bluuebunny/crossref_metadata_2025 huggingface dataset:
Competitiveness during Dual-Species Biofilm Formation of Fusarium oxysporum and Candida albicans and a Novel Treatment Strategy
Authors: Falanga Annarita , Maione Angela , La Pietra Alessandra , de Alteriis Elisabetta , Vitale Stefania , Bellavita Rosa , Carotenuto Rosa , Turrà David , Galdiero Stefania , Galdiero Emilia , Guida Marco
Published: May 2022

During an infection, a single or multispecies biofilm can develop. Infections caused by non-dermatophyte molds, such as Fusarium spp. and yeasts, such as Candida spp., are particularly difficult to treat due to the formation of a mixed biofilm of the two species. Fusarium oxysporum is responsible for approximately 20% of human fusariosis, while Candida albicans is responsible for superficial mucosal and dermal infections and for disseminated bloodstream infections with a mortality rate above 40%. This study aims to investigate the interactions between C. albicans and F. oxysporum dual-species biofilm, considering variable formation conditions. Further, the ability of the WMR peptide, a modified version of myxinidin, to eradicate the mixed biofilm when used alone or in combination with fluconazole (FLC) was tested, and the efficacy of the combination of WMR and FLC at low doses was assessed, as well as its effect on the expression of some biofilm-related adhesin and hyphal regulatory genes. Finally, in order to confirm our findings in vivo and explore the synergistic effect of the two drugs, we utilized the Galleria mellonella infection model. We concluded that C. albicans negatively affects F. oxysporum growth in mixed biofilms. Combinatorial treatment by WMR and FLC significantly reduced the biomass and viability of both species in mature mixed biofilms, and these effects coincided with the reduced expression of biofilm-related genes in both fungi. Our results were confirmed in vivo since the synergistic antifungal activity of WMR and FLC increased the survival of infected larvae and reduced tissue invasion. These findings highlight the importance of drug combinations as an alternative treatment for C. albicans and F. oxysporum mixed biofilms.
New Insight on the Bioactivity of Solanum aethiopicum Linn. Growing in Basilicata Region (Italy): Phytochemical Characterization, Liposomal Incorporation, and Antioxidant Effects
Authors: Faraone Immacolata , Lela Ludovica , Ponticelli Maria , Gorgoglione Domenico , De Biasio Filomena , Valentão Patricia , Andrade Paula B. , Vassallo Antonio , Caddeo Carla , Falabella Roberto , Ostuni Angela , Milella Luigi
Published: May 2022

Food extract’s biological effect and its improvement using nanotechnologies is one of the challenges of the last and the future decades; for this reason, the antioxidant effect of scarlet eggplant extract liposomal incorporation was investigated. Scarlet eggplant (Solanum aethiopicum L.) is a member of the Solanaceae family, and it is one of the most consumed vegetables in tropical Africa and south of Italy. This study investigated the antioxidant activity and the phytochemical composition of S. aethiopicum grown in the Basilicata Region for the first time. The whole fruit, peel, and pulp were subjected to ethanolic exhaustive maceration extraction, and all extracts were investigated. The HPLC-DAD analysis revealed the presence of ten phenolic compounds, including hydroxycinnamic acids, flavanones, flavanols, and four carotenoids (one xanthophyll and three carotenes). The peel extract was the most promising, active, and the richest in specialized metabolites; hence, it was tested on HepG2 cell lines and incorporated into liposomes. The nanoincorporation enhanced the peel extract’s antioxidant activity, resulting in a reduction of the concentration used. Furthermore, the extract improved the expression of endogenous antioxidants, such as ABCG2, CAT, and NQO1, presumably through the Nrf2 pathway.
A Microwave Photonic Converter with High in-Band Spurs Suppression Based on Microwave Pre-Upconversion
Authors: Wang Chaoquan , Zhao Yiru , Zhao Zeping , Zhang Weijie , Wang Wenyu , Jia Qianqian , Liu Jianguo
Published: May 2022

A microwave photonic converter based on microwave pre-upconversion is proposed and experimentally demonstrated. Only a single Mach–Zehnder modulator (MZM) is used in the converter system so that the complexity and bandwidth limiting of the link can be reduced. The transmitted and received signals before entering the MZM are firstly upconverted to high frequency (HF) by a microwave upconverter. The HF and local oscillator (LO) signals are combined to drive the MZM. Carrier-suppressed double-sideband (CS-DSB) modulation is introduced to the MZM for effective spectrum utilization. Then, the target signals can be obtained by photoelectric conversion and beating. Experimental results confirm that the mixing spurs including harmonics and intermodulation as well as original signals are all out of system frequency band from 0.8–18 GHz, and the in-band spurious suppression of at least 40 dBc is achieved. In addition, the spurious-free dynamic range (SFDR) reaches 86.23 dB·HZ2/3 for upconversion and 80.95 dB·HZ2/3 for downconversion. The proposed microwave photonic converter provides a wideband and high-purity alternative for the applications of radars and signal processing.
Onset of Color Transparency in Holographic Light-Front QCD
Authors: Brodsky Stanley J. , de Téramond Guy F.
Published: May 2022

The color transparency (CT) of a hadron, propagating with reduced absorption in a nucleus, is a fundamental property of QCD (quantum chromodynamics) reflecting its internal structure and effective size when it is produced at high transverse momentum, Q. CT has been confirmed in many experiments, such as semi-exclusive hard electroproduction, eA→e′πX, for mesons produced at Q2>3GeV2. However, a recent JLab (Jefferson Laboratory) measurement for a proton electroproduced in carbon eC→e′pX, where X stands for the inclusive sum of all produced final states, fails to observe CT at Q2 up to 14.2 GeV2. In this paper, the onset of CT is determined by comparing the Q2-dependence of the hadronic cross sections for the initial formation of a small color-singlet configuration using the generalized parton distributions from holographic light-front QCD. A critical dependence on the hadron’s twist, τ, the number of hadron constituents, is found for the onset of CT, with no significant effects from the nuclear medium. This effect can explain the absence of proton CT in the present kinematic range of the JLab experiment. The proton is predicted to have a “two-stage” color transparency with the onset of CT differing for the spin-conserving (twist-3, τ=3) Dirac form factor with a higher onset in Q2 for the spin-flip Pauli (twist-4) form factor. In contrast, the neutron is predicted to have a “one-stage” color transparency with the onset at higher Q2 because of the dominance of its Pauli form factor. The model also predicts a strong dependence at low energies on the flavor of the quark current coupling to the hadron.
Preliminary Findings on Cadmium Bioaccumulation and Photosynthesis in Rice (Oryza sativa L.) and Maize (Zea mays L.) Using Biochar Made from C3- and C4-Originated Straw
Authors: Ghorbani Mohammad , Konvalina Petr , Neugschwandtner Reinhard W. , Kopecký Marek , Amirahmadi Elnaz , Moudrý Jan , Menšík Ladislav
Published: May 2022

Understanding the structural differences between feedstocks is critical for biochar effectiveness in plant growth. To examine the efficiency of biochars with unique physiological structures in a cadmium (Cd)-polluted soil, rice and maize as C3 and C4 plants, as well as biochar generated from their residues, defined as BC3 and BC4, were utilized. The experiment involved a control and a Cd-polluted soil (20 mg kg−1) without biochar application, and applications of each type of biochar (20 t ha−1) on Cd-polluted or unpolluted soil. In rice and maize fields, BC3 application led to the highest value of cation exchange capacity (CEC), with increases of 162% and 115%, respectively, over the control, while CEC increased by 110% and 71% with BC4 in the rice and maize field, respectively. As compared to the control, BC3 and BC4 dramatically enhanced the photosynthetic rate (Pn) of rice by 116% and 80%, respectively, and maize by 67% and 31%. BC3 and BC4 significantly decreased the Cd transfer coefficient in rice by 54% and 30% and in maize by 45% and 21%. Overall, BC3 is preferred over BC4 for establishing rice and maize in Cd-polluted soil, as it has a lower C/N ratio, a considerably higher surface area, and more notable alkaline features such as a higher CEC and nutrient storage.
Anti-Biofilm and Associated Anti-Virulence Activities of Selected Phytochemical Compounds against Klebsiella pneumoniae
Authors: Adeosun Idowu J. , Baloyi Itumeleng T. , Cosa Sekelwa
Published: May 2022

The ability of Klebsiella pneumoniae to form biofilm renders the pathogen recalcitrant to various antibiotics. The difficulty in managing K. pneumoniae related chronic infections is due to its biofilm-forming ability and associated virulence factors, necessitating the development of efficient strategies to control virulence factors. This study aimed at evaluating the inhibitory potential of selected phytochemical compounds on biofilm-associated virulence factors in K. pneumoniae, as well as authenticating their antibiofilm activity. Five phytochemical compounds (alpha-terpinene, camphene, fisetin, glycitein and phytol) were evaluated for their antibacterial and anti-biofilm-associated virulence factors such as exopolysaccharides, curli fibers, and hypermucoviscosity against carbapenem-resistant and extended-spectrum beta-lactamase-positive K. pneumoniae strains. The antibiofilm potential of these compounds was evaluated at initial cell attachment, microcolony formation and mature biofilm formation, then validated by in situ visualization using scanning electron microscopy (SEM). Exopolysaccharide surface topography was characterized using atomic force microscopy (AFM). The antibacterial activity of the compounds confirmed fisetin as the best anti-carbapenem-resistant K. pneumoniae, demonstrating a minimum inhibitory concentration (MIC) value of 0.0625 mg/mL. Phytol, glycitein and α-terpinene showed MIC values of 0.125 mg/mL for both strains. The assessment of the compounds for anti-virulence activity (exopolysaccharide reduction) revealed an up to 65.91% reduction in phytol and camphene. Atomic force microscopy detected marked differences between the topographies of untreated and treated (camphene and phytol) exopolysaccharides. Curli expression was inhibited at both 0.5 and 1.0 mg/mL by phytol, glycitein, fisetin and quercetin. The hypermucoviscosity was reduced by phytol, glycitein, and fisetin to the shortest mucoid string (1 mm) at 1 mg/mL. Phytol showed the highest antiadhesion activity against carbapenem-resistant and extended-spectrum beta-lactamase-positive K. pneumoniae (54.71% and 50.05%), respectively. Scanning electron microscopy correlated the in vitro findings, with phytol significantly altering the biofilm architecture. Phytol has antibiofilm and antivirulence potential against the highly virulent K. pneumoniae strains, revealing it as a potential lead compound for the management of K. pneumoniae-associated infections.
Differential Responses to UV-A Stress Recorded in Carotenogenic Microalgae Haematococcus rubicundus, Bracteacoccus aggregatus, and Deasonia sp.
Authors: Chekanov Konstantin , Shibzukhova Karina , Lobakova Elena , Solovchenko Alexei
Published: May 2022

UV-A is the main ultraviolet component of natural (solar) radiation. Despite it, its effect on phototrophs is studied less than UV-B. Effects of UV-A on photosynthetic apparatus of three carotenoid-producing microalgae were elucidated. Photosynthetic activity was studied using chlorophyll fluorescence analysis. Cell extracts were evaluated by absorbance spectroscopy. On the one hand, there were some common features of three strains. In all cases the changes involved PSII primary photochemistry and antennae size. All strains accumulated UV-absorbing polar compounds. On the other hand, some responses were different. Upregulation of non-photochemical quenching was observed only in B. aggregatus BM5/15, whereas in other cases its level was low. H. rubicundus BM7/13 and Deasonia sp. NAMSU 934/2 accumulated secondary carotenoids, whereas B. aggregatus BM5/15 accumulated primary ones. Microscopic features of the cultures were also different. H. rubicundus BM7/13 and Deasonia sp. NAMSU 934/2 were represented mostly by solitaire cells or small cell clusters, lacking their green color; the cells of B. aggregatus BM5/15 formed aggregates from green cells. Cell aggregation could be considered as an additional UV-protecting mechanism. Finally, the strains differed by their viability. B. aggregatus BM5/15 was most resistant to UV-A, whereas massive cell death was observed in two other cultures.
Screening of Durum Wheat Cultivars for Selenium Response under Contrasting Environments, Based on Grain Yield and Quality Attributes
Authors: Ayed Sourour , Bouhaouel Imen , Othmani Afef
Published: May 2022

In the literature, little information is available on the effect of Selenium (Se) on durum wheat yield and grain quality performances. A field investigation was conducted to explore the effect of exogenous Se foliar supply on two types of durum wheat germplasm; i.e., 16 advanced lines and nine modern varieties. The Se effect was assessed on grain yield as well as on technological quality traits (moisture, protein and gluten contents, Zeleny sedimentation index, and deformation energy) in two contrasting environments in Tunisia, namely Kef–Boulifa (semi-arid region) and Beja (sub-humid region). The results displayed significant effects of environments, Se foliar application, and cultivars on grain yield and quality attributes. For grain yield performance, the beneficial effect of Se was more pronounced under the Kef–Boulifa environment, and conversely for the grain quality. A genetic variation was observed within and among the two environments under both Se treatments (with and without Se). Notably, the Se-treated advanced lines displayed the highest grain yield under Kef–Boulifa and Beja conditions. Although these cultivars showed better grain quality in both sites, the modern varieties valorized the Se foliar application better. Cultivars that recorded the highest values for the studies attributes were not necessarily those that valorized the Se supply better. Interestingly, some advanced lines have noted superiority compared to the modern varieties. In this study, cultivars that combine both good yield and good grain quality were determined for semi-arid (L11, L1, Dhahbi, and Maali) and sub-humid (L2, L14, L6, L3, Salim, and INRAT 100) zones. The screening results provide genetic material that could be exploited in breeding programs to improve Se use efficiency.
Antimicrobial Screening and Fungicidal Properties of Eucalýptus globulus Ultrasonic Extracts
Authors: Sukhikh Stanislav , Ivanova Svetlana , Babich Olga , Larina Viktoria , Krol Olesia , Prosekov Alexander , Popov Alexander , Kriger Olga
Published: May 2022

The prohibition of antibiotics has led to extensive research and use of phytogenic feed additives. James Barrie Kirkpatrick described four subspecies of eucalyptus (family Myrtaceae), including Eucalýptus globulus, in 1974. The maximum concentrations of quercetin-3D-glycoside (1703.30 g/mL), astragalin (1737.82 g/mL), chlorogenic acid (342.14 g/mL), catechin (282.54 g/mL), rosmarinic acid (36.39 g/mL), and 3,4-dihydroxybenzoic acid (27.55 g/mL) were found in samples of ultrasonic extraction with ethyl alcohol (extraction module 1:5, temperature of 32 °C, an ultrasonic exposure time of 25 min). Antimicrobial activity was observed in all studied samples after 12 h of incubation (against gram-positive (Bacillus subtilis) and gram-negative (Pseudomonas aeruginosa) bacteria, as well as representatives of yeast fungi (Candida albicans)); a more pronounced antimicrobial effect (lysis zone) was observed after ultrasonic processing of extracts for 20 and 25 min. Bacillus subtilis, Pseudomonas aeruginosa, and Candida albicans had lysis areas of 10.0 mm (20 min extraction with ultrasonic treatment), 13.0 mm (20 min extraction without ultrasonic treatment), and 15.5 mm (25 min extraction with ultrasonic treatment), respectively. E. globulus was demonstrated to be a source of biologically active phenolic compounds with antibacterial and fungicidal activity. More research on the use of E. globulus in feed additives is required.
Development and Characterization of 20 Genomic SSR Markers for Ornamental Cultivars of Weigela
Authors: Hamm Trinity P. , Boggess Sarah L. , Kandel Jinita Sthapit , Staton Margaret E. , Huff Matthew L. , Hadziabdic Denita , Shoemaker DeWayne , Adamczyk Jr. John J. , Nowicki Marcin , Trigiano Robert N.
Published: May 2022

Weigela (Caprifoliaceae) is a genus of ornamental plants popular for its phenotypic variation and hardiness, that includes species hybridized to produce the commercially available cultivars. Despite its popularity, limited genetic resources exist for the genus. Twenty genomic simple sequence repeat (gSSR) markers distributed across the genome were developed using low coverage whole-genome sequencing data of Weigela Spilled Wine®. A cross-amplification evaluation with these 20 gSSR markers on a collection of 18 Weigela cultivars revealed a total of 111 unique alleles, including 36 private alleles. A diagrammatic key was constructed to identify cultivars using only six of the gSSR markers, demonstrating the newly developed gSSR markers are immediately useful for cultivar identification. Future uses could include breeding with marker-assisted selection, determining the history of hybridization of the current cultivated lines, aiding in the construction of genetic maps, and assessing the patterns of population genetic structure of Weigela spp.
Identification and Pathogenicity of Paramyrothecium Species Associated with Leaf Spot Disease in Northern Thailand
Authors: Withee Patchareeya , Haituk Sukanya , Senwanna Chanokned , Karunarathna Anuruddha , Tamakaew Nisachon , Pakdeeniti Parichad , Suwannarach Nakarin , Kumla Jaturong , Suttiprapan Piyawan , Taylor Paul W. J. , Samarakoon Milan C. , Cheewangkoon Ratchadawan
Published: May 2022

Species of Paramyrothecium that are reported as plant pathogens and cause leaf spot or leaf blight have been reported on many commercial crops worldwide. In 2019, during a survey of fungi causing leaf spots on plants in Chiang Mai and Mae Hong Son provinces, northern Thailand, 16 isolates from 14 host species across nine plant families were collected. A new species Paramyrothecium vignicola sp. nov. was identified based on morphology and concatenated (ITS, cmdA, rpb2, and tub2) phylogeny. Further, P. breviseta and P. foliicola represented novel geographic records to Thailand, while P. eichhorniae represented a novel host record (Psophocarpus sp., Centrosema sp., Aristolochia sp.). These species were confirmed to be the causal agents of the leaf spot disease through pathogenicity assay. Furthermore, cross pathogenicity tests on Coffea arabica L., Commelina benghalensis L., Glycine max (L.) Merr., and Dieffenbachia seguine (Jacq.) Schott revealed multiple host ranges for these pathogens. Further research is required into the host–pathogen relationship of Paramyrothecium species that cause leaf spot and their management. Biotic and abiotic stresses caused by climate change may affect plant health and disease susceptibility. Hence, proper identification and monitoring of fungal communities in the environment are important to understand emerging diseases and for implementation of disease management strategies.
Revisiting Trigonella foenum-graecum L.: Pharmacology and Therapeutic Potentialities
Authors: Visuvanathan Theysshana , Than Leslie Thian Lung , Stanslas Johnson , Chew Shu Yih , Vellasamy Shalini
Published: May 2022

Fenugreek (Trigonella foenum-graecum L.) is a medicinal plant that has been used as a food condiment as well as for its multiple therapeutic characteristics since ancient times. Fenugreek plant grows up to 60 cm in height, and its seeds are golden-yellow rhomboidal-shaped. Though fenugreek is more commonly known for its seeds, the leaves and stem have also been reported to have medicinal uses. These properties exhibited are due to the content of the secondary metabolites, also known as phytochemicals, in the fenugreek plant. Such metabolites are alkaloids, saponins, tannins, phenols, and many others. Fenugreek has been used traditionally for numerous indications, such as aid in labour, lactation stimulant, and laxatives. In modern research, there have been several animal and clinical studies that have shown therapeutic effects of fenugreek when taken orally. Fenugreek is a suitable plant candidate with a high prospect of being used as a credible medicinal plant to derive new drugs. This review aims to summarize the physical and chemical properties of fenugreek and its bioactive compounds that have been isolated for medicinal purposes and discusses the traditional and pharmacological uses of fenugreek.
Ethnobotany and Toxicity Status of Medicinal Plants with Cosmeceutical Relevance from Eastern Cape, South Africa
Authors: Ndhlala Ashwell R. , Thibane Vuyisile S. , Masehla Cecilia M. , Mokwala Phatlane W.
Published: May 2022

The indigenous people of the Eastern Cape residing within the richest plant biodiversity in the world, including Africa’s floral ‘gold mine’, have a long history of plant use for skincare. However, such rich flora comes with numerous plants that have the potential to cause harm to humans through their usage. Therefore, the study was aimed at documenting the toxicity status of important medicinal plants used by the indigenous people from the Eastern Cape for skincare and supported by literature for cosmeceutical relevance. A list of plants used for skincare was produced following an ethnobotanical survey. In addition, data on the level of toxicity and cosmeceutical relevance of plants listed from the survey were collected from literature resources. The study listed a total of 38 plants from 25 plant families, the majority being represented by the Asphodelaceae and Asteraceae, both at 13.2%. The most preferred plant parts were the leaves (60.4%) indicating sustainable harvesting practices by the community. The literature reports validated 70% of the medicinal plants surveyed for skincare were nontoxic. Most of the plants can be incorporated in the formulation of products intended for skincare due to their low toxicity and high cosmeceutical relevance.
Targeting TOR and SnRK1 Genes in Rice with CRISPR/Cas9
Authors: Pathak Bhuvan , Maurya Chandan , Faria Maria C. , Alizada Zahra , Nandy Soumen , Zhao Shan , Jamsheer K Muhammed , Srivastava Vibha
Published: May 2022

Genome targeting with CRISPR/Cas9 is a popular method for introducing mutations and creating knock-out effects. However, limited information is currently available on the mutagenesis of essential genes. This study investigated the efficiency of CRISPR/Cas9 in targeting rice essential genes: the singleton TARGET OF RAPAMYCIN (OsTOR) and the three paralogs of the Sucrose non-fermenting-1 (SNF1)-related kinase 1 (OsSnRK1α), OsSnRK1αA, OsSnRK1αB and OsSnRK1αC. Strong activity of constitutively expressed CRISPR/Cas9 was effective in creating mutations in OsTOR and OsSnRK1α genes, but inducible CRISPR/Cas9 failed to generate detectable mutations. The rate of OsTOR mutagenesis was relatively lower and only the kinase domain of OsTOR could be targeted, while mutations in the HEAT region were unrecoverable. OsSnRK1α paralogs could be targeted at higher rates; however, sterility or early senescence was observed in >50% of the primary mutants. Additionally, OsSnRK1αB and OsSnRK1αC, which bear high sequence homologies, could be targeted simultaneously to generate double-mutants. Further, although limited types of mutations were found in the surviving mutants, the recovered lines displayed loss-of-function or knockdown tor or snrk1 phenotypes. Overall, our data show that mutations in these essential genes can be created by CRISPR/Cas9 to facilitate investigations on their roles in plant development and environmental response in rice.
Online Control of Lemna minor L. Phytoremediation: Using pH to Minimize the Nitrogen Outlet Concentration
Authors: Sigcau Kwanele , van Rooyen Ignatius Leopoldus , Hoek Zian , Brink Hendrik Gideon , Nicol Willie
Published: May 2022

Phytoremediation technologies are employed worldwide to remove nutrient pollutants from agricultural and industrial wastewater. Unlike in algae-based nutrient removal, control methodologies for plant-based remediation have not been standardized. Control systems that guarantee consistently low outlet concentrations of nitrogen and phosphorous often use expensive analytical instruments and are therefore rarely viable. In this study, pH measurement was used as the sole input to control the nitrate outlet concentration in a continuously operated Lemna minor (lesser duckweed) phytoremediation tank. When grown in 20 L batches of modified Hoagland’s solution, it was found that a constant ratio exists between the amount of nitrate removed and the amount of acid dosed (required for pH control), which was equal to 1.25 mol N·(mol H+)−1. The nitrate uptake rates were determined by standard spetrophotometric method. At critically low nitrate concentrations, this ratio reduced slightly to 1.08 mol N·(mol H+)−1. Assuming a constant nitrogen content, the biomass growth rate could be predicted based on the acid dosing rate. A proportional-integral controller was used to maintain pH on 6.5 in a semi-continuously operated tank covered by L. minor. A nitrogen control strategy was developed which exploited this relationship between nitrate uptake and dosing and successfully removed upwards of 80% of the fed nitrogen from synthetic wastewater while a constant biomass layer was maintained. This study presents a clear illustration of how advanced chemical engineering control principles can be applied in phytoremediation processes.
An Improved Procedure for Agrobacterium-Mediated Transformation of ‘Carrizo’ Citrange
Authors: Li Yanjun , Tang Dan , Liu Zongrang , Chen Jianjun , Cheng Baoping , Kumar Rahul , Yer Huseyin , Li Yi
Published: May 2022

Although several protocols for genetic transformation of citrus have been published, it is highly desirable to further improve its efficiency. Here we report treatments of Agrobacterium cells and citrus explants prior to and during co-cultivation process to enhance transformation efficiency using a commercially used rootstock ‘Carrizo’ citrange [Citrus sinensis (L.) Osb. × Poncirius trifoliata (L.) Raf.] as a model plant. We found explants from light-grown seedlings exhibited higher transformation efficiency than those from etiolated seedlings. We pre-cultured Agrobacterium cells in a 1/10 MS, 0.5 g/L 2-(N-morpholino) ethanesulfonic acid (MES) and 100 µM acetosyringone liquid medium for 6 h at 25 °C before used to infect citrus explants. We incubated epicotyl segments in an MS liquid medium containing 13.2 µM 6-BA, 4.5 µM 2,4-D, 0.5 µM NAA for 3 h at 25 °C prior to Agrobacterium infection. In the co-cultivation medium, we added 30 µM paclobutrazol and 10 µM lipoic acid. Each of these treatments significantly increased the efficiencies of transformation up to 30.4% (treating Agrobacterium with acetosyringone), 31.8% (treating explants with cytokinin and auxin), 34.9% (paclobutrazol) and 38.6% (lipoic acid), respectively. When the three treatments were combined, we observed that the transformation efficiency was enhanced from 11.5% to 52.3%. The improvement of genetic transformation efficiency mediated by these three simple treatments may facilitate more efficient applications of transgenic and gene editing technologies for functional characterization of citrus genes and for genetic improvement of citrus cultivars.
Impacts of Chronic Habitat Fragmentation on Genetic Diversity of Natural Populations of Prunus persica in China
Authors: Jiang Quan , Xu Qiang , Pan Junfeng , Yao Xiaohong , Cheng Zhongping
Published: May 2022

Wild peach is an important resource for improving existing peach varieties. However, the extant populations of wild peach show fragmented distribution due to human disturbance and geographic isolation. In this study, we used natural populations (or wild populations) of Prunus persica (Rosaceae) to assess the genetic effects of habitat fragmentation. A total of 368 individuals sampled from 16 natural populations were analyzed using 23 polymorphic simple sequence repeat (SSR) markers. Prunus persica maintained low within-population genetic variation and high level of genetic differentiation. Two genetic clusters were revealed based on three different methods (UPGMA, PCoA, and STRUCTURE). All populations showed a significant heterozygosity deficiency and most extant populations experienced recent reduction in population size. A significant isolation by distance (IBD) was observed with Mantel’s test. Compared to historical gene flow, contemporary gene flow was restricted among the studied populations, suggesting a decrease in gene flow due to habitat fragmentation. Habitat fragmentation has impacted population genetic variation and genetic structure of P. persica. For breeding and conservation purpose, collecting as many individuals as possible from multiple populations to maximize genetic diversity was recommended during the process of germplasm collection. In addition, populations from central China had higher genetic diversity, suggesting these populations should be given priority for conservation and germplasm collection.
A Putative Effector LtCSEP1 from Lasiodiplodia theobromae Inhibits BAX-Triggered Cell Death and Suppresses Immunity Responses in Nicotiana benthamiana
Authors: Xing Qikai , Cao Yang , Peng Junbo , Zhang Wei , Wu Jiahong , Zhou Yueyan , Li Xinghong , Yan Jiye
Published: May 2022

Lasiodiplodia theobromae is a causal agent of grapevine trunk disease, and it poses a significant threat to the grape industry worldwide. Fungal effectors play an essential role in the interaction between plants and pathogens. However, few studies have been conducted to understand the functions of individual effectors in L. theobromae. In this study, we identified and characterized a candidate secreted effector protein, LtCSEP1, in L. theobromae. Gene expression analysis suggested that transcription of LtCSEP1 in L. theobromae was induced at the early infection stages in the grapevine. Yeast secretion assay revealed that LtCSEP1 contains a functional signal peptide. Transient expression of LtCSEP1 in Nicotiana benthamiana suppresses BAX-trigged cell death and significantly inhibits the flg22-induced PTI-associated gene expression. Furthermore, the ectopic expression of LtCSEP1 in N. benthamiana enhanced disease susceptibility to L. theobromae by downregulating the defense-related genes. These results demonstrated that LtCSEP1 is a potential effector of L. theobromae, which contributes to suppressing the plant’s defenses.
The Effect of Soil Water Deficiency on Water Use Strategies and Response Mechanisms of Glycyrrhiza uralensis Fisch
Authors: Song Kechen , Hu Haiying , Xie Yingzhong , Fu Li
Published: May 2022

We aimed to investigate the water use strategies and the responses to water shortages in Glycyrrhiza uralensis, which is a dominant species in the desert steppe. Water stress gradients included control, mild, moderate, and severe. The time intervals were 15, 30, 45, and 60 d. Our study suggested that with the aggravation of water stress intensity, the total biomass of Glycyrrhiza uralensis gradually decreased and allometric growth was preferred to underground biomass accumulation. From 30 d and mild to moderate water stress, the water potential (WP) of leaves decreased considerably compared to the CK. The relative water content (EWC) decreased over time and had a narrow range of variation. Proline (PR) was continuously increased, then declined at 45–60 d under severe and more severe water stress. The δ13C values increased in all organs, showed roots > stems > leaves. The net photosynthetic rate (Pn) and transpiration rate (Tr) decreased to varying degrees. The instantaneous water use efficiency (WUEi) and limiting value of stomata (Ls) increased continuously at first and decreased under severe water stress. Meanwhile, severe water stress triggered the most significant changes in chloroplast and guard cell morphology. In summary, Glycyrrhiza uralensis could maintain water content and turgor pressure under water stress, promote root biomass accumulation, and improve water use efficiency, a water-conservation strategy indicating a mechanism both avoidable dehydration and tolerable drought.
Phytochemicals Profiling, Antimicrobial Activity and Mechanism of Action of Essential Oil Extracted from Ginger (Zingiber officinale Roscoe cv. Bentong) against Burkholderia glumae Causative Agent of Bacterial Panicle Blight Disease of Rice
Authors: Gunasena Mahesh Tiran , Rafi Amara , Mohd Zobir Syazwan Afif , Hussein Mohd Zobir , Ali Asgar , Kutawa Abdulaziz Bashir , Abdul Wahab Mohd Aswad , Sulaiman Mohd Roslan , Adzmi Fariz , Ahmad Khairulmazmi
Published: May 2022

Essential oils protect plants, and due to their natural origin, there is much interest in using them as antimicrobial agents. The purpose of this study was to determine the phytochemical constituents of ginger essential oil (GEO), antimicrobial activity, and mode of action against Burkholderia glumae (Bg). In addition, the volatile active compounds (AIs) were studied using GC-MS, FTIR, and Raman spectroscopy. A total of 45 phytochemical components were detected and the most prevalent bioactive compounds were Geranial, 1,8-Cineole, Neral, Camphene, α-Zingiberene, and α-Farnesene. Furthermore, it was found that the most dominant terpenes in GEO were monoterpenes. The diameter zone of inhibition values varied from 7.1 to 15 mm depending on the concentration tested. In addition, the MIC and MBC values were 112.5 µL/mL. Faster killing time and lower membrane potential were observed in 1xMIC treatment compared to 0.5xMIC treatment, whereas the control had the maximum values. From observations of various images, it was concluded that the mode of action of GEO affected the cytoplasmic membrane, causing it to lose its integrity and increase its permeability. Therefore, the antibacterial study and mechanism of action revealed that GEO is very effective in suppressing the growth of B. glumae.
The Auxin-Response Repressor IAA30 Is Down-Regulated in Reproductive Tissues of Apomictic Paspalum notatum
Authors: Siena Lorena , Azzaro Celeste , Podio Maricel , Stein Juliana , Leblanc Olivier , Pessino Silvina , Ortiz Juan Pablo
Published: May 2022

The capacity for apomixis in Paspalum notatum is controlled by a single-dominant genomic region, which shows strong synteny to a portion of rice chromosome 12 long arm. The locus LOC_Os12g40890, encoding the Auxin/Indole-3-Acetic Acid (Aux/IAA) family member OsIAA30, is located in this rice genomic segment. The objectives of this work were to identify transcripts coding for Aux/IAA proteins expressed in reproductive tissues of P. notatum, detect the OsIAA30 putative ortholog and analyze its temporal and spatial expression pattern in reproductive organs of sexual and apomictic plants. Thirty-three transcripts coding for AUX/IAA proteins were identified. Predicted protein alignment and phylogenetic analysis detected a highly similar sequence to OsIAA30 (named as PnIAA30) present in both sexual and apomictic samples. The expression assays of PnIAA30 showed a significant down-regulation in apomictic spikelets compared to sexual ones at the stages of anthesis and post-anthesis, representation levels negatively correlated with apospory expressivity and different localizations in sexual and apomictic ovules. Several PnIAA30 predicted interactors also appeared differentially regulated in the sexual and apomictic floral transcriptomes. Our results showed that an auxin-response repressor similar to OsIAA30 is down-regulated in apomictic spikelets of P. notatum and suggests a contrasting regulation of auxin signaling during sexual and asexual seed formation.
Labdanum Resin from Cistus ladanifer L.: A Natural and Sustainable Ingredient for Skin Care Cosmetics with Relevant Cosmeceutical Bioactivities
Authors: Frazão David F. , Martins-Gomes Carlos , Steck Jan L. , Keller Judith , Delgado Fernanda , Gonçalves José C. , Bunzel Mirko , Pintado Cristina M. B. S. , Díaz Teresa Sosa , Silva Amélia M.
Published: May 2022

Labdanum resin from Cistus ladanifer L. (Cistaceae) is an abundant natural resource in the Iberian Peninsula worth being explored in a sustainable manner. It is already used in the cosmetic industry; mainly by the fragrances/perfumery sector. However, given the highest market share and traditional uses, labdanum resin also has the potential to be used and valued as a cosmetic ingredient for skincare. Aiming to evaluate this potential, labdanum methanolic absolute and fractions purified by column chromatography were characterized by UPLC-DAD-ESI-MS and then evaluated for UV-protection, antioxidant, anti-elastase, anti-inflammatory, and antimicrobial activities. Labdanum absolute represented ~70% of the resin; diterpenoid and flavonoid fractions represented ~75% and 15% of the absolute, respectively. Labdane-type diterpenoids and methylated flavonoids were the main compounds in labdanum absolute and in diterpenoid and flavonoid fractions, respectively. Labdanum absolute showed a spectrophotometric sun protection factor (SPF) near 5, which is mainly due to flavonoids, as the flavonoids’ SPF was 13. Low antioxidant activity was observed, with ABTS radical scavenging being the most significant (0.142 ± 0.017, 0.379 ± 0.039 and 0.010 ± 0.003 mgTE/mgExt, for the absolute and flavonoid and terpene fractions, respectively). Anti-aging and anti-inflammatory activity are reported here for the first time, by the inhibition of elastase activity (22% and 13%, by absolute and flavonoid extract at 1 mg/mL), and by the inhibition of nitric oxide production in LPS-induced RAW 264.7 cells (84% to 98%, at 15 µg/mL extracts, flavonoid fraction the most active), respectively. Antimicrobial activity, against relevant skin and cosmetic product microorganisms, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Escherichia coli, revealed that only S. aureus was susceptible to labdanum absolute (MIC: 1.2 mg/mL) and its fractions (MIC: <0.3 mg/mL). In conclusion, labdanum resin showed potential to be used in sunscreen cosmetics, anti-inflammatory skincare cosmeceuticals or medicines but has low potential as a cosmetic product preservative given the low antioxidant and low-spectrum antimicrobial activities.
Microstructure of Croatian Wild Grapevine (Vitis vinifera subsp. sylvestris Gmel Hegi) Pollen Grains Revealed by Scanning Electron Microscopy
Authors: Lukšić Katarina , Zdunić Goran , Mucalo Ana , Marinov Luka , Ranković-Vasić Zorica , Ivanović Jelena , Nikolić Dragan
Published: May 2022

Wild grapevine (Vitis vinifera subsp. sylvestris Gmel Hegi) is dioecious with male and female plants, whereas domesticated grapevine is mostly hermaphrodite with self-fertile hermaphrodite flowers. The pollen morphology of wild grapevine has been poorly studied. There is no detailed palynological study of V. sylvestris in Croatia and neighboring countries. Here, scanning electron microscopy (SEM) was used to analyze the pollen of V. sylvestris from male and female individuals growing at two natural sites in Croatia. The selective APT3 marker was used to confirm the flower phenotype with the genetic background. SEM analysis showed that the pollen grains of V. sylvestris were isopolar and radially symmetrical, with foveolate perforated ornamentation, regardless of the flower type of the individuals. All male flowers were 3-colporate and prolate in shape, whereas female individuals varied from subprolate to spheroidal and had inaperturate pollen grains. Pollen shape, dimensions and exine ornamentation proved very informative, and here we address the most polymorphic traits in the analyzed V. sylvestris individuals. Principal component analysis (PCA) and clustering based on pollen morphology variables clearly differentiated individuals by their flower type, and no grouping specific to population was observed, pointing to the conserved pollen structure of V. sylvestris. The results indicate the need to continue the palynological study of V. sylvestris and serve as a good phenotypic basis for functional genetic studies on genes involved in pollen morphology and function.
Genetic Structure of Native Blue Honeysuckle Populations in the Western and Eastern Eurasian Ranges
Authors: Naugžemys Donatas , Patamsytė Jolanta , Žilinskaitė Silva , Hoshino Yoichiro , Skridaila Audrius , Žvingila Donatas
Published: May 2022

Blue honeysuckle (Lonicera caerulea L.) is a promising berry crop producing edible early-ripening berries with a valuable chemical composition. We evaluated the genetic diversity of native L. caerulea populations from the western (Baltic states) and eastern (the Russian Far East and Japan) edges of the Eurasian range using inter-simple sequence repeat (ISSR) and chloroplast DNA (psbA-trnH and trnL-trnF) markers. The genetic relationships of populations and genotypes were analyzed using principal coordinate and cluster analyses (neighbor joining and Bayesian clustering). Sampling was carried out in two disjunct areas of this circumpolar species and the analyses showed clustering of individuals and populations according to geographic origin. The analysis of genetic structure based on ISSR markers showed that the studied populations of L. caerulea were highly differentiated. However, sequence analysis of two chloroplast DNA (cpDNA) regions revealed no phylogeographic structure among the populations. We also found that the eastern populations of blue honeysuckle had significantly greater genetic diversity parameters than the populations from the Baltic region. This finding correlates with the endangered status of blue honeysuckle in the Baltic states.
Experimental Analysis of Matrix Cracking in Glass Fiber Reinforced Composite Off-Axis Plies under Static and Fatigue Loading
Authors: Just Gordon , Koch Ilja , Gude Maik
Published: May 2022

The inter-fiber failure of glass fiber-reinforced epoxy specimens with four different fiber angles was analyzed. Flat specimens were subjected to static and fatigue loading considering different load levels and load ratios. Damage investigation in terms of crack density measurement was performed by transmitted white light imaging using a digital camera and LED illumination from the back of the specimen on a servo-hydraulic testing machine. Static and fatigue results were examined with respect to crack initiation and crack growth, considering the special case of bonding yarns parallel to the fiber directions. The bonding yarns act as stress concentrations, influencing the early cracking behavior, and complicate the detectability of cracks growing underneath or next to the bonding yarns. In cyclic loading, the influence of load level, load ratio, mean stress, fiber orientation, and ply thickness was the focus of the experimental campaign. Cyclic cracking behavior in terms of initiation and growth was analyzed based on the applied loading conditions and laminate configurations. It was found that halving the ply thickness nearly doubled the amount of microcracks in case of high loads. For low loads, no such effect was observed up to 5×105 loading cycles. Experimental findings on individual crack growth confirmed that crack interaction started for crack spacings less than four times the ply thickness and that subsequent crack growth shifted into regions of larger local crack spacing.
Space Charge Behavior of Thermally Aged Polyethylene Insulation of Track Cables
Authors: Qiao Zhichao , Wu Wangsong , Wang Zhaowei , Zhang Ling , Zhou Yuanxiang
Published: May 2022

The interface of multi-layer insulation is a relatively weak point in the cable system during the long-term high-temperature service. Space charge is prone to continuously accumulate in the interface area, leading to the deterioration of electrical properties and even insulation failure in advance. The knowledge about thermal oxidation of polyethylene (PE) materials at the molecular level is still urgent to explore. Herein, single-layer and double-layer PE insulation, representing the typical insulation structure of frequency-shift pulse voltage track cables, were prepared and thermally aged in the oven for up to 360 h. Thermal, mechanical, electrical, and space charge characterizations were systematically carried out. Thermogravimetric analyzer and oxidation induced temperature (OIT) measurements confirmed that LDPE’s thermal-oxidative aging temperature range was the lowest among the three PE groups in the O2 atmosphere. After 360 h thermal aging, the tensile property of HDPE material kept relatively stable, while the elongation at break of the other two groups was lower than 50%. Unaged HDPE exhibits apparent charge injection and migration, leading to the severe electric field distortion of 20%. Noticeable charge accumulation can be observed at the unaged double-layer sample interface due to the mismatching of DC conductivity, which play a significant role in the aged double-layer samples. This work utilizes precise thermal analysis to provide new information about the resistance ability of thermal oxidation of LDPE, FPE, and HDPE, and its influence on space charge behaviors, which is helpful for the insulation design and evaluation in cable applications.
Mechanical and Tribological Properties of 3D Printed Polyamide 12 and SiC/PA12 Composite by Selective Laser Sintering
Authors: Yu Guoyan , Ma Jingdong , Li Jun , Wu Jingquan , Yu Jiang , Wang Xianzhang
Published: May 2022

Polymeric matrix composites are important to the advancement of industries such as the automobile and medicine industries. In this study, the silicon carbide (SiC) particle-reinforced polyamide12 (PA12) matrix composites were fabricated by selective laser sintering system as well as the pure PA12. The surface topographies, mechanical, and tribological properties were further examined. The results indicated that the friction and wear resistance of the composite were improved compared with the PA12 matrix. The compressive strength increased about 8.5%, shore D hardness increased about 6%. The friction coefficient decreased about 10%, the specific wear rate decreased 20% after adding silicon carbide 10% weight to PA12. The wear mechanisms were also discussed. The deformed asperities on the worn surface can withstand more tangential load, and therefore resulted in lower specific wear rate. It was found that the content of SiC particles on the surface were reduced after friction tests. According to the analysis of SEM, EDS, and FTIR results, the wear mechanisms were considered to be the abrasive and fatigue mode. This type of PA12 matrix composite might be a promising potential in marine and energy applications.
Zein Microparticles and Nanoparticles as Drug Delivery Systems
Authors: De Marco Iolanda
Published: May 2022

Zein is a natural, biocompatible, and biodegradable polymer widely used in the pharmaceutical, biomedical, and packaging fields because of its low water vapor permeability, antibacterial activity, and hydrophobicity. It is a vegetal protein extracted from renewable resources (it is the major storage protein from corn). There has been growing attention to producing zein-based drug delivery systems in the recent years. Being a hydrophobic biopolymer, it is used in the controlled and targeted delivery of active principles. This review examines the present-day landscape of zein-based microparticles and nanoparticles, focusing on the different techniques used to obtain particles, the optimization of process parameters, advantages, disadvantages, and final applications.