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Mature xerophytes access groundwater and minimize the risk of water and nutrient deficits in arid environments. However, how their young seedlings respond to the availability of water and nutrients before they reach groundwater is largely unknown. We investigated the effects of different drought regimes (controlled, medium-drought (MD), and severe-drought (SD)] and nitrogen (N; with or without) addition on biomass and physio-biochemical responses in Alhagi sparsifoliaseedlings. Both drought stresses significantly increased superoxide dismutase (O2•−), hydrogen peroxide (H2O2), malondialdehyde, and oxidized-glutathione in leaves and roots, thereby impairing growth and metabolism. Furthermore, there is a significant accumulation of fructose and glucose, but lower sucrose and starch, possibly due to higher sucrose synthase, α-amylase, β-amylase and hexokinase but lower sucrose phosphate synthase and fructokinase. Drought-stressed seedlings also displayed higher abscisic and, jasmonic acids, strigolactones, glucose-6-phosphate dehydrogenase (G-6-PDH), phosphoenolpyruvate carboxylase, O2•−-H2O2-scavenging enzymes, but lower gibberellin, cytokinin, and indole-acetic acid. However, N-addition quantifies the productivity of drought-stressed seedlings by improving the leaf relative water content (LRWC), biomass, chlorophyll-a, sucrose-synthesizing enzymes (SPP and SPS), and hormones. It also increased the G-6-PDH in stressed seedlings to satisfy the need for NADPH and reduced the sucrose and starch degrading enzymes, leading to higher starch and sucrose levels. Upregulation of O2•−-H2O2-scavenging enzymes under N-supply reduced lipid peroxidation and improved the ascorbate–glutathione redox states. N addition might be an effective strategy to improve drought resistance in A. sparsifoliaseedlings to manage and conserve its vegetation in hyper-arid conditions in the face of future climate change.

Cotton is a highly sensitive crop to drought stress. Consequently, it is crucial to devise strategies that optimize crop production in conditions of limited water availability. While potassium silicate has demonstrated effectiveness in mitigating drought stress in various crops, its specific impact on different cotton cultivars under drought conditions remains not fully clarified. This research aimed to assess the efficacy of six potassium silicate levels (0, 100, 200, 300, 400 and 500 mg L−1) on four cotton genotypes (Zong main-113, Xin Nong-525, Xin lu Zhong-55, and Xin lu Zhong-66) under two field capacity levels (80% and 50% FC) in a sand culture. Foliar applied potassium silicate significantly improved photosynthetic efficiency, shoot biomass, root biomass, and leaf area under water stress (50% FC). The most substantial reduction in H2O2, malondialdehyde levels, and electrolyte leakage was recorded with potassium silicate applied at a rate of 400 mg L−1. This concentration effectively mitigated reactive oxygen species accumulation, safeguarding plants against oxidative damage at 50% FC. Furthermore, potassium silicate contributed to maintaining water status, resulting in increased leaf water content and elevated water-soluble proteins in cotton plants. The order of drought resistance (50% FC) with the application of potassium silicate at 400 mg L−1was Zong Mian-113, Xin Nong-525, Xin lu Zhong-55, and Xin lu Zhong-66. The findings could help in selection of drought resistance cultivars of cotton in water limited conditions.

Biochar , a low-cost material produced from the thermal pyrolysis of biomass, has multiple applications in the environment, energy, and agriculture sectors. These biochar applications have attracted global attention in the context of preparation, behaviour in a particular environment, modification, and especially aging processes. Biochar undergoes certain changes in their physical and biochemical characteristics due to different factors which are called aging and are triggered by biotic and abiotic processes. Numerous studies have focussed on the effectiveness of biochar by improving their properties using rapid and controlled laboratory conditions to scale up their applications. However, the impact of biotic- and abiotic-derived aging processes, their possible impact on biochar physicochemical properties, and how they affect the eco-toxicity and long-term stability of biochar in the environment has not been discussed in detail. This review mainly focused on the biotic- and abiotic-derived alterations in pore volume, surface area, elemental composition, surface functional groups, and molecular structures of biochar, leading to higher adsorption capacity, improving soil fertility, and possible changes in biochar stability. Extrapolation of biotic- and abiotic-derived changes in the biochar properties will help to understand the environmental risk of biochar and their sustainable field application for soil remediation and improving agricultural productivity.

At present, a variety of vaccines have been approved, and existing antiviral drugs are being tested to find an effective treatment for coronavirus disease 2019 (COVID-19). However, no standardized treatment has yet been approved by the World Health Organization. The virally encoded chymotrypsin-like protease (3CLpro) from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which facilitates the replication of SARS-CoV in the host cells, is one potential pharmacological target for the development of anti-SARS drugs. Online search engines, such as Web of Science, Google Scholar, Scopus and PubMed, were used to retrieve data on the traditional uses of medicinal plants and their inhibitory effects against the SARS-CoV 3CLpro. Various pure compounds, including polyphenols, terpenoids, chalcones, alkaloids, biflavonoids, flavanones, anthraquinones and glycosides, have shown potent inhibition of SARS-CoV-2 3CLproactivity with 50% inhibitory concentration (IC50) values ranging from 2–44 µg/mL. Interestingly, most of these active compounds, including xanthoangelol E (isolated from Angelica keiskei), dieckol 1 (isolated from Ecklonia cava), amentoflavone (isolated from Torreya nucifera), celastrol, pristimerin, tingenone and iguesterin (isolated from Tripterygium regelii), tannic acid (isolated from Camellia sinensis), and theaflavin-3,3′-digallate, 3-isotheaflav1in-3 gallate and dihydrotanshinone I (isolated from Salvia miltiorrhiza), had IC50values of less than 15 µg/mL. Kinetic mechanistic studies of several active compounds revealed that their mode of inhibition was dose-dependent and competitive, with Kivalues ranging from 2.4–43.8 μmol/L. Given the significance of plant-based compounds and the many promising results obtained, there is still need to explore the phytochemical and mechanistic potentials of plants and their products. These medicinal plants could serve as an effective inexpensive nutraceutical for the general public to help manage COVID-19.

In this biosorption study, the potential of Acacia nilotica bark in simultaneous removal of Ni and aminoazobenzene was investigated. For this purpose, the impact of different experimental conditions on the co-biosorption potential of Acacia nilotica bark was studied. In result, the maximum biosorption of Ni and dye was in the acidic range pH, that is, 6 and 4, with sorbent dosage of 1 and 0.8 g after 40 min of the experiment when both were at 4 ppm, respectively. In case of adsorption isotherms, both mono- and multi-layer adsorption occurred simultaneously in the case of Ni as clear from the R2values of isotherms (R2for Langmuir = 0.999) and (R2for Freundlich = 0.941). In case of dye, uniform monolayer adsorption was predominant (R2for Langmuir = 0.980) as compared to the multi-layered adsorption. The maximum amount of monolayer adsorption of Ni and dye onto the biosorbent was 0.60 and 0.348 mg g–1, respectively. From the kinetics model, chemisorption was predominant in the case of both Ni and dye adsorption on biosorbent. In conclusion, the bark of Acacia nilotica has great potential for Ni and dye removal from co-contaminated wastewater.

Climate change is expected to alter the frequency and intensity of drying and rewetting cycles, impacting water availability and consequently soil nutrient availability. However, the effects of these fluctuations on the chemical speciation and bioavailability of phosphorus (P) in soil with or without desert species remain uncertain. We conducted a pot experiment involving bare soil and two desert species (Alhagi sparsifoliaand Calligonum mongolicum) to determine the short-term impacts of drought (no water supply), drying-rewetting-1 (D-RW1, high frequency of low water amounts), and drying-rewetting-2 (D-RW2, low frequency of high-water amounts) treatments on soil Hedley-P pools, plant P concentration and biomass accumulation. Results demonstrated that the presence of plants significantly increased soil labile-P and organic P (Po) concentrations by 60–150% and 1–68%, respectively, compared to bare soil. Both D-RW1 and D-RW2 treatments significantly increased soil dissolved organic carbon concentration by 2–35% relative to the drought treatment. Moreover, soil resin-P and NaHCO3-Pi concentrations under Alhagi sparsifoliain D-RW1 treatment significantly increased by 31% and 75%, respectively, when compared to the drought treatment, with NaHCO3-Po and NaOH-Po concentrations under D-RW2 treatment rising by 14% and 32%, respectively. Furthermore, D-RW2 treatment significantly increased leaf P concentration and biomass compared to D-RW1 and drought treatments. Overall, compared to drought treatment, frequent low-intensity drying-rewetting cycles enhanced soil Pi turnover, whereas infrequent high-intensity drying-rewetting cycles increased Po turnover and P bioavailability. These findings will inform better water management strategies for desertification restoration in hyper-arid desert ecosystems.

•Plants respond differently to repeated stress than to a single stress•Alhagi sparsifoliaadapts different strategies to cope with drought stress•Drought-primed seedlings had a lower oxidative status than non-primed•Stress memory helped A. sparsifoliaseedlings to overcome subsequent stress

Understanding the elevational patterns of soil microbial carbon (C) metabolic potentials is instrumental for predicting changes in soil organic carbon (SOC) stocks in the face of climate change. However, such patterns remain uncertain in arid mountain ecosystems, where climosequences are quite different from other ecosystems. To address this gap, this study investigated the distribution determinants of microbial communities, C-cycling functional genes, and SOC fractions along the elevational gradient (1 707−3 548 m, a mean annual precipitation (MAP) range of 38 to 344 mm) of the north slope of Central Kunlun Mountain, using a metagenomic approach. Results showed that elevation significantly influenced the α-diversity (Shannon index) and composition of microbial communities as well as the C-cycling functional genes. The α-diversity of microbial taxonomy and C-cycling functional genes linearly increased with the increase in MAP along the elevational gradient. The elevational patterns of genes encoding glycoside hydrolases and glycosyltransferases (GTs) were mainly driven by electrical conductivity (EC), mean average temperature (MAT), MAP, and plant diversity. Furthermore, mineral-associated organic carbon (MAOC), particulate organic carbon (POC), and their sum generally increased with elevation. However, the MAOC/POC ratio followed a unimodal pattern, suggesting greater stability of the SOC pool in the mid-elevation regions. This unimodal pattern was likely influenced by the abundance of Actinobacteria and genes encoding GTs and carbohydrate esterases (CEs) and threshold effects of EC and MAT. In summary, our findings indicate that the distribution patterns of microbial communities and C-cycling functional genes along the elevational gradient in an arid ecosystem are distinct from those of regions with higher MAP, facilitating the prediction of climate change effects on SOC metabolism under more arid conditions. Soil salinity, plant diversity, precipitation, and temperature are the main regulatory factors of microbial C metabolism processes, and they potentially play a central role in mediating SOC pool stability.

Nutrient allocation closely correlates plant functional traits and development to ecosystem supply services. Desert shrubs maintain the stability of desert ecosystems, whereas the knowledge of how they coordinate nutrients among organs is still limited when responding to differing nitrogen (N) and water regimes. Here we investigated the allocation, composition, and variability of nine elements within organs of Alhagi sparsifoliaand Calligonum caput-medusaeseedlings under various N addition (0, 3, 6, and 9 gN m−2year−1) and water regimes (drought versus well-watered). Results showed that plant species identity, organ type, and nitrogen and water treatments significantly affected the concentrations of nine elements independently and interactively (P< 0.05). N addition significantly improved elemental allocation to roots of drought-stressed A. sparsifoliaseedlings, whereas N addition of 9.0 gN m−2year−1exerted adverse influence on C. caput-medusae. Photosynthetic organs contained more macronutrients, such as N and potassium (K), whereas trace metals accumulated in roots, such as iron (Fe) and manganese (Mn). Soil elemental concentrations were weakly correlated with those in plants. Macroelements in all organs show less variability (coefficient of variation). Coarse root Fe and stem K contents constituted hub traits in plant element networks (PENs) of A. sparsifoliaand C. caput-medusaeseedlings, respectively, and may play a key role in plant adaptation in desert environments. The looser PEN of A. sparsifoliaimplied its stronger adaptability than C. caput-medusae. Desert shrubs can coordinate the allocation of multiple elements within and among organs in response to changes in water and N in the environment.

AbstractIsodon rugosusis a medicinally valuable herb containing a variety of important secondary metabolites and essential oil with important chemical constituents of pharmaceutical precursors. The active components of volatile oil of I. rugosuswere analyzed using GC-MS. Anti-oxidant potential of the oil was assessed with 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Anti-bacterial power of the essential oil accessed disc diffused method. A total of 19 constituents were quantified and identified with different concentrations in essential oil. Among which Caryophyllene oxide was 28.99%. Limonene oxide cis was 26.52%, (Z, E)-Farnesol was 17.34%, followed by 1-erpinen-4-ol 3.33%, o-Cymene 2.04 while the concentrations of rest of constituents were between 1.11 to 0.2%. The investigation showed that the essential oil of I. rugosuspossessed significant antibacterial and antioxidant potential

Although substantial information had been generated on the effects of land use change on soil organic carbon (SOC) and total nitrogen (TN) storage, studies are absent on multifactorial effects of land use types, land use age, and elevation on SOC and TN storage. SOC and TN were therefore investigated in 30 field sites comprising natural forests, planted forests, shrub, and grasslands. SOC and TN stocks differed and correlated significantly with land use age; the C stocks correlates significantly with land use change compared the TN stocks. However, there was no relation between the C and N stocks with elevation, implying that SOC and TN are solely dependent on land use age. SOC sequestration potentials of the sampled ecosystems were 345.86, 293.19, 266.45, and 251.23 t ha−1for the natural forests, planted forests, shrub, and grasslands with total mean value of 289.18 t·ha−1(1,060.42 t·ha−1CO2−eq). A significant SOC stock loss (17.96%, 29.80%, and 37.66%) occurred in converting natural forests to planted forests, shrub, and grasslands, whereas gains (27.36%, 14.31%, and 5.71%) would occur in reconverting grassland to natural forests, planted forests, and shrublands. Therefore, the C that was lost during deforestation and conversion of natural forests into other land use types could not match the carbon gains thereafter. Our results suggest that land use change and land use age have influenced soil C and N stocks. Moreover, natural forests are better in ecological conservation and restoration of degraded lands. This study provides baseline information for C and N management in ecologically restored and degraded lands. SOC and TN stocks differed and correlated significantly with land use age; the C stocks correlates significantly with land use change compared the TN stocksA significant SOC stock loss (17.96%, 29.80, and 37.66%) occurred in converting natural forests to planted forests, shrub, and grasslandsLand use change and land use age have influenced soil C and N stocks; moreover, natural forests are better in restoration of degraded lands

The Malakand valley of District Dir (Lower) is endowed with a diverse plant wealth. Ethnoveterinary knowledge provides the traditional medicines of livestock that are cheaper than standard treatment and are easily accessible.