100-Gbps per-channel all-optical wavelength conversion without pre-amplifiers based on an integrated nanophotonic platform

All-optical wavelength conversion based on four-wave mixing attracts intense interest in many areas, especially in optical fiber communications, due to the advantages of femtosecond response, modulation-format transparency, and high flexibility in optical network management. In this paper, we present the first optical translation of 32-GBaud 16QAM signals with an integrated Si3N4 nonlinear nanophotonic waveguide. An on-chip continuous-wave conversion efficiency of up to -0.6dB from S band to C band is achieved in the dispersion-engineered low-loss Si3N4 nonlinear waveguide that is back-end compatible with complementary metal-oxide-semiconductor processes. The high conversion efficiency avoids the use of external optical amplifiers for signal demodulation. The converted idler is successfully received with a sensitivity penalty of less than 0.5dB. Moreover, pre-amplifier-free multichannel wavelength conversion of over-100-Gbps coherent signals in C band is also demonstrated using the same Si3N4 nanophotonic waveguide via changing the pump wavelength, which shows good flexibility in all-optical signal processing. Additionally, wavelength conversion with a bandwidth over 100nm can be expected by optimizing the current Si3N4 nanophotonic waveguide, which is promising for commercial coherent fiber communications and has bright prospects in various areas including optical signal processing, imaging, optical spectroscopy, and quantum optics

100-Gbps per-channel all-optical wavelength conversion without pre-amplifiers based on an integrated nanophotonic platform

All-optical wavelength conversion based on four-wave mixing attracts intense interest in many areas, especially in optical fiber communications, due to the advantages of femtosecond response, modulation-format transparency, and high flexibility in optical network management. In this paper, we present the first optical translation of 32-GBaud 16QAM signals with an integrated Si3N4 nonlinear nanophotonic waveguide. An on-chip continuous-wave conversion efficiency of up to −0.6 dB from S band to C band is achieved in the dispersion-engineered low-loss Si3N4 nonlinear waveguide that is back-end compatible with complementary metal–oxide–semiconductor processes. The high conversion efficiency avoids the use of external optical amplifiers for signal demodulation. The converted idler is successfully received with a sensitivity penalty of less than 0.5 dB. Moreover, pre-amplifier-free multichannel wavelength conversion of over-100-Gbps coherent signals in C band is also demonstrated using the same Si3N4 nanophotonic waveguide via changing the pump wavelength, which shows good flexibility in all-optical signal processing. Additionally, wavelength conversion with a bandwidth over 100 nm can be expected by optimizing the current Si3N4 nanophotonic waveguide, which is promising for commercial coherent fiber communications and has bright prospects in various areas including optical signal processing, imaging, optical spectroscopy, and quantum optics

Meta-topolin-mediated regeneration and accumulation of phenolic acids in the critically endangered medicinal plant Crinum malabaricum (Amaryllidaceae): A potent source of galanthamine

International audienceCrinum malabaricum (Family: Amaryllidaceae) is a critically endangered aquatic medicinal plant endemic to India. This species is a promising natural source of bioactive compounds including galanthamine (GAL), an anti-Alzheimer drug. In vitro regeneration in the Amaryllidaceae is often challenging. This study assessed the use of meta-Topolin (mT) on in vitro regeneration of C. malabaricum. Shoot explants were cultured on Murashige and Skoog (MS) medium supplemented with 0.5, 2.5, 5.0, 7.5 and 10.0 µM mT for six weeks, whereby 7.5 µM mT resulted in the maximum multiplication of adventitious shoots, much higher than the control. The biochemical accumulation of eleven different phenolic acids was quantified by UHPLC-MS/MS analysis, and it appeared that mT-treated cultures exhibited the highest concentration of phenolic acids. In particular, increased concentrations of gallic acid, protocatechuic acid, syringic acid, p-hydroxybenzoic acid, salicylic acid and vanillic acid were detected compared to the control. mT (2.5 and 5.0 µM) produced the maximum amount of chlorogenic acid, ferulic acid, p-coumaric acid and sinapic acid. However, an increased content of caffeic acid was produced on PGR-free medium. These findings highlight the beneficial effect and validate the rising importance of mT for in vitro regeneration studies. This study will serve as a potential protocol to conserve and restore the medically important C. malabaricum

Beneficial Role of Selenium (Se) Biofortification in Developing Resilience Against Potentially Toxic Metal and Metalloid Stress in Crops: Recent Trends in Genetic Engineering and Omics Approaches

Selenium (Se) is found in plants both in inorganic and organic forms as selenoamino acids and methylated complexes. Se influences growth and physiological parameters, viz. root and shoot growth, starch accumulation, water status regulation, respiration, germination promotion, nitrogen assimilation and delaying senescence in plants. Se deficiency causes many human medical conditions, viz. cancer, liver disease, cardiovascular disease, thyroid disease, Keshan disease and central nervous system disorders. Plants need Se to alleviate abiotic stresses, viz. high/low temperatures, drought, salinity, light, UV-B radiation and toxic metals/metalloids. Ameliorative role of Se, applied in relatively low doses, against abiotic stresses was mediated via enzymatic and non-enzymatic antioxidation. Chemical form, application method, edaphic presence and bioavailability of Se and its interaction with other elements regulate Se biofortification and abiotic stress tolerance in food and medicinal crops. Popular scientific search engines, viz. PubMed, Pubget, ScienceDirect, Medline, Scopus, SpringerLink, Mendeley, EMBASE, Google Scholar and JSTOR were searched to retrieve published articles by using pre-determined search strings involving selenium, plants, stress, metals, metalloids, etc. The retrieved literature encompasses the role of Se biofortification in enhancing dietary Se in crops and its bioavailability. The review also presents recent trends in Se-mediated amelioration of toxic metal and metalloid stresses via maintaining cell membrane integrity, functioning of photosynthetic machinery, inhibition against uptake and translocation of toxic metals and metalloids, control over the uptake and distribution of mineral nutrition and conversion of toxic metals and metalloids to non-toxic Se-metal complexes. Furthermore, current research on the genetic engineering and omics studies on Se biofortification and Se-mediated abiotic stress tolerance are also discussed. The present review comprehensively elucidates the beneficial role Se biofortification in developing resilience in crops against toxic metals and metalloids.Presidency University, IndiaThis work was supported by the Faculty Research and Professional Development Fund (FRPDF), a financial assistance from Presidency University, India

Harnessing plant biotechnology-based strategies for in vitro galanthamine (GAL) biosynthesis: a potent drug against Alzheimer’s disease

International audienceKey message Galanthamine biosynthesis by plant in vitro systems and its mode of action are reviewed to provide a starting point for scaling-up of the biotechnological production of this valuable medicinal alkaloid. Medicinal plants are important for improving human health and represent an essential pool for the identification of novel pharmacological leads. Plant-derived biomolecules have historically proven their value as a source of therapeutic drugs and hold an important potential for the identification and characterization of novel drug leads. Many different alkaloids possessing a broad range of pharmacological activities have been isolated from plants belonging to the Amaryllidaceae family. Galanthamine (GAL) is a selective, reversible and an Amaryllidaceae-derived acetylcholinesterase inhibitor used for the treatment of Alzheimer's disease (AD) and other neurological diseases. Naturally, the bioavailability of Amaryllidaceae alkaloids including GAL is low. Due to the significantly increased demand of GAL by the pharmaceutical industries and the inadequate availability of natural resources, in vitro culture offers an alternative approach for its sustainable production. Thus, different biotechnological tools can optimize the in vitro GAL biosynthesis for treating AD, such as manipulation of plant growth regulators, photoperiod, elicitors, and bioreactors systems, besides being an environmentally sustainable approach, which protects the native biodiversity in a circular bioeconomy context. In the present review, we highlight the biosynthesis of GAL by plant in vitro systems including its mode of action. This article should also provide a starting point in the scaling-up of the biotechnological production of this valuable alkaloid

Assessment of Genetic Variability for Fruit Nutritional Composition in the Ex-Situ Collection of Jujube (Ziziphus spp.) Genotypes of Arid Regions of India

Jujube or ber (Ziziphus spp.) is one of the most important fruit crops of India’s arid and semi-arid regions because of its high adaptability to resource constraints hot (semi)arid region. Jujube is a rich source of minerals, vitamins and dietary antioxidants to arid zone dwellers, where it is known as poor man’s apple. Given the present rising trends in discovering and exploiting plant-based health-promoting compounds, it is imperative to know the extent of variability with respect to fruit nutritional compositions present in the jujube germplasms. In this study, we assessed genetic variability for fruit nutritional and functional quality traits in eighteen jujube accessions belonging to three species (Z. mauritiana, Z. rotundifolia and Z. oenoplia) from an ex-situ collection from Indian arid and semi-arid regions in two consecutive fruiting seasons (2020-21 and 2021-22). Results revealed significant variability among eighteen jujube genotypes for important fruits physico-biochemical parameters. The IC 625864 (Z. oenoplia) identified as a superior accession for fruit antioxidant potential with having high levels of total phenols (256.2 mg/100 g dry weight) and total antioxidants (423 mg/100 g in FRAP). Moreover, IC 625849 (Z. mauritiana) and IC 625848 (Z. rotundifolia) were other genotypes containing high levels of phenols and total antioxidant (FRAP). Thus, while aiming for simultaneous improvement for total antioxidants with phenols, IC 625848, IC 625849 and IC 625864 genotypes can be considered as valuable resource for jujube fruit quality improvement program. Further, the high levels of phenotypic variance with high genotypic variance coupled with high heritability and genetic advance particularly for total antioxidants, total phenols, and ascorbic acid contents in fruits, indicating them to be considered as reliable biochemical markers to identify the productive genotypes having higher amounts of dietary antioxidants. Depending on the identified genotypes for their richness in the particular phytonutrients, these can be exploited either for table purpose or biofortification of other products, or using in jujube breeding program for quality improvement

Assessment of Genetic Variability for Fruit Nutritional Composition in the Ex-Situ Collection of Jujube (<i>Ziziphus</i> spp.) Genotypes of Arid Regions of India

Jujube or ber (Ziziphus spp.) is one of the most important fruit crops of India’s arid and semi-arid regions because of its high adaptability to resource constraints hot (semi)arid region. Jujube is a rich source of minerals, vitamins and dietary antioxidants to arid zone dwellers, where it is known as poor man’s apple. Given the present rising trends in discovering and exploiting plant-based health-promoting compounds, it is imperative to know the extent of variability with respect to fruit nutritional compositions present in the jujube germplasms. In this study, we assessed genetic variability for fruit nutritional and functional quality traits in eighteen jujube accessions belonging to three species (Z. mauritiana, Z. rotundifolia and Z. oenoplia) from an ex-situ collection from Indian arid and semi-arid regions in two consecutive fruiting seasons (2020-21 and 2021-22). Results revealed significant variability among eighteen jujube genotypes for important fruits physico-biochemical parameters. The IC 625864 (Z. oenoplia) identified as a superior accession for fruit antioxidant potential with having high levels of total phenols (256.2 mg/100 g dry weight) and total antioxidants (423 mg/100 g in FRAP). Moreover, IC 625849 (Z. mauritiana) and IC 625848 (Z. rotundifolia) were other genotypes containing high levels of phenols and total antioxidant (FRAP). Thus, while aiming for simultaneous improvement for total antioxidants with phenols, IC 625848, IC 625849 and IC 625864 genotypes can be considered as valuable resource for jujube fruit quality improvement program. Further, the high levels of phenotypic variance with high genotypic variance coupled with high heritability and genetic advance particularly for total antioxidants, total phenols, and ascorbic acid contents in fruits, indicating them to be considered as reliable biochemical markers to identify the productive genotypes having higher amounts of dietary antioxidants. Depending on the identified genotypes for their richness in the particular phytonutrients, these can be exploited either for table purpose or biofortification of other products, or using in jujube breeding program for quality improvement