Search

The ameliorative effect of seed priming with salicylic acid (SA) on Cr6+ and Zn2+ induced stress responses in wheat (Triticum aestivum L.) was evaluated using biochemical and computational approaches. The results suggested that Cr6+ and Zn2+ stress in wheat seedlings in absence of SA priming resulted in significant inhibition of growth, biomass loss with high accumulation of reactive oxygen species (ROS) leading to oxidative stress and inactivation of antioxidant metabolism. Wheat seeds primed with SA ameliorated the effects of Cr6+ and Zn2+ induced stress by maintaining appropriate growth and biomass of the seedlings. Moreover, when compared to the SA non-primed wheat seedlings, the levels of ROS and oxidative stress load were low in SA-primed seedlings subjected to Cr6+ and Zn2+ stress, which clearly indicated an ameliorative effect of seed priming with SA. Though, significant variation of antioxidant enzymes such as catalase (CAT) and superoxide dismutase (SOD) was not observed in wheat seedlings under stress conditions, and the non-enzymatic antioxidants such as ascorbic acid (AsA) and reduced glutathione (GSH) showed higher levels in SA-primed seedlings as compared to non-primed groups. The computational (molecular docking) analysis with Cu–Zn–SOD, Mn–SOD and CAT as target enzymes revealed that SA may potentially interfere with the binding and interaction of Cr6+ and Zn2+ ions with the active site of Cu–Zn–SOD effectively. Though, this computational analysis is based on structures of the targets derived through homology modeling, nevertheless it fundamentally substantiated our experimental findings on CAT and SOD activities.

The post-genomic era has witnessed several new possibilities to understand diverse functional aspects of plants quite precisely. From genomics to metabolomics and now phenomics, the complex interplay of these biological networks has been successfully elucidated. Abiotic stresses, such as drought, flooding, exposure to heavy metals and metalloids, and high or low temperature are foremost constraints in agriculture, and remains as the major reason for poor crop productivity and low yield globally. The primary aim of metabolomics is to identify final gene products, the metabolites, which serve as prospective markers (or traits) to comprehend abiotic stress adaptation and tolerance in plants. This review provides an overview on the application of metabolomics as a comprehensive tool for “Systems Biology Approach” to unravel the complex interaction of networks and components in plants towards abiotic stress adaptation and tolerance.

The present investigation aims to evaluate the possible ameliorative role of iron (Fe3+) on cadmium (Cd2+)-induced oxidative stress in mung bean (Vigna radiata L.) seedlings using biochemical and computational approaches. Imposition of Cd2+ stress for a period of 7d showed substantial changes in the growth of root and shoot, and was accompanied by significant Cd2+ accumulation and alteration of biochemical parameters. Cd2+ stress resulted in a significant reduction in root and shoot length, biomass and moisture content, and increased the levels of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) and superoxide (O2·−). Furthermore, a significant increase in the rate of lipid peroxidation and degradation of antioxidant defence metabolism were observed. Supplementation of the Cd2+-stressed seedlings with Fe3+ for 7d resulted in amelioration of growth, and restoration of normal cellular homeostasis as observed by considerable changes in oxidative stress parameters as compared to Cd2+ treated seedlings alone. Besides, in absence of Fe3+, Cd2+ accumulation in both root and shoot were significantly high as compared to both control and Fe3+-supplemented seedlings. Computational (molecular docking) analysis with superoxide dismutase and catalase as target enzymes revealed that both Cd2+ and Fe3+ have got affinities for the active sites of these antioxidant enzymes. Thus, it is hereby proposed that Cd2+ may potentially interfere with the activities of these antioxidant enzymes, while Fe3+ may prevent such interactions. Our findings based on biochemical and computational analysis clearly reveals the ameliorative role of Fe3+ on Cd2+-induced alterations in growth and oxidative stress in mung bean seedlings.

Severe Acute Respiratory Syndrome coronavirus (SARS-CoV), Middle East Respiratory Syndrome coronavirus (MERS-CoV) and the novel SARS-CoV-2 evade the host innate immunity, and subsequently the adaptive immune response, employing one protease called Papain-like protease (PLpro). The PLpro and the 3CL main protease are responsible for the cleavage of the polyproteins encoded by the + sense RNA genome of the virus to produce several non-structured proteins (NSPs). However, the PLpro also performs deubiquitination and deISGylation of host proteins and signaling molecules, and thus antagonize the host innate immune response, since ubiquitination and ISGylation are critical processes which invoke host’s antiviral immune responses. Thus, to maintain host antiviral defense, inhibition of the PLpro is the primary therapeutic strategy. Furthermore, inhibition of the enzyme prevents replication of the virus. The present study employs molecular modeling approaches to determine potential of different approved and repurposed drugs and other compounds as inhibitors of the SARS-CoV-2 PLpro. The results of the study demonstrated that drugs like Stallimycin, and known protease inhibitors including Telaprevir, Grazoprevir and Boceprevir, were highly potent in inhibiting the enzyme. In addition, several plant-derived polyphenols, including Corylifol A and Kazinol J, were found to be potent inhibitors. Based on the findings, we suggest that clinical trials be initiated with these inhibitors. So far, PLpro inhibition has been given less attention as a strategy to contain COVID-19 pandemic, and thus the present study is of high significance and has therapeutic implications in containing the pandemic. Supplementary Information The online version contains supplementary material available at 10.1007/s40203-021-00085-y.

Population growth is the increase in the number of individuals in a population. Growth of the human population globally is about 83 million annually and it is anticipated that the population is going to reach 7.774 billion in 2020. The Intergovernmental Panel on Climate Change has anticipated that food and environmental security will be a big challenge, due to the extreme events of abiotic stress under the changing climate. On the other hand, genetic improvement of crops through conventional breeding is a slow and difficult process, causes high heterozygosity, prolongs juvenile periods, and is also inconsistent. Besides conventional development of crop species to attain the food and nutritional security of the increasing population, next-generation new biotechnological tools (NBTs), namely genetic engineering (GE), may be a useful tool for the sustainability of crop production under the changing climate. Scientists revealed that NBTs/GE may be useful for the induction of desired agronomic and breeding traits through the inclusion of responsible genes into the genome. NBTs/GE has been practiced for more than three decades through direct transformation methods (biolistic) and indirect methods (Agrobacterium tumefaciens-mediated transformation) as primary strategies for the introduction of heterologous DNA into plants. All genetically modified crops generally use one of these methods, since NBTs/GE methods are able to maintain a high stability of the major traits of the clone. Breeding of genetically modified plants through the introduction of desirable agronomic and quality traits by utilizing NBTs/GE has been found to be apposite for many crops. The present chapter will discuss the concept, methods, and mechanism of NBTs/GE for improvement of crop species against abiotic stresses for meeting the food and nutritional security of the increasing population.

Plant metabolites including ascorbic acid (AA), reduced glutathione (GSH), serotonin, jasmonic acid (JA) and salicylic acid (SA) alleviate metal/metalloid-induced stress in plants, mainly by regulating the redox homeostasis. This possibly improves stress tolerance and augments productivity. The present computational modeling analysis was performed to understand the potential of these five metabolites in ameliorating metal/metalloid stress in rice, using dehydroascorbate reductase (DHAR) as a model. Six metal/metalloid ions (As3+, As5+, Cd2+, Cu2+, Pb2+, Zn2+) were used in the study, and the relative affinity, binding geometry and electrostatic surfaces of secondary metabolites and ions with the active site of DHAR were predicted. The results revealed that all the metabolites and ions may potentially interact with the active catalytic site of DHAR. However, the free energies of binding (docking score) of the metabolites (ranging from − 50.64 to − 81.56 kcal/mol) were many-folds higher than those of the ions (ranging from − 16.21 to − 16.23 kcal/mol). On comparison, the docking score of As3+ was found to be 28.29% of that of AA. Further, compared to AA, SA had lower score, and GSH, JA and serotonin showed 1.42-, 1.30- and 1.18-fold higher score than AA. Further analysis revealed that the electrostatic surfaces of the metabolites and ions overlap with one another. Statistical analysis was performed to determine the properties of the ligands which are crucial in facilitating interaction of the ligands. Based on the findings, it is argued that the secondary metabolites may interfere with the binding of the ions with DHAR, and when present in higher quantities, these metabolites may ameliorate metal/metalloid-induced stress responses.

Maize (Zea mays L.) is the third most important cereal after rice and wheat. As a C4 plant in the family Poaceae, maize can be grown under a wide range of agroecological conditions. Earlier evidence showed that as a result of wide intraspecific genetic variation, it is moderately sensitive to saline stress. Soil salinity is a serious threat worldwide, particularly in coastal- and arid–saline ecosystems of the world. According to the biphasic model of salinity-induced growth reduction, osmotic stress during the first phase and ion toxicity during the second phase are responsible for reduced growth in most of the cereals, but in the first phase in maize, ion toxicity, and the accompanying growth to the excessive Na+ accumulation in the leaves. An understanding of the physiological, biochemical, genetic, and molecular mechanisms of maize against salinity stress is desirable to alleviate the hostile effect of salinity stress on maize. Conventional breeding approaches have been found to be less effective for improving maize tolerance to salinity stress. Numerous studies have revealed that enhancement of osmoprotectants in plant cells, particularly glycine betaine (GB), has been found to be most effective for the osmotic adjustment of plants during salinity stress. The chapter aims to highlight the role of osmoprotectant GB against salt-induced oxidative stress in maize.

The pandemic due to the novel coronavirus 2019, SARS-CoV-2, has led to a global health and economic crisis. The disease, named coronavirus disease (COVID-19), has already affected 3090445 and killed over 217769 people worldwide, as of April 30, 2020. So far, there is no specific effective medicine or vaccine against SARS-CoV-2. Several existing and approved drugs are under clinical studies for re-purposing. However, owing to the emergent situation and thereby to avoid time needed for de novo drug discovery, drug re-purposing remains to be the best option to find an effective therapeutic against the virus. Thus, the preset study was designed to evaluate potency of 82 compound/drugs in inhibiting the main protease (3CLPro) of SARS-CoV-2, using molecular docking tool. This protease is a vital enzyme for replication of the virus, and is thus a promising drug target. The analyzed compounds include 16 known protease inhibitors, two recently suggested α-ketoamides, 24 recently reported putative inhibitors, and 40 phytochemicals. The results indicate that Ritonavir, Indinavir, Montelukast, Nelfinavir, Candoxatril, Tigecycline and Lopinavir to be very potent protease inhibitors. Further, several other drugs and compounds, including phytochemicals, have been identified / predicted to be potent in inhibiting the enzyme. In addition, we hereby report relative efficacies of these compounds in inhibiting 3CLPro. Thus, the present study is significant in the therapeutic intervention of COVID-19.

Declining rate of productivity and environmental sustainability is forcing growers to use organic manures as a source of nutrient supplement in maize farming. However, weed is a major constraint to maize production. A field study was carried out over two seasons to evaluate various integrated nutrient and weed management practices in hybrid maize. The treatment combinations comprised of supplementation of inorganic fertilizer (25% nitrogen) through bulky (Farmyard manure and vermicompost) and concentrated (Brassicaceous seed meal (BSM) and neem cake (NC)) organic manures and different mode of weed management practices like chemical (atrazine 1000 g ha&minus, 1) and integrated approach (atrazine 1000 g ha&minus, 1 followed by mechanical weeding).Repeated supplementation of nitrogen through concentrated organic manures reduced the density and biomass accumulation of most dominant weed species, Anagalis arvensis by releasing allelochemicals into the soil. But organic manures had no significant impact on restricting the growth of bold seeded weeds like Vicia hirsuta and weed propagated through tubers i.e., Cyperus rotundus in maize. By restricting the weed growth and nutrient removal by most dominating weeds, application of BSM enhanced the growth and yield of maize crop. Repeated addition of organic manures (BSM) enhanced the maize grain yield by 19% over sole chemical fertilizer in the second year of study. Application of atrazine as pre-emergence (PRE) herbicide significantly reduced the density of A. arvensis, whereas integration of mechanical weeding following herbicide controlled those weeds which were not usually controlled with the application of atrazine. As a result, atrazine at PRE followed by mechanical weeding produced the highest maize grain yield 6.81 and 7.10 t/ha in the first year and second year of study, respectively.

The coronaviruses (CoV), including SARS-CoV, MERS-CoV and the novel SARS-CoV-2, evade the host innate immunity employing Papain-like protease (PLPro). PLPro performs deubiquitination and deISGylation of host proteins and signaling molecules, and thus antagonize the host’s innate immune response. Thus, PLPro is a promising drug target against SARS-CoV-2. The present study employs molecular modeling approaches to determine potential of different compounds as inhibitors of the PLPro. The results demonstrated that drugs like Stallimycin, and known PLPro inhibitors including Telaprevir, Grazoprevir and Boceprevir, were highly potent in inhibiting the enzyme. In addition, several plant-derived polyphenols were also found to be potent inhibitors.

Background Coronavirus disease 2019 (COVID-19) has already affected 2883603 and killed 198842 people, as of April 27, 2020. Because there is no specific therapeutic drug, drug repurposing has been proposed. RNA-dependent RNA polymerase (RdRp) is a promising drug against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to control its replication, and several compounds have been suggested. The present study predicts relative efficacies of thirty known or repurposed compounds in inhibiting the RdRp. Methods The three-dimensional structure of the target enzyme was loaded into Molegro virtual docker software, followed by chemical structures of the test compounds. The docking was performed between the compounds and the active site of the enzyme to determine docking scores, and the energy liberated when the two dock. Thus, docking scores signify the affinity of ligand(s) with the active site of enzyme(s) and thus its inhibitory potential. Results Among known inhibitors, remdesivir was found to have the highest affinity for the active site of the RdRp. Among all compounds, chlorhexidine was predicted as the most potent inhibitor. Furthermore, the results predict the relative efficacy of different drugs as inhibitors of the drug target. Conclusion While the study identifies several compounds as inhibitors of RdRp of SARS-CoV-2, the prediction of their relative efficacies may be useful in future studies. While nucleoside analogs compete with the natural substrate of RdRp, thereby terminating RNA replication, other compounds would physically block entry of the natural substrates into the active site. Thus, based on the findings, we recommend in vitro and in vivo studies and clinical trials to determine their effectiveness against COVID-19.

Salinity stress is a constraint to the world crop production. The crop plants of Fabaceae family are a major source of dietary proteins for the population of third world countries. But salinity stress poses a serious threat in their yield. Several studies have been performed to elucidate the legume salinity stress responses as well as strategies to ameliorate salt stress. Here, in this chapter, we have tried to summarize the salt stress responses in as well as techniques employed to improve yield under salinity stress in three important crop plants of this family focusing on groundnut (Arachis hypogaea L.), mungbean (Vigna radiata L.) and blackgram (Vigna mungo L.).

Rice (Oryza sativa) has been regarded as one of the oldest food crops, feeding more than half (55% approximately) of the entire world population. Seventy-five percent of the daily calorific demand is fulfilled by polished white rice in Asian population. Besides being easily digestible, rice also has a considerable amount of protein and a significant amount of minerals (magnesium, phosphorus and iron) and nutrients like niacin and thiamine. However, only a handful of rice varieties can be distinguished in terms of both yield and cooking quality traits and with significantly large areas of cultivation. Compared to the other field crops, from the economic point of view, postharvest processing, i.e. milling quality or grain quality of rice, actually determines the true market value. The manifestation of endless global warming and its allied climatic aberrations have caused various field crops to come across a wide range of stresses imposed by biotic and abiotic factors, either alone or in combinations. Such adverse conditions disturb the normal growth as well as yield potential of crop plants in various magnitudes. This chapter is intended to draw attention of the scientific community to look into the issues related to improving grain quality attributes.

The south-east Asian countries are facing a serious threat of arsenic (As) toxicity due to extensive use of As contaminated groundwater for rice cultivation. This experiment was configured to assess the consequences of rice seed priming with selenium (Se) and cultivation in As free and As contaminated soil. The experiment was arranged in a factorial complete randomized design having two factors viz. seed priming and soil As stress with total twenty-five treatment combinations replicated thrice. Seed priming with Se promotes growth, yield under both As free and As stressed conditions. Se supplementation considerably enhanced the tiller numbers, chlorophyll content, plant height, panicle length and test weight of rice by 23.1%, 23.4%, 15.6% and 30.1%, respectively. When cultivated in As spiked soil and compared with control, Se primed plant enhance growth and yield by reducing As translocation from root to aerial parts, expressed as translocation factor (TF). A reduction of TF root to shoot (46.96%), TF root to husk (36.78-38.01%), TF root to grain (39.63%) can be seen among the Se primed plants than unprimed plants both cultivated in similar As stress. Besides these, a noteworthy reduction in estimated daily intake (EDI) and cancer risk (CR) were also noticed with the consumption of cooked rice obtained after cooking of brown rice of Se primed plants than their unprimed counterparts.

Arsenic (As) contamination and its adverse consequences on rice agroecosystem are well known. Rice has the credit to feed more than 50% of the world population but concurrently, rice accumulates a substantial amount of As, thereby compromising food security. The gravity of the situation lays in the fact that the population in theAs uncontaminated areas may be accidentally exposed to toxic levels of As from rice consumption. In this review, we are trying to summarize the documents on the impact of As contamination and phytotoxicity in past two decades. The unique feature of this attempt is wide spectrum coverages of topics, and that makes it truly an interdisciplinary review. Aprat from the behaviour of As in rice field soil, we have documented the cellular and molecular response of rice plant upon exposure to As. The potential of various mitigation strategies with particular emphasis on using biochar, seed priming technology, irrigation management, transgenic variety development and other agronomic methods have been critically explored. The review attempts to give a comprehensive and multidiciplinary insight into the behaviour of As in Paddy –Water – Soil – Plate prospective from molecular to post-harvest phase. From the comprehensive literature review, we may conclude that considerable emphasis on rice grain, nutritional and anti-nutritional components, and grain quality traits under arsenic stress condition is yet to be given. Besides these, some emerging mitigation options like seed priming technology, adoption of nanotechnological strategies, applications of biochar should be fortified in large scale without interfering with the proper use of biodiversity.

Interactive aspect of among selenium (Se) and As (As) to mitigate As induced phytotoxicity in rice during germination and seedling growth has been based on mostly to petriplates and hydroponic mode of experiments. In this investigation we explore the consequences of sowing Se primed rice seeds in As spiked soil. Unprimed, hydroprimed and Se primed rice (IET-4094) seeds sown in As spiked soil, with five replications, arranged in complete randomized design for evaluating the impacts of seed priming on germination and seedling growth as well as As uptake and translocation pattern. Se promotes germination, seedling growth by modulating proline content, lipid peroxidation in root and shoot beside enhancing total chlorophyll content significantly in both As free and As spiked soil as compared to their respective unprimed and hydroprimed counterparts grown alike. Findings also indicates that seed priming with Se was able to execute dual roles i.e. a promotive and antagonistic aspect against As by restricting maximum soil As load to the root (with greater bioconcentration factor) and reducing translocation of As from root to shoot in a more practical and farmer friendly way to mitigate As induced toxicity and enhance germination and growth in rice seedlings.

Due to extensive use of arsenic (As) contaminated ground water in rice cultivation As toxicity has become a growing concern to rice growers of south east Asian countries. The presence of As in soil and irrigation water causes impaired crop growth and development. Selenium (Se) at lower concentration (1.0 mg L −1 ) is reported to be stimulatory on crop growth and it has also an antagonistic behavior with As. With this rationale the present study was conducted to investigate into the potentiality of seed priming technology with Se to ameliorate the As stress on rice seed germination and seedling growth. The seed germination percentage, seedling growth, total phenolics, proline and malonaldehyde content as well as total As uptake pattern of rice seedlings grown under As stressed condition were measured. The As induced toxicity markedly reduced the germination percentage by 70%, whereas, Se supplementation through seed priming enhanced the rice seed germination by 9% and root and shoot length vis-a-vis seedling biomass accumulation by 1.3, 1.6 and 1.4 fold respectively. The inhibitory effect of As stress was more on root growth than that of shoot. The toxicity due to arsenite stress was higher than the arsenate stress. Seed priming with Se enhanced seed germination and seedling growth by reducing As uptake, suppressing the oxidative damage through increase in antioxidants accumulation in rice seedlings. Seed primed with 0.8 mg Se L −1 was more effective in improving rice seed germination and seedling growth, compared to 1.0 mg Se L −1 .

The level of heavy metals has increased in the environment due to anthropogenic activities. Arsenic and cadmium are two nonessential heavy metals that are reported to have crossed permissible limits in the soil and water of many regions worldwide. Both heavy metals severely hamper plant growth and development. Arsenic and cadmium when taken up by plants are responsible for overproduction of Reactive Oxygen Species (ROS), which is quite lethal. Plants have their own enzymatic and non-enzymatic mechanisms to reduce the production of ROS but when oxidative stress exceeds the limit, plants succumb. The focus of this chapter is to present an overview of many ameliorating agents that have been used in both laboratory and field conditions to minimize accumulation and toxicity in crop plants caused by these heavy metals.

We laid down this experiment with two objectives. First to evaluate the germination and early seedling growth behaviour of rice seeds primed with water (hydroprimed or HP) and primed with zinc (Zn) using zinc sulphate under arsenic free (As-) and As spiked (As+) condition. Whereas, our second intention was to asses whether seed priming with Zn in rice can ameliorate As induced phytotoxicity or not. Here in this experiment, total six priming treatments (0.0, HP, 0.5,1.0,1.5 and 2.0 % Zn priming) and three stress regimes {0.0, 8.0 (As3+) and 8.0 (As5+) mg L−1} were considered and arranged these treatment combinations in complete randomized design (CRD) in 90.0 mm glass petriplates. Results from the current investigation suggest that priming rice seeds with Zn significantly (at p ≤ 0.0001) improves germination and seedling growth and minimize the stress-induced biochemical markers under normal condition than those primed with water and unprimed seeds at 10 days after sowing (DAS). Whereas, under As stress germination and seedling growth were inhibited in a noteworthy fashion, irrespective of seed priming treatments. Among the stressor As3+ seems to be more phytotoxic than As5+ on germination and seedling. Seeds which were primed had greater germination and longer root and shoot growth when compared with the seedlings of hydroprimed and unprimed seeds. Our findings also indicate that, may be due to a significant interactive aspect (at p ≤ 0.001) among Zn and As (Zn × As), Zn primed seedlings accumulated lesser amount of As at 10 DAS than the unprimed and hydroprimed seedlings, irrespective of nature of stress.

Plants are sessile entities and hence have to face the environmental havocs without any chance of avoiding it. Abiotic stress like drought and salinity encumbers plant growth and developmental activities rendering drastic drop in crop yields. Though plants have evolved stress response mechanisms, many a times it doesn’t suffice, and the plant succumbs to stress intensity and duration. But sometimes priming and pretreatment with exogenous agents (selenium, silicon, zinc, copper, etc.) enhance the inherent tolerance capability of plants to some extent. These priming and pretreatment technologies (using sodium nitroprusside, hydrogen peroxide, etc.) are cost-effective and user-friendly for stress alleviation in various plants. This chapter centre rounds these ameliorating agents and the mechanisms involved in enhancing the tolerance capability. Various reports suggested different techniques and treatments in combinations while using variety of agents. This chapter aims to compare and summarise the technologies used. Though we mainly represent the mitigations reported in the past decade or so, this chapter is divided into two sections, with a glimpse of various inorganic and organic amendments used to alleviate salinity and drought stresses in wide range of plants.

Heavy metal contamination of soil due to rapid industrialization and urbanization is an exponentially increasing menace, rendering hectares of arable land barren. Adding to the problem is the global climate change which sums up to the challenge of providing food security and meeting the global sustainability goals. Heavy metals like Cd, Pb, Hg, and As (non essential) and Fe, Mn, Zn, Cr, Cu, and Ni (essential) when present in abnormal amounts in the environment pose a serious threat to growth and yield of crop plants. Various stress factors including heavy metals result in exaggerated synthesis of reactive oxygen species (ROS) causing immense metabolic imbalance in plants. Plants possess both enzymatic and non-enzymatic processes to reduce the load of oxidative stress, but many times, it doesn’t suffice. The scope of this chapter centers around the recent strives made in the field of heavy metal-induced heavy metal stress mitigation in crop plants. This chapter specially focuses on exogenous amendments (organic, inorganic, and microbial) to induce stress adaptation in crop plants.

Increasing productivity of maize while decreasing production costs and maintaining soil health are emerging challenges for the rice&ndash, maize system in South Asia. A range of integrated nutrient and weed management practices were tested in winter maize for their effects on yield, profitability, and soil health. The nutrient management treatments were a partial substitution of nitrogen with bulky (Farmyard manure, vermicompost) and concentrated organic manures (Brassicaceous seed meal, BSM, neem cake), whereas weed management practices compared chemical controls only versus an integrated approach. The N supplementation through BSM diminished the weed growth by reducing weed N uptake, and enhanced the maize crop uptake of nutrients. As compared to the sole chemical approach, atrazine-applied pre-emergence followed by hoeing reduced weed density by 58 and 67% in years 1 and 2, respectively. The N supplementation through BSM resulted in the maximum yield of maize grain (6.13 and 6.50 t ha&minus, 1 in year 1 and year 2, respectively) and this treatment increased yield in year 2 compared to N application through synthetic fertilizer. Hoeing in conjugation with herbicide enhanced the maize grain yield by 9% over herbicide alone. The maximum net return and economic efficiency were achieved with the application of BSM for N supplementation, together with the integrated weed management practice.

Consequences of paddy cultivation in arsenic (As)-contaminated environment on crop growth, yield, and transmission to food chain through consumption of rice are known to all. Furthermore, the adverse consequences of As toxicity continues upon consumption of As rich rice by human, irrespective of gender and socioeconomic perspective, have been documented in large number of literature. In the current investigation, our prime objectives were to explore (a) As accumulation pattern in different rice varities cultivated in “As Hot – Spot area” located in “lower Indo – Gangetic Plane” for two successive years, and a least addressed issue (b) how rice grain quality traits get influenced by As contaminated environment. Findings from the current investigation suggest that (i) As content in irrigation water in the study sites were higher than the permissible limit mentioned by FAO; (ii) there is a season-wise, variety-wise, year-wise, as well as location-wise variation in As accumulation pattern noticed; and (iii) variation in grain quality attributes can also be seen. Results also suggest that grain As content were within the range of 0.242 ± 0.007 to 1.222 ± 0.005 mg As per kg. Statistical interpretation indicates that with fluctuation in grain As content significant modulation in grain quality traits like grain weight, head rice recovery % in downward fashion can be observed. Beside these, with variation in grain As content an increase in gel consistency, cooking time, and amylose content were also noted.

The current investigation was laid down to investigate the consequences of cultivating selenium (Se) primed seedlings of two contrasting rice varieties in arsenic (As) free and As spiked pot soil. At maturity, Se primed seedlings (both tested varieties) cultivated alike the controls (in As free condition) were found to posses significantly (p < 0.001) greater amount of chlorophyll, biomass, tiller number, panicle weight and test weight beside these, also having longer plant height than the control. Adverse effects of As stress can be seen in the unprimed plants of both the tested varieties in accordance to dose in the above studied parameters. Compare to the unprimed varieties cultivated in As spiked soil, Se primed plants exhibited an upward trend in restoring adverse effects of As like longer height, greater biomass content, tiller number, test weight etc, in a low to highly significant manner. Brown rice and cooked rice of Se primed plants content significantly (p < 0.001) less As load than those of unprimed plants. Se primed plants were found to restrict As translocation into the aerial parts by confining As into its root in greater amount than those of unprimed plants in variety irrespective fashion.

We laid down this investigation to explore the promotive and antagonistic aspect of selenium (Se) when supplemented through seed priming technology in rice before sowing into arsenic (As) free and As spiked soil. Findings suggest that As stress inhibits germination (35.38%), seedling growth (38.19%), chlorophyll content by 42.31%, and reduced translocation of iron, zinc, manganese by 19.40, 17.33, and 18.40% respectively, in the seedlings of unprimed seeds. Seedlings of unprimed seeds also had greater As translocation into the aerial part beside repressing micronutrient translocation, significantly. On the contrary, Se-primed seeds had higher germination (27.82%), longer root length (20.14%), greater chlorophyll content beside having greater translocation of iron, zinc, manganese in shoots along with restricting As translocation in rice seedlings by confining more As in the root, in a significant manner (p

Heavy metal toxicity is a major bottleneck to crop production throughout the world. India being a fast developing country is highly affected by heavy metal stress. Cd and Zn both pose great threat to crop production when present in excess. This work documents the differential tolerance of three cultivated varieties of Brassica juncea through physiological and molecular approaches at germination and early seedling growth. We observed that Zn doesn’t inhibit germination whereas Cd does. But Zn effects the growth and development of the seedling after germination. Treatments of Cd (0, 0.5, 1.0, 2.0 and 4.0 mM) and Zn (0, 2.5, 5.0, 7.5 and 10 mM) doses were imparted in germinating mustard seeds. Seedling length, biomass (fresh and dry weight), metal tolerance index and chlorophyll content reduced in mustard varieties. The wrath of stress was more severe in Pusa agrani and less in Pusa bold under both Cd (2.0mM) and Zn (10.0mM) stress. The histochemical results showed H2O2, O2ˉ, MDA, and cell death enhanced as dose was increased. Pusa agrani was the worst effected whereas Pusa bold the least. Various genes govern metal detoxification in mustards. Pusa bold showed better regulation in stress mediated abundance of genes depicting enhanced metal tolerance. It was found that among the three varieties Pusa bold was the most tolerant followed by Pusa bahar and Pusa agrani respectively. This is the first of its kind study where the effect of heavy metals has been studied and compared from molecular and varietal prospective at the germination stage.