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Veterinary antibiotics (VAs) are widely used in Pakistan for growth enhancement, production, and in the prevention and treatment of infectious diseases in the livestock and poultry industry. Their emergence into the agro-environment began during the resource utilization of farmyard and poultry manure. However, these bioactive organic pollutants are non-degradable in the natural environment and can be uptaken by plants, eventually ending up in the human food chain. Despite the danger these antibiotics pose, unfortunately, it is an issue that still remains underreported, especially in Pakistan. As such, this review critically summarizes the current consumption, exposure pathways, strategies for controlling dissemination, and serious environmental concerns associated with VAs. Additionally, the fate of antibiotics in the dry arid climate of Pakistan is thoroughly explained along with the lack of monitoring and strict legislation in developing countries. It is reported that antibiotic consumption negatively impacts raw manure, hence suggestions such as limiting the consumption of antibiotics from the source, proper disposal of farmyard manure with effective technologies, and remediation techniques are introduced. Finally, the authors highlight the importance of farmer's education and awareness campaigns in the pollution control of antibiotics, as the problem can only be properly addressed with the cooperation of government agencies, companies, and involved stakeholders. © 2021 Friends Science Publishers

Lead is getting more and more alarming because of its toxicity and destructive effects on plants, animals, and human health. The higher lead uptake by plants deteriorate the consistency in growth a...

The effect of organic amendments on phytoavailability of nickel (Ni) and other metals in soil may change with time due to transformation of organic matter. We investigated the residual effect of or...

Background: Feminizing adrenal tumors are rare and generally malignant tumors usually seen in male adults and children. We report the case of a benign feminizing adrenal tumor in a male patient. To our knowledge, only 2 other cases of benign, estrogen-only-secreting adrenal tumors have been reported. Case Report: A 44-year-old male with a history of hypertension presented to his primary care physician with chest tenderness, fatigue, and erectile dysfunction. Hormonal workup and imaging identified an estrogen-only-secreting adrenal adenoma. The adenoma was removed via laparoscopic adrenalectomy, and the patient had a normal postoperative course. Pathologic findings were an adrenal cortical adenoma with a Weiss score of 0 and a Ki-67 score of 0%. At 6-month follow-up, the patient's symptoms had significantly improved, and his previously abnormal sex hormone levels were within normal limits. Conclusion: Given the ambiguity in distinguishing between malignant and benign feminizing adrenal tumors, we suggest that radiologic (via Hounsfield units), clinical (via trending hormone levels), and histopathologic (via Weiss and Ki-67 scores) findings are sufficient to confirm the benign nature of this commonly malignant tumor.

Background Photosynthesis is a key process in plants that is compromised by the oxygenase activity of Rubisco, which leads to the production of toxic compound phosphoglycolate that is catabolized by photorespiratory pathway. Transformation of plants with photorespiratory bypasses have been shown to reduce photorespiration and enhance plant biomass. Interestingly, engineering of a single gene from such photorespiratory bypasses has also improved photosynthesis and plant productivity. Although single gene transformations may not completely reduce photorespiration, increases in plant biomass accumulation have still been observed indicating an alternative role in regulating different metabolic processes. Therefore, the current study was aimed at evaluating the underlying mechanism (s) associated with the effects of introducing a single cyanobacterial glycolate decarboxylation pathway gene on photosynthesis and plant performance. Methods Transgenic Arabidopsis thaliana plants (GD, HD, OX) expressing independently cyanobacterial decarboxylation pathway genes i.e., glycolate dehydrogenase, hydroxyacid dehydrogenase, and oxalate decarboxylase, respectively, were utilized. Photosynthetic, fluorescence related, and growth parameters were analyzed. Additionally, transcriptomic analysis of GD transgenic plants was also performed. Results The GD plants exhibited a significant increase (16%) in net photosynthesis rate while both HD and OX plants showed a non-significant (11%) increase as compared to wild type plants (WT). The stomatal conductance was significantly higher (24%) in GD and HD plants than the WT plants. The quantum efficiencies of photosystem II, carbon dioxide assimilation and the chlorophyll fluorescence-based photosynthetic electron transport rate were also higher than WT plants. The OX plants displayed significant reductions in the rate of photorespiration relative to gross photosynthesis and increase in the ratio of the photosynthetic electron flow attributable to carboxylation reactions over that attributable to oxygenation reactions. GD, HD and OX plants accumulated significantly higher biomass and seed weight. Soluble sugars were significantly increased in GD and HD plants, while the starch levels were higher in all transgenic plants. The transcriptomic analysis of GD plants revealed 650 up-regulated genes mainly related to photosynthesis, photorespiratory pathway, sucrose metabolism, chlorophyll biosynthesis and glutathione metabolism. Conclusion This study revealed the potential of introduced cyanobacterial pathway genes to enhance photosynthetic and growth-related parameters. The upregulation of genes related to different pathways provided evidence of the underlying mechanisms involved particularly in GD plants. However, transcriptomic profiling of HD and OX plants can further help to identify other potential mechanisms involved in improved plant productivity.

Chromium (Cr) is an ecological poison and its concentration is reaching to lethal intensities in soil and plants by irrigating the soil with raw industrial effluents, particularly in developing nations like Pakistan. Poultry manure and gypsum are recognized for their capability to immobilize heavy metals in soils for plant uptake and filtering to ground water. The current trial was conducted under controlled conditions to evaluate the viability of poultry manure (PM) and gypsum applications to mitigate Cr toxicity in spinach grown-up in soil watered with textile effluent. The trial was designed in a completely randomized design (CRD) with three repetitions. The treatments were: T1 (Control), T2 (Poultry Manure @ 0.5%), T3 (Poultry Manure @ 1%), T4 (Gypsum @ 0.3%) and T5 (Gypsum @ 0.6%). Chromium uptake by shoots and roots of spinach were enhanced in control plants where only textile effluent was applied. Chromium uptake in roots was higher than shoots. Application of poultry manure and gypsum reduced the Cr toxicity. The shoot length and dry weight of spinach was higher where PM was incorporated @ 1% as compared to gypsum and control. The extent of Cr toxicity mitigation by PM application @ 1% was higher when compared with control. The outcomes of this investigation demonstrated that application of PM @ 1% to the soil could be utilized as a viable approach for diminishing Cr concentration in spinach plants in Crcontaminated soils irrigated with untreated textile effluents

Transgenic Arabidopsis thaliana plants expressing cyanobacterial decarboxylation genes GLCD1 (GLYCOLATE DEHYDROGENASE I), HDH (HYDROXYACID DEHYDROGENASE), ODC (OXALATE DECARBOXYLASE) alone, and HDH::ODC simultaneously were successfully developed. Plants independently expressing GLCD1, HDH, ODC, and HDH::ODC were referred to as GD, HD, OX, and HX plants, respectively. The single-copy homozygous GD, HD, OX, and HX plants exhibited appreciable expression of chimeric genes. Phenotypic characterization demonstrated that rosette diameter of GD, HD, OX, and HX was 20, 22, 17, and 16% higher than wild-type (WT) plants. Total numbers of leaves were 32, 35, 37, and 34% more than WT plants after 32 days of sowing. Similarly, all transgenic plants produced more cauline branches than WT plants. All transgenic plants gained more height as compared to WT when recorded after 42 days of growth except HX transgenic plants. Plants vegetative dry biomass was 43% (GD), 35% (HD), 42% (OX), and 36% (HX) higher than WT plants. This is the first report on characterization of cyanobacterial decarboxylation pathway genes, which will pave the way for transformation of complete pathway in plants for better biomass accumulation.

Among all micronutrients, metallic micronutrients are heavy metals by nature. These heavy metal micronutrients (HMmNs) are necessary for the proper functioning of plant cells, growth, and defense mechanisms but can be toxic to plants when taken up in higher concentrations. On the other hand, their deficiency can also cause physiological disturbance in plants and can also make them prone to various biotic and abiotic stresses. An adequate amount of these micronutrients, thus must be applied to plants for normal functioning. In the current scenarios, an excessive supply of these HMmNs through wastewater irrigation, industrial effluent application, and excessive use of agrochemicals is adding to their higher amounts, which is a major concern for sustainable agriculture. Excessive uptake of these metals can create oxidative stress in plants, thus disturbing plants biochemical machinery. The plant tends to avoid these disturbances via adopting tolerance and avoidance strategies which can further be amplified by exogenous suppression of metal concentrations (via application of amendments) as well as genetic engineering. This chapter is an effort to summarize all aspects of plant physiology associated with the normal functioning of plants under HMmNs deficiency and toxicity.

Plants employ photosynthesis to produce sugars for supporting their growth. During photosynthesis, an enzyme Ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco) combines its substrate Ribulose 1,5 bisphosphate (RuBP) with CO2 to produce phosphoglycerate (PGA). Alongside, Rubisco also takes up O2 and produce 2-phosphoglycolate (2-PG), a toxic compound broken down into PGA through photorespiration. Photorespiration is not only a resource-demanding process but also results in CO2 loss which affects photosynthetic efficiency in C3 plants. Here, we propose to circumvent photorespiration by adopting the cyanobacterial glycolate decarboxylation pathway into C3 plants. For that, we have integrated the cyanobacterial glycolate decarboxylation pathway into a kinetic model of C3 photosynthetic pathway to evaluate its impact on photosynthesis and photorespiration. Our results show that the cyanobacterial glycolate decarboxylation bypass model exhibits a 10% increase in net photosynthetic rate (A) in comparison with C3 model. Moreover, an increased supply of intercellular CO2 (Ci) from the bypass resulted in a 54.8% increase in PGA while reducing photorespiratory intermediates including glycolate (− 49%) and serine (− 32%). The bypass model, at default conditions, also elucidated a decline in phosphate-based metabolites including RuBP (− 61.3%). The C3 model at elevated level of inorganic phosphate (Pi), exhibited a significant change in RuBP (+ 355%) and PGA (− 98%) which is attributable to the low availability of Ci. Whereas, at elevated Pi, the bypass model exhibited an increase of 73.1% and 33.9% in PGA and RuBP, respectively. Therefore, we deduce a synergistic effect of elevation in CO2 and Pi pool on photosynthesis. We also evaluated the integrative action of CO2, Pi, and Rubisco carboxylation activity (Vcmax) on A and observed that their simultaneous increase raised A by 26%, in the bypass model. Taken together, the study potentiates engineering of cyanobacterial decarboxylation pathway in C3 plants to bypass photorespiration thereby increasing the overall efficiency of photosynthesis.

Soil salinity is a worldwide problem deteriorating around 950 million hectares (mha) hectare of land with salts including about 250 mha irrigated lands causing about $27.3 billion per annum loss in world revenue. Soil degradation due to salinization must be addressed to ensure the food quality and food security for world. Salinity in irrigated lands is to be taken as genuine issue as it implies stress to growing plants causing their growth retardation, hormonal imbalance, and oxidative stress initiation. Plant tends to counter these stresses by adopting different mitigating strategies involving solute accumulation in roots to reduce root internal water potential, modifying proline metabolism by modifying hormonal signaling, innating Na efflux by cellular signaling or by operating high-affinity potassium transporters (HKTs) to mitigate Na toxicity and initiating and stimulating different genes to insure ion homeostasis. Besides endogenous mitigating strategies, some exogenous inputs also have significant role in managing saline agriculture. Increasing indigenous plant growth-promoting rhizobacteria or arbuscular mycorrhizae count in rhizosphere helps plant in withstanding severe salinity by producing growth-promoting hormones and absorbing more nutrients. Organic and inorganic amendments are helpful in mitigating soil salinity by improving soil physicochemical properties and nutrient supplement. Similarly, exogenous plant hormones and different soil conditioners improve plant growth, reproductive development modification, phyto-morphogenesis, and defense against salt stresses. Recently, genetic engineering is being focused on screening and introducing halotolerant varieties to provide economic and more effective strategy to tolerate against salinity without or low input of exogenous amendments. This technology is becoming more popular than conventional breeding as it involves the transfer of concerned gene, combating with the osmo deregulations, to high-yielding strains to get engineered plants. These genetically modified plants have better ionic homeostasis and tolerance against salinity, ensuring high-yield potentials under stressed environment. This chapter summarizes all possible strategies and mechanisms involving tolerance and mitigation of salinity, which will help in finding means for food security for the world.

Endosulfan an organochlorinated pesticide was used extensively throughout the world. Its enormous and inadequate use creates environmental as well as health problems. A bacterial strain capable to utilize endosulfan as a sole source of sulfur was isolated from pesticide contaminated soil and identified as Pseudomonas sp. on the basis of 16S rRNA. Batch experiments were conducted at various initial concentrations of endosulfan, i.e. 5, 25, 50, 75 and 100 mg/l to study its rate of degradation. After three days of incubation, 70–80% of each initial concentration was degraded by the isolated strain as compared to the control. Degradation of endosulfan increased with the time of incubation and maximum degradation was observed after 5 days of incubation. GC–MS revealed that the major metabolite was endosulfan lactone, which accumulated after 5 days of incubation. Kinetic studies at various initial concentrations also revealed that the bacterium has very promising attitude to utilize endosulfan as sole source of sulfur. It was observed that the addition of auxiliary sulfur Fe(SO4)3 in any concentration (0.05, 0.01 and 0.1%) decreased the rate of degradation of endosulfan. The ratio of μmax/ Ks was high (0.03 mg/l) when endosulfan was single sulfur source as compared to the value recorded when Fe(SO4)3 was added alongwith the endosulfan. This indicates that the newly isolated bacterium attacks sulfur moiety for its degradation.

Recent reports on acetylcholine muscarinic receptor subtype 3 (CHRM3) have shown its growth-promoting role in prostate cancer. Additional studies report the proliferative effect of the cholinergic agonist carbachol on prostate cancer by its agonistic action on CHRM3. This study shows that the type 1 acetylcholine muscarinic receptor (CHRM1) contributes toward the proliferation and growth of prostate cancer. We used growth and cytotoxic assays, the prostate cancer microarray database and CHRM downstream pathways' homology of CHRM subtypes to uncover multiple signals leading to the growth of prostate cancer. Growth assays showed that pilocarpine stimulates the proliferation of prostate cancer. Moreover, it shows that carbachol exerts an additional agonistic action on nicotinic cholinergic receptor of prostate cancer cells that can be blocked by tubocurarine. With the use of selective CHRM1 antagonists such as pirenzepine and dicyclomine, a considerable inhibition of proliferation of prostate cancer cell lines was observed in dose ranging from 15-60 µg/ml of dicyclomine. The microarray database of prostate cancer shows a dominant expression of CHRM1 in prostate cancer compared with other cholinergic subtypes. The bioinformatics of prostate cancer and CHRM pathways show that the downstream signalling include PIP3-AKT-CaM-mediated growth in LNCaP and PC3 cells. Our study suggests that antagonism of CHRM1 may be a potential therapeutic target against prostate cancer.

Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control practices involving the excessive use of synthetic insecticides over many years have resulted in aphid resistance to a number of pesticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. To further explore this finding, the current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid, as the bioactive compound in I. rugosus. Insecticidal potential of rosmarinic acid against A. pisum was evaluated using standard protocols and the data obtained was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application.

Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control involving the excessive use of synthetic insecticides over decades has led to multiple forms of aphid resistance to most classes of insecticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. It was however not known as which compound was responsible for such activity. To further explore this finding, current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid as the bioactive compound in I. rugosus. Insecticidal activity of rosmarinic acid was carried out using standard protocols on A. pisum. The data was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application.

The successful phytoextraction of potentially toxic elements (PTEs) from polluted soils can be achieved by growing non-food and industrial crops. Tobacco (Nicotiana tabacum L.) is one of the main industrial crops and is widely grown in many countries. Tobacco can uptake high concentrations of PTEs especially in aboveground biomass without suffering from toxicity. This review highlighted the potential of tobacco for the phytoextraction of heavy metals and tolerance mechanisms under metal stress. Different management practices have been discussed which can enhance the potential of this plant for metal extraction. Finally, suitable options for the management/disposal of biomass enriched in excess metal have been elaborated to prevent secondary pollution.

Transgenic potato (Solanum tuberosum L. cv. Desiree) plants expressing components of a novel cyanobacterial photorespiratory glycolate catabolism pathway were developed. Transgenic plant expressing glcD1 (glycolate dehydrogenase I) gene was referred to as synGDH and transgenic plants expressing gcl (glyoxylate carboligase) and tsr (tartronic semialdehyde reductase) genes simultaneously were designated as synGT. Both synGDH and synGT plants showed stable gene transformation, integration and expression. Enhanced glyoxylate contents in synGDH plants were detected as compared to synGT and non-transgenic (NT) plants. Phenotypic evaluation revealed that synGDH plants accumulated 11 % higher dry weight, while, tuber weight was 38 and 16 % higher than NT and synGT, respectively. Upon challenging the plants in high temperature and high light conditions synGDH plants maintained higher Fv/Fm and showed less bleaching of chlorophyll as compared to synGT and NT plants. These results indicate that genetic transformation of complete pathway in one plant holds promising outcomes in terms of biomass accumulation to meet future needs for food and energy.

Malathion, a well-known organophosphate pesticide, has been used in agriculture over the last two decades for controlling pests of economically important crops. In the present study, a single bacterium, ML-1, was isolated by soil-enrichment technique and identified as Bacillus licheniformis on the basis of the 16S rRNA technique. The bacterium was grown in carbon-free minimal salt medium (MSM) and was found to be very efficient in utilizing malathion as the sole source of carbon. Biodegradation experiments were performed in MSM without carbon source to determine the malathion degradation by the selected strain, and the residues of malathion were determined quantitatively using HPLC techniques. Bacillus licheniformis showed very promising results and efficiently consumed malathion as the sole carbon source via malathion carboxylesterase (MCE), and about 78% malathion was degraded within 5 days. The carboxylesterase activity was determined by using crude extract while using malathion as substrate, and the residues were determined by HPLC. It has been found that the MCE hydrolyzed 87% malathion within 96 h of incubation. Characterization of crude MCE revealed that the enzyme is robust in nature in terms of organic solvents, as it was found to be stable in various concentrations of ethanol and acetonitrile. Similarly, and it can work in a wide pH and temperature range. The results of this study highlighted the potential of Bacillus licheniformis strain ML-1 as a biodegrader that can be used for the bioremediation of malathion-contaminated soil.

Background Salinity is one of the most lethal abiotic stresses which affect multiple aspects of plant physiology. Natural variations in plant germplasm are a great resource that could be exploited for improvement in salt tolerance. Eruca sativa (E. sativa) exhibits tolerance to abiotic stresses. However, thorough evaluation of its salt stress tolerance and screening for traits that could be reliably applied for salt tolerance needs to be studied. The current study was designed to characterize 25 E. sativa accessions, originating from diverse geographical regions of Pakistan, for the salt stress tolerance. Methods Salt stress (150 mM NaCl) was applied for 2 weeks to the plants at four leaf stage in hydroponics. Data of the following morpho-physiological traits were collected from control and treated plants of all the accessions: root length (RL), shoot length (SL), plant height (PH), leaf number (LN), leaf area (LA), fresh weight (FW), dry weight (DW), chlorophyl content (SPAD), electrolyte leakage (EL), relative water content (RWC), gas exchange parameters and mineral ion content. Salt tolerance was determined based on membership function value (MFV) of the tested traits. Results Compared with control, the salt-stressed group had significantly reduced mean SL, RL, PH, LN, LA, FW, DW and SPAD. NaCl treatment triggered a slight increase in EL in few accessions. Mean RWC of control and treated groups were not significantly different although few accessions exhibited variation in this trait. Salt stress caused a significant reduction in photosynthesis rate (PR), transpiration rate (TR) and stomatal conductance (SC) but intercellular CO2 (Ci) was not significantly different between control and treated groups. Compared with control, the salt-stressed plants accumulated significantly higher Na+, K+ and Ca2+ while significantly lower Mg2+. K+/Na+ ratio was significantly decreased in salt-stressed plants compared with control. Importantly, significant inter-accession variations were found for all the tested traits. The principal component analysis identified SL, RL, PH, LN, LA, FW, DW and PR as the most significant traits for resolving inter-accession variability. Based on MFV of the tested traits, accessions were categorized into five standard groups. Among 25 accessions, one accession was ranked as highly tolerant, four as tolerant while 15 accessions were ranked as moderately tolerant. Of the remaining five accessions, four were ranked as sensitive while one accession as highly sensitive. Conclusion E. sativa accessions were found to exhibit significant genetic diversity in all the tested traits. A few most significant traits for dissecting the genetic variability were identified that could be used for future large-scale germplasm screening in E. sativa. Salt tolerant accessions could be a good resource for future breeding programs aiming to improve salt stress tolerance.

Drought stress causes lower crop production globally. Plants have acquired many adaptations to overcome drought stress. Mungbean (Vigna radiata (L.) R.Wilczek) is a legume crop widely cultivated in South, East and Southeast Asia. It is grown in high-temperature areas where drought is the main cause of reduced plant growth and productivity. Plants cope with drought stress by activating different signalling mechanisms. The sucrose non-fermenting-1-related protein kinase 2 family (SnRK2s) is known to play vital roles in osmotic stress and in abscisic acid (ABA) signalling pathways by phosphorylating downstream targets. The genes encoding SnRK2s in mungbean and their detailed characterisation remain unexplored. We have conducted extensive genome-wide analysis for gene prediction, in silico gene analysis, evolutionary analysis and gene-expression profiling under drought-stress conditions by quantitative real-time PCR. Through genome-wide analysis, eight SnRK2 genes were predicted in the mungbean genome and were assigned the names VrSnRK2.1–VrSnRK2.8, according to their order on the chromosomes. The VrSnRK2 genes identified were classified into three clusters based on their phylogenetic relationship with those of Arabidopsis thaliana. Drought stress was imposed on 11-day-old mungbean plants by completely withholding water for 3 days. According to real-time qPCR data, the expression of most of the VrSnRK2 genes was induced by drought stress, indicating their role in the drought-stress response. One of the genes, namely SnRK2.6c, showed highest expression level (12-fold) under drought stress, possibly indicating a critical role under water-deficit conditions. These data provide important information about the VrSnRK2 gene family in mungbean. The results will help in future functional characterisation of VrSnRK2 genes.

Methanolic extracts of Isodon rugosus Wall. ex Benth (Labiatae), Boenninghausenia albiflora (Hook.) Rchb. ex Meisn. ( Rutaceae ) , Calotropis procera Aiton (Dryand) ( Apocynaceae ) , Daphne mucronata Royle (Thymelaeaceae), Tagetes minuta L. (Asteraceae), Cinnamomum camphora (L.) J. Presl ( Lauraceae ) and Eucalyptus sideroxylon A. Cunn. ex Woolls ( Myrtaceae ), grown in lower Himalayan regions of Pakistan were evaluated at 2% concentration against Peach fruit fly Bactrocera zonata Saunders, 1842 (Diptera: Tephritidae). Tagetes minuta extract showed maximum of 73% mortality against male fruit flies and in case of female maximum mortality shown by C. camphora and I. rugosus was only 16.6%. Boenninghausenia albiflora extract had maximum repellence of 44.4% followed by 42% by D. mucronata extract and the minimum number of flies were settled on these two plant extracts as compared to the others. The lowest number of pupae 3.3% as collected from guavas treated with T. minuta extract; this was significantly lower than the 62.6% pupae recovered from untreated guavas. The lowest numbers of adults (0.33%) were recovered from guavas treated with T. minuta extract compared to 45.3% adults from untreated guavas. The pupae inhibition was highest (94.6%) for T. minuta extract. Inhibition of adult emergence was highest i.e. 99.2% for T. minuta extract. Tagetes minuta can be exploited as a potent source of pesticide against fruit fly, B. zonata , due to maximum pesticidal potential as compared to all other plant extracts applied. The results are discussed in relation with potential benefits of incorporating plant based insecticides in integrated pest management strategies against B. zonata .

Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control practices involving the excessive use of synthetic insecticides over many years have resulted in aphid resistance to a number of pesticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. To further explore this finding, the current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid, as the bioactive compound in I. rugosus. Insecticidal potential of rosmarinic acid against A. pisum was evaluated using standard protocols and the data obtained was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application.

The simple sequence repeats (SSRs) are short tandem arrayed sequence motifs consisting of 2–6 bp, which are not only involved in causing human fatal diseases but also have various applications in plant genetic studies. Thanks to the advancements made in sequencing technology, now we can easily generate genomic/transcriptomic sequences in a shorter period of time. Therefore, trend to identify SSR markers needs up gradation to handle these high-throughput data. Unfortunately, existing web programs for identifying SSR markers are useful but they are unable to process high-throughput data. To overcome this disadvantage, we have constructed a web-based tool, RISA (http://sol.kribb.re.kr/RISA/), with a goal of one-click service to identify SSR markers from high-throughput data (up to 200 Mbp). RISA controls automatic input and output pipeline by demon which combines the SSR classification and investigation by Robert Kofler (SciRoKo) to search SSRs and Primer3 to identify primers specific to SSRs simultaneously. In our test, 45,495 qualified primer sets specific to 47,070 SSRs were identified by RISA from whole Arabidopsis lyrata genome (about 207 Mbp) in 15 minutes. In results, it includes SSR statistics generated from user’s queries and SSR markers information along with primers suitable for their amplification. To support handling of large amount of results, RISA provides various filtering options such as motif length, repeat units, total length and PCR product size. Therefore, we propose that RISA minimizes labour-intensive works or any other considerations which can be required during the development of SSR markers without having deep understanding of computer system and/or algorithms.

Plants are frequently exposed to a plethora of environmental stresses. Being sessile creatures, they have to tolerate any stresses by altering their metabolism. To achieve tolerance, plants synthesize compatible compounds such as glycine betaine (GB). Continuous research over the years has increased our understanding about the mechanisms of stress protection by GB, which range from an osmolyte to a chaperone and from maintenance of reactive oxygen species to gene expression inducer. Various crop plants have also been transformed to synthesize GB along with model plants by introducing bacterial or plant genes. The GB-synthesizing crop plants exhibit enhanced tolerance to various abiotic stresses and out-yield wild-type plants in stressful conditions. GB has also been utilized to improve enhanced stress tolerance by utilizing it in gene stacking experiments due to its synergistic and stabilizing effects. It is reviewed here (along with comparative analysis of GB synthesis pathways and its mechanism to improve tolerance) showing that gene stacking by using GB as one component provides substantial protection. This synergistic role of GB leads us to hypothesize that it can be utilized in virtually any kind of gene stacking experiments to develop crop plants to be grown in arable and marginal lands for better tolerance to ever-changing environmental conditions and to ensure food security in underdeveloped regions of the world.

Plants express resistance (R) genes to recognize invaders and prevent the spread of pathogens. To analyze nucleotide binding site, leucine-rich repeat (NB-LRR) genes, we constructed a fast pipeline to predict and classify the R gene analogs (RGAs) by applying in-house matrices. With predicted ~37,000 RGAs, we can directly compare RGA contents across entire plant lineages, from green algae to flowering plants. We focused on the highly divergent NBLRRs in land plants following the emergence of mosses. We identified entire loss of Toll/Interleukin-1 receptor, NBLRR (TNL) in Poaceae family of monocots and interestingly from Mimulus guttatus (a dicot), which leads to the possibility of species-specific TNL loss in other sequenced flowering plants. Using RGA maps, we have elucidated a positive correlation between the cluster sizes of NB-LRRs and their numbers. The cluster members were observed to consist of the same class of NB-LRRs or their variants, which were probably generated from a single locus for an R gene. Our website ( http://sol.kribb.re.kr/PRGA/ ), called plant resistance gene analog (PRGA), provides useful information, such as RGA annotations, tools for predicting RGAs, and analyzing domain profiles. Therefore, PRGA provides new insights into R-gene evolution and is useful in applying RGA as markers in breeding and or systematic studies.

The present study reports the potential of Arundo donax for phytoextraction of arsenic from synthetic wastewater. A. donax plants were grown under greenhouse conditions in pots containing a nutrient solution amended with increasing doses of As (0, 50, 100, 300, 600 and 1000 microg L(-1)) for 21 days in a completely randomized design. Shoot and roots dry matter production, growth parameters, arsenic and nutrient tissue concentrations were measured at the end of the experiment. Increasing As concentration in nutrient solution caused an increase in shoot and root biomass without toxicity symptoms in A. donax growing under a range of As concentration from 50 to 600 microg L(-1). Elevated oxidative stress was observed at As supplied level of 1000 microg L(-1). The As doses up to 600 microg L(-1) did not affect the growth of A. donax. It is suggested that A. donax plants may be employed to treat contaminated waters containing arsenic concentrations up to 600 microg L(-1).

A binary vector devoid of a plant selection-marker gene (designated as pSSA-F) was constructed to overcome bio-safety concerns about genetically modified plants. This vector carried chloroplast-targeted superoxide dismutase (SOD) and ascorbate peroxidase (APX) genes under the control of an oxidative stress-inducible(SWPA2) promoter, and was utilized to transform potato (Solanum tuberosum L.). Integration of these foreign genes into transgenic plants was primarily performed via PCR with genomic DNA. Twelve marker-free transgenic lines were obtained by inoculating stem explants. The maximum transformation efficiency was 6.25% and averaged 2.2%. Successful integration of the SOD and APX genes rendered transgenic plants tolerant to methyl viologen-mediated oxidative stress at the leaf-disc and whole-plant levels. Our findings suggest that this technique for developing selection marker-free transgenic plants is feasible and can be employed with other crop species.

Transgenic potato plants (Solanum tuberosum L. cv. Superior) with the ability to synthesize glycinebetaine (GB) in chloroplasts (referred to as SC plants) were developed via the introduction of the bacterial choline oxidase (codA) gene under the control of an oxidative stress-inducible SWPA2 promoter. SC1 and SC2 plants were selected via the evaluation of methyl viologen (MV)-mediated oxidative stress tolerance, using leaf discs for further characterization. The GB contents in the leaves of SC1 and SC2 plants following MV treatment were found to be 0.9 and 1.43 micromol/g fresh weight by HPLC analysis, respectively. In addition to reduced membrane damage after oxidative stress, the SC plants evidenced enhanced tolerance to NaCl and drought stress on the whole plant level. When the SC plants were subjected to two weeks of 150 mM NaCl stress, the photosynthetic activity of the SC1 and SC2 plants was attenuated by 38 and 27%, respectively, whereas that of non-transgenic (NT) plants was decreased by 58%. Under drought stress conditions, the SC plants maintained higher water contents and accumulated higher levels of vegetative biomass than was observed in the NT plants. These results indicate that stress-induced GB production in the chloroplasts of GB non-accumulating plants may prove useful in the development of industrial transgenic plants with increased tolerance to a variety of environmental stresses for sustainable agriculture applications.

Phosphorus (P) deficiency is a common nutritional factor limiting agricultural production around the globe. Application of phosphatic fertilizers is generally recommended to cope with P deficiency; however, low use efficiency of available P fertilizers both in calcareous and acid soils limits its viability and also had serious environmental concerns. Higher plants have adapted a number of mechanism to live with low available P in soil such as changes in root morphology and architecture, decreased growth rate, improved P uptake and utilization efficiency, and exudation of organic acids and enzymes to solubilize external inorganic and organic P compounds in the rhizosphere. Plant species and even cultivars widely differ in P efficiency because of differences in one or more of these mechanisms. Exploitation of these genetic variations among crop plants can sustain agricultural production. Understanding the mechanism involved in sensing P deficiency could facilitate selection, breeding, and genetic engineering approaches to improve crop production in P-stressed environments and could reduce dependence on nonrenewable inorganic P resources. In this chapter, we briefly reviewed the responses of P deficiency in higher plants, their adaptive mechanisms, and signaling pathways.

Constitutive overexpression of transgenes occasionally interferes with normal growth and developmental processes in plants. Thus, the development of tissue-specific promoters that drive transgene expression has become agriculturally important. To identify tomato tissue-specific promoters, tissue-specific genes were screened using a series of in silico-based and experimental procedures, including genome-wide orthologue searches of tomato and Arabidopsis databases, isolation of tissue-specific candidates using an Arabidopsis microarray database, and validation of tissue specificity by reverse transcription-polymerase chain reaction (RT-PCR) analysis and promoter assay. Using these procedures, we found 311 tissue-specific candidate genes and validated 10 tissue-specific genes by RT-PCR. Among these identified genes, histochemical analysis of five isolated promoter::GUS transgenic tomato and Arabidopsis plants revealed that their promoters have different but distinct tissue-specific activities in anther, fruit, and root, respectively. Therefore, it appears these in silico-based screening approaches in addition to the identification of new tissue-specific genes and promoters will be helpful for the further development of tailored crop development.

Plants synthesize compatible solutes such as glycinebetaine (GB) in response to abiotic stresses. To evaluate the synergistic and protective effect of GB, transgenic potato plants expressing superoxide dismutase (SOD) and ascorbate peroxidase (APX) targeting to chloroplasts (referred to as SSA plants) were retransformed with a bacterial choline oxidase (codA) gene to synthesize GB in chloroplast in naturally occurring non-accumulator potato plants (including SSA) under the control of the stress-inducible SWPA2 promoter (referred to as SSAC plants). GB accumulation resulted in enhanced protection of these SSAC plants and lower levels of H 2 O 2 compared with SSA and non-transgenic (NT) plants after methyl viologen (MV)-mediated oxidative stress. Additionally, SSAC plants demonstrated synergistically enhanced tolerance to salt and drought stresses at the whole-plant level. GB accumulation in SSAC plants helped to maintain higher activities of SOD, APX and catalase following oxidative, salt and drought stress treatments than is observed in SSA and NT plants. Conclusively, GB accumulation in SSAC plants along with overexpression of antioxidant genes rendered the plants tolerant to multiple environmental stresses in a synergistic fashion.

Reactive oxygen species (ROS) are produced naturally in plants during normal growth conditions. However, their production is accelerated manifold during various abiotic and biotic stresses. Rapid and efficient detoxification of ROS is vital to avoid any damage at cellular level. This is done by a well defined antioxidative system which comprises of various enzymes (superoxide dismutase, catalases and peroxidases) and low molecular weight compounds such as; praline, betaine, ascorbate and glutathione. Among these, ascorbate and glutathione are directly involved in scavenging of ROS. The present article will emphasize on the biosynthesis and role of ascorbate and glutathione during oxidative stress.

We have examined the role of entire major histocompatibility complex (MHC) disparity, individual class II or class I alloantigens in the rejection of vascularized heart allografts. Our results demonstrate that entire MHC, as well as both class II and class I disparities, may induce acute heart graft rejection or severe and irreversible heart muscle destruction. However, in 1 of 2 combinations differing at class II and 1 of 5 differing at class I, hearts have shown a good function greater than 100 days postgrafting. Furthermore, each donor-recipient combination has demonstrated a unique pattern of heart allograft function as well as a degree of heart muscle damage. In conclusion, these data suggest that the rejection process depends upon multiple factors such as the immune-response-gene-regulated immunoresponsiveness of the recipient as well as the expression of alloantigens on heart grafts during the induction and effector phases of the immune response.