Tolerance Index Research Articles

Crosstalk between melatonin and nitric oxide restrains Cadmium-induced oxidative stress and enhances vinblastine biosynthesis in Catharanthus roseus (L) G Don.

Nitric oxide functions downstream of the melatonin in adjusting Cd-induced osmotic and oxidative stresses, upregulating the transcription of D4H and DAT genes, and increasing total alkaloid and vincristine contents. A few studies have investigated the relationship between melatonin (MT) and nitric oxide (NO) in regulating defensive responses. However, it is still unclear how MT and NO interact to regulate the biosynthesis of alkaloids and vincristine in leaves of Catharanthus roseus (L.) G. Don under Cd stress. Therefore, this context was explored in the present study. Results showed that Cd toxicity (200µM) induced oxidative stress, decreased biomass, Chl a, and Chl b content, and increased the content of total alkaloid and vinblastine in the leaves. Application of both MT (100µM) and sodium nitroprusside (200µM SNP, as NO donor) enhanced endogenous NO content and accordingly increased metal tolerance index, the content of total alkaloid and vinblastine. It also upregulated the transcription of two respective genes (D4H and DAT) under non-stress and Cd stress conditions. Moreover, the MT and SNP treatments reduced the content of H2O2 and malondialdehyde, increased the activities of superoxide dismutase and ascorbate peroxidase, enhanced proline accumulation, and improved relative water content in leaves of Cd-exposed plants. The scavenging NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxy l-3-oxide (cPTIO) averted the effects of MT on the content of total alkaloid and vinblastine and antioxidative responses. Still, the effects conferred by NO on attributes mentioned above were not significantly impaired by p-chlorophenylalanine (p-CPA as an inhibitor of MT biosynthesis). These findings and multivariate analyses indicate that MT motivated terpenoid indole alkaloid biosynthesis and mitigated Cd-induced oxidative stress in the leaves of periwinkle in a NO-dependent manner.

Indexing heat stress-induced changes in Indian mustard germplasm using biochemical traits, stress tolerance indices and seed morphological features

Heat stress in Brassica is a great threat to its productivity and it is a major abiotic challenge in the current scenario of changing global climatic conditions. Oil production from Brassica is the second largest production after soybean, globally. In this study, 32 Indian mustard accessions were evaluated (post-anthesis stage) under heat stress in field conditions during the rabi season of 2019-20, by being exposed to 3 different growing conditions i.e., early, optimum and late sowing. Biochemical assays were performed at the post-anthesis stage to analyze the best-performing accessions under heat stress during the rabi season of 2021-22. Seed morphological parameters and stress indices (MDA, proline content) were used to find high-performing accessions. The results showed a significant correlation between yield under stress and STI (stress tolerance index), YI (yield index), SSPI (stress susceptibility percent index) and MP (mean productivity), indicating the utility of these indices in the selection of heat-tolerant and high-yielding lines. Based on the morphological, seed yield and quality parameters, accessions IC280920, IC401575, IC426400, IC491509 and IC570301 were found tolerant to heat stress as compared to other accessions. Therefore, the selected accessions can be utilized to improve crop Brassica, especially under heat stress.

Establishing Strategies to Improve Cracking Resistance of High Recycled Binder Ratio Asphalt Mixtures

This study aims to investigate promising mitigation strategies for improving the cracking performance of high recycled binder ratio (RBR) asphalt mixtures. Moisture-resistant aggregates that do not require anti-stripping agents, reclaimed asphalt pavement (RAP), and recycled asphalt shingles (RAS) were sampled for this study from sources in two climatic zones, south and north. The south-moisture-resistant (SR) mixtures were designed with 0.16 and 0.29 RBRs with RAP, while the north-moisture-resistant (NR) mixtures included 0.21 and 0.37 RBRs with RAP and 0.44 RBR with RAP/RAS. The mitigation strategies evaluated included a softer binder, a different binder source with higher ΔTc, a recycling agent (RA), reduced recycled binder availability (RBA), polymer-modified asphalt (PMA), and hybrid approaches including softer binder + RBA and PMA+RBA. The Indirect Tensile Asphalt Cracking Test (IDEAL-CT) and Disc-Shaped Compact Tension (DCT) test were conducted to capture intermediate-temperature and low-temperature cracking performance, respectively. In addition to the cracking tolerance index (CTindex), an IDEAL-CT interaction diagram analysis was added to further understanding the effect of mixture variables on cracking performance. The findings suggest that while no single strategy works for all RBR mixtures tested, RA, RBA, softer binder, or their combinations yield adequate cracking performance depending on factors including RAP binder stiffness and quantity, RA dose, climatic zone, and RBA.

Exploring phosphorus starvation tolerance in as (Oryza sativa L.) rice: An analysis of stress tolerance attributes and understanding the effect of PSTOL1 gene

AbstractThe limited availability of Phosphorus (P) in the soil poses a significant challenge to of rice productivity in rainfed tropical regions. There has been a constant demand of diverse donors for enhancing tolerance to P‐deficient soils. In this study, we evaluated 181 aus rice accessions of the 3000 Rice Genome Project (3 K‐RGP) for grain yield and six other agronomical traits under control (~20 mg kg−1 available P) and low‐P (8–10 mg kg−1 available P) field trials. The objectives were to assess the level of low‐P tolerance in the aus germplasm and select stable high‐yielding accessions using stress tolerance attributes. We also surveyed the presence of PSTOL1 gene and Pup1 polymorphisms to find the effect of PSTOL1 as well as t Pup1 haplotypes on low‐P tolerance. Principal component analysis (PCA) using five stress tolerance attributes revealed that attributes like mean productivity (MP) and stress tolerance index (STI) are useful for selecting high‐yielding accessions with stable yield under stress and control conditions. Notably, accessions like Kalabokari, Devarasi, ARC 12021, Jasure Aus, ARC 7336 and ARC 12101 had higher level of tolerance than the check varieties Vandana and Sahbhagi Dhan. Majority of aus accessions carried the PSTOL1 gene (73%) and had the tolerant haplotype of Pup1 (65%) like the tolerant checks. Although, at large, the PSTOL1‐positive accessions were more vigorous, and high yielding under low‐P, there were a few PSTOL1‐negative aus accessions showing higher level of tolerance. The findings suggest that non‐PSTOL1 type tolerance exists in aus rice which needs to be substantiated through further studies.

Hydroponic Screening at Early Seedling Stage Identified Sources of Salinity Tolerance in Wheat (Triticum aestivum L.) Crop

Wheat is a vital crop globally, essential for agriculture, economics, and food security. However, in arid and semi-arid conditions, wheat production faces significant challenges due to low water availability, uneven rainfall distribution, and high soil salinity. The germination and early seedling stages are particularly vulnerable to these stresses. Therefore, this study assessed 15 wheat genotypes for their tolerance to salinity stress during early growth stages, using a hydroponic system with four salt stress levels (0, 50, 100, and 150 mM NaCl). Significant differences were observed for genotype and salinity main effects and their interaction on all investigated traits, indicating considerable variability in the response to salt stress among the investigated wheat cultivars. High NaCl concentrations led to substantial reductions in measured parameters across genotypes, with some showing resilience while others exhibited heightened sensitivity. Stress tolerance indices, such as mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HM), stress tolerance index (STI) and yield index (YI), were identified as reliable indicators for selecting salt-tolerant wheat cultivars. Consequently, Sidi Okba (G11), Ziad (G12), Tamezghida (G13) and Zidane (G14) emerged as the most promising, displaying acceptable performance under both non-stress and salt-stress conditions. These genotypes could serve as valuable genetic resources for breeding programs aimed at enhancing wheat’s salinity tolerance, particularly in arid and semi-arid regions.

Investigating the influence of polyethylene terephthalate fibres with different lengths on the cracking resistance of high-performance asphalt concrete

High-performance asphalt concrete is an innovative paving material that typically relies on the properties of polymer-modified asphalt binders. However, the application is limited due to their high cost and phase separation issues. A solution is explored in the present study by blending 12% asphaltenes and a straight-run asphalt binder with a true performance grade of 70.2–25.9, resulting in a true performance grade of 82.9–21.8, which elevates the binder’s stiffness. Three lengths of polyethylene terephthalate fibres are used to improve the cracking resistance of these asphaltenes-modified mixes. An indirect tensile cracking test is conducted at 25 and 37 °C, revealing a significant improvement in cracking tolerance and failure energy, particularly at 37 °C. The cracking tolerance index value peaked at 105 for 12 mm polyethylene terephthalate fabricated sample, while control asphaltenes-modified, 6 mm, and 18 mm polyethylene terephthalate fabricated samples achieved 61, 87, and 99, respectively, with failure energy increasing with longer fibres.

Physio-biochemical Behavior and Health Effects of Pepper Plants Subjected to Lead Stress and Their Responses to Remediating Agents as Microbial Activity and Phosphorus

This work assessed the alleviating effects of bacteria (Bacillus subtilis) and phosphorus as environmentally friendly materials on the cultivation of pepper plants in polluted soil with lead (Pb) in forms of PbSO4, and Pb(NO3)2 at rates of 0, 1000, 2000 and 3000 µg Pb/g soil. Pot experiments were conducted to study the growth parameters, some physiological factors, biochemical constituents, and yield attributes, as well as the tolerance index (TI), translocation factor (TF), bioconcentration factor (BCF), and health effects [daily intake of heavy metals (DIM), health risk index (HRI), and carcinogenic risk (CR)]. Increasing the Pb concentration of all Pb salt used in soil severely affected the plant vegetative growth parameters. In comparison with other Pb salt forms, Pb(NO3)2 salt had a strong inhibitory impact. Additionally, the photosynthetic pigments in leaves were negatively impacted by all Pb salt forms. The application of Pb in all salt forms led to changes in the leaf water deficit (LWD), osmotic pressure, and membrane integrity and decreased the total water content, relative water content (RWC), transpiration rate, and leaf succulence. Pollution with Pb salts considerably decreased the yield constituents and various chemical properties of pepper, more so in the presence of Pb nitrate than in the presence of Pb sulfate type. A comparison of the concentration of Pb presence of Pb nitrate was greatly increased than the Pb sulfate in the whole plants. The safe limit of 0.3 mg/kg was exceeded by the Pb concentration in pepper fruits (6.3 and 4.3 mg/kg) cultivated in Pb-contaminated soil [with Pb(NO3)2 and PbSO4, respectively]. Additionally, Pb sulfate had a greater detrimental effect on Pb uptake in several plant organs than other Pb salt forms. The TI of pepper plants treated with salt types was >60% with PbSO4 (75.6%), whereas it was <60% with Pb(NO3)2 (35.2%). The BCF values of pepper plants in the polluted Pb soils varied from 0.10 to 0.41, indicating a moderate accumulator plant. At every level of Pb contamination with all Pb salt types, the sequence of Pb TF values was as follows: roots (TFr) > shoots (TFsh) > fruits (TFf), with TF values < 1. When compared with TFr and TFsh, TFs for shoot to fruits (TFf) had the lowest values (range, 0.07–0.22). The DIM, HRI, and CR values of pepper plants revealed that the Pb of fruit of stressed pepper plants is within safe limits. In addition to reducing the detrimental effects of intolerable Pb levels (2000 and 3000 µg Pb/g soil) on the majority of the aforementioned characters, adding Bacillus bacteria as a bio-agent and phosphorus as a chemo-agent to Pb-polluted soils also stimulated growth, increased yield, controlled plant water relations, protected photosynthetic pigments, and sharply decreased the Pb accumulation in plant organs. The Bacillus bacteria application resulted in some superior characteristics, such as root length, leaf number, leaf length, leaf area, leaf area index, fresh biomass, dry biomass, photosynthetic pigments, quantity yield attributes, reduction Pb accumulation in all plant organs, TI, TFr, TFf, BCF, in health effects trials, whereas phosphorus application improved plant height, leaf width, RWC, LWD, osmotic pressure, total soluble solids, acidity, total carbohydrates, total protein, and TFsh.

Physiological responses, ion accumulation and yield performance of wheat (Triticum aestivum L.) to salt stress

Wheat is affected by various biotic and abiotic stresses, especially salinity, which reduces the growth and yield drastically. High salinity is a major constraint for wheat productivity in many countries, including Bangladesh. With this view, here, an experiment was conducted to observe genotypic differences in physiological, ion accumulation, agro-morphological and yield performance of wheat against different levels of salinity. Experimental variables consisted of five salt tolerant genotypes (G 20–2–2, G 20–1–2, G 13–2, G 22–2, G 9–2), one susceptible genotype (G 24–2) and one standard check variety (BARI ghom 25), which assigned to four levels of salinity with electrical conductivities control (0.3), 4, 8 and 12 dS m−1. Irrespective of genotypes, salinity stress significantly decreased the yield and yield attributes. Results of analyses based on salt tolerance indices of plant growth related and yield contributing parameters, ionic balance (Na+, K+ and Na+ /K+ ratio), and stress indicators such as chlorophyll content, photosynthetic rate (Pn), stomatal conductance (gs) and transpiration rate (Tr) revealed genotypes G 20–2–2, G 13–2 and G 20–1–2 as salt tolerant, genotype G 9–2 as moderately salt-tolerant and G 24–2 and G 22–2 as salt-sensitive genotypes. Additionally, lower accumulations of hydrogen peroxide and malondialdehyde, and higher activities of antioxidant enzymes in the salt-tolerant genotypes G 20–2–2 and G 13–2 than in the salt-sensitive genotype G 24–2 indicated reduced oxidative damage in genotypes G 20–2–2 and G 13–2 relative to that in genotype G 24–2. Collectively, our findings suggest that the optimum growth and yield of salt tolerant genotypes are associated with decreased Na+/K+ ratio, increased antioxidant enzymes activity and reduced oxidative stress.

Detect urban trees air pollution sensitivity & tolerance by leaf trait analysis in the industrial zone of Kumaun Himalaya Uttarakhand India

The plant absorbs gases and particulate matter through its leaves and contributes to cleaning the atmospheric pollutants. Sensitive plant species act as bioindicators of air pollution, while tolerant species are sinks of air pollutants. However, in ecologically sensitive regions like the Himalayas, there are no guiding rules for the selection of roadside plants for urban development due to a lack of scientific research. To address this, this study aimed to identify roadside plant species sensitivity and tolerance to air pollution near the industrial hub Rudrapur located in Kumaun Himalaya using the Air Pollution Tolerance Index (APTI). The APTI is used as a tool for evaluating and categorizing plants according to their levels of tolerance or sensitivity to air pollutants. In this study, the APTI of five plant species has been measured. A One-Way ANOVA was conducted to assess variations in biochemical parameters of five chosen roadside plant species situated at two distinct sites. Mangifera indica and Nerium species were recorded with high APTI values, indicating their tolerance to air pollution. However, the Eucalyptus species was identified as the most sensitive species with low APTI. Selecting suitable tree species to combat air pollution can improve the urban environment.

Abscisic acid and glycine betaine-mediated seed and root priming enhance seedling growth and antioxidative defense in wheat under drought

The extent of drought tolerance in the seedlings of three wheat cultivars (WMRI-1, BARI GOM-33 and BARI GOM-21) was investigated by seed and root priming using abscisic acid (ABA) and glycine betaine (GB). The seeds were primed with ABA (10 and 20 μM) and GB (50 and 100 mM) and grown in pots maintaining control (0% PEG) and drought (10% PEG) conditions. Under drought, the root and shoot length, root and shoot biomass were significantly increased in ABA and GB primed seedlings than non-primed seedlings in all cultivars. Among the priming agents, either 20 μM ABA or 50 mM GB triggered better seedling growth in all wheat cultivars. These two levels were then applied with the nutrient solution in the hydroponics following four treatments: Control, Drought, Drought + ABA and Drought + GB. The seedling growth significantly declined in drought, while an improved seedling growth was observed in ABA and GB-treated plants in all cultivars. A considerable increase in lipid peroxidation, proline content, total antioxidant capacity and total flavonoid content in roots and leaves were recorded in all drought conditions, while these values were reduced in ABA and GB treatments. Heatmap using stress tolerance index (STI) values showed that Drought+ABA and Drought+GB secured higher STI scores suggesting a greater degree of drought tolerance in all cultivars. In conclusion, seed and root priming of ABA and GB enhanced drought tolerance in the wheat seedlings by improving seedling growth and antioxidative defense suggesting a declined state of oxidative damage.

Identification of potential morpho-biochemical determinants conferring salt tolerance in wheat (Triticum aestivum L.) through seedling- and -reproductive stage phenotyping

To optimize a reproductive-stage-specific phenotyping protocol and isolate potential determinants conferring salinity tolerance in wheat, two consecutive experiments were conducted using salt-tolerant varieties (Binagom-1 and BARI Gom 25) and a sensitive variety (BARI Gom 20). In the first experiment, seedlings were grown hydroponically, and 14-day-old seedlings were subjected to two different levels of salt stress (EC=12 dS/m and 16 dS/m) for 7 days. Based on the results of tolerant and susceptible varieties, parameters such as root and shoot weight, shoot Na+/K+ ratio, chlorophyll content, proline content, methylglyoxal content, H2O2 content and lipid peroxidation content and the activities of enzymes such as ascorbate peroxidase, peroxidase, and glyoxalase I were considered as potential determinants of salt tolerance. The second experiment employed four leaf cutting treatments under both control and salinity stress conditions. Seedlings were grown in perforated pots filled with field soil, and at the heading stage, plants were subjected to salt stress (12 dS/m) after trimming as indicated. The combined analysis of control and salt stress data obtained from setup B reflected a significant decrease in yield and yield-attributing traits; however, a lesser decrease was observed in tolerant varieties. Correlation studies revealed that grain yield per spike exhibited a significant positive correlation with the number of seeds per spike, spike weight, plant height, and days to first flowering under both stress and control conditions. Additionally, different stress tolerance indices also supported the results of reproductive stage phenotyping. However, further studies will be required to tag the genes/QTLs controlling salinity tolerance in wheat at various growth phases.

Association Analysis in Rice Germplasm Lines for High Temperature Tolerance

Background: Relative to other abiotic factors like salinity and drought, breeding rice cultivars that are resistant of high temperatures has received a little attention. The purpose of this study is to find parents and genotypes that are suitable for utilizing in high temperature stress breeding program. Methods: The genetic material for this study comprised of a set of germplasm collections (293 accessions) from different sources such as International Rice Research Institute germplasm. These populations were raised at the Department of Rice, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore. The Heat tolarance Indices (TOL) viz., Heat tolerance index (HTI) and Heat susceptibility index (HSI) and association analysis were estimated among germplasm lines for yield attributes under normal and high temperature stress condition. Result: Out of 293 genotypes, sixty nine genotypes significantly exceeded for both HTI and HSI. Association studies revealed that, single plant yield had highly significant and positive association with panicle exertion, number of total tillers per plant, number of productive tillers per plant, panicle length, number of filled grains per panicle and total dry matter production. Spikelet sterility and high temperature susceptibility index had highly significant and negative association with single plant yield. Number of productive tillers had significant and positive correlation with total dry matter production, panicle length, number of filled grains per panicle, days to maturity, hundred grain weight, grain breadth and high temperature susceptible index. Hence these traits may be considered as selection indices for yield and high temperature tolerance improvement programme. Hence it may be possible to combine single plant yield and heat susceptibility index by specific breeding programme for high temperature tolerance in rice.

Advanced Digital Technologies in Unionized Firms

AbstractThis work examines how workplace employee organizations causally affect the adoption of advanced digital technologies in Italy. It does so by using information from the survey “Rilevazione Imprese e Lavoro” conducted by the National Institute for Public Policy Analysis on a nationally representative sample of Italian firms in the non-agricultural private sector in 2018. It shows that workplace employee organizations increase the probability of advanced digitalization by around 15 percentage points per year, and the number of different technologies adopted by 0.41. The empirical strategy follows an IV approach that eliminates simultaneity bias and builds upon a lagged internal instrument combined with a NUTS-3 measure of altruism—namely, per capita blood donations. Results survive when cybersecurity is excluded from the analysis and prove robust when the internal instrument is left alone, combined with an index of tolerance or with propensity score matching.

7-Hydroxyflavone improves nonalcoholic fatty liver disease by acting on STK24.

The escalating incidence of nonalcoholic fatty liver disease (NAFLD) is closely associated with a high-fat diet, leading to a decline in quality of life and significant health impairment. 7-Hydroxyflavone (7-HY) is a flavonoid known for its anti-inflammatory, anticarcinogenic, and antioxidant effects. This study aims to assess the ameliorative effects of 7-HY on NAFLD induced by a high-fat diet and elucidate underlying mechanisms. Oleic acid/palmitic acid-induced HepG2 cells and C57BL/6 mice on a high-fat diet were utilized as in vitro and in vivo models. In animal experiments, 7-HY was utilized as a dietary supplement. The 15-week in vivo experiment monitored body weight, body fat percentage, glucose tolerance, insulin tolerance, and metabolic indexes. Commercial kits assessed triglyceride (TG) and total cholesterol levels in cells, liver tissue, and blood. Discovery Studio identified potential targets of 7-HY, compared with NAFLD-associated targets in the GeneCards database. Results indicated 7-HY mitigated fat accumulation, hepatic steatosis, and oxidative stress induced by a high-fat diet. Furthermore, 7-HY showed potential efficacy in ameliorating abnormal glucose metabolism and promoting energy metabolism. Reverse target finding and molecular docking demonstrated a robust interaction between 7-HY and serine/threonine kinase 24 (STK24). Subsequent experimental results confirmed 7-HY's ability to inhibit TG deposition in HepG2 cells through interaction with STK24. In conclusion, 7-HY demonstrated the capacity to alleviate high-fat diet-induced NAFLD, presenting a novel strategy for the prevention and treatment of NAFLD.

Warm-Mix Asphalt Containing Reclaimed Asphalt Pavement: A Case Study in Switzerland

Among the technologies proposed for achieving carbon neutralization in asphalt road pavements, warm-mix asphalt (WMA) has garnered increasing attention in recent years. While WMA holds the potential for various environmental and technical benefits, a comprehensive understanding of its implementation, technology selection, and additives is essential for successful application. This study presents a case where a bio-based chemical additive was employed to produce WMA containing 50% reclaimed asphalt pavement (RAP) for a surface course in Bern, Switzerland. To minimize additional variables during testing and analysis, no other additive or rejuvenator was introduced into the mixtures. The testing plan encompassed laboratory tests on samples collected during material placement and recompacted at varying temperatures in the laboratory, as well as cores extracted from the job site. As anticipated, the presence of the chemical WMA additive did not alter the rheological properties of the reference bitumen. Although in the mixture-scale tests, the WMA mixture exhibited comparable properties to the control hot-mix asphalt (HMA), it is not expected that the small dosage of the chemical additive functions the same grade after reheating and compaction. Nevertheless, the cores extracted from the job site proved the efficiency of the applied WMA technology. In addition, consistent with existing literature, the cracking tolerance (CT) index values of 62 for HMA and 114 and 104.9 for WMA mixtures indicated that the latter is less susceptible to cracking. Consequently, this characteristic could contribute to the enhanced durability of asphalt pavements.

Evaluation of the effects of dust pollution on specific plant species near and around the marble mining site in Rajasthan, India.

Airborne particles (dust pollution) pose a significant threat to both human and plant populations. Plant leaves act as crucial biofilters, capturing significant amounts of air pollution; this characteristic offers a valuable tool to measure local pollution levels and assess individual plant species' ability to intercept and mitigate harmful dust particles. The present study was carried out to asses the effect of responses of various plant species to dust pollution near and around the marble mining site comprising residential site, highway area, and Central University of Rajasthan as control. The anticipated pollution index, air pollution tolerance index (APTI), dust absorption capacity, metal accumulation index (MAI), and biochemical factors were used to evaluate plant responses. Azadirachta indica A. Juss. demonstrated the highest (29.0) and Vachellia nilotica L. showed lowest (5.6) APTI, respectively. A. indica showed maximum MAI values in comparison to other plant species situated at residential site. Additionally, monitoring of particulate matter (PM10) observed to highest at highway, followed by mining, residential, and control sites. Overall A. indica representing highest APTI and effective dust capturing capacity at all sites could serve as potential pollution sinks. V. nilotica, with its very low APTI, can be marked as biomonitoring tool for detecting dust pollution.

Physiological and proteomic characterization revealed the response mechanisms underlying aluminium tolerance in lentil (Lens culinaris Medikus).

Aluminium (Al) toxicity causes major plant distress, affecting root growth, nutrient uptake and, ultimately, agricultural productivity. Lentil, which is a cheap source of vegetarian protein, is recognized to be sensitive to Al toxicity. Therefore, it is important to dissect the physiological and molecular mechanisms of Al tolerance in lentil. To understand the physiological system and proteome composition underlying Al tolerance, two genotypes [L-4602 (Al-tolerant) and BM-4 (Al-sensitive)] were studied at the seedling stage. L-4602 maintained a significantly higher root tolerance index and malate secretion with reduced Al accumulation than BM-4. Also, label-free proteomic analysis using ultra-performance liquid chromatography-tandem mass spectrometer exhibited significant regulation of Al-responsive proteins associated with antioxidants, signal transduction, calcium homeostasis, and regulation of glycolysis in L-4602 as compared to BM-4. Functional annotation suggested that transporter proteins (transmembrane protein, adenosine triphosphate-binding cassette transport-related protein and multi drug resistance protein), antioxidants associated proteins (nicotinamide adenine dinucleotide dependent oxidoreductase, oxidoreductase molybdopterin binding protein & peroxidases), kinases (calmodulin-domain kinase & protein kinase), and carbohydrate metabolism associated proteins (dihydrolipoamide acetyltransferase) were found to be abundant in tolerant genotype providing protection against Al toxicity. Overall, the root proteome uncovered in this study at seedling stage, along with the physiological parameters measured, allow a greater understanding of Al tolerance mechanism in lentil, thereby assisting in future crop improvement programmes.

EFFECT OF DAIRY AND MEAT WASTEWATER IRRIGATION ON SEEDLING GROWTH

Milk and meat processing industries release large quantities of nutrient-rich wastewater with organic compounds (proteins, fats, carbohydrates) in high concentrations. Reusing and recycling this biodegradable wastewater for crop irrigation could be a sustainable solution once the phytotoxic effects of wastewater on crops have been investigated. Therefore, the aim of this study was to evaluate the effects of milk and meat processing wastewaters on germination percentage, seed vigour indices, the seedling tolerance index and the phytotoxicity index of pea (Pisum sativum L.), sugar maize (Zea mays saccharata), purslane (Portulaca oleracea), wheat (Triticum aestivum) and red spinach (Amaranthus dubius). The two wastewater types were collected at the inlet of the city’s sewage system and analysed to determine their physicochemical and microbiological characteristics. The seeds of all five plant species were irrigated with untreated wastewater effluents. The highest - germination percentages were obtained for wheat (92%) and the lowest for red spinach (2.5%). Wheat, purslane, pea and red spinach samples irrigated with meat processing wastewater had higher germination percentages than samples irrigated with dairy wastewater. A higher phytotoxicity was observed for sugar maize, followed by red spinach irrigated with both types of wastewater. Future investigation into the effects of effluent dilution on these types of plants is recommended.

Dopamine Hydrochloride Alleviates the Salt-induced Stress in Glycine max (L.) Merr. plant

AbstractThe objective of this study is to evaluate the role of dopamine hydrochloride (DH) in alleviating the detrimental effects of salt stress on Glycine max (L.) plant. Soybean seeds were treated with 150 mM NaCl and DH (100 µM or 200 µM) after they had been grown in plastic pots then the growth parameters, physiological and molecular analyses were assessed. Data showed that salinity stress decreased the germination percentage by 63.6%, the tolerance index (TI) and the seedling vigor index (SVI) were highly decreased. Salinity stress led to a markedly decline in the photosynthetic efficiency and the content of chlorophyll a and chlorophyll b by 43.5%, 77.4% and 44.6%, respectively. Salinity stress increased MDA and activity of CAT, SOD, POD, APX, GST and GR by 150%, 39.8%, 75%, 160%, 77.7%, 50% and 57%, respectively. However, DH (100 µM or 200 µM) significantly alleviated the toxic effects of salinity stress, marinated ions absorption, and enhanced the molecular level. Wherein out of 30 ISSR amplified fragments were formed. There were 10 unique bands (587 bp, 453 bp, 393 bp, 435 bp, 157 bp, 679 bp, 473 bp, 675 bp, 758 bp and 531 bp) were appeared in response to DH (100 µM and 200 µM) compared with untreated plants. Our analysis suggests a constructive effect of DH (100 µM and 200 µM) in alleviating the toxic effects of salinity stress on Glycine max (L.) plant not only at the level of antioxidative defense but also by regulating the molecular response highlighting the potential use of DH to improve the sustainability of horticultural production under climate change.

Identification of QTNs, QTN-by-environment interactions, and their candidate genes for salt tolerance related traits in soybean

BackgroundSalt stress significantly reduces soybean yield. To improve salt tolerance in soybean, it is important to mine the genes associated with salt tolerance traits.ResultsSalt tolerance traits of 286 soybean accessions were measured four times between 2009 and 2015. The results were associated with 740,754 single nucleotide polymorphisms (SNPs) to identify quantitative trait nucleotides (QTNs) and QTN-by-environment interactions (QEIs) using three-variance-component multi-locus random-SNP-effect mixed linear model (3VmrMLM). As a result, eight salt tolerance genes (GmCHX1, GsPRX9, Gm5PTase8, GmWRKY, GmCHX20a, GmNHX1, GmSK1, and GmLEA2-1) near 179 significant and 79 suggested QTNs and two salt tolerance genes (GmWRKY49 and GmSK1) near 45 significant and 14 suggested QEIs were associated with salt tolerance index traits in previous studies. Six candidate genes and three gene-by-environment interactions (GEIs) were predicted to be associated with these index traits. Analysis of four salt tolerance related traits under control and salt treatments revealed six genes associated with salt tolerance (GmHDA13, GmPHO1, GmERF5, GmNAC06, GmbZIP132, and GmHsp90s) around 166 QEIs were verified in previous studies. Five candidate GEIs were confirmed to be associated with salt stress by at least one haplotype analysis. The elite molecular modules of seven candidate genes with selection signs were extracted from wild soybean, and these genes could be applied to soybean molecular breeding. Two of these genes, Glyma06g04840 and Glyma07g18150, were confirmed by qRT-PCR and are expected to be key players in responding to salt stress.ConclusionsAround the QTNs and QEIs identified in this study, 16 known genes, 6 candidate genes, and 8 candidate GEIs were found to be associated with soybean salt tolerance, of which Glyma07g18150 was further confirmed by qRT-PCR.