the 100 mg kg treatment group on day 28. After 21 days of treatment, GST activity in 10-50 mg kg treatment groups was markedly stimulated compared to the control group. MDA content in treatment groups was higher than in the control group throughout the exposure time, suggesting that DBP may lead to lipid peroxidation (LPO) in cells. GSH content increased in the treatment group that received 50 mg kg DBP from 7 days of exposure to 28 days. These results suggest that DBP induces serious oxidative damage on earthworms and induce the formation of reactive oxygen species (ROS) in earthworms. However, DBP concentration in current agricultural soil in China will not constitute any threat to the earthworm or other animals in the soil. [ABSTRACT FROM AUTHOR]

The influences of fiber preform structure and thread engagement length on the mechanical properties of Carbon fiber reinforced silicon carbide matrix ( C/SiC) threaded joints were studied. The results show that stacking 3K carbon fiber cloth followed by stitching is a good preform for preparing a C/SiC nut because of its high bearing ability. Stacking 1K carbon fiber cloth followed by stitching is a preferred preform to prepare a C/SiC bolt, and its minimum thread engagement length resulting in bolt rupture instead of thread spalling failure is 4 mm, which is obviously smaller than those of other bolts. [ABSTRACT FROM AUTHOR]

A new method to form helical C/ Si C spring is proposed. Using paraffin mold as a sacrificial core, unidirectional carbon fiber bundles (infiltrated with resin) are wrapped around the mold to form helical spring, and after resin curing, the mold is removed, leaving a preform of C/ Si C spring. Following densification is finished with precursor infiltration and pyrolysis ( PIP) process. The spring constant of C/ Si C spring reaches 7.88 N/mm and could be regulated by varying composite density and carbon fiber content. The spring properties could be improved by twisting the carbon fibers at 35-50 twist/m. The restoration ratio reaches 100%, but energy dissipation happens during unloading process. After oxidation in air at 1200°C for 10 min, the spring has an 82.4% spring constant remaining ratio. [ABSTRACT FROM AUTHOR]

Abstract: This work is aimed at providing a new joining technology for C/SiC composites and investigating the influence of drilling holes, hole distribution (including ratios of edge distance to diameter (E/D), width to diameter (W/D) and hole distance to diameter (H/D)) and the number of applied pins on the mechanical properties of C/SiC substrates and joints. The mechanical testing results show that drilling holes and hole distribution greatly affects the mechanical properties of C/SiC substrates but when adopting an optimized design principle (E/D ⩾3, W/D ⩾3 and H/D ⩾3) the effect could be neglected. 1D C/SiC pins with higher shearing strength (107.2MPa) are more suitable to join the substrates. With the increase of pins (1, 2 and 4), the bearing loads of the joints increase almost linearly, and the reliability of joints is also improved in that the fracture mode changes from the interlayer damage to the substrate rupture. Besides, the joining process generates uniform and dense joining layer (composition of ZrC and SiC) and a strong bonding without obvious interface. [Copyright &y& Elsevier]

A field experiment was conducted in 2017 and 2018 to investigate the responses of fine root growth and morphology plasticity to drip irrigation and nitrogen fertigation (DIF) in a young triploid P. tomentosa plantation in the North China Plain. We monitored four DIF treatments (I20F0, I20FH, I45F0, I45FH), which were the combinations of two irrigation thresholds (− 20 kPa and − 45 kPa, denoted as I20 and I45) and two N fertigation amounts (0, denoted as F0; 220 and 260 kg N ha−1 year−1 in 2017 and 2018, denoted as FH). Some soil properties and aboveground growth parameters were also monitored. I20 significantly improved fine root biomass density (FRBD) by 156.92% and induced a significant reduction of specific root length (SRL) by 28.79% in 0–30 cm soil layers than I45, and FH significantly decreased fine root length density (− 62.88%), surface area (− 54.01%), and SRL (− 39.01%) in 30–80 cm soil layers than F0 in 2017. Fine root traits differed little among DIF treatments in 0–30 cm soil layers in 2018, but I20 significantly improved FRBD by 259.98% than I45 and FH significantly improved fine root averaged diameter by 67.14% in 30–80 cm soil layers than F0. These suggested that fine root had a conservative foraging strategy in water- and nitrogen-rich conditions. All the trait plasticity might be due to the changeable soil properties (i.e. soil water content, organic matter, nitrate and ammonium nitrogen, and total phosphorus). Based on the little difference of fine root mass among DIF treatments in two years, we hold the view that fine root distribution pattern and some growth and morphological traits adapted to water-nitrogen heterogeneity more easily than the mass plasticity in young aged P. tomentosa plantations. Yet enhancing our understanding of fine root foraging strategy in response to DIF practices and how it affects tree growth requires more attention to some physiological and biochemical processes and the growth dynamics of the root systems. • Fine root had a conservative foraging strategy in resource-rich conditions. • Key indices affecting fine root trait plasticity were SWC, OM, NO 3- -N, NH 4+ -N, and TP. • Fine root showed higher trait plasticity compared with mass plasticity under DIF practices. [ABSTRACT FROM AUTHOR]

Populus tomentosa is a dominant poplar species in North China. Clarifying the short-term response of fine roots to soil water gradient in the P. tomentosa plantation is helpful to have a better understanding on the ecological adaption strategy of plant roots to soil moisture. Three irrigation treatments were set in a two-year-old P. tomentosa stand planted on the sandy loam, i.e. full irrigation (DIFI), controlled irrigation (DICI), and control (CK). After 2 months of irrigation, root sampling down to 150 cm depth was conducted in each treatment using the soil core method. Through the measurement of root samples, the root growth, distribution and morphology data in each treatment, soil depth and horizontal distance were obtained. Vertically, in each soil layer, there is no significant difference in fine root biomass density (FRBD) among treatments (p > 0.05). In the whole root zone and the area with a large moisture difference in shallow soil layer among treatments, the distribution depth of fine root showed a characteristic of CK > DICI > DIFI. However, this characteristic was not observed in the area with less difference in soil water content. Horizontally, FRBD in CK decreased gradually with the increase of the distance from tree, but this trend was very weak in DIFI and DICI treatment. There was no significant difference of FRBD among treatments at each horizontal distance (p > 0.05), except for the distance of 30 cm from tree, where FRBD of CK was obviously higher than DIFI and DICI treatment (p < 0.05). On a two-dimensional scale, fine roots distribution tended to be shallower with the increasing distance from tree. Under irrigation, fine roots mainly concentrated in the shallow soil layers at both sides of the dripper, while a majority of fine roots in CK distributed in the relatively deeper soil layers close to the tree. For each soil layer within 0–50 cm, no significant difference in fine root morphology was found among treatments (p > 0.05). Both the variation of the total fine root biomass and length among the treatments followed an order of CK > DIFI > DICI. In conclusion, when a short-term moisture difference occurred in the shallow soil layers, 1) the fine roots of P. tomentosa distributed deeper and tended to concentrate closer to the tree with the aggravation of drought stress, 2) P. tomentosa preferentially adjusted the fine root distribution rather than the fine root morphology in the shallow soil layer to adapt to soil water stress, 3) as to the total amount of fine roots, P. tomentosa adopted a regulation strategy of slight decrease at first and then distinct increase. [ABSTRACT FROM AUTHOR]

To provide a theoretical basis for developing intensive cultivation practices for Populus tomentosa plantations, the leaf phenology variation within the canopy and its relationship with transpiration of well-watered P. tomentosa tree in a dense plantation were investigated. The variation in canopy light interception, indicated by the ratio between net radiation under (Rn-u) and above (Rn-a) canopy, with leaf development was also studied. During the growing season, the achievement of maximum leaf number tended to be later in higher parts of the canopy. In the lower and middle canopy, the leaf number maximized earlier in the east-facing side than in the west-facing side, but this difference disappeared in the upper canopy. The Rn-u/Rn-a was stable in May, but declined and then varied steadily until late August. Generally, in May, the crop coefficient (Kcb) of the tree reached its highest level and was not correlated with leaf area (LA) in all layers (p > 0.05). However, it increased linearly (p < 0.001) with LA in the layers above a canopy height of 3 m from June to late August, and most of its variation was explained by LA in the 5–7 m layer. After late August, Kcb decreased linearly with decreasing LA in all layers (p < 0.001). Consequently, a temporal ecological strategy seems to be adopted by P. tomentosa leaves in different layers and azimuthal sides for efficient light acquisition. The contribution of the different canopy layers to tree transpiration can vary, with the leaves in the upper and all layers mainly controlling transpiration in summer and in spring and autumn, respectively. [ABSTRACT FROM AUTHOR]

Late embryogenesis abundant (LEA) genes were confirmed to confer resistance to drought and water deficiency. An LEA gene from Tamarix androssowii (named TaLEA) was transformed into Xiaohei poplar (Populus simonii × P. nigra) via Agrobacterium. Twenty-five independent transgenic lines were obtained that were resistant to kanamycin, and 11 transgenic lines were randomly selected for further analysis. The polymerase chain reaction (PCR) and ribonucleic acid (RNA) gel blot indicated that the TaLEA gene had been integrated into the poplar genome. The height growth rate, malondialdehyde (MDA) content, relative electrolyte leakage and damages due to salt or drought to transgenic and non-transgenic plants were compared under salt and drought stress conditions. The results showed that the constitutive expression of the TaLEA gene in transgenic poplars could induce an increase in height growth rate and a decrease in number and severity of wilted leaves under the salt and drought stresses. The MDA content and relative electrolyte leakage in transgenic lines under salt and drought stresses were significantly lower compared to those in non-transgenic plants, indicating that the TaLEA gene may enhance salt and drought tolerance by protecting cell membranes from damage. Moreover, amongst the lines analyzed for stress tolerance, the transgenic line 11 (T11) showed the highest tolerance levels under both salinity and drought stress conditions. These results indicated that the TaLEA gene could be a salt and drought tolerance candidate gene and could confer a broad spectrum of tolerance under abiotic stresses in poplars. [ABSTRACT FROM AUTHOR]

• High-level irrigation increased soil water contents during dry months. • High-level irrigation enhanced early stand growth on sandy loam soils. • N fertigation increased mineral N concentration in top 0-20 cm soil layer. • N fertigation had no effect on tree growth in such young stands. • Precipitation influenced tree seasonal growth and mineral N distribution in soils. The patterns of soil water and mineral nitrogen (N min) distribution, stand growth, and N uptake in a triploid Populus tomentosa plantation under two-year drip irrigation and N fertigation (DIF) treatments were investigated. There was a positive relationship between stand growth and the amount of precipitation and irrigation. Precipitation and irrigation affected the content of N min in top 0−20 cm soil layer after fertigation and the redistribution of N min in the soil. There was no significant difference in N uptake in poplar plantation among DIF treatments, and the high-fertigation in the rainy seasons didn't enhance stand growth. Thus, high-level irrigation with lower N fertigation was recommended in the study area. The long-term effects of fertigation on tree stand growth and N min distribution in deep soil layers and underground water remain to be studied further. [ABSTRACT FROM AUTHOR]

Abstract: The form and water uptake characteristics of the fine root system in a 5-year-old triploid Populus tomentosa plantation were investigated to make recommendations related to irrigation water management for P. tomentosa plantation. Fine roots for analysis were collected from 2106 soil cores taken around eight trees. Soil moisture, trunk sap flow and evaporation were measured concurrently for four months in two experimental plots using time-domain reflectometry, thermal dissipation sensors and micro-lysimeters, respectively. Nearly half (44%) of fine roots corresponded to 0.2–0.5mm diameter. Generally, lateral root distribution was even, however, the vertical root profile showed an unusual pattern (nearly an ‘S’ shape). Dense fine roots occurred in surface soil and nearly one third (28%) of total fine roots occurred below 100cm depth, indicating the plantation had developed a dimorphic root system. With increasing distance from the tree, root distribution tended to be shallower. Mean fine root diameter was significantly larger (P <0.05) below 120cm, probably due to soil texture change or/and anoxia. Root water uptake in the 0–20cm layer contributed 58% of that within the 0–90cm soil layer, suggesting surface roots played the major water uptake role in shallow soil (<90cm). On average, P. tomentosa extracted 57% of transpired water from deep soil (>90cm), implying deep roots can contribute significantly to the water relations of mature P. tomentosa plantations. This functional significance of deep roots might be determined by their high length density and relatively large diameter. Based on these results, three irrigation management strategies were recommended: (1) irrigation schedules should be devised based on periodic measurement of the depth to water table; (2) water should be mainly provided to and maintained in the surface 40cm soil; and (3) water should be applied to the zone within 1m from the tree. [Copyright &y& Elsevier]

Late embryogenesis abundant (LEA) genes were confirmed to confer resistance to drought and water deficiency. An LEA gene from Tamarix androssowii (named TaLEA) was transformed into Xiaohei poplar (Populus simonii × P. nigra) via Agrobacterium. Twenty-five independent transgenic lines were obtained that were resistant to kanamycin, and 11 transgenic lines were randomly selected for further analysis. The polymerase chain reaction (PCR) and ribonucleic acid (RNA) gel blot indicated that the TaLEA gene had been integrated into the poplar genome. The height growth rate, malondialdehyde (MDA) content, relative electrolyte leakage and damages due to salt or drought to transgenic and non-transgenic plants were compared under salt and drought stress conditions. The results showed that the constitutive expression of the TaLEA gene in transgenic poplars could induce an increase in height growth rate and a decrease in number and severity of wilted leaves under the salt and drought stresses. The MDA content and relative electrolyte leakage in transgenic lines under salt and drought stresses were significantly lower compared to those in non-transgenic plants, indicating that the TaLEA gene may enhance salt and drought tolerance by protecting cell membranes from damage. Moreover, amongst the lines analyzed for stress tolerance, the transgenic line 11 (T11) showed the highest tolerance levels under both salinity and drought stress conditions. These results indicated that the TaLEA gene could be a salt and drought tolerance candidate gene and could confer a broad spectrum of tolerance under abiotic stresses in poplars. [ABSTRACT FROM AUTHOR]