Molecular aspects of regeneration in insects.

Regeneration is a fascinating phenomenon observed in various organisms across the animal kingdom. Different orders of class Insecta are reported to possess comprehensive regeneration abilities. Several signalling molecules, such as morphogens, growth factors, and others trigger a cascade of events that promote wound healing, blastema formation, growth, and repatterning. Furthermore, epigenetic regulation has emerged as a critical player in regulating the process of regeneration. This report highlights the major breakthrough research on wound healing and tissue regeneration. Exploring and reviewing the molecular basis of regeneration can be helpful in the area of regenerative medicine advancements. The understanding gathered from this framework can potentially contribute to hypothesis designing with implications in the field of synthetic biology and human health.

Physiological alterations and heavy metal accumulation in the transplanted lichen Pyxine cocoes (Sw.) Nyl. in Lucknow city, Uttar Pradesh.

Air pollution has become a major concern due to its detrimental effects on living beings. The present study is aimed at assessing the current status of air pollution in Lucknow city using lichen transplantation technique and assesing its effect on physiology of Pyxine cocoes. The samples of P. cocoes were collected from relatively pollution-free area Malihabad and transplanted in 10 designated sites in five regions for 30 days. Various parameters such as heavy metals, chlorophyll pigments, carotenoid, chlorophyll degradation, and electrolyte conductivity were estimated in transplanted lichens. The study revealed that the concentration of all 10 heavy metals was higher in all transplanted samples than in the control sample, which was found in order of Al > Fe > Mn > Zn > Cu > Cr > Pb > Ni > Co > Cd. Among all 10 transplanted sites, the significantly increased accumulation of aluminum (5.11 to 5.47 µg L-1), iron (4.73 to 5.46 µg L-1), manganese (110.99 to 144.58 µg g-1), and zinc (87.96 to 97.40 µg g-1) was found in Charbagh, Qaisarbagh, and Alambagh sites. Further, in all samples, chlorophyll a (3.98 µg L-1), chlorophyll b (1.22 µg L-1), total chlorophyll (5.20 µg L-1), and chlorophyll degradation (0.55 µg g-1) were significantly decreased, whereas elevated levels of carotenoid (0.71 µg g-1), and electrolyte conductivity (64.99 µS cm-1), were observed. The scanning electron microscope (SEM) investigated the morphological changes in transplanted lichen samples, and significant damage to the anatomy of mycelium was found in most of the polluted site's samples, which correlated with the pollution levels. The present study clearly demonstrated that the transplanted lichen P. cocoes is an efficient bioaccumulator and bioindicator of air quality in urban environments.

Novel cost-effective design for bio-volatilization studies in photosynthetic microalgae exposed to arsenic with emphasis on growth and glutathione modulation.

A novel laboratory model was designed to study the arsenic (As) biotransformation potential of the microalgae Chlorella vulgaris and Nannochloropsis sp. and the cyanobacterium Anabaena doliolum. The Algae were treated under different concentrations of As(III) to check their growth, toxicity optimization, and volatilization potential. The results revealed that the alga Nannochloropsis sp. was better adopted in term of growth rate and biomass than C. vulgaris and A. doliolum. Algae grown under an As(III) environment can tolerate up to 200 µM As(III) with moderate toxicity impact. Further, the present study revealed the biotransformation capacity of the algae A. doliolum, Nannochloropsis sp., and Chlorella vulgaris. The microalga Nannochloropsis sp. volatilized a large maximum amount of As (4,393 ng), followed by C. vulgaris (4382.75 ng) and A. doliolum (2687.21 ng) after 21 days. The present study showed that As(III) stressed algae-conferred resistance and provided tolerance through high production of glutathione content and As-GSH chemistry inside cells. Thus, the biotransformation potential of algae may contribute to As reduction, biogeochemistry, and detoxification at a large scale.

Major phenolic compounds, antioxidant, antimicrobial, and cytotoxic activities of Selinum carvifolia (L.) collected from different altitudes in India.

Antibiotic resistance poses a serious threat to public health, raising the number of diseases in the community. Recent research has shown that plant-derived phenolic compounds have strong antimicrobial, antifungal, and cytotoxic properties against a variety of microorganisms and work as great antioxidants in such treatments. The goal of the current work is to evaluate the anticancerous, antibacterial, antifungal, antioxidant, and cytotoxicity activities in the extracts of the different plant parts (leaves, stems, and roots) of S. carvifolia (L.) L. This is a medicinally important plant and has been used for different kinds of diseases and ailments such as hysteria and seizures. The phenolic compounds from the different plant parts were analyzed using HPLC and the following were found to be present: chlorogenic acid, gallic acid, rutin, syringic acid, vanillic acid, cinnamic acid, caffeic acid, and protocatechuic acid. Gallic acid was found to have the highest concentration (13.93 mg/g), while chlorogenic acid (0.25 mg/g) had the lowest. The maximum TPC value, which ranged from 33.79 to 57.95 mg GAE/g dry extract weight, was found in the stem. Root extract with 9.4 mg RE/g had the greatest TFC level. In the leaf and stem extracts, the RSC ranged from 0.747 mg/mL to 0.734 mg/1 mL GE/g dry extract weight, respectively. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to measure in vitro antioxidant activity. In a concentration-dependent way, promising antioxidant activity was reported. Moreover, 3,5-dinitrosalicylic acid (DNSA) and the Folin-Ciocalteu phenol reagent technique were used to determine reducing sugar content and total phenolic content, respectively. Antibacterial activity against eight strains (MIC: 250-1,000 µg/mL) was analyzed, and the stem extract exhibited maximum activity. Antifungal activity was also assessed, and potent activity was reported especially in the extract obtained from the stem. Cytotoxicity was evaluated using an MTT assay in the A549 cell line, where different doses (0.0625, 0.125, 0.25, 0.5, and 1 mg/mL) of leaf, root, and stem extracts were used. Treatment with these extracts reduced the cell viability, indicating that S. carvifolia may possess anticancer potential, which can be of great therapeutic value.

The industrially important genus Kaempferia: An ethnopharmacological review.

Kaempferia, a genus of the family Zingiberaceae, is widely distributed with more than 50 species which are mostly found throughout Southeast Asia. These plants have important ethnobotanical significance as many species are used in Ayurvedic and other traditional medicine preparations. This genus has received a lot of scholarly attention recently as a result of the numerous health advantages it possesses. In this review, we have compiled the scientific information regarding the relevance, distribution, industrial applications, phytochemistry, ethnopharmacology, tissue culture and conservation initiative of the Kaempferia genus along with the commercial realities and limitations of the research as well as missing industrial linkages followed by an exploration of some of the likely future promising clinical potential. The current review provides a richer and deeper understanding of Kaempferia, which can be applied in areas like phytopharmacology, molecular research, and industrial biology. The knowledge from this study can be further implemented for the establishment of new conservation strategies.

Comparative transcriptional analysis of metabolic pathways and mechanisms regulating essential oil biosynthesis in four elite Cymbopogon spp.

Cymbopogon is an important aromatic and medicinal grass with several species of ethnopharmaceutical importance. The genus is extremely rich in secondary metabolites, monoterpenes like geraniol and citral being principal constituents, also used as biomarker for classification and identification of Cymbopogon chemotypes. In the light of this, present study involved RNA sequencing and comparison of expression profiles of four contrasting Cymbopogon species namely C. flexuosus var. Chirharit (citral rich and frost resistant), C. martinii var. PRC-1 (geraniol rich), C. pendulus var. Praman (the most stable and citral-rich genotype), and Jamrosa (a hybrid of C. nardus var. confertiflorus × C. jwarancusa (rich in geraniol and geranyl acetate). The transcriptome profiles revealed marked differences in gene expression patterns of 28 differentially expressed genes (DEGs) of terpenoid metabolic pathways between the four Cymbopogon sp. The major DEGs were Carotenoid Cleavage Dioxygenases (CCD), Aspartate aminotransferase (ASP amino), Mevalonate E-4 hydroxy, AKR, GGPS, FDPS, and AAT. In addition, few TFs related to different regulatory pathways were also identified. The gene expression profiles of DEGs were correlated to the EO yield and their monoterpene compositions. Overall, the PRC-1 (C. martinii) shows distinguished gene expression profiles from all other genotypes. Thus, the transcriptome sequence database expanded our understanding of terpenoid metabolism and its molecular regulation in Cymbopogon species. Additionally, this data also serves as an important source of knowledge for enhancing oil yield and quality in Cymbopogon and closely related taxa. KEY MESSAGE: Unfolding the new secretes surrounding EO biosynthesis and regulation in four contrasting Cymbopogon species.

Ethnomedical Applications and Conservation Status of Leguminosae- Caesalpinioideae Plants in Uttar Pradesh, India.

BACKGROUND: This review highlights the folklore, ethnomedicinal uses and conservation status of Caesalpinioideae in Uttar Pradesh (India). AIMS: It aims at compiling available data on traditional medicine, biological activity, phytochemical information and assessing the regional red list status of Caesalpinioideae in Uttar Pradesh. The information provided would help in formulating new drugs and medicines and addressing global conservation issues of such medicinally exploited species. METHODS: The current study included an extensive and systematic review of available literature, the study of previous collections of herbarium specimens, random interviews with locals and tribals, field surveys, and GeoCAT tool-based assessment during 2016-2020. The study reports that the majority of species of Caesalpinioideae are used for curing digestive problems (about 20 species) and skin diseases (19 species). RESULTS: Almost all the species have antimicrobial and antioxidant properties. These pharmacological activities can be attributed to the presence of various types of anthraquinones in plants. CONCLUSION: The regional conservation status reveals that eight species qualified for the status of regionally threatened category while two species fall under the near threatened category.

A Glance at the Phytochemical and Ethno-pharmacological Understanding of Four Ocimum Species.

The genus Ocimum comprises many species widely cultivated in different parts of the world for their pharmaceutical, neutraceutical and other commercial importance. Many biological activities such as antimicrobial, cytotoxic, anti-nociceptive, anti-inflammatory, hypoglycaemic, hepatoprotective and antioxidant have been ascribed to Ocimum, which can be linked to the occurrence of biologically active phytochemicals like phenolic acids, essential oil, flavonoids, and terpenes hence making it a potential source for discovery and development of novel drugs. The present review covers the successive advances in the traditional medicinal aspects, phytochemistry, bioactivities and the bioavailability of four Ocimum species, i.e., Ocimum basilicum L., Ocimum sanctum L., Ocimum gratissimum L. and Ocimum tenuiflorum L., to explore their applications in versatile industries. Furthermore, this thorough compilation will be used as a potential resource for further Ocimum-related medication development and research and to identify the research gaps to fill.

Toxicity assessment of metribuzin and its amelioration through plant growth regulators in Vigna radiata (L.) R. Wilczek.

The present experiment was conducted to evaluate the metribuzin-induced stress response in Vigna radiata and to explore the ameliorative role of exogenous application of plant growth regulators (PGRs) against metribuzin toxicity by assessing important biochemical and yield parameters. Prior to the field experiment, dose standardization experiments were performed, and EC50 was calculated for metribuzin. On day 21, field grown V. radiata plants were treated with graded concentrations of metribuzin (0-1000 mg [Formula: see text]). Plants treated with 600 mg [Formula: see text] (EC50) and 1000 mg [Formula: see text] (highest dose) of metribuzin were co-treated individually and simultaneously with gibberellic acid-3 (GA), indole-3 acetic acid (IAA), and salicylic acid (SA). After 7 days of treatment, leaf tissues were analyzed for biochemical parameters, whereas those related to yield were recorded during harvest. The result of this study indicated that metribuzin treatment to V. radiata resulted in increase in lipid peroxidation and reduce chlorophyll and carotenoid contents as well as yield parameters. However, metribuzin-treated plants induced proline accumulation and activity of antioxidant enzymes. Exogenous application of GA, IAA, and SA significantly reduced lipid peroxidation and increased contents of photosynthetic pigments, proline, and antioxidant enzymes thereby increasing yield parameters. It was observed that during metribuzin stress, SA exhibited a better ameliorative response out of the three exogenously applied PGRs, while the combined use of all PGRs exhibited much improved ameliorative response on biochemical and yield parameters of plants.

Biotic elicitor-induced changes in growth, antioxidative defense, and metabolites in an improved prickleless Solanum viarum.

Solanum viarum serves as a raw material for the steroidal drug industry due to its alkaloid and glycoalkaloid content. Elicitation is well-known for measuring the increase in the yield of bioactive compounds in in vitro cultures. The current study was performed for the accumulation of metabolites viz. solasodine, solanidine, and α-solanine in S. viarum culture using microbial-based elicitors added in 1%, 3%, 5%, and 7% on 25th and 35th day of culture period and harvested on 45th and 50th days of culture cycle. The treatment of 3% Trichoderma reesei and Bacillus tequilensis culture filtrate (CF) significantly increased biomass, alkaloids/glycoalkaloid content, and yield in S. viarum. T. reesei was found to be the best treatment for enhanced growth (GI = 11.65) and glycoalkaloid yield (2.54 mg DW plant-1) after the 50th day of the culture cycle when added on the 25th day. The abundance of gene transcripts involved in the biosynthesis of alkaloids/glycoalkaloids, revealed by quantitative real-time PCR expression analysis correlates with the accumulation of their respective metabolites in elicited plants. Biochemical analysis shows that elicited plants inhibited oxidative damage caused by reactive oxygen species by activating enzymes (superoxide dismutase and ascorbate peroxidase) as well as non-enzymatic antioxidant mechanisms (alkaloids, total phenols, total flavonoids, carotenoids, and proline). The findings of this study clearly demonstrate that the application of T. reesei and B. tequilensis CF at a specific dose and time significantly improve biomass as well as upregulates the metabolite biosynthetic pathway in an important medicinal plant- S. viarum. KEY POINTS: • Biotic elicitors stimulated the alkaloids/glycoalkaloid content in S. viarum plant cultures. • T. reesei was found to be most efficient for enhancing the growth and alkaloids content. • Elicited plants activate ROS based-defense mechanism to overcome oxidative damage.

Interspecific and intraspecific analysis of Selinum spp. collected from Indian Himalayas using DNA barcoding.

BACKGROUND: DNA barcoding is a powerful method for phylogenetic mapping and species identification. However, recent research has come to a consistent conclusion about the universality of DNA barcoding. We used matK and rbcL markers to test the universality of twelve accessions from different locations belonging to two Selinum species, Selinum tenuifolium Wall. C. B. Clarke and Selinum vaginatum C. B. Clarke, keeping in mind their ability to identify species and establish phylogenetic relationships within and between the accessions. RESULTS: The success rates of PCR amplification using matK and rbcL were 75.26% ± 3.65% and 57.24% ± 4.42%, and the rate of DNA sequencing was 63.84% ± 4.32% and 50.82% ± 4.36%, respectively, suggesting that success rates of species identification of the two fragments were higher than 41.00% (matK, 41.50% ± 2.81%; rbcL, 42.88% ± 2.59%), proving that these fragments might be used to identify species. The best evolutionary tree with good supporting values was produced utilizing combinations of matK + rbcL markers when phylogenetic relationships were built with random fragment combinations. The twelve accessions of Selinum collected from different locations and their molecular sequences of matK and rbcL markers were blasted with other genera of Apiaceae family, and it was found that Selinum is most closely related to Angelica species of Apiaceae family. CONCLUSION: The present study has grouped twelve accessions of Selinum species using molecular markers into phylogenies, which is first-of-its-kind report that established interrelationships within different species of Apiaceae with respect to Selinum.

Ethylene regulates miRNA-mediated lignin biosynthesis and leaf serration in Arabidopsis thaliana.

microRNAs (miRNAs) regulate target gene expression by pairing to target mRNAs, leading to mRNA degradation or translation inhibition. Out of several miRNAs in Arabidopsis, miR397b and miR857 regulate secondary growth by modulating lignin polymerization and deposition in secondary xylem cells by targeting laccases. Interestingly, the phytohormone ethylene is also suggested to have a role in lignin biosynthesis in tension wood formation. Despite this information, it is not known whether ethylene has any role in controlling secondary growth via miRNAs-mediated pathways. In this study, we elucidate that ethylene acts upstream to the miR397b/miR857-laccases module and negatively regulates lignin biosynthesis by directly activating the expression of both the miRNAs. The binding of EIN3 to the promoter of miR397b is further validated by yeast one-hybrid assay. In addition to its role in lignification, ethylene also regulates leaf serration by directly regulating the expression of NAC transcription factors, like CUP-SHAPED COTYLEDON2 (CUC2) and CUC3. Together, our study suggests a novel mechanism involving ethylene and miRNAs in lignin biosynthesis and leaf serration in Arabidopsis thaliana.

Application of Pteris vittata L. for phytoremediation of arsenic and biomonitoring of the process through cyto-genetic biomarkers of Trigonella foenum-graecum L.

The arsenic (As) contamination demands its remediation from the environment which is naturally possible by the application of Pteris vittata L. However, biomonitoring of phytoremediation potential of P. vittata at chromosomal and DNA level is still meager. The present study was designed to biomonitor the phytoremediation efficiency of P. vittata through phytotoxic and cyto-genotoxic biomarkers assessment using Trigonella foenum-graecum L. (Fenugreek; Methi) as test system. Study revealed hyperaccumulation potential of P. vittata which extracted arsenic in its tissues. Biomonitoring evaluation depicted that phytotoxic damage was reduced in Trigonella exposed to remediated soil, which was revealed through reduced electrolyte leakage, hydrogen peroxide and MDA content. Moreover, cyto-genetic endpoints like mitotic depression (44.03%), relative abnormality rate (16.6%) and chromosomal abnormality frequency (1.06%) were also lesser in test plants grown in remediated soil compared to those grown in non-remediated soil. Along with this various chromosomal aberrations like stickiness, breaks, laggards, bridges, fragmentations and micronuclei were also augmented in test plants exposed to non-remediated arsenic enriched soil. It was evident that arsenic enriched soil caused toxicity to plants in dose-dependent manner that was assessable through the analysis of biochemical parameters and cyto-genetic biomarkers. The cyto-genetic biomarkers are very efficient, simple and non-expensive tools to biomonitor arsenic toxicity at chromosomal as well as DNA level to assess the remediation potential of P. vittata in field conditions.

Bioaccumulation and Toxicity of As in the Alga Chlorococcum sp.: Prospects for As Bioremediation.

Ubiquitous distribution, fast growth rate and manifold relevance has credited algae a potential bioresource in current state of affairs of environmental degradation. In the present study, green alga Chlorococcum sp. has been collected from waste water, isolated and cultured to assess their accumulation and toxicity responses at different As(III) concentration. Results revealed that Chlorococcum sp. treated with 10 µM As(III) showed a minimal reduction (21%) in chlorophyll concentration with high proline and carotenoids content indicating its adaptive tolerance potential against As(III). The EC50 of As(III) for inhibiting growth of the microalgae after 10 days of experiment was 9.4 µM. Further, Chlorococcum sp. accumulated 239.09 µg g- 1 dw As at the concentration of 10 µM of As(III) after 10 days of treatment. Concentration dependent accumulation pattern and antioxidant responses in Chlorococcum sp. could be a used as a potential bioindicator and bioremediator of As from waste water.

Mobile media exposure and use in children aged zero to five years with diagnosed neurodevelopmental disability.

OBJECTIVE: The present study was conducted to determine the extent of exposure to and use of mobile devices by children (aged 0-60 months) with a diagnosed neurodevelopmental disability. DESIGN: A self-report survey-based design was employed. SETTING: Questionnaires were administered at a tertiary care hospital in Mumbai, India. PARTICIPANTS: The study included a convenience sample of 423 children with a neurodevelopmental disability (aged 0-60 months). The self-report survey was administered to the parents of the children. RESULTS: Analyses showed that 92.7% (n = 392) of all respondents have smartphones. 61% (n = 258) of the respondents stated that their children used mobile devices before 2 years of age. 58% (n = 246) of the parents gave children devices while feeding. A statistically significant difference was found in the mobile media usage between groups of children with different diagnoses (p < 0.001). Children diagnosed with ASD appeared to spend the largest amount of time on mobile media (m = 180.44 mins), as compared to children included with other diagnoses. Of the diagnosed children, only 13.4% (n = 57) of parents were informed about the possible negative effects of media use by their paediatricians. CONCLUSION: The results suggest premature mobile media habits, frequent use and lack of awareness about the effects of mobile media usage among children diagnosed with a neurodevelopmental disability. We suggest there is a need to update recommendations for caregivers on the use of mobile media by young children with disability.Implications for rehabilitationThe usage and consequences of mobile media use differ based on the type of neurodevelopmental disorder diagnosis. Parents of children with neurodevelopmental disorders often use mobile media as a distraction while engaging in various activities themselves, this information helps identify times at which mobile media might be purposefully used by parents as distractorsThere is an urgent need for clinical guidelines regarding mobile media usage among young children with neurodevelopmental disorders.

Evaluation of Phytoremediation Potential of Pteris vittata L. on Arsenic Contaminated Soil Using Allium cepa Bioassay.

The present study assessed the utility of Allium cepa based cyto-genotoxicity bioassays in evaluating the arsenic toxicity and remediation potential of Pteris vittata on contaminated soil of Lakhimpur-Kheri district. Untreated and P. vittata treated soil extracts were used for cyto-genotoxicity tests in A. cepa. Results showed that P. vittata extracted high concentration of arsenic, which ranged from 220 to 1420 mgkg-1 in different soils. Cyto-genotoxic assessment of A. cepa showed that extract of P. vittata treated soil had lower cyto-genotoxic effects as compared to untreated soil. A higher mitotic index (10%) while lower mitotic depression (29%), relative abnormality rate (10%), chromosomal aberrations (1%) and micronuclei (2%) were detected in root meristematic cells of A. cepa exposed to remediated soil extract in comparison to untreated soil. The studies provide a simple, rapid and economic cyto-genotoxicity bioassay tool for evaluating toxicity of contaminated soils of contaminated soils as well as revealed the phytoremdiation property of P. vittata against arsenic toxicity.

A Review of Chemistry and Pharmacology of Piperidine Alkaloids of Pinus and Related Genera.

BACKGROUND: Pinus belongs to the family Pinaceae, represented by several species across the globe. Various parts of the plant including needles are rich in biologically active compounds, such as thunbergol, 3-carene, cembrene, α-pinene, quercetin, xanthone. Of all the alkaloids, the piperidine group is one of the important component and holds considerable medicinal importance. METHODS: The group of alkaloids was initially identified from the genus Piper through which a large variety of piperidine molecules have been extracted. The planar structure of this heterocyclic nucleus enables acetamide groups to be added at various ring configurations. RESULTS: Piperidines have gained considerable importance. The broad range of its therapeutic application has paved a way for researchers to implant the nucleus from time to time in diversified pharmacophores and establish new profile. DISCUSSION: Biological functions of piperidine metabolites have been mostly examined on a limited scale, and that most of the findings are preliminary. We have tried to present various clinical applications of piperidine alkaloids in this study that researchers have already attempted to demystify with time. CONCLUSION: We have also illustrated different types of piperidine structures and their sources in different members of the family Pinaceae with special emphasis on Pinus. Given the importance of the piperidine nucleus, the study will enable the researchers to produce scaffolds of highest therapeutic efficacy.

miR775 integrates light, sucrose and auxin associated pathways to regulate root growth in Arabidopsis thaliana.

MicroRNAs (miRNAs), a class of single-stranded non-coding RNA of 20-24 nucleotides, regulate gene expression by target gene transcript cleavage or translation inhibition. The phytohormone auxin is a crucial regulator of almost every process involved in plant growth and development. Several studies have demonstrated the involvement of miRNA(s) in the regulation of the auxin signaling pathway and plant development. However, very few studies have identified the auxin-mediated regulation of miRNA(s). In this study, we reveal the detailed mechanism of auxin-mediated regulation of the cell wall-related miR775- Galactosyl transferase (GalT) module, which plays an important role in root growth in Arabidopsis thaliana. We also showed two interdependent mechanisms by which miR775 regulates root growth: miR775-GalT and light-mediated sucrose-dependent pathways. Treatment of GUS reporter lines with Indole Acetic Acid (IAA), sucrose, and light apparently enhanced the abundance of miR775 in root tissue. miR775 overexpressing (miR775OX) lines showed changes in root architecture, including increased primary root growth and root hair, by targeting GalT. miR775OX lines also showed tolerance toward low Pi. These results provide new insights into the auxin regulation of cell wall-related miR775 and suggest its significant role in plant root growth and development by modifying the cell wall.

Biomarker-based evaluation of cytogenotoxic potential of glyphosate in Vigna mungo (L.) Hepper genotypes.

Herbicides have proven to be a boon for agricultural fields. Their inherent property to kill weeds and unwanted vegetation makes them an essential biological tool for farmers and agricultural systems. Besides being capable of destroying weeds, they also exhibit certain effects on non-target crop plants. In the present study, a laboratory experiment was performed to assess the effect of glyphosate on Vigna mungo root meristem cells. Seeds of five different genotypes of V. mungo were treated with a series of concentrations of glyphosate ranging from 1 to 10 mM, and their effects on mitotic cell division were studied. Healthy and uniform-sized seeds were selected and were allowed to grow in Petri plates for 3 days, and all the doses were maintained in triplicates. Roots were fixed at day 3 after treatment (DAT) for cytological microscopic slide preparation. The results obtained indicate the dose-dependent reduction in the mitotic index in all the genotypes and an increase in the percentage of chromosomal aberrations (CAs) and relative abnormality rate (RAR). Most commonly observed chromosome aberrations at lower doses (< 6 mM) were fragments, stickiness, and disoriented metaphase, while at higher doses (6 to 10 mM) bridges, laggards, spindle disorientation, and clumping were obvious. The increase in the percentage of CAs and RAR indicates the inhibitory effect of glyphosate on cell cycle progression at various stages in root tip cells. The present study is a fine example of a biomarker-based genotoxic assessment of mitotic damage caused by glyphosate.

RNAi-based gene silencing in Phenacoccus solenopsis and its validation by in planta expression of a double-stranded RNA.

BACKGROUND: Cotton is a cash crop majorly affected by many hemipteran pests, among them the cotton mealybug, Phenacoccus solenopsis. Cotton mealybug attack has a devastating effect on cotton production and causes huge yield losses. RESULTS: In this study, 25 potential RNA interference (RNAi) target genes were selected from the iBeetle database and a transcriptome data set for P. solenopsis. To assess the effectiveness of the selected target genes, three methods were utilized to deliver double-stranded (ds)RNA (ingestion, artificial diet bioassay and transient gene silencing). dsRNA molecules at different concentrations were fed to insects and insect mortality was recorded for each target gene. Based on the mortality data, three genes, Krüppel homologue-1, ADP-ATP/Translocase and IDGF-1, were selected for further gene expression studies using a reduced concentration of dsRNA (5 µg/ml). Of the three genes, Krüppel homologue-1 showed significantly downregulated expression (by 70.81% and 84.33%) at two different time points (8 and 14 days). An RNAi silencing construct was designed for Krüppel homologue-1 under control of the double enhancer CamV35S promoter in the plant binary vector. Significant downregulation of gene expression, by 66.69% and 81.80%, was found for Krüppel homologue-1 using transient gene silencing at the same time intervals. CONCLUSION: This work provides the first evidence for targeting the Krüppel homologue-1 gene in a hemipteran pest, P. solenopsis, using RNAi technology through oral delivery and in planta-based transient gene silencing methods. © 2020 Society of Chemical Industry.