Browsing by Author "Shashi Bhushan Agrawal"

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Air pollution governance in China and India: Comparison and implications
(Elsevier Ltd, 2023) Pu Wang; Dachuan Liu; Arideep Mukherjee; Madhoolika Agrawal; Huawei Zhang; Evgenios Agathokleous; Xue Qiao; Xiaobin Xu; Yan Chen; Tong Wu; Mengye Zhu; Eri Saikawa; Shashi Bhushan Agrawal; Zhaozhong Feng
Severe air pollution in China and India threatens the health of over one-third of the global population. When it comes to air pollution governance, the two countries have vastly different approaches. China's approach features centralized target-setting and implementation, with policies enforced primarily through top-down administrative lines. While India's approach reflects the division of power among central and state governments and relies substantially on legislative and judiciary systems for accountability. We conduct a detailed review of the trends and sources of six air pollutants in China and India, and make a structured comparison of China and India's air pollution policy frameworks. An extensive literature review is conducted to evaluate the effectiveness of policies in each country. The studies show that China's policy efforts have achieved significant improvements in air quality, while India's policies have been largely ineffective. Nevertheless, both approaches have the potential to lead to effective air pollution governance, if a country can build strong political will and clearly defined accountability systems. We further identify key lessons learned from the two countries for air pollution policymaking in developing countries, including taking good advantage of “post-crisis policy window”, and targeting “low-hanging fruits” to make incremental improvements in a cost-effective way. © 2023 Elsevier Ltd
Alterations in growth, antioxidative defense and medicinally important compounds of Curcuma caesia Roxb. under elevated ultraviolet-B radiation
(Elsevier B.V., 2020) Deepanshi Jaiswal; Avantika Pandey; Arideep Mukherjee; Madhoolika Agrawal; Shashi Bhushan Agrawal
Ultraviolet-B (UV-B) radiation is a well-known stress factor, as involved in the generation of free radicals, and induction factor which permutates growth, metabolic processes, and secondary metabolites synthesis of plants. However, its impact on medicinal plants is less explored particularly in relation to secondary metabolites associated with the medicinally important rhizomes. An endangered medicinal plant (Curcuma caesia Roxb.) grown under natural field conditions was exposed to elevated UV-B (ambient ± 9.6 kJ m−2 d-1) to assess changes in growth, antioxidant profile, defense strategy and the secondary metabolites of the rhizome. Results showed that eUV-B induced the generation of different reactive oxygen species (·O2- radical and H2O2) which were counteracted by induction of UV absorbing pigments (flavonoids and anthocyanin), non-enzymatic (ascorbic acid) and enzymatic antioxidants (peroxidase, ascorbate peroxidase and catalase) at different growth stages. However, phenol, thiol and superoxide dismutase activity showed reduction at all the growth stages. Protection from UV-B was also manifested by an increase in total free radical scavenging activity, metal chelation and reducing activity. Alterations in biomass allocation might be a possible mechanism of defense which persuaded to higher increment in above ground biomass and tuber biomass with 47 % diminution of rhizome biomass. Among the four classes of compounds identified, sterols were increased whereas reductions were more prominent in fatty acids followed by monoterpenes and sesquiterpenes. Increased production of epicurzereonone, elemene, pinandiol, and 1,8-cineole whereas curcumenol, D-camphor, eucalyptol, curcumenone, isocurcumenol, and zederone were reduced. Elevated UV-B also induced the production of some anti-cancerous compounds such as furanodiene and caryophyllene. © 2020 Elsevier B.V.
Amendment of organic manure to natural saline soil reduced N2O but enhanced CO2 and CH4 emissions
(Springer, 2024) Bhavna Jaiswal; Suruchi Singh; Shashi Bhushan Agrawal; Erandathie Lokupitiya; Madhoolika Agrawal
Association of agriculture with climate change is widely established. Soil constituents and soil salinity along with the amendments for soil improvement are the key contributors in affecting this association. The present study targets the above issue to find the best management practice in terms of reduction in greenhouse gas (GHG) emissions in Indo-Gangetic plain of Uttar Pradesh. The six sites selected for the study varied in salinity level and followed different management practices of organic and inorganic amendments. Emissions of CO2, CH4 and N2O from soil were measured at different stages of rice and wheat/ mustard/ fallow systems. The findings revealed that soil salinity, crop type and organic/ inorganic amendments differently affected the emission as the fluxes of GHGs varied at different stages of crop growth cycle at different sites. Salinity induced variations generally tended to reduce the CH4 emission while increased the emission of CO2 and N2O, whereas organic matter amendment increased CO2 and CH4 fluxes in comparison to inorganic fertilizer application at the studied sites. The site with rice-mustard cropping exhibited the highest CO2 and N2O fluxes, measuring 3645 and 1.9 mg m− 2 h− 1, respectively. Conversely, the highest CH4 flux of 0.873 mg m− 2 h− 1 was recorded at the saline rice-wheat cropping site. Electrical conductivity, moisture content, soil temperature and total organic carbon acted as major explanatory factors for soil emission of all the GHGs. Further exploration and experimentation are suggested with the use of different amendments to reduce GHG emissions in rice-wheat system, for greater sustainability potential. This ongoing research is vital for optimizing agricultural practices and enhancing their long-term environmental viability. © International Society for Tropical Ecology 2024.
An assessment of dose-dependent UV-B sensitivity in Eclipta alba: Biochemical traits, antioxidative properties, and wedelolactone yield
(Springer Science and Business Media Deutschland GmbH, 2021) Kshama Rai; Shashi Bhushan Agrawal
The UV-B-induced signals play a crucial role in improving the analeptic values of medicinally important plants. Eclipta alba L. (Hassak), commonly known as False Daisy, holds supreme stature with its pharmaceutical association in treating various ailments, particularly in Ayurvedic medicine. The present study aimed to evaluate the response of E. alba plants exposed to ambient (AT) and two different supplemental UV-B doses (eUV-B, ambient ±7.2 kJ m−2 day−1), i.e., intermittent (IT) and continuous (CT) UV-B treatment for 130 and 240 h respectively. Antioxidative activities and medicinally important compounds (wedelolactone) were measured in different plants’ parts at three growth stages. Under both the eUV-B treatments, the photosynthetic pigments were adversely affected (along with reductions in protein content) with a concomitant increase in secondary metabolites. Substantial variations in enzymatic antioxidants and non-enzymatic compounds showed the adaptive resilience strategies of plants against eUV-B. The wedelolactone content increased in leaves but compromised in stem and roots under IT. The results concluded that IT UV-B exposure led to the improvement of plant growth and the yield of wedelolactone compared to CT, suggesting its ameliorative role in improving the test plant’s medicinal value. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
An assessment of growth, floral morphology, and metabolites of a medicinal plant Sida cordifolia L. under the influence of elevated ozone
(Springer Science and Business Media Deutschland GmbH, 2021) Naushad Ansari; Madhoolika Agrawal; Shashi Bhushan Agrawal
Tropospheric ozone (O3) is a major secondary air pollutant and greenhouse gas, and its impact on growth, yield, and its quality is well established in the case of crop plants. However, the effects of tropospheric O3 have not been comprehensively studied on medicinal plants. Therefore, a field study was planned on a medicinally important Sida cordifolia L. plant (commonly known as country mallow or Bala) to assess the expected changes on the morphology, growth, and leaf injury under elevated O3 (ambient + 20 ppb) by using open-top chambers (OTCs) at 30, 60, and 90 days after treatment (DAT), while leaf and root metabolites were observed at 60 DAT. At all the growth stages, significant leaf damage was recorded as foliar injury symptoms. Most of the growth parameters also showed significant reductions at all the growth stages. Plants under elevated O3 showed a significant negative impact on most of the reproductive parts of the plant. Leaf weight ratio (LWR) showed significant increment at early stages while reduced at 90 DAT; however, root shoot ratio (RSR) showed a significant reduction at 60 DAT. The majority of the steroid metabolites showed an increase in root and leaves under elevated O3, while terpenes showed variable response. Due to O3 stress, most of the major metabolites showed an increase possibly due to their role in defense and other metabolic activities. Based on the outcomes, it is concluded that the future increase in the levels of tropospheric O3 will impact a significant effect on important metabolites of medicinal plants growing in tropical countries like India. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
Ascorbic acid and thiols as potential biomarkers of ozone tolerance in tropical wheat cultivars
(Academic Press, 2019) Adeeb Fatima; Aditya Abha Singh; Arideep Mukherjee; Madhoolika Agrawal; Shashi Bhushan Agrawal
Tropospheric ozone (O 3 ) has been identified as the most damaging air pollutant to crop plants in terms of growth and yield reductions. Considering the negative effect of O 3 in tropical regions, fourteen commonly grown Indian wheat cultivars with known sensitivity to O 3 were tested for their sensitivity/tolerance with respect to two major antioxidants (ascorbic acid and thiols) and grain yield responses against elevated O 3 (ambient + 30 ppb) exposure. The objectives of the study were to assess the usefulness of the biochemical markers in the screening of wheat cultivars having differential level of sensitivity to O 3 and different release time (modern and old cultivars). Ozone exposure led to an upsurge of ascorbic acid, thiols as well as their ratio greatly in the tolerant group followed by the intermediately sensitive group while least in sensitive one. Both ascorbic acid and thiol contents offered more resistance to early released cultivars compared to modern ones. Ascorbic acid served to be the most influential parameter for determining varietal response under elevated O 3 stress and directly linked with O 3 tolerance. Overall, the sensitive group suffered maximum yield losses while the minimum was observed in the tolerant group due to the differential enhancement of tolerance offered by antioxidants. Higher concentrations of antioxidants at early growth stages were highly correlated with final yield responses suggesting the role of antioxidants as a determinant of final yield. Findings of this study will help in the identification of O 3 tolerant and sensitive wheat cultivars for future screening programs using ascorbic acid and thiols as important markers of O 3 tolerance. © 2019 Elsevier Inc.
Assessment of ethylene diurea-induced protection in plants against ozone phytotoxicity
(Springer New York LLC, 2015) Aditya Abha Singh; Shalini Singh; Madhoolika Agrawal; Shashi Bhushan Agrawal
[No abstract available]
Assessment of Fatty Acid Profile and Seed Mineral Nutrients of Two Soybean (Glycine max L.) Cultivars under Elevated Ultraviolet-B: Role of ROS, Pigments and Antioxidants
(Blackwell Publishing Inc., 2016) Krishna Kumar Choudhary; Shashi Bhushan Agrawal
Current scenarios under global climate change envisage a considerable increase in ultraviolet B (UV-B) radiation in near future which may affect the productivity and yield quality of major agricultural crops. Present investigation was conducted to examine various defense strategies adopted against elevated UV-B (ambient + 7.2 kJ m-2 day-1) and their impact on seed nutrients, content and quality of oil including fatty acid profile of two soybean cultivars (JS-335 and PS-1042). Elevated UV-B (eUV-B) exposure leads toward higher unsaturation of fatty acids and changes in other oil quality parameters (acid, iodine and saponification value) indicated that eUV-B favored the synthesis of long-chain fatty acids with fewer carboxylic acid groups, making the oil rancid, with undesirable flavor and low nutritional value. The effect was more severe in JS-335 as compared to PS-1042. Negative effects were also seen on nutrients of soybean seeds. Adverse effects resulted due to insufficient quenching of ROS (superoxide radical and hydrogen peroxide) by the defense system and thus unable to overcome the imposed oxidative stress. Credit of better performance by PS-1042 against eUV-B may be given to the adoption of efficient defense strategies like higher wax deposition, increase in lignin and flavonoids (quercetin and kaempferol) contents. © 2015 The American Society of Photobiology.
Assessment of growth, physiological, and yield attributes of wheat cultivar HD 2967 under elevated ozone exposure adopting timely and delayed sowing conditions
(Springer, 2020) Annesha Ghosh; Ashutosh Kumar Pandey; Madhoolika Agrawal; Shashi Bhushan Agrawal
The present study was conducted to assess the impact of elevated levels of O3 and shifting of crop calendar practice, singly, and in combination on Triticum aestivum cv. HD 2967 on its growth, gas exchange parameters, and yield attributes in open-top chambers (OTCs). Two sowing dates were considered: timely sown and late sown. Late sowing was delayed by 20 days from the timely sowing date. The result revealed that wheat plants under elevated O3 and timely sown conditions (ET) showed reductions in growth parameters, while such effects were synergistic when plants were exposed to elevated O3 under late sown conditions (EL). Photosynthetic rate, stomatal conductance, and water use efficiency reduced significantly under EL followed by ET and AL as compared with AT (ambient O3 + timely sown) whereas transpiration rate showed maximum increment under EL. Grain yield reduced by 45.3% in EL as compared with AT and 16.2% in ET as compared with AT. The growth parameters and yield attributes obtained from the present experiment revealed that (i) O3 is affecting the growth and productivity of the wheat and (ii) late sowing practice has not proved to be a feasible adaptation strategy for the wheat cultivation against O3-induced production losses under the prevailing conditions of Indo-Gangetic Plain. This is the first report documenting the shifting of crop calendar practice at the present and future scenario of O3 concentration under agro-ecological conditions in the tropical region of India. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
Assessment of herbaceous community structure for identifying metal-tolerant species at different land uses in and around Varanasi city
(Springer, 2024) Srishti Mishra; Shashi Bhushan Agrawal; Madhoolika Agrawal
Plant community structure under different land uses provides an important understanding of vegetation dynamics to safeguard future restoration programmes and balance ecosystem services. Therefore, this study was carried out to estimate the alterations in soil properties and contamination by potentially toxic metals at different land uses (industrial, brick kiln, highway, and residential areas) compared to the reference (botanical garden area) site coupled with their subsequent influence on herbaceous community structure, bioconcentration, translocation, and extraction amount of metals in different plant species. Most of the total and phytoavailable metals (Co, Cr, Cd, Cu, Ni, Pb, Mn, and Zn) were higher at the contaminated sites compared to the reference site. The number of herbaceous species was highest at the reference site and minimum at the industrial site. Dominant and tolerant species were Cyanodon dactylon, Croton bonaplandianus, Achyranthus aspera, Malvestrum coromendelianum, Dicanthium annulatum, Nicotiana hindostana, Sporobolus virginicus, and Parthenium hysterophorus, found at the industrial, brick kiln, and highway sites. Based on transfer coefficients, C. bonaplandianus, D. annulatum, and Eleusine indica were recognized as potential accumulators, whereas C. dactylon, Commelina benghalensis, A. aspera, Amaranthus sessilis, and M. coromendelianum were found as excluder species for different metals. The identified tolerant herbaceous species could be used for future phytoremediation strategies and the prevention of hazardous risks to living components of contaminated sites. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Assessment of ozone sensitivity in three wheat cultivars using ethylenediurea
(MDPI AG, 2019) Adeeb Fatima; Aditya Abha Singh; Arideep Mukherjee; Tsetan Dolker; Madhoolika Agrawal; Shashi Bhushan Agrawal
Three wheat (Triticum aestivum L.) cultivars [HD 2987 (ozone (O 3 ) sensitive), PBW 502 (intermediately sensitive) and Kharchiya 65 (O 3 tolerant)] with known sensitivity to O 3 were re-evaluated using ethylenediurea (EDU; 400 ppm) to ascertain the use of EDU in determiningO3 sensitivity under highly O3-polluted tropical environments. EDU treatment helped in improving the growth, biomass, photosynthetic pigments and the antioxidative defense system of all the wheat cultivars. Under EDU treatment, PBW 502 retained more biomass, while HD 2987 showed better performance and ultimately the greatest increment in yield. Cultivar Kharchiya 65 also showed a positive response to EDU as manifested with an increase in pigment contents, total biomass and enzymatic antioxidants; however, this increment was comparatively lower compared to the other two cultivars. The results indicated that EDU did not have many physiological effects on cultivars but helped in counteracting O 3 primarily by scavenging reactive oxygen species and enhancing the antioxidative defense system where superoxide dismutase emerged as the major responsive biochemical parameter against ambient O 3 . The observed results clearly indicated that differential O 3 sensitivity in three wheat cultivars established by the previous study is in accordance with the present study using EDU as a sensitivity tool, which is an easy and efficient technology in comparison to chamber and Free-Air Carbon dioxide Enrichment (FACE) experiments although its mechanistic understanding needs to be further validated. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
Assessment of ozone toxicity among 14 Indian wheat cultivars under field conditions: growth and productivity
(Springer International Publishing, 2018) Aditya Abha Singh; Adeeb Fatima; Amit Kumar Mishra; Nivedita Chaudhary; Arideep Mukherjee; Madhoolika Agrawal; Shashi Bhushan Agrawal
Tropospheric ozone (O3) is a well-known threat to global agricultural production. Wheat (Triticum aestivum L.) is the second most important staple crop in India, although little is known about intra-specific variability of Indian wheat cultivars in terms of their sensitivity against O3. In this study, 14 wheat cultivars widely grown in India were exposed to 30 ppb elevated O3 above ambient level using open top chambers to evaluate their response against O3 stress. Different growth and physiological parameters, foliar injury and grain yield were evaluated to assess the sensitivity of cultivars and classified them on the basis of their cumulative stress response index (CSRI). Due to elevated O3, growth parameters, plant biomass, and photosynthetic rates were negatively affected, whereas variable reductions in yield were observed among the test cultivars. Based on CSRI values, HD 2987, DBW 50, DBW 77, and PBW 550 were classified as O3 sensitive; HD 2967, NIAW 34, HD 3059, PBW 502, HUW 213, and HUW 251 as intermediately sensitive, while HUW12, KUNDAN, HUW 55, and KHARCHIYA 65 were found to be O3-tolerant cultivars. Cultivars released after year 2000 were found to be more sensitive compared to earlier released cultivars. Path analysis approach showed that leaf area, plant biomass, stomatal conductance, net assimilation rate, and absolute growth rate were the most important variables influencing yield under O3 stress. Findings of the current study highlight the importance of assessing differential sensitivity and tolerance of wheat cultivars and response of different traits in developing resistance against elevated O3. © 2018, Springer International Publishing AG, part of Springer Nature.
Assessment of physiological, biochemical and yield responses of wheat plants under natural saline and non-saline field conditions
(Springer, 2021) Bhavna Jaiswal; Suruchi Singh; Shashi Bhushan Agrawal; Madhoolika Agrawal
Soil salinity is a major threat to crop productivity all over the world including the Indo-Gangetic plain (IGP) region of India. Therefore, a field study was conducted for two consecutive years in wheat growing areas in IGP affected by salinity. Plants grown at a saline site (Salempur, SLM) and a non-saline site (Rajatalab, RJT), were analysed for selected biochemical, physiological and yield traits. Results showed that photosynthetic rate was not significantly affected, but transpiration rate and stomatal conductance declined at saline compared to non-saline site. Photosynthetic pigments increased during vegetative growth period, but decreased during reproductive stage at SLM site, while anthocyanin showed an opposite trend. Membrane damage, solute leakage, H2O2 and ·O2− productions were intensified at saline site, SLM. Accumulation of osmolytes and antioxidants occurred in plants at saline compared to non-saline sites. K/Na and Ca/Na ratios in plants at SLM were reduced significantly compared to non-saline site, RJT. Biomass and yield also declined at SLM compared to RJT. Principle component and path analyses on the measured parameters clearly showed that defense strategies adopted by plants helped to maintain the photosynthetic rate but biomass and yield of wheat got compromised under high salinity. © 2021, Prof. H.S. Srivastava Foundation for Science and Society.
Assessment of the differential trade-off between growth, subsistence, and productivity of two popular Indian hybrid mango varieties under elevated ozone exposure
(Elsevier B.V., 2023) Pallavi Singh; Harshita Singh; Shashi Bhushan Agrawal; Madhoolika Agrawal
The multifunctionality of plants is well known to be compromised in the areas experiencing higher concentrations of tropospheric ozone (O3). Mango (Mangifera indica L.) cultivation is essential to the economy of tropical regions, including India. Mango, widely grown in suburban and rural areas, experiences production loss due to air pollutants. Ozone, the most important phytotoxic gas in mango growing areas, warrants an investigation of its effects. Therefore, we assessed the differential sensitivity of mango saplings (two-year-old hybrid and regular-bearing mango varieties, Amrapali and Mallika) at two levels of O3: ambient and elevated (ambient + 20 ppb) using open-top chambers from September 2020 to July 2022. Under elevated O3, both varieties showed similar seasonal responses (winter and summer) for all the growth parameters but differed in their height-diameter allocation pattern. A decrease in stem diameter and an increase in plant height were observed in Amrapali, whereas Mallika showed a reverse response. Early emergence of phenophases was noticed during the reproductive growth of both varieties under elevated O3 exposure. However, these changes were more pronounced in Amrapali. Stomatal conductance was more negatively affected in Amrapali than in Mallika under elevated O3 during both seasons. Furthermore, leaf morpho-physiological traits (leaf nitrogen concentration, leaf area, leaf mass per area, and photosynthetic nitrogen use efficiency) and inflorescence parameters responded variably in both varieties under elevated O3 stress. A decrease in photosynthetic nitrogen use efficiency, further enhanced yield loss which was more pronounced in Mallika than in Amrapali under elevated O3 exposure. The results of this study could be useful in selecting a better-performing variety based on its productivity, which will be economically more beneficial in achieving the goal of sustainable production at the anticipated high O3 levels under a climate change scenario. © 2023 Elsevier B.V.
Assessment of the Reverberations Caused by Predominant Air Pollutants on Urban Vegetation: A Multi-Site Study in Varanasi Located in Indo-Gangetic Plains
(Multidisciplinary Digital Publishing Institute (MDPI), 2023) Harshita Singh; Pallavi Singh; Shashi Bhushan Agrawal; Madhoolika Agrawal
Plant responses to air pollution have been extensively studied in urban environments. Nevertheless, detailed and holistic studies assessing their retaliation to air contaminants are still limited. The present study evaluates the effect of criteria pollutants (SO2, NO2, PM10 and O3) on the overall biochemistry and resource allocation strategy of plants in order to categorize the dominant roadside species (Mangifera indica, Psidium guajava, Ficus religiosa, Azadirachta indica, Dalbergia sissoo, Cascabela thevetia and Bougainvillea spectabilis) of the Indo-Gangetic Plains (IGP), with different morphologies and habits, into species that are tolerant and sensitive to the prevailing air pollutants. This study was performed at three different land-use sites (industrial, commercial and reference) in Varanasi for two seasons (summer and winter). It was inferred that NO2 and PM10 consistently violated the air quality standards at all the sites. The fifteen assessed parameters reflected significant variations depending upon the site, season and plant species whereupon the enzymatic antioxidants (superoxide dismutase and catalase) and resource utilization parameters (leaf area and leaf dry matter content) were remarkably affected. Based on the studied parameters, it was entrenched that deciduous tree species with compound leaves (D. sissoo > A. indica) were identified as the less sensitive, followed by a shrub (C. thevetia > B. spectabilis), while evergreen species with simple leaves were the most sensitive. It was also substantiated that the morphology of the foliage contributed more toward the differential response of the plants to air pollutants than its habit. © 2023 by the authors.
Biosurfactants for Heavy Metal Remediation and Bioeconomics
(wiley, 2021) Shalini Srivastava; Monoj Kumar Mondal; Shashi Bhushan Agrawal
In recent years, environmental pollution arising from heavy metal ions is found to be a serious health issue and irresponsible industrial activities are the major wrongdoer behind this. Researchers develop various conventional techniques for metal ions cleanup from environment but most of them are either expensive or they generate toxic by-products. Thus, inevitability for an environmentally safe approach goaded interest towards biological techniques. An alternative to the costly and complex conventional remediation method for metal ions is in-situ application of biosurfactants. Plants and microbes synthesized biosurfactants as extracellular polymeric substances of high molecular weight and amphiphilic nature. The mode of action of biosurfactants are metal ion specific and they carry variety of physico-chemical properties. In this chapter, the authors highlight the potential of microbial biosurfactants for the remediation of metal ion contaminated media with extremely sustainable, economic and eco-friendly labels. The authors also briefly discuss the bioeconomics of biosurfactants. © 2021 by John Wiley & Sons Ltd. All rights reserved.
Can fertilization OF CO2 heal the ozone-injured agroecosystems?
(Elsevier B.V., 2024) Ashish Kumar Mishra; Gereraj Sen Gupta; Aditya Abha Singh; Shashi Bhushan Agrawal; Supriya Tiwari
The rising concentrations of carbon dioxide (CO2) and ozone (O3) in the atmosphere hold significant implications for various ecosystem services, particularly agroecosystem productivity. This review examines the intricate interplay between the divergent effects of CO2 fertilization and oxidative O3 damage on agroecosystems, with a focus on the pivotal role they play in shaping global food security. A comprehensive analysis of aggregated data from previous studies, employing regression analysis, suggests that CO2 may hold the upper hand and exhibit the potential to mitigate the damage induced by O3. The physiological responses of plants to these atmospheric gases are crucial determinants of their impacts in the coming years. Stomatal conductance (gs) regulates the entry of CO2 and O3 into plant systems, while carboxylation efficiency (Vmax) influences photosynthetic yield (Ps). However, the complex spatial and temporal variations, and the uncertain future projections of O3 concentrations, make it challenging to precisely predict the outcomes of O3–CO2 interactions in agroecosystems. Moreover, the differential responses of various crop functional types add to the complexity, making it even more demanding to assess agroecosystem productivity under future scenarios of atmospheric O3 and CO2 concentrations. To address these uncertainties, urgent efforts are required to quantify the interactive effects of O3 and CO2 across all RCP scenarios. This will provide a clearer understanding of crop responses and agroecosystem productivity in the coming years, ensuring sustainable food security, amidst changing environmental conditions. This review highlights the pressing need for further research to elucidate these critical interactions and their implications for global agriculture. © 2024 Turkish National Committee for Air Pollution Research and Control
Characterization, isotherm and kinetic study of Phaseolus vulgaris husk as an innovative adsorbent for Cr(VI) removal
(Springer New York LLC, 2016) Shalini Srivastava; Shashi Bhushan Agrawal; Monoj Kumar Mondal
Phaseolus vulgaris husk as a novel, very common milling agro waste, showed good performance for mutagenic Cr(VI) removal from chromium enriched aqueous solution. The study involves batch experiments to investigate the effects of influencing parameters, such as pH, temperature, contact time, initial Cr(VI) concentration, and adsorbent dose, on the adsorption process. Results showed a maximum of 99.88% removal of Cr(VI) at pH 1.16, temperature 20 °C and adsorbent dose of 6 g L−1. The adsorption equilibrium data followed the Freundlich model, suggesting a heterogeneous nature of the adsorbent surface and the correlation coefficient for pseudo-second-order kinetic model was found to be very high, showing its applicability during the adsorption process. The maximum Cr(VI) uptake capacity was 3.4317mg g−1. Thermodynamic parameters like standard free energy change (−7.175 kJ mol−1), enthalpy change (−8.29 kJ mol−1) and entropy change (0.005 kJ mol−1 K−1) revealed the spontaneous and exothermic nature of adsorption of Cr(VI) onto P. vulgaris husk. Desorption with 1mol L−1 NaOH followed by 1mol L−1 HCl was effective (92.76%) and, hence, it exhibited the possibility of recycling of used husk. © 2016, Korean Institute of Chemical Engineers, Seoul, Korea.
Chromosomal and molecular indicators: A new insight in biomonitoring programs
(Elsevier, 2022) Priyanka Singh; Shashi Bhushan Agrawal; Supriya Tiwari
The rapid rate of urbanization and industrialization leads to an increase in the concentration of atmospheric air pollutants, which are a mixture of various gases (like O3, SO2, NOx, & CO), particulate matter (PM 2.5 and PM 10), liquids, and airborne heavy metals. This mixture of air pollutants is responsible for their adverse effect on human health and other living organisms. Because of their genotoxic nature, they are one of the potential causes of cytological disorders and damages occurring at the molecular level in plants and animals. The common air pollutant-induced cytological disorders observed in plants and animals, at the chromosomal level are chromosomal stickiness, bridges, chromosomal rupture, ring formation, laggards, and micronuclei formation, while the commonly observed DNA damages are fragmentation, double and single-strand breaks, base loss, and transition mutations. The extent of DNA damage in plants depends on various parameters like duration of exposure, pollutant concentration, and sensitivity of plants toward the particular pollutant. The present chapter aims to understand the extent and severity of air pollutant-induced injury at the cytological and molecular levels in plants. The response of these parameters can be utilized in the biomonitoring programs to study the impact of air pollutants in plants. The knowledge gathered in the present chapter will not only help us in determining the consequences of air pollutants on the genetic constitution of the plants, but it will also give us an insight into how the coming generations of plants will adapt and respond to the increasing air pollution load. © 2022 Elsevier Inc. All rights reserved.
Climate change and secondary metabolism in plants: Resilience to disruption
(Elsevier, 2019) Suruchi Singh; Kshama Rai; Naushad Ansari; Shashi Bhushan Agrawal
Climate change is associated to how weather patterns change over decades or longer due to natural and human influences. Since the industrial revolution, humans have contributed to climate change through the emission of greenhouse gases and aerosols as well as changes in land use resulting in an increase in global temperature. To overcome climatic challenges, plants evolved various metabolic pathways, which is a crucial step in molecular and cellular evolution. Climate change led to evolutionary divergence, thus, genes coding for new metabolic abilities emerged. However, the pace of the present and future trajectory indicate the possibility of disruptive responses of plants unlike what evolutionary history has revealed. © 2019 Elsevier Inc. All rights reserved.