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Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The experiment used the in vitro gas production method to study the feeding value of mixed silage with defective pears and Atriplex canescens, selecting 5 healthy Karakul sheep with similar body conditions as the rumen fluid donors. A single-factor random design was adopted, with a total of five treatment groups, each with five replicates. The proportions of Atriplex canescens to defective pears were added as 10:0 (control, CON group), 8:2 (20 LW group), 7:3 (30 LW group), 6:4 (40 LW group), and 5:5 (50 LW group), and then mixed with 1×106 CFU/g of lactic acid bacteria for silage. After ensiling for 90 days, the nutritional components, fermentation quality, gas production parameters, and ruminal degradability of the main nutrients were measured. The results showed that compared to the control group, the neutral detergent fiber (NDF) and acid detergent fiber (ADF) content in the silage of all mixed experimental groups were significantly reduced (P<0.05), while the content of water-soluble compounds (WSC) was significantly increased (P<0.05). Compared to the control group, the contentrations of lactic acid (LA), acetic acid (AA) and the concentration of ammonia nitrogen (NH3-N) in the silage of the mixed experimental groups were significantly increased (P<0.05), while the concentrations of propionic acid (PA) and butyric acid (BA) and the pH value were significantly decreased (P<0.05). The gas production rate of the 40 LW group and 50 LW group were significantly higher than the other three groups (P<0.05). Compared to the control group, the ruminal degradability of dry matter (DM), NDF, and ADF in all mixed experimental groups was significantly increased (P<0.05). The study indicates that the mixed silage of defective pears and Atriplex canescens can promote rumen fermentation in vitro, and the proportions of Atriplex canescens to defective pears is 7:3 and 6:4. [ABSTRACT FROM AUTHOR]

The reclamation of disturbed lands worldwide is a difficult and increasing problem. In the Mountain West region of the United States, mining activities commonly occur in zones dominated by native woody plants. The restoration of woody plants in these areas is challenging, and direct seeding efforts result in poor seedling emergence and establishment. Therefore, seedling transplants are often used, but they frequently experience high mortality during the first year, particularly due to summer stresses. We evaluated if the Groasis Waterboxx device could be used to mitigate drought stress on seedling transplants and improve their establishment on a reclaimed waste rock dump. The Waterboxx device collects precipitation into a polypropylene reservoir and slowly dispenses water onto the soil next to the seedling. To test such a hypothesis, 400 seedlings from five native woody plants (Atriplex canescens, Cercocarpus ledifolius, Pinus edulis, Purshia tridentata, and Rhus glabra) were planted with and without a Waterboxx. The Waterboxx device improved soil water potential, at 40 cm, it took 1 month longer to go below −1 MPa under a Waterboxx. Survival increased 30–65% in four of the five species, and seedling vigor increased for three of the five species. Vigor was higher with all plant species at both planting times and was significantly better in 50% of comparisons. Results support the use of the Waterboxx for improving seedling establishment on mineland overburden sites in the semiarid mountain west. The effectiveness of the Waterboxx device provides merit for future testing where drought challenges seedling establishment. [ABSTRACT FROM AUTHOR]

To combat desertification and lessen its effects on the impacted population, the Algerian government chose fodder plantation strategy by introducing Atriplex canescens, an invasive plant with high fodder value brought from the USA. A. canescens into Algerian pastures can potentially alter the floristic procession of the areas into which it is introduced. The objective of this work is to analyze the effect of planting A. canescens on the biodiversity and soil properties of a steppe pasture. In a planted rangeland, a floristic study is carried out using the linear method. Physico-chemical analyzes of the soil of this rangeland are carried out on a thickness of 0-40 cm. The results showed presence of 58 species, 46 genera and 22 families, with the predominance of Aster-aceae and Poaceae. The specific contribution of the two locale species Macrochloa tenacissima and Artemisia campestris decreases as soon as A. canescens is present in the rangeland. The soils water content is ranged from 0.356 to 1.291. Total nitrogen content in the planted rangeland, was within the normative range of 0.021 to 0.02 g/kg. A lowest value of pH 7.38 is observed in the plantation and the highest value 8.26 is measured in the non-planted rangeland. Electrical conductivity ranged from 0.155 mmhos/cm to 0.428 mmhos/cm. Sodium content varies from a minimum of 1.407g/kg to a maximum of 3.423 g/kg observed in the planted rangeland. Assimilable phosphorus levels are very low, almost traces. The observed potassium values are between 0.465 g/kg and 1.207 g/kg. Overall, A. canescens contributes to soil fertility but in the long term, it can compete with the presence of local plant species, particularly perennial ones. [ABSTRACT FROM AUTHOR]

Accumulated evidence indicates that species with small, rounded seeds predominantly maintain a persistent soil seed bank, while those having larger and less isodiametric seeds have a transient seed bank. We assumed that species in certain special habitats may be exceptions to this rule. In habitats with sandy soil and open vegetation, the seeds do not necessarily have to penetrate the deeper soil layers through cracks in the soil. Instead, the seeds can become buried by a windblown layer of sand, thus seed morphology does not really affect the burial process. To test our hypothesis, we selected five semi-desert shrubs and one perennial herb of open sandy grasslands, all of which had large and flattened seeds. For each species, 12 repetitions of 50 seeds were buried in the soil. Seeds were recovered after 3, 20 and 26 months of burial and subjected to germination tests. Seeds of each species germinated in all test occasions, with final germination as follows: Atriplex canescens 89.0%, Haloxylon ammodendron 11.5%, H. persicum 11.5%, Pteropyrum aucheri 43.5%, Xylosalsola richteri 12.0% and Asclepias syriaca 26.0%. The results confirm the hypothesis that each of the six species is capable of forming a persistent soil seed bank. The results also show that in habitats where seed burial can take place passively through windblown soil, plant species might bypass the tradeoff between seed size/shape and seed longevity. [ABSTRACT FROM AUTHOR]

[Objective] Atriplex canescens is a high-quality xerophytic shrub widely introduced in desertification control areas, and stubble is a main management measure for desertification control. Revealing the adaptability and compensatory growth mechanism in the recovery process after stubble can provide theoretical support for developing A . canescens into a high-quality feed in desert areas. [Methods] In this study, 5-year-old A . canescens plants were used as object. Through stubble treatment, plant height, crown width, photosynthetic reaction, leaf water potential, leaf hydraulic conductivity, and water use efficiency were measured during the recovery process of A . canescens, and the relationship between functional traits was discussed. [Results] (1) The plant height, crown width, and aboveground biomass of A . canescens after stubble were recovered to the pre-stubble state after a growing season. (2) The leaf water potential, leaf hydraulic conductivity, water use efficiency, and photosynthetic parameters of the stubble plants were higher than those of the control plants. (3) Linear fitting analysis showed that the midday leaf water potential and stomatal conductance of the stubble plants were significantly positively correlated with the growth rate. [Conclusion] A . canescens had good compensatory growth ability after stubble. In the early stage of recovery growth, the flat stubble plants showed higher compensatory growth ability and typical acquisition strategy, and then turned to conservative strategy with the decrease of hydraulic condition in the later stage. Stubble plants allocated more biomass and resource to the growth of aboveground parts such as branches and leaves, and the later resource allocation turned to the growth of underground parts.

The Algerian steppes face ecological imbalances due to overgrazing, cereal cultivation, and resource pressure. In response, the government implemented the "Great Works for the Development of Steppe Pastures" program in 1994, planting the nonnative Atriplex canescens, a shrub resistant to cold, drought, and salinity. However, introducing exotic plants can harm native biodiversity through allelopathy interaction. This work aims to test the allelopathic potentiel of A. canescens on the most representative North African steppe plant Macrochloa Tenacissima. Phytochemical tests are performed on the aerial parts of these two plants. Aqueous extracts are prepared from the aerial parts of A. canescens with three concentrations respectively T0 (0%), T1 (2.5%) and T2 (5%), and are applied in situ for 45 days on M. tenacissima plants. The response of M. tenacissima to the extract of A. canescens is monitored by measuring chlorophyll and proline in the fresh leaves of the target plant M. tenacissima. The results showed the presence of allopathic molecules in the aerial parts of both plants, notably Alkaloide, flavoniode, tannins, triterpnoide, Quinon and phenolic acid. The response of M. tenacissima to the application of A. canescens extract caused during the trial remarkable change in the total chlorophyll content of M. tenacissima, with reductions of 1 to 4 (mg/g FM) observed at the end of 45 days of application. The highest decrease is observed for treatment T3. After 45 days of treatment with A. canescens extract aqueous, M. tenacissima showed the highest proline accumulation 2.6 (mmol/g MF) for the treatment T3. Our findings show that A. canescens can induce physiological disruptions in M. tenacissima. [ABSTRACT FROM AUTHOR]

Key message: The content of flavonoids could increase in A. canescens under saline conditions. Overexpression of AcCHI in transgenic A. thaliana promotes flavonoid biosynthesis, thereby functioning in the tolerance of transgenic plants to salt and osmotic stress by maintaining ROS homeostasis. Atriplex canescens is a halophytic forage shrub with excellent adaptation to saline environment. Our previous study showed that a large number of genes related to the biosynthesis of flavonoids in A. canescens were significantly up-regulated by NaCl treatments. However, it remains unclear whether flavonoids are involved in A. canescens response to salinity. In this study, we found that the accumulation of flavonoids significantly increased in either the leaves or roots of A. canescens seedling under 100 and 300 mM NaCl treatments. Correspondingly, AcCHS, AcCHI and AcF3H, which encode three key enzymes (chalcone synthases (CHS), chalcone isomerase (CHI), and flavanone 3-hydroxylase (F3H), respectively) of flavonoids biosynthesis, were significantly induced in the roots or leaves of A. canescens by 100 or 300 mM NaCl. Then, we generated the transgenic Arabidopsis thaliana overexpressing AcCHI and found that transgenic plants accumulated more flavonoids through enhancing the pathway of flavonoids biosynthesis. Furthermore, overexpression of AcCHI conferred salt and osmotic stress tolerance in transgenic A. thaliana. Contrasted with wild-type A. thaliana, transgenic lines grew better with greater biomass, less H2O2 content as well as lower relative plasma permeability in either salt or osmotic stress conditions. In conclusion, our results indicate that flavonoids play an important role in A. canescens response to salt stress through reactive oxygen species (ROS) scavenging and the key enzyme gene AcCHI in flavonoids biosynthesis pathway of A. canescens has the potential to improve the stress tolerance of forages and crops. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Atriplex canescens adapts to saline soils by sequestering excessive Na+ in salt bladders on the surface of aerial tissues, which is a complex comprising epidermal cells (ECs), stalk cells (SCs) and epidermal bladder cells (EBCs). However, the mechanism of how Na+ enters salt bladders of A. canescens is not yet clear. We previously identified two A. canescens HKT1 genes that might be related to Na+ sequestration in salt bladders. The aim of this study was to evaluate the function of AcHKT1 genes in Na+ secretion. Results: Two AcHKT1 genes were cloned; AcHKT1;1 was largely expressed in roots, while AcHKT1;2 was mainly expressed in shoots and strongly induced by NaCl. Heterologous expression of AcHKT1;2 aggravated the Na+-sensitive phenotype in yeast. This result was further confirmed in Xenopus system, in which AcHKT1;2 exerted high selectivity for Na+, indicating that AcHKT1;2 functions as a plasma membrane-localized Na+ transporter and mediates robust Na+ influx at the cellular level. Interestingly, AcHKT1;2 expression in leaves was significantly reduced once salt bladders were removed from the leaf surfaces; in particular, it had the greatest impact on the expression in mature leaves with the strongest activity toward ion secretion, suggesting that AcHKT1;2 was predominantly expressed in the EC-SC-EBC complex of A. canescens leaves. Conclusions: AcHKT1;2 is a key candidate transporter involved in mediating the entry of Na+ into A. canescens EBCs, thereby facilitating continuous Na+ sequestration in EBCs to ensure the survival of plants in harsh saline environments. [ABSTRACT FROM AUTHOR]

Atriplex canescens is a representative halophyte with excellent tolerance to salt. Previous studies have revealed certain physiological mechanisms and detected functional genes associated with salt tolerance. However, knowledge on the ROS scavenging system and regulatory mechanisms in this species when adapting to salinity is limited. Therefore, this study further analyzed the transcriptional changes in genes related to the ROS scavenging system and important regulatory mechanisms in A. canescens under saline conditions using our previous RNA sequencing data. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation revealed that the differentially expressed genes (DEGs) were highly enriched in signal transduction- and reactive oxygen species-related biological processes, including "response to oxidative stress", "oxidoreductase activity", "protein kinase activity", "transcription factor activity", and "plant hormone signal transduction". Further analyses suggested that the transcription abundance of many genes involved in SOD, the AsA-GSH cycle, the GPX pathway, PrxR/Trx, and the flavonoid biosynthesis pathway were obviously enhanced. These pathways are favorable for scavenging excessive ROS induced by salt and maintaining the integrity of the cell membrane. Meanwhile, many vital transcription factor genes (WRKY, MYB, ZF, HSF, DREB, and NAC) exhibited increased transcripts, which is conducive to dealing with saline conditions by regulating downstream salt-responsive genes. Furthermore, a larger number of genes encoding protein kinases (RLK, CDPK, MAPK, and CTR1) were significantly induced by saline conditions, which is beneficial to the reception/transduction of salt-related signals. This study describes the abundant genetic resources for enhancing the salt tolerance in salt-sensitive plants, especially in forages and crops. [ABSTRACT FROM AUTHOR]

The experiment was to evaluate the feeding value of Atriplex canescens by in vitro gas production method and nylon bag method. The in vitro gas production test was used to determine the dynamic gas production at 72 h and the ammonia nitrogen (NH3-N) content and pH value of fermentation broth at 72 h of atriplex canescens (annual leaves, annual whole plants, annual stems, and biennial leaves). The above four samples were subjected to nylon bag experiment to determine the dry matter content at 72 h and main nutrient content at 12 and 24 h, and the rumen degradation rate was calculated. The results showed that under the same conditions, the nutrient content of biennial leaves was significantly higher than that of other experimental groups (P<0.05). The concentration of NH3-N in 72 h fermentation broth ranged from 134.30 to 165.50 mg/L, the annual stems, annual leaves and annual whole plants were significantly lower than those of two-year leaves (P<0.05). The degradation rates of DM, CP, EE, NDF and ADF nylon bags were as follows: Biennial leaves > annual leaves > annual whole plants > annual stems. The study indicates that Atriplex canescens has high nutritional value, which can be used as feed resources for ruminants, the nutrient content of biennial leaves is more comprehensive. [ABSTRACT FROM AUTHOR]

In situ revegetation is effective in improving water-stable aggregation, preserving structural stability, and decreasing groundwater pollution to reduce the environmental risks posed by alkaline bauxite residue (ABR). Pseudomonas simiae, a plant growth-promoting rhizobacteria (PGPR), was used to promote Atriplex canescens growth challenged by ABR. The mechanism of P. simiae-induced plant growth promotion and tolerance against ABR stresses has been investigated. P. simiae was shown to alleviate ABR-induced stress in A. canescens by regulating photosynthesis and transpiration, inducing antioxidant defense, causing osmolyte accumulation, and altering plant morphology. Shoot dry weight, root dry weight, and root length of A. canescens were increased by 5.9%, 6.7%, and 11.5%, respectively, after inoculation with P. simiae for 60 days. Thus, it seems that P. simiae systemically regulated physiological processes in A. canescens favoring its growth under ABR treatments. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is among the top staple foods in the world, and salinity adversely affects its yield and quality. To improve salt tolerance in potato, the present study is focused on the Agrobacterium-mediated transformation of potato by the Atriplex canescens betaine aldehyde dehydrogenase (BADH) gene driven by single, double, and triple CaMV 35S promoters. The study led first to the detection of seven lines containing the BADH gene followed by the identification of T-DNA insertions via DNA hybridization and enzyme-linked immunosorbent assays. The salt tolerance was found to be promoter dependent, as the lines with triple promoters showed a higher resistance than those tranformed with single and double promoters. The transgenic lines showed lower content of H2O2 and malondialdehyde and a lower relative electrical conductivity than wild-type plants. Furthermore, these lines also showed higher proline and chlorophyll content. In silico analysis confirmed that the A. canescens BADH protein had a remarkable tendency to interact with sodium ions and water molecules like other BADH proteins. Taken together, the overexpression of BADH under triple CaMV 35S promoters enhanced salt tolerance of potato.

Abstract Background Atriplex canescens is a typical C4 secretohalophyte with salt bladders on the leaves. Accumulating excessive Na+ in tissues and salt bladders, maintaining intracellular K+ homeostasis and increasing leaf organic solutes are crucial for A. canescens survival in harsh saline environments, and enhanced photosynthetic activity and water balance promote its adaptation to salt. However, the molecular basis for these physiological mechanisms is poorly understood. Four-week-old A. canescens seedlings were treated with 100 mM NaCl for 6 and 24 h, and differentially expressed genes in leaves and roots were identified, respectively, with Illumina sequencing. Results In A. canescens treated with 100 mM NaCl, the transcripts of genes encoding transporters/channels for important nutrient elements, which affect growth under salinity, significantly increased, and genes involved in exclusion, uptake and vacuolar compartmentalization of Na+ in leaves might play vital roles in Na+ accumulation in salt bladders. Moreover, NaCl treatment upregulated the transcripts of key genes related to leaf organic osmolytes synthesis, which are conducive to osmotic adjustment. Correspondingly, aquaporin-encoding genes in leaves showed increased transcripts under NaCl treatment, which might facilitate water balance maintenance of A. canescens seedlings in a low water potential condition. Additionally, the transcripts of many genes involved in photosynthetic electron transport and the C4 pathway was rapidly induced, while other genes related to chlorophyll biosynthesis, electron transport and C3 carbon fixation were later upregulated by 100 mM NaCl. Conclusions We identified many important candidate genes involved in the primary physiological mechanisms of A. canescens salt tolerance. This study provides excellent gene resources for genetic improvement of salt tolerance of important crops and forages.

Soil pollution by petroleum hydrocarbon pollutants is one of the most important environmental problems in different parts of the world. In the oil-rich regions of the west of the country and recent years, the depreciation of the oil extraction and exploitation system has led to leakage and distribution of oil pollutants in the soil and biological resources of the region. This study aimed to investigate the potential use of native rangeland plants and the addition of bacteria, and the amount of appropriate fertilizer to reduce pollution of total petroleum hydrocarbons (TPHs) in the soil. The pot experiment was performed in the form of a factorial design with a completely randomized design (CRD) with four replications. Plant treatments included three native or compatible plants of Medicago sativa, Agropyron trichophorum, and Atriplex canescens and bacterial treatments included Bacillus pumilus (B1), Pseudomonas putida (B2), and the combined use of these two bacteria with fertilizer recommendation based on soil testing. Also, control treatment (no plant culture, no bacterial inoculation, and no fertilization) was applied. The results showed that Medicago sativa, with a 55.16% reduction in soil TPHs had better performance than other plants. Inoculation of B1 bacterium in interaction with Medicago sativa and Agropyron trichophorum by decomposing 56.19% of soil TPHs was more successful than B2. However, Atriplex canescens was more successful than B1 in interacting with B2 bacteria and decomposing 54.64% of soil TPHs. With full fertilizer recommendation, Medicago sativa and Atriplex canescens plants were most effective, with a 68.56% reduction in soil TPHs. In soil treatment without plant cultivation, B2 bacterium had the best performance along with fertilizer recommendation. Bacteria improve phytoremediation efficiency by improving metabolic activities and developing the root system, and ultimately increasing plant biomass. The results showed a significant effect of interaction between bacteria and plant type on plant shoot dry weight at the level of α = 0.01. [ABSTRACT FROM AUTHOR]

La steppe algérienne est le milieu d’élevage du mouton par l’exploitation de ses parcours. Dans sa partie aride, la vulnérabilité du milieu est aggravée par une exploitation principalement pastorale de plus en plus intense durant ces dernières décennies. Cette tendance régressive est caractérisée par une baisse de la productivité fourragère et les espèces pérennes sont les plus touchées. L’Etat algérien a mis en oeuvre un programme d’aménagement des espaces steppiques très dégradés à travers la plantation d’espèces végétales résistantes et productives de biomasse comme Atriplex spp. L’objectif de ce travail a été d’estimer la productivité pastorale de quelques stations réhabilitées par la plantation d’Atriplex canescens, comparativement aux parcours naturels pâturés. Les résultats ont montré une amélioration du recouvrement végétal (de 49 % à 60 %) et de meilleures valeurs pastorales (phytomasse, productivité, valeur énergétique et charge pastorale). Sur les zones réhabilitées une productivité énergétique et protéique de 604 unités fourragères lait / ha/an et 29 kg de matière sèche / ha/an, et une charge pastorale de 1,51 unité ovine / ha/an ont été enregistrées, alors que sur les parcours naturels dégradés ces valeurs ont été respectivement de 14 UFL, 0,422 kg MS/ha/an, et 0,03 unité ovine / ha/an. Les stations naturelles sont surexploitées et tendent vers un état de dégradation sévère de la végétation et des sols steppiques. A moins de restaurer ou de réhabiliter les parcours steppiques, leur capacité de productivité pastorale sera fortement réduite.

Aim of study: We tested the hypothesis that long periods of grazing exclusion in areas with a history of high grazing intensity will have a positive impact on soil nutrient conditions and favor soil infiltration, increase biomass and lead to a recovery in vegetation. Area of study: Noria de Guadalupe, Zacatecas, Mexico. Material and methods: We analyzed the impact of grazing exclusion on biomass, species richness, evenness, soil nutrient content and soil water infiltration after 25 years of exclusion during each of the four seasons by excluding two 15 × 15 m plots of grazing and compared with two control plots. Main results: Exclusion management did not lead to biomass increases; however, it did lead to an important recovery in the plant community. Moreover, soil nutrient content was more affected by the seasonality of rainfall in the study site than by 25 years of exclusion. The elimination of dominant shrubs in the excluded area led to a faster recovery in palatable shrubs and shortgrass vegetation, which was improved by better infiltration values during the end of spring and summer explaining some of the differences in nutrient avaibility. Research highlights: In our study, exclusion management can lead to an important recovery in vegetation without affecting the growth of Atriplex canescens, a valuable source of fodder. Although biomass presented a higher dependence on seasonality and was not related to the treatment, the impact on the forage quality is evident by the different plant communities established after 25 years of exclusion.

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Atriplex canescens is a C 4 shrub with excellent adaptation to saline and arid environments. Our previous study showed that the secretion of excessive Na+ into leaf salt bladders is a primary strategy in salt tolerance of A. canescens and external 100 mM NaCl can substantially stimulate its growth. To investigate whether NaCl could facilitate Atriplex canescens response to drought stress, five-week-old seedlings were subjected to drought stress (30% of field water capacity) in the presence or absence of additional 100 mM NaCl. The results showed that, under drought stress, the addition of NaCl could substantially improve the growth of A. canescens by increasing leaf relative water content, enhancing photosynthetic activity and inducing a significant declined leaf osmotic potential (Ψs). The addition of NaCl significantly increased Na+ concentration in leaf salt bladders and the Na+ contribution to leaf Ψs , while had no adverse effects on K+ accumulation in leaf laminae. Therefore, the large accumulation of Na+ in salt bladders for enhancing osmotic adjustment (OA) ability is a vital strategy in A. canescens responding to drought stress. In addition, the concentration of free proline, bataine and soluble sugars exhibited a significant increase in the presence of NaCl under drought stress, and the betaine contribution to leaf Ψs was significantly increased by additional NaCl compared with that under drought treatment alone, suggesting that compatible solutes are also involved in OA in addition to functioning as protectants to alleviate water deficit injury. • A. canescens could grow well in drought soils that contain certain salt. • Na+ secretion and K+ retention are vital strategies for A. canescens to cope with water deficit. • NaCl improves photosynthesis and hydration of A. canescens under drought stress. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is among the top staple foods in the world, and salinity adversely affects its yield and quality. To improve salt tolerance in potato, the present study is focused on the Agrobacterium-mediated transformation of potato by the Atriplex canescens betaine aldehyde dehydrogenase (BADH) gene driven by single, double, and triple CaMV 35S promoters. The study led first to the detection of seven lines containing the BADH gene followed by the identification of T-DNA insertions via DNA hybridization and enzyme-linked immunosorbent assays. The salt tolerance was found to be promoter dependent, as the lines with triple promoters showed a higher resistance than those tranformed with single and double promoters. The transgenic lines showed lower content of H2O2 and malondialdehyde and a lower relative electrical conductivity than wild-type plants. Furthermore, these lines also showed higher proline and chlorophyll content. In silico analysis confirmed that the A. canescens BADH protein had a remarkable tendency to interact with sodium ions and water molecules like other BADH proteins. Taken together, the overexpression of BADH under triple CaMV 35S promoters enhanced salt tolerance of potato. [ABSTRACT FROM AUTHOR]

Climate change is known as one of the most important environmental challenges. Sequestration of carbon in terrestrial ecosystems is a low-cost option that may be available in the near-term to mitigate increasing atmospheric CO2 concentrations, while providing additional benefits. In this study, we estimated the effects of planting density and grazing intensity on the potential of Atriplex canescens for carbon sequestration in a rangeland in Qazvin Province, Iran. The experimental design consisted of a randomized block design, including two planting densities (2 × 2m and 4 × 4m) and four grazing intensity treatments simulated by different plant pruning intensities. We observed no significant difference between the rate (%) of organic carbon in the treatments of density, grazing intensity, and their interaction in the 0-30cm and 30-80cm soil layers. Between the treatments of height pruning, control (no pruning) and light grazing, had the highest total biomass and total carbon. The total biomass carbon content of 2370 kg.m-2 in the 2×2m treatment was about twice as much that of 4x4m treatment. These findings can be useful in rangeland management plans.

Key Message: The content of flavonoids could increase in A. canescens under saline conditions. Overexpression of AcCHI in transgenic A. thaliana promotes flavonoid biosynthesis, thereby functioning in the tolerance of transgenic plants to salt and osmotic stress by maintaining ROS homeostasis. Atriplex canescens is a halophytic forage shrub with excellent adaptation to saline environment. Our previous study showed that a large number of genes related to the biosynthesis of flavonoids in A. canescens were significantly up-regulated by NaCl treatments. However, it remains unclear whether flavonoids are involved in A. canescens response to salinity. In this study, we found that the accumulation of flavonoids significantly increased in either the leaves or roots of A. canescens seedling under 100 and 300 mM NaCl treatments. Correspondingly, AcCHS, AcCHI and AcF3H, which encode three key enzymes (chalcone synthases (CHS), chalcone isomerase (CHI), and flavanone 3-hydroxylase (F3H), respectively) of flavonoids biosynthesis, were significantly induced in the roots or leaves of A. canescens by 100 or 300 mM NaCl. Then, we generated the transgenic Arabidopsis thaliana overexpressing AcCHI and found that transgenic plants accumulated more flavonoids through enhancing the pathway of flavonoids biosynthesis. Furthermore, overexpression of AcCHI conferred salt and osmotic stress tolerance in transgenic A. thaliana. Contrasted with wild-type A. thaliana, transgenic lines grew better with greater biomass, less H 2 O 2 content as well as lower relative plasma permeability in either salt or osmotic stress conditions. In conclusion, our results indicate that flavonoids play an important role in A. canescens response to salt stress through reactive oxygen species (ROS) scavenging and the key enzyme gene AcCHI in flavonoids biosynthesis pathway of A. canescens has the potential to improve the stress tolerance of forages and crops., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Graphical abstract Highlights • Selenium was a limiting factor for gazing ruminants. • NAA was used to determine seasonal changes of Se in A. canescens and S. fruticosa. • Seasons had a significant effect on Se content in both species. • Se contents were deficient to meet ruminant requirements. • Se supplementation was to support optimum livestock productivity. Abstract Neutron activation analysis laboratory (NAA measurement) was applied for the determination of selenium (Se) contents in two perennial forage species (Atriplex canescens (Pursh.) Nutt. and Suaeda fruticosa (Linn.) Forssk) used in extensive livestock production systems, in arid rangelands of Algeria. Se content was estimated in leaves and in the soil in which the plants were grown. The vegetal and soil samples were irradiated for 6 h duration with a thermal neutron flux of 4.5 × 1013 cm−2 s−1 of Es-Salam research reactor (Berine, Algeria). The daily intake of Se was determined and compared with the values recommended by National Research Council (NRC) guidelines. Result showed that the highest contents of Se were found in the rainy period (January–15 winter) for both species. By way of contrast, for the surrounding soil this metalloid was higher during dry season (July–15 summer). The maximum uptake of Se was predominantly recorded in A. canescens (0.16 ± 0.07 μg g−1) compared to S. fruticosa (0.07 ± 0.03 μg g−1). The bioaccumulation factor (BF Se) from soil to plant showed a high enrichment of Se especially for A. canescens. In conclusion, this study envisages that A. canescens can be gazed by livestock in winter season as a source of Se; however the problem of Se deficiency was expected during the other seasons for animals grazing A. canescens and S. fruticosa. [ABSTRACT FROM AUTHOR]

Ethylene-responsive factors (ERFs) comprise a large family of transcription factors in plants and play important roles in developmental processes and stress responses. Here, we characterized a novel AP2/ERF transcription factor, AcERF2, from the halophyte Atriplex canescens (four-wing saltbush, Chenopodiaceae ). AcERF2 was proved to be a transcriptional activator in yeast and localized to the nucleus upon transient expression in Nicotiana benthamiana, indicating its potential role as a transcription factor. Overexpression of AcERF2 driven by a CaMV35S promoter led to decreased accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), and increased antioxidant enzymatic activities, as well as rapid stomatal closure under osmotic treatment in Arabidopsis . Arabidopsis plants overexpressing AcERF2 were hypersensitive to abscisic acid (ABA) during germination, seedling establishment, and primary root elongation, and exhibited significant tolerance to osmotic stress. Furthermore, overexpression of AcERF2 induced transcript accumulation of plant defense-related genes ( PR1 , PR2 , PR5 , ERF1 and ERF3 ) and increased Arabidopsis resistance to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 and the necrotrophic fungal pathogen Botrytis cinerea. These results suggest that AcERF2 may play a positive modulation role in response to osmotic stress and pathogen infection in plants. [ABSTRACT FROM AUTHOR]

Plant productivity is limited by salinity stress, both in natural and agricultural systems. Identification of salt stress-related genes from halophyte can provide insights into mechanisms of salt stress tolerance in plants. Atriplex canescens is a xero-halophyte that exhibits optimum growth in the presence of 400 mM NaCl. A cDNA library derived from highly salt-treated A. canescens plants was constructed based on a yeast expression system. A total of 53 transgenic yeast clones expressing enhanced salt tolerance were selected from 105 transformants. Their plasmids were sequenced and the gene characteristics were annotated using a BLASTX search. Retransformation of yeast cells with the selected plasmids conferred salt tolerance to the resulting transformants. The expression patterns of 28 of these stress-related genes were further investigated in A. canescens leaves by quantitative reverse transcription-PCR. In this study, we provided a rapid and robust assay system for large-scale screening of genes for varied abiotic stress tolerance with high efficiency in A. canescens. [ABSTRACT FROM AUTHOR]

Atriplexspecies are tolerant to salinity and water stress and thus they are suitable for restoration of many degraded ecosystems. In addition, manyAtriplexspecies offer good value as forages. We compared growth and leaf chemistry ofAtriplex canescens, a well-known halophyte, andA. acanthocarpa, a poorly-studied species, as affected by salinity in a greenhouse study. Seeds and soil were collected in northern Mexico, the native range of these species. Plants were grown in pots containing native soil and irrigated with NaCl solutions of 0, 50, and 100 mM. Shoot growth ofA. canescensdeclined 37% as NaCl treatments increased from 0 to 100 mM while shoot growth ofA acanthocarpawas not significantly affected by salinity. The high salt tolerance ofA. acanthocarpawas linked to a high accumulation of leaf sodium (Na) (7- to 13-fold higher thanA. canescens).A. acanthocarpahad also higher growth rate thanA. canescenes, making the former species a good candidate for cultivation, especially under saline conditions. Tissue concentration of potassium (K) in both species was minimally affected by the salinity treatments. Leaf nitrogen (N) concentration increased as plants faced higher salinity treatments, especially inA. canescens. The high salt tolerance and higher Na accumulation ofA. acanthocarpamake this species an attractive choice for reclamation of saline areas. We suggestA. acanthocarpashould be explored as viable forage for cultivation and for reclamation of degraded areas just asA. canescenshas been throughout the world. [ABSTRACT FROM AUTHOR]

The present study investigated pH, electrical conductivity (EC), Al level, and exchangeable sodium percentage (ESP) in a range of alkaline bauxite residue (ABR) treatments. Also investigated was the content change of reactive oxygen species (ROS), malondialdehyde (MDA), and protein carbonyl (PCO) in leaves of Atriplex canescens [L.] challenged by ABR in the presence/absence of gypsum (Gy). Local cinnamon soil (CS) was used to improve the nutrient status and physical condition of ABR. Analysis revealed that CS/ABR (2:1, w/w) induced much more hydroxyl radical (OH ) accumulation, lipid peroxidation (LPO), and protein oxidation (PO) than CS/ABR/Gy (6:3:1, w/w) did. While superoxide radical (O 2 −) and hydrogen peroxide (H 2 O 2 ) accumulation showed little difference between CS/ABR and CS/ABR/Gy treatments. Further, exogenous OH aggravated LPO and PO in a way similar to CS/ABR treatment, which was impaired by OH  scavengers such as proline and mannitol. Taken together, the data indicate that OH  is more connected with severe oxidative damages than O 2 − and H 2 O 2 in this case. The caustic properties of ABR can be ameliorated by gypsum to support vegetation. [ABSTRACT FROM AUTHOR]

It has often been stated or implied that grazing is an important factor in the land degradation process, a suggestion supported by various research projects, and this study investigated the effect of livestock grazing on stem height, crowncover, production, basal diameter, stem biomass, litter, leaf-stem index (leaf to stem weight) , root diameter and weight and seed production per individual of the even-aged Atriplex canescens , by comparing two sites (grazed and non-grazed) across Zarand, Shahreiar rangelands located in the southwestern of Tehran, Iran. For this purpose, by using systematicrandom sampling method, four 300 m long transects were set up in each sampling area and ten quadrats were randomly assigned per transect [8] to measure the stem height as well as the crown cover, production, basal diameter, stem biomass, litter, leaf-stem index , seed production per individual and root biomass and diameter were measured at 3 soil depth (0-30, 30-70, >70 cm) with 4 replications within each of the two studied sites, results indicated that, grazing had no significantinfluence on stem height and leaf-stem index but crown cover, production, basal diameter, stem biomass, litter, seed production per individual, root weight and diameter of the even -aged Atriplex canescens were significantly greater than those of the un-grazed site.

Abstract One basic method of improving rangelands in a country is the use of native as well as exotic species of plants adaptable. Among the but introduced species, Atriplex canescens has been introduced in many rangelands, but it is important and necessary to consider it’s effects on native species. In the current study the effect of chemical competition (allelopathy) of Atriplex canescens on germination of Salsola rigida has been taken into account. Salsola rigida is known as a native species of good quality traits in arid and semi-arid rangelands. In this survey 10% weight/volume (w/v) of extract from leaves and fruits of A. canescens was prepared and 25%, 50%, 75% and 100% concentrations were obtained through addition of distilled water. Distilled water was used as control treatment. Altogether five treatments of four replicates, based on a completely randomized design (CRD) were studied germination during 8 days. Different groups of treatments were categorized through Duncan’s new multiple range test. The results indicated that the available material in shoots of Atriplex canescens (fruits and leaves) exhibited allelopathic effect on germination of Salsola rigida. The highest percentage of germination was obtained from control while the lowest from the 100% treatment. In fact after exceeding of 25% concentration, germination reached its lowest percentage due to Atriplex effects.

An ErbB-3-binding protein gene AcEBP 1, also known as proliferation-associated 2G4 gene ( PA2G4s ) belonging to the M24 superfamily, was obtained from the saltbush Atriplex canescens . Subcellular localization imaging showed the fusion protein AcEBP1-eGFP was located in the nucleus of epidermal cells in Nicotiana benthamiana. The AcEBP1 gene expression levels were up-regulated under salt, osmotic stress, and hormones treatment as revealed by qRT-PCR. Overexpression of AcEBP1 in Arabidopsis demonstrated that AcEBP1 was involved in root cell growth and stress responses (NaCl, osmotic stress, ABA, low temperature, and drought). These phenotypic data were correlated with the expression patterns of stress responsive genes and PR genes. The AcEBP1 transgenic Arabidopsis plants also displayed increased sensitivity under low temperature and evaluated resistance to drought stress. Together, these results demonstrate that AcEBP1 negatively affects cell growth and is a regulator under stress conditions. [ABSTRACT FROM AUTHOR]

Atriplex canescens (fourwing saltbush) is a C4 perennial fodder shrub with excellent resistance to salinity. However, the mechanisms underlying the salt tolerance in A. canescens are poorly understood. In this study, 5-weeks-old A. canescens seedlings were treated with various concentrations of external NaCl (0-400 mM). The results showed that the growth of A. canescens seedlings was significantly stimulated by moderate salinity (100 mM NaCl) and unaffected by high salinity (200 or 400 mM NaCl). Furthermore, A. canescens seedlings showed higher photosynthetic capacity under NaCl treatments (except for 100 mM NaCl treatment) with significant increases in net photosynthetic rate and water use efficiency. Under saline conditions, the A. canescens seedlings accumulated more Na+ in either plant tissues or salt bladders, and also retained relatively constant K+ in leaf tissues and bladders by enhancing the selective transport capacity for K+ over Na+ (ST value) from stem to leaf and from leaf to bladder. External NaCl treatments on A. canescens seedlings had no adverse impact on leaf relative water content, and this resulted from lower leaf osmotic potential under the salinity conditions. The contribution of Na+ to the leaf osmotic potential (9s) was sharply enhanced from 2% in control plants to 49% in plants subjected to 400 mM NaCl. However, the contribution of K+ to 9s showed a significant decrease from 34% (control) to 9% under 400 mM NaCl. Interestingly, concentrations of betaine and free proline showed significant increase in the leaves of A. canescens seedlings, these compatible solutes presented up to 12% of contribution to 9s under high salinity. These findings suggest that, under saline environments, A. canescens is able to enhance photosynthetic capacity, increase Na+ accumulation in tissues and salt bladders, maintain relative K+ homeostasis in leaves, and use inorganic ions and compatible solutes for osmotic adjustment which may contribute to the improvement of water status in plant. [ABSTRACT FROM AUTHOR]