WRKY transcription factors play an important role in transcriptional reprogramming associated with plant abiotic stress responses. In this study, the role of Solanum tuberosum (S. tuberosum; St) WRKY transcription factors StWRKY4 and StWRKY56 were explored in response to salt stress by generating transgenic potato lines using RNAi. The results showed that the total chlorophyll content in transgenic StWRKY4 was 6.1 mg/g at 200 mM after 35 days; however, in StWRKY56, an elevated 12.6 mg/g total chlorophyll was observed which indicated different operating mechanisms of these StWRKY transcription factors under salt stress. Proline content increased to 1.0 mg/g in StWRKY4 while it decreased to 0.54 mg/g in StWRKY56 as compared to their respective control plants after 35 days at 200 mM of salt stress. For Na+/K+ ratios, StWRKY4 and StWRKY56 showed 32.3 and 5.5 values, respectively, in silenced plants under similar conditions. This shows contrasting trends in StWRKY4 and StWRKY56 for Na+/K+. However, the expression analyses of StSOS1s were found to be upregulated, whereas for StNHX3s these were found to be downregulated in StWRKY4 and StWRKY56 under salt stress. Thus, this study, for the first time, demonstrated the different but critical roles of StWRKY4 and StWRKY56 for fine-regulating salt stress tolerance in complex signaling network of potato plant.

Potato tubers collected from different areas showed the prevalence of dry rot with characteristic white mycelia like symptoms of Fusarium pathogen. Fusarium species from diseased tubers were isolated based on morphological features. 18 S-Internal Transcribed Spacer (ITS) and Translation Elongation factor 1-α (TEF1-α) based analysis followed by phylogenetic tree constructed using ITS, TEF1-α and RNA polymerase II subunit B (RPB2) identified Fusarium isolates as Fusarium verticilloides, Fusarium soloni, Fusarium falciforme and Fusarium oxysporum. According to our knowledge, this study is the first report of the occurrence of Fusarium falciforme causing dry rot on potato tubers in Pakistan. The pathogenicity test confirmed the re-appearance of dry rot symptoms with Fusarium falciforme on potato tuber. The formation of Fusarium falciforme Ag NPs was confirmed using UV-Visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Field-emission scanning electron microscopy (FE-SEM) analysis. The synthesized Ag NPs showed color change with Fusarium falciforme and accordingly, UV peak was observed at 431 nm. The XRD revealed Ag based specific angles at 36.14°, 44.26°, 64.42° and 77.44° corresponding to face cubic structure. Similarly, FTIR band absorption at 3297 cm−1, 1626 cm−1 and 1057 cm−1 ascribed the presence of various biomolecules with O-H, N-H and C-N stretching vibrations based on Ag NPs synthesis. SEM indicated 29 nm synthesized mainly spherical Ag NPs and EDS analysis showed the presence of Ag in NPs. Maximum zone of inhibition with Fusarium falciforme Ag NPs was observed against Pseudomonas aeruginosa, Escherichia coli, Pseudomonas syringae and Staphylococcus aureus at 0.05 LSD significance.

Soil salinity caused by NaCl is a major challenge to agricultural crops worldwide. For this, two WRKY transcription factors were evaluated for their role in salt stress tolerance in tomato plants (Solanum lycopersicum; Sl). SlWRKY36 and SlWRKY51 provided novel insight into the regulatory mechanism in tomato against salt stress via virus-induced gene silencing (VIGS). Salt stress significantly reduced chlorophyll-a, an abundant form of chlorophyll content to 6.0 and 5.1mg/g and proline content to 0.06mg/g and 0.09mg/g respectively in SlWRKY36 and SlWRKY51 silenced tomato plants. This shows that salt stress affected proline content that act as osmo-protectant and damaged photosynthetic pigments in silenced SlWRKY36 and SlWRKY51 tomato plants. Similarly, the concentrations of Na+/ K+ ratio also showed a significantly higher trend 14 days after salt stress with 5.5mg/g and 8.9mg/g concentration at 200mM for SlWRKY36 and SlWRKY51 showing silencing promotes Na+/K+ ion ratio under salt stress. Also, salt stress responsive genes such as salt overly sensitive SOS1 and Na+/H+ exchanger NHX1 displayed lower transcript level in silenced plants at 200mM salt stress showing their negative regulation by SlWRKY36 and SlWRKY51 gene silencing. Collectively, these findings suggest for the first time the role of SlWRKY36 and SlWRKY51 as positive regulators of salt stress tolerance by managing ion homeostasis, proline content and photosynthetic machinery via transcriptional reprogramming. Overall, SlWRKY36 and SlWRKY51 were explored as potential candidates for engineering salt tolerance in tomato crop plants.

Potato tubers collected from different areas showed the prevalence of dry rot with characteristic white mycelia of Fusarium pathogen. Fusarium species on diseased tubers were isolated based on morphological features. 18S-ITS based analysis followed by Phylogenetic tree constructed using TEF1-α identified Fusarium isolates as Fusarium verticilloides, Fusarium soloni, Fusarium oxysporum and Fusarium falciforme. According to our knowledge, this study is the first report of occurrence of Fusarium falciforme causing dry rot on potato tubers in Pakistan. The pathogenicity test confirmed the reappearance of dry rot symptoms with Fusarium falciforme on potato tuber. Similarly, the formation of Fusarium falciforme Ag NPs was confirmed using UV, XRD, FTIR and SEM. The synthesized Ag NPs showed color change with Fusarium falciforme and accordingly UV peak was observed at 430 nm. The XRD revealed Ag based specific angles at 36.14°, 44.26°, 64.42° and 77.44° corresponding to face cubic structure. Similarly, FTIR band absorption at 1413 cm1, 1041 cm1 and 690 cm1 ascribed the presence of various biomolecules with O-H and N-H stretching vibrations based on Fusarium falciforme Ag NPs synthesis. SEM indicated the synthesized Ag NPs and EDS analysis showed the presence of Ag in NPs. Maximum zone of inhibition with Fusarium falciforme Ag NPs was observed against Pseudomonas aeruginosa, Escherichia coli, Pseudomonas syringae and Staphylococcus aureus at 0.05 LSD significance.

Potato is one of the highly consumed vegetable crop grown in different regions across Pakistan that is affected by fungal diseases. The current research was conducted to identify fungal pathogen causing mold-like disease of potato in Khyber Pakhtunkhwa (KP), Pakistan. For molecular identification and characterization of the fungal disease; potato tuber samples were collected followed by culturing on potato dextrose agar (PDA). Based on morphological features, the pathogen was identified as a Penicillium species. This result was obtained in 45 different isolates from potato tubers. Molecular identification was done using β-tubulin primers and ITS5 sequencing of 13 different isolates that releveled 98% homology with BLAST (GenBank accession no. KX958076) as Penicillium solitum (GenBank accession nos. ON307317; ON307475 and ON310801). Phylogenetic tree was constructed that showed Penicillium solitum prevalence along with Penicillium polonicum and Penicillium citrinum on potato tubers. Based on this, Penicillium solitum based silver nanoparticles (Ag NPs) were synthesized and characterized using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX) and field emission scanning electron microscopy (FE SEM). UV-analysis showed a characteristic peak at 410 nm confirming synthesis of Penicillium solitum based Ag NPs. This was further confirmed by XRD followed by EDX and SEM that showed face cubic crystal structure with Ag as major constituent of 18 nm formed spherical Ag NPs. FTIR showed band stretching of O-H, N-O and C-H of biological origin. Similarly, Penicillium solitum based Ag NPs presented strong anti-bacterial and anti-fungal activity at 0.5 level of significance LSD. According to our knowledge, this is the first report of Penicillium solitum identification in Pakistan, its Ag NPs synthesis and characterization to be used against pathogens of agricultural significance.

Arsenic (As) is a bioactive metalloid that is highly toxic to humans, animals, and plants. Environmental contamination of As especially in groundwater increases due to natural and anthropogenic activities. The present study was performed to evaluate the potential of wild Tagetes species for the phytoremediation of As contaminated soil/water. This comparative research aims to analyze As accumulation and tolerance in two wild species of Tagetes, T. minuta and T. patula. The 20 days old seedlings were grown hydroponically and exposed to the different concentrations of As, 0, 50, 150, and 300 µM As2O3 for 1-, 4- and 7- days intervals. Effect of As stress was measured on the rate of seed germination, growth parameters like fresh and dry biomass weight, root/shoot length, chlorophyll contents and As contents in root and shoot in both Tagetes species. Increasing concentration of As restricts the growth activity of T. minuta with toxicity symptoms on leaves such as chlorosis. Accumulation of As in the shoot was significantly (p ≤ 0.01) high (634 µg g-1 DW) in T. patula as compared to T. minuta (397 µg g-1 DW) at 300 µM As2O3. Both Tagetes species exhibited high variation for As tolerance parameters as well as for As accumulation patterns. Comparatively good tolerance and accumulation of As in T. patula suggests that this species could be used in phytoextraction and re-vegetation in As contaminated sites.

Urea is a crucial nutrient for plant growth, but because of its substantial losses due to nitrification, ammonification, and subsurface leaching, there is currently a push to reduce these losses. Urea is frequently uploaded and trapped in gelatin. In this research, the improvement of urea uploading and encapsulation efficiency is investigated using wood ash made from plant biomass (Pinus roxburghii). The 8 g w/v of gelatin was mixed with various concentrations of wood ash (from 4 to 16 g w/w), urea (from 4 to 24 g w/w), and glutaraldehyde (from 0.5 to 3 mL g−1) to prepare various formulations of slow-release fertilizer (SRF). According to this study, adding wood ash to gelatin increases its ability to upload and encapsulate urea. The urea on its surface and the metal in wood ash both considerably contribute to the compositional alterations in gelatin in SRFs, which were demonstrated by IR spectroscopy. Visualization from photographs revealed that the homogenous dispersion of wood ash improved structural compatibility. The water content of the SRF formulation showed that wood ash can reduce water absorption by changing how hydrophobic gelatin is. Wood ash improves the gelatin’s ability to reduce the rapid release of urea over time, according to testing of cumulative urea release from SRF. The optimal combinations for achieving the maximum 53.43% of urea uploading were 2.44 g of urea, 2.47 mL of glutaraldehyde, and 1.50 g of wood ash, according to the Box–Behnken model. The gelatin-based SRF that had been amended with wood ash was applied to the Mentha spicata plant, and the plant’s healthy development and higher chlorophyll content revealed its agronomic potential. This study has a significant contribution to the development of an affordable and more effective wood ash-modified gelatin-based SRF.

The rise of methicillin-resistant Staphylococcus epidermidis (MRSE) makes it difficult to treat infections that increase morbidity and mortality rates in various parts of the world. The study’s objectives include identifying the clinical prevalence, antibiogram profile, and Gompertz growth kinetics of MRSE treated with synthetically created nanoparticles of rosin obtained from Pinus roxburghii. A total of 64 of 200 clinical isolates of S. epidermidis (32% of the total) displayed sensitivity (40.62%) and resistance (59.37%) to seven different antibiotic classes. The most sensitive patterns of antibiotic resistance were seen in 20 (78.95%) and 24 (94.74%) isolates of MRSE against piperacillin/tazobactam and cephradine, respectively. Fosfomycine was found to be the most effective antibiotic against MRSE in 34 (89.47%) isolates, followed by amoxicillin. Successfully produced, described, and used against MRSE were rosin maleic anhydride nanoparticles with a size range of 250 nm to 350 nm. Five different concentrations of 25, 50, 75, 100, and 150 mg mL−1 rosin maleic anhydride nanoparticles were investigated to treat MRSE resistance. According to Gompertz growth kinetics, the maximal growth response was 32.54% higher and the lag phase was also 10.26% longer compared to the control when the amount of rosin maleic anhydride nanoparticles was increased in the MRSE. Following the application of rosin maleic anhydride nanoparticles, the growth period is extended from 6 to 8 h. A potential mechanism for cell disintegration and distortion is put forth. This investigation came to the conclusion that rosin maleic anhydride nanoparticles better interfere with the surface of MRSE and demonstrated a preferred bacteriostatic action.

Background Taxus wallichiana is an evergreen tree species found in the Himalayan region of Pakistan. The tree possesses important secondary metabolites such as Taxol that has been implicated in treating breast, ovarian and colon cancer. Therefore keeping in view the importance of this plant species, silver nanoparticles were synthesized using Taxus wallichiana aqueous leaf extract and evaluated for their anti-bacterial and anti-cancer properties. Methods Silver (Ag) nanoparticles (NPs) were characterized for their optical, morphological and structural features using techniques such as UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) and were evaluated for their antibacterial activity and anti-cancer activity using U251 cell line. Results The study showed that the UV-absorbance peak of Ag2O NPs at 450 nm shifted to 410 nm, affirming the formation of leaf extract Ag NPs. Similarly structural studies revealed the crystalline nature of the cubic structure of the Ag crystal with an average crystallite size of 29 nm. FTIR analysis exhibited the existence of different functional elements including O-H and N-H and phenolic groups. Non-spherical glomerular shaped Taxus wallichiana Ag NPs were observed from SEM studies and EDX profile showed Ag as the main element along with constituent of biological origin. The synthesized Ag NPs showed significant antibacterial activity against Salmonella typhi, and Staphylococcus aureus. The cytotoxic activity of Ag NPs on U251 brain cancer cells showed a synergistic effect with 10 ug/mL concentration after 48 and 72 h incubation based on cell viability assay indicating promising glioblastoma drug potential.

Salmonella enteric serovar Typhimurium is the most common enteric pathogen in humans and animals. Consumption of contaminated food or water triggers inflammation that allows Salmonella to spread into the gut and causes gastrointestinal diseases. The infection spreads by intestinal invasion, phagocyte internalization and subsequent dissemination in many other patients. This research used TolA, a Salmonella typhimurium membrane protein, to computationally design a multi-epitope vaccine against the pathogen. Complete consistency of the candidate vaccine was checked In silico, and molecular dynamics simulations confirmed the vaccine's stability. According to docking report, the vaccine has a good affinity with toll-like receptors. In silico cloning and codon optimization techniques improved the vaccine's efficacy in Salmonella typhimurium manifestation process. The candidate vaccine induced an efficient immune response, as determined by In silico immune simulation. Computational studies revealed that the engineered multi-epitope vaccine is structurally stable, capable of eliciting particular immunological reactions, and therefore a candidate for a latent Salmonella typhimurium vaccine. However, wet lab studies and further investigations are required to confirm the results.

Abstract. Increasing atmospheric carbon dioxide concentration [CO2] caused by anthropogenic activities has triggered a requirement to predict the future impact of [CO2] on forests. The Hindu Kush Himalayan (HKH) region comprises a vast territory including forests, grasslands, farmlands and wetland ecosystems. In this study, the impacts of climate change and land use change on forest carbon fluxes and vegetation productivity are assessed for HKH using the Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS). LPJ-GUESS simulations were driven by an ensemble of three climate models participating in the CMIP5 (Coupled Model Intercomparison Project Phase 5) database. The modeled estimates of vegetation carbon (VegC) and terrestrial primary productivity were compared with observation-based estimates. Furthermore, we also explored the net biome productivity (NBP) and VegC over HKH for the period 1850–2100 under the future climate scenarios RCP2.6 and RCP8.5. A reduction is observed in modeled NBP and VegC from 1951–2005 primarily due to land use change. However, an increase in both NBP and VegC is predicted under RCP2.6 and RCP8.5. The findings of the study have important implications for management of the HKH region and inform strategic decision making, land use planning and clarify policy concerns.

The impacts of climate change are projected to become more intense and frequent. One of the indirect impacts of climate change is food insecurity. Agriculture in Pakistan, measured fourth best in the world, is already experiencing visible adverse impacts of climate change. Among many other food sources, potato crop remains one of the food security crops for developing nations. Potatoes are widely cultivated in Pakistan. To assess the impact of climate change on potato crop in Pakistan, it is imperative to analyze its distribution under future climate change scenarios using Species Distribution Models (SDMs). Maximum Entropy Model is used in this study to predict the spatial distribution of Potato in 2070 using two CMIP5 models for two climate change scenarios (RCP 4.5 and RCP 8.5). 19 Bioclimatic variables are incorporated along with other contributing variables like soil type, elevation and irrigation. The results indicate slight decrease in the suitable area for potato growth in RCP 4.5 and drastic decrease in suitable area in RCP 8.5 for both models. The performance evaluation of the model is based on AUC. AUC value of 0.85 suggests the fitness of the model and thus, it is applicable to predict the suitable climate for potato production in Pakistan. Sustainable potato cultivation is needed to increase productivity in developing countries while promoting better resource management and optimization.

Agriculture is greatly impacted by climate change, which can lead to situations of food security or insecurity at both regional and global levels. Pakistan is predicted to experience an area reduction and geographical shifting of major crops in the near future. In the present study, we assessed the potential future distribution of wheat and maize in Pakistan. Based on current locations of these crops, we ran a Maxent species distribution model to predict future changes in crop distributions. We used 58 presence records for wheat and 48 presence records for maize. The model simulated current and future climate change scenarios (RCP 4.5 and RCP 8.5) based on the CMIP5 model, MPI-ESM-LR. Results from our model showed a decline in production area, with a 30-35% reduction in wheat and a 23-36% reduction in maize in the year 2070, depending upon which climate change scenario was modelled (i.e. RCP 4.5 or RCP 8.5). The model predictions were highly accurate, with test AUC values of 0.88 for wheat and 0.89 for maize. A jackknife test for variable importance indicated that irrigation, precipitation seasonality and precipitation of the warmest quarter are the most important environmental variables determining the potential geographic distribution of the crops. Due to the varying severity and nature of climate impacts, adaptation strategies are needed. This study can aid policy makers in devising policies that can help reduce the threat of future food insecurity in the region.

The main objective of the present study was to investigate the effect of different combinations of two growth regulators IAA and BAP on the In vitro regeneration of potato for successful transformation. The best optimized concentrations for potato regeneration was used for Agrobacterium mediated transformation with Arabidopsis Nucleotide Diphosphate Kinase2 (NDPK2). Potato is vulnerable to a number of biotic and abiotic stresses which limit its production. The effective In vitro regeneration of potato was carried out using Indol acetic acid (IAA) and Benzyl aminopurine (BAP) for transformation with (NDPK2) known to be involved in various environmental stresses. The internode explants of potato Desiree variety were cultured on MS media augmented with different concentrations of IAA i.e. (1.2, 1.5, 1.7, 2.0, 2.5 mg.L-1) in combination with BAP 1 mg.L-1. Data was collected after 15, 30 and 45 days of culturing and analyzed for statistical significance using analysis of variance (ANOVA). Fisher least significance using R- program was used to compare means at p = 0.05 level of significance. Transformation with NDPK2 was carried out using optimized regeneration protocol. The results indicated that high concentration of IAA i.e. 2.0 mg.L-1 with 1 mg.L-1 of BAP proved to be best for root regeneration. In all other parameters like shoot length, number of leaves, stem diameter and leaf area and potato regeneration, 1:1.5 mg.L-1 of BAP: IAA produced best result and thus was transformed with NDPK2 that generated 7 confirmed transgenic potato plants on PCR based sequencing. The findings demonstrate that the combination of BAP:IAA of 1:1.5 mg.L-1 can be regarded as the best optimized concentration for regeneration for stress related NDPK2 Agrobacterium mediated transformation of Desiree variety in potato.

The forecast of CO2 emissions is very crucial, especially for Pakistan as it is one of the top victims of climate change. A univariate model, (ARIMA) autoregressive integrated moving average (ARIMA), was used to forecast CO2 emissions for Pakistan. The CO2 emissions scenarios were developed for Pakistan till 2020, forecasting them further to 2030. The scenarios developed include China-Pakistan Economic Corridor (CPEC) scenario, where CO2 emissions from high-priority energy projects under the CPEC were considered. The scenarios attempt to estimate the impactful emission reduction percentage, which the country needs to adopt along with other necessary changes in the existing policies of the country. The forecast results clearly indicate that the emissions are bound to increase under business as usual and CPEC scenarios and the country would fail to meet the Nationally Determined Contributions pledged at COP21. In other scenarios, where we assumed the country has adopted mitigatory strategies to curb the emissions, the forecast shows decreased CO2 emissions for Pakistan. The mean absolute percentage error for all the forecasts was found to be less than 10%, making the forecast highly accurate. (c) 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

Abstract Not Available Plant Tissue Cult. & Biotech. 30(1): 161-166, 2020 (June)

The global increase in the consumption of antibiotics has resulted in contamination of different ecosystems with severe implications on crop productivity. This study investigated the effects of ampicillin and ofloxacin on Lactuca sativa germination upon solution exposure and growth when cultivated in soils treated with three organic amendments (compost, rice husk and vermicompost). Two levels of both antibiotics 5 and 10 mg L-1 (for solution) or mg kg-1 (for soil) were tested in addition to the control. Results indicated that addition of compost significantly (p < 0.05) increased (50%) the root lengths of plant exposed to ampicillin (5 mg L-1). Similarly, vermicompost-amended treatments displayed a 64% increase (p < 0.05) in the shoot length of seedlings under the effect of 5 mg L-1 ofloxacin, depicting a positive synergistic effect between the antibiotics and amendments in the germination test. Nevertheless, the germination percentage remained unaffected in all the treatments. In greenhouse experiment, enhanced plant biomass was observed with the use of rice husk across all the treatment groups. Comparable to the germination test, plants treated with rice husk and compost signaled a higher content of rubisco large subunit (157% and 85%, respectively) and soluble protein (248% and 108%, respectively) post antibiotics application. On the contrary, an antagonistic effect of the rice husk and ofloxacin 5 mg kg-1 was observed on the chlorophyll content, evident by a 37% decrease. Overall, it was observed that the effect of antibiotics on different plant traits vary depending on the antibiotic concentration as well as type of amendment used.

Climate change may have multi-faceted adverse effects on forests worldwide such as pest outbreaks, fires, heat waves, and drought. These stresses including changes in water and nutrient availability, cause an imbalance in carbon uptake by plants. In this study, two species Eucalyptus camaldulensis (evergreen) and Populus deltoides (deciduous) were selected for carbon content and allocation analysis with the application of nitrogen fertilizer and water stress treatments. A pot experiment was done by planting 2 years old seedlings in 5kg pots in a glasshouse for four weeks. The experiment was a 2-factor factorial completely randomized design having three water stress levels D0, D1, D2 (1000, 500 and 250 mL) and three nitrogen treatments N0, N1, N2 (0, 0.5 and 1 gNkg(-1)). Significant and non-significant nitrogen into drought interactions (NxD) were observed for each treatment. Results showed that in Populus deltoides, at N2D2 treatment, shoot carbon content was increased up to 63% to 75%. Whereas in Eucalyptus camaldulensis, shoot carbon content was increased up to 51% to 52% at N0D2 treatment. Leaf carbon contents were increased 23% to 44% in E. camaldulensis and 0.3% to 4% in P. deltoides, at N1D1 treatment respectively. Dry shoot biomass was increased 3.8g to 7g at N2D2 treatment in E. camaldulensis whereas 45g to 81g at N1D2 in P. deltoides. Increased root biomass production was observed in N1D0 of P. deltoides (31.96g) and E. camaldulensis (2.73g). Leaf biomass was more observable in E. camaldulensis, at N1D2, up to 4.72g and in P. deltoides at N2D1 up to 3.4g. A significant increase at NxD interactions was observed in root carbon content, shoot length, root length, root biomass and Relative Water Content (RWC) in E. camaldulensis. Likewise, root length, shoot biomass, root biomass, Water Use Efficiency (WUE) and RWC was significantly increased in P. deltoides at NxD interactions. These significant improvements related to carbon allocation and physiological growth, with NxD interactions, can be attributed to the improved acquisition of nutrients by these species in the drought-stressed environments.

Unprecedent usage of nanoparticles (NPs) over very large scale has raised concerns about their release into agro-environments. The effects of these emerging pollutants on staple food crops and contrasted soils are not very well documented. The main aim of present work was to investigate the exposure-response of 10 wheat cultivars to titanium dioxide (TiO2) NPs (0-1000 mg kg(-1)) in terms of early growth parameters followed by evaluation of the selected cultivar for complete growth cycle cultivated on contrasted soils in terms of various physicochemical characteristics. Among all the 10 tested wheat cultivars, only Galaxy cultivar sustained to the whole TiO2 NPs exposure range. TiO2 NPs exposure at 1000 mg kg(-1) adversely affected the early growth response parameters in MH, Ujala, Uqab, Shafaq and FSD wheat cultivars which clearly indicated the toxic effects induced by NPs. Pot studies were performed using Galaxy cultivar cultivated in different textured soils (loam and sandy loam). At the highest tested concentration of TiO2 NPs, plant growth, biomass and phosphorus (P) concentration along with other tested parameters were not improved in both types of soils compared to their respective control groups. These results suggested the controlled use of NPs to avoid the NPs contamination in soil-plant ecosystems in the longer run.

Stomatal conductance is a land-surface attribute that links the water and carbon cycles. Analysis of a global database covering a wide range of plant functional types and biomes now provides a framework for predicting the behaviour of stomatal conductance that can be applied to model ecosystem productivity, energy balance and ecohydrological processes in a changing climate. Stomatal conductance (gs) is a key land-surface attribute as it links transpiration, the dominant component of global land evapotranspiration, and photosynthesis, the driving force of the global carbon cycle. Despite the pivotal role of gs in predictions of global water and carbon cycle changes, a global-scale database and an associated globally applicable model of gs that allow predictions of stomatal behaviour are lacking. Here, we present a database of globally distributed gs obtained in the field for a wide range of plant functional types (PFTs) and biomes. We find that stomatal behaviour differs among PFTs according to their marginal carbon cost of water use, as predicted by the theory underpinning the optimal stomatal model1 and the leaf and wood economics spectrum2,3. We also demonstrate a global relationship with climate. These findings provide a robust theoretical framework for understanding and predicting the behaviour of gs across biomes and across PFTs that can be applied to regional, continental and global-scale modelling of ecosystem productivity, energy balance and ecohydrological processes in a future changing climate.