Corrigendum: Cytokinin and abiotic stress tolerance -What has been accomplished and the way forward?

[This corrects the article DOI: 10.3389/fgene.2022.943025.].

Corrigendum: Cytokinins: a genetic target for increasing yield potential in the CRISPR era.

[This corrects the article DOI: 10.3389/fgene.2022.883930.].

Genome editing technologies, mechanisms and improved production of therapeutic phytochemicals: Opportunities and prospects.

Plants produce a large number of secondary metabolites, known as phytometabolites that may be employed as medicines, dyes, poisons, and insecticides in the field of medicine, agriculture, and industrial use, respectively. The rise of genome management approaches has promised a factual revolution in genetic engineering. Targeted genome editing in living entities permits the understanding of the biological systems very clearly, and also sanctions to address a wide-ranging objective in the direction of improving features of plant and their yields. The last few years have introduced a number of unique genome editing systems, including transcription activator-like effector nucleases, zinc finger nucleases, and miRNA-regulated clustered regularly interspaced short palindromic repeats/Cas9 (CRISPR/Cas9). Genome editing systems have helped in the transformation of metabolic engineering, allowing researchers to modify biosynthetic pathways of different secondary metabolites. Given the growing relevance of editing genomes in plant research, the exciting novel methods are briefly reviewed in this chapter. Also, this chapter highlights recent discoveries on the CRISPR-based modification of natural products in different medicinal plants.

Microbial strategies for degradation of microplastics generated from COVID-19 healthcare waste.

COVID-19 pandemic has led to the generation of massive plastic wastes, comprising of onetime useable gloves, masks, tissues, and other personal protective equipment (PPE). Recommendations for the employ of single-use disposable masks made up of various polymeric materials like polyethylene, polyurethane, polyacrylonitrile, and polypropylene, polystyrene, can have significant aftermath on environmental, human as well as animal health. Improper disposal and handling of healthcare wastes and lack of proper management practices are creating serious health hazards and an extra challenge for the local authorities designated for management of solid waste. Most of the COVID-19 medical wastes generated are now being treated by incineration which generates microplastic particles (MPs), dioxin, furans, and various toxic metals, such as cadmium and lead. Moreover, natural degradation and mechanical abrasion of these wastes can lead to the generation of MPs which cause a serious health risk to living beings. It is a major threat to aquatic lives and gets into foods subsequently jeopardizing global food safety. Moreover, the presence of plastic is also considered a threat owing to the increased carbon emission and poses a profound danger to the global food chain. Degradation of MPs by axenic and mixed culture microorganisms, such as bacteria, fungi, microalgae etc. can be considered an eco-sustainable technique for the mitigation of the microplastic menace. This review primarily deals with the increase in microplastic pollution due to increased use of PPE along with different disinfection methods using chemicals, steam, microwave, autoclave, and incineration which are presently being employed for the treatment of COVID-19 pandemic-related wastes. The biological treatment of the MPs by diverse groups of fungi and bacteria can be an alternative option for the mitigation of microplastic wastes generated from COVID-19 healthcare waste.

COVID-19 presenting as acute adominal pain: A case series.

The coronavirus infection presents primarily as a respiratory illness, however, extra-pulmonary manifestations are known to occur, including gastrointestinal manifestations. Hereby, we report three cases of the COVID-19 infection who presented with acute-onset abdominal pain during illness. All three patients had respiratory symptoms suggestive of COVID-19 and abdominal symptoms consistent with acute pancreatitis, acute cholecystitis, and acute appendicitis. All three patients improved in terms of acute abdominal pain; however, the overall clinical course, the three illnesses were variable because of differences in underlying organ involment and pathophysiology.

In vitro propagation and secondary metabolite production in Gloriosa superba L.

Gloriosa superba L., commonly known as "gloriosa lily," "glory lily," and "tiger claw," is a perennial climber in the Liliaceae family. This plant is used in African and Southeast Asian cultures as an ayurvedic medicinal herb to treat various health conditions. Its main bioactive component is colchicine, which is responsible for medicinal efficacies as well as poisonous properties of the plant. A high market demand, imprudent harvesting of G. superba from natural habitat, and low seed setting have led scientists to explore micropropagation techniques and in vitro optimization of its phytochemicals. Plant growth regulators have been used to induce callus, root, and shoot organogenesis, and somatic embryogenesis in vitro. This review is aimed at presenting information regarding the occurrence, taxonomic description, phytochemistry, micropropagation, in vitro secondary metabolite, and synthetic seed production. The data collected from the existing literature, along with an analysis of individual study details, outcomes, and variations in the reports, will contribute to the development of biotechnological strategies for conservation and mass propagation of G. superba. KEY POINTS: • Latest literature on micropropagation of Gloriosa superba. • Biotechnological production and optimization of colchicine. • Regeneration, somatic embryogenesis, and synthetic seed production.

Cytokinin and abiotic stress tolerance -What has been accomplished and the way forward?

More than a half-century has passed since it was discovered that phytohormone cytokinin (CK) is essential to drive cytokinesis and proliferation in plant tissue culture. Thereafter, cytokinin has emerged as the primary regulator of the plant cell cycle and numerous developmental processes. Lately, a growing body of evidence suggests that cytokinin has a role in mitigating both abiotic and biotic stress. Cytokinin is essential to defend plants against excessive light exposure and a unique kind of abiotic stress generated by an altered photoperiod. Secondly, cytokinin also exhibits multi-stress resilience under changing environments. Furthermore, cytokinin homeostasis is also affected by several forms of stress. Therefore, the diverse roles of cytokinin in reaction to stress, as well as its interactions with other hormones, are discussed in detail. When it comes to agriculture, understanding the functioning processes of cytokinins under changing environmental conditions can assist in utilizing the phytohormone, to increase productivity. Through this review, we briefly describe the biological role of cytokinin in enhancing the performance of plants growth under abiotic challenges as well as the probable mechanisms underpinning cytokinin-induced stress tolerance. In addition, the article lays forth a strategy for using biotechnological tools to modify genes in the cytokinin pathway to engineer abiotic stress tolerance in plants. The information presented here will assist in better understanding the function of cytokinin in plants and their effective investigation in the cropping system.

Betelvine (Piper betle L.): A comprehensive insight into its ethnopharmacology, phytochemistry, and pharmacological, biomedical and therapeutic attributes.

Piper betle L. (synonym: Piper betel Blanco), or betel vine, an economically and medicinally important cash crop, belongs to the family Piperaceae, often known as the green gold. The plant can be found all over the world and is cultivatedprimarily in South East Asian countries for its beautiful glossy heart-shaped leaves, which are chewed or consumed as betelquidand widely used in Chinese and Indian folk medicine, as carminative, stimulant,astringent, against parasitic worms, conjunctivitis, rheumatism, wound, etc., andis also used for religious purposes. Hydroxychavicol is the most important bioactive compound among the wide range of phytoconstituents found in essential oil and extracts. The pharmacological attributes of P. betle are antiproliferation, anticancer, neuropharmacological, analgesic, antioxidant, antiulcerogenic, hepatoprotective, antifertility, antibacterial, antifungal and many more. Immense attention has been paid to nanoformulations and their applications. The application of P. betle did not show cytotoxicity in preclinical experiments, suggesting that it could serve as a promising therapeutic candidate for different diseases. The present review comprehensively summarizes the botanical description, geographical distribution, economic value and cultivation, ethnobotanical uses, preclinical pharmacological properties with insights of toxicological, clinical efficacy, and safety of P. betle. The findings suggest that P. betle represents an orally active and safe natural agent that exhibits great therapeutic potential for managing various human medical conditions. However, further research is needed to elucidate its underlying molecular mechanisms of action, clinical aspects, structure-activity relationships, bioavailability and synergistic interactions with other drugs.

Cytokinins: A Genetic Target for Increasing Yield Potential in the CRISPR Era.

Over the last decade, remarkable progress has been made in our understanding the phytohormones, cytokinin's (CKs) biosynthesis, perception, and signalling pathways. Additionally, it became apparent that interfering with any of these steps has a significant effect on all stages of plant growth and development. As a result of their complex regulatory and cross-talk interactions with other hormones and signalling networks, they influence and control a wide range of biological activities, from cellular to organismal levels. In agriculture, CKs are extensively used for yield improvement and management because of their wide-ranging effects on plant growth, development and physiology. One of the primary targets in this regard is cytokinin oxidase/dehydrogenase (CKO/CKX), which is encoded by CKX gene, which catalyses the irreversible degradation of cytokinin. The previous studies on various agronomically important crops indicated that plant breeders have targeted CKX directly. In recent years, prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been increasingly used in editing the CKO/CKX gene and phenomenal results have been achieved. This review provides an updated information on the applications of CRISPR-based gene-editing tools in manipulating cytokinin metabolism at the genetic level for yield improvement. Furthermore, we summarized the current developments of RNP-mediated DNA/transgene-free genomic editing of plants which would broaden the application of this technology. The current review will advance our understanding of cytokinins and their role in sustainably increase crop production through CRISPR/Cas genome editing tool.

Biotechnology for micropropagation and camptothecin production in Ophiorrhiza sp.

Camptothecin (CPT) is a monoterpenoid-alkaloid, an anticancer compound from plant. Ever since its discovery in 1996 from the bark of Camptotheca acuminata, various researches have been conducted for enhancing its production. CPT has also been reported in several other species belonging to the plant families Icacinaceae, Rubiaceae, Apocynaceae, Nyssaceae, Betulaceae, Violaceae, Meliaceae, and Gelseminaceae. Out of these, Ophiorrhiza sp. (Rubiaceae) is the next possible candidate for sustainable CPT production after C. acuminata and Nothapodytes nimoonia. Various biotechnological-studies have been conducted on Ophiorrhiza sp. for searching the elite species and the most optimal strategies for CPT production. The genus Ophiorrhiza has been used as medicines for antiviral, antifungal, antimalarial, and anticancer activities. Phytochemical analysis has revealed the presence of alkaloids, flavonoids, triterpenes, and CPT from the plant. Because of the presence of CPT and its herbaceous habit, Ophiorrhiza sp. has now become a hot topic in research area. Currently, for mass production of the elite spp., tissue culture techniques have been implemented. In the past decades, several researchers have contributed on the diversity assessment, phytochemical analysis, mass production, and in vitro production of CPT in Ophiorrhiza sp. In this paper, we review the on the biotechnological strategies, optimal culture medium, micropropagation of Ophiorrhiza sp., effect of PGR on shoot formation, rhizogenesis, callus formation, and enhanced production of CPT for commercial use. KEY POINTS: • Latest literature on in vitro propagation of Ophiorrhiza sp. • Biotechnological production of camptothecin and related compounds • Optimization, elicitation, and transgenic studies in Ophiorrhiza sp.

Removal of hexavalent chromium via biochar-based adsorbents: State-of-the-art, challenges, and future perspectives.

Chromium originates from geogenic and extensive anthropogenic activities and significantly impacts natural ecosystems and human health. Various methods have been applied to remove hexavalent chromium (Cr(VI)) from aquatic environmental matrices, including adsorption via different adsorbents, which is considered to be the most common and low-cost approach. Biochar materials have been recognized as renewable carbon sorbents, pyrolyzed from various biomass at different temperatures under limited/no oxygen conditions for heavy metals remediation. This review summarizes the sources, chemical speciation & toxicity of Cr(VI) ions, and raw and modified biochar applications for Cr(VI) remediation from various contaminated matrices. Mechanistic understanding of Cr(VI) adsorption using different biochar-based materials through batch and saturated column adsorption experiments is documented. Electrostatic interaction and ion exchange dominate the Cr(VI) adsorption onto the biochar materials in acidic pH media. Cr(VI) ions tend to break down as HCrO4-, CrO42-, and Cr2O72- ions in aqueous solutions. At low pH (∼1-4), the availability of HCrO4- ions attributes the electrostatic forces of attraction due to the available functional groups such as -NH4+, -COOH, and -OH2+, which encourages higher adsorption of Cr(VI). Equilibrium isotherm, kinetic, and thermodynamic models help to understand Cr(VI)-biochar interactions and their adsorption mechanism. The adsorption studies of Cr(VI) are summarized through the fixed-bed saturated column experiments and Cr-contaminated real groundwater analysis using biochar-based sorbents for practical applicability. This review highlights the significant challenges in biochar-based material applications as green, renewable, and cost-effective adsorbents for the remediation of Cr(VI). Further recommendations and future scope for the implications of advanced novel biochar materials for Cr(VI) removal and other heavy metals are elegantly discussed.

Multiple roles for basement membrane proteins in cancer progression and EMT.

Metastasis or the progression of malignancy poses a major challenge in cancer therapy and is the principal reason for increased mortality. The epithelial-mesenchymal transition (EMT) of the basement membrane (BM) allows cells of epithelial phenotype to transform into a mesenchymal-like (quasi-mesenchymal) phenotype and metastasize via the lymphovascular system through a metastatic cascade by intravasation and extravasation. This helps in the progression of carcinoma from the primary site to distant organs. Collagen, laminin, and integrin are the prime components of BM and help in tumor cell metastasis, which makes them ideal cancer drug targets. Further, recent studies have shown that collagen, laminin, and integrin can be used as a biomarker for metastatic cells. In this review, we have summarized the current knowledge of such therapeutics, which are either currently in preclinical or clinical stages and could be promising cancer therapeutics. DATA AVAILABILITY: Not applicable.

Biotechnology for propagation and secondary metabolite production in Bacopa monnieri.

Bacopa monnieri (L.) Wettst. or water hyssop commonly known as "Brahmi" is a small, creeping, succulent herb from the Plantaginaceae family. It is popularly employed in Ayurvedic medicine as a nerve tonic to improve memory and cognition. Of late, this plant has been reported extensively for its pharmacologically active phyto-constituents. The main phytochemicals are brahmine, alkaloids, herpestine, and saponins. The saponins include bacoside A, bacoside B, and betulic acid. Investigation into the pharmacological effect of this plant has thrived lately, encouraging its neuroprotective and memory supporting capacity among others. Besides, it possesses many other therapeutic activities like antimicrobial, antioxidant, anti-inflammatory, gastroprotective properties, etc. Because of its multipurpose therapeutic potential, it is overexploited owing to the prioritization of natural remedies over conventional ones, which compels us to conserve them. B. monnieri is confronting the danger of extinction from its natural habitat as it is a major cultivated medico-botanical and seed propagation is restricted due to less seed availability and viability. The ever-increasing demand for the plant can be dealt with mass propagation through plant tissue culture strategy. Micropropagation utilizing axillary meristems as well as de novo organogenesis have been widely investigated in this plant which has also been explored for its conservation and production of different types of secondary metabolites. Diverse in vitro methods such as organogenesis, cell suspension, and callus cultures have been accounted for with the aim of production and/or enhancement of bacosides. Direct shoot-organogenesis was initiated in excised leaf and internodal explants without any exogenous plant growth regulator(s) (PGRs), and the induction rate was improved when exogenous cytokinins and other supplements were used. Moreover, biotechnological toolkits like Agrobacterium-mediated transformation and the use of mutagens have been reported. Besides, the molecular marker-based studies demonstrated the clonal fidelity among the natural and in vitro generated plantlets also elucidating the inherent diversity among the natural populations. Agrobacterium-mediated transformation system was mostly employed to optimize bacoside biosynthesis and heterologous expression of other genes. The present review aims at depicting the recent research outcomes of in vitro studies performed on B. monnieri which include root and shoot organogenesis, callus induction, somatic embryogenesis, production of secondary metabolites by in vitro propagation, acclimatization of the in vitro raised plantlets, genetic transformation, and molecular marker-based studies of clonal fidelity. KEY POINTS: • Critical and up to date records on in vitro propagation of Bacopa monnieri • In vitro propagation and elicitation of secondary metabolites from B. monnieri • Molecular markers and transgenic studies in B. monnieri.