Plants, Volume 10, Issue 5 (May 2021) – 212 articles

To better understand the source–sink flow and its relationships with zinc (Zn) and other nutrients in wheat (Triticum aestivum L.) plants for biofortification and improving grain nutritional quality, the effects of reducing the photoassimilate source (through the flag leaf removal and spike shading) or sink (through the removal of all spikelets from one side of the spike, i.e., 50% spikelets removal) in the field of the accumulation of Zn and other nutrients in grains of two wheat cultivars (Jimai 22 and Jimai 44) were investigated at two soil Zn application levels. The kernel number per spike (KNPS), single panicle weight (SPW), thousand kernel weight (TKW), total grain weight (TGW) sampled, concentrations and yields of various nutrient elements including Zn, iron (Fe), manganese (Mn), copper (Cu), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg), phytate phosphorus (phytate-P), phytic acid (PA) and phytohormones (ABA: abscisic acid, and the ethylene precursor ACC: 1-aminocylopropane-1-carboxylic acid), and carbon/N ratios were determined. Soil Zn application significantly increased the concentrations of grain Zn, N and K. Cultivars showing higher grain yields had lower grain protein and micronutrient nutritional quality. SPW, KNPS, TKW (with the exception of TKW in the removal of half of the spikelets), TGW, and nutrient yields in wheat grains were most severely reduced by half spikelet removal, secondly by spike shading, and slightly by flag leaf removal. Grain concentrations of Zn, N and Mg consistently showed negative correlations with SPW, KNPS and TGW, but positive correlations with TKW. There were general positive correlations among grain concentrations of Zn, Fe, Mn, Cu, N and Mg, and the bioavailability of Zn and Fe (estimated by molar ratios of PA/Zn, PA/Fe, PA × Ca/Zn, or PA × Ca/Fe). Although Zn and Fe concentrations were increased and Ca was decreased in treatments of half spikelet removal and spike shading, the treatments simultaneously increased PA and limited the increase in bioavailability of Zn and Fe. In general, different nutrient elements interact with each other and are affected to different degrees by source–sink manipulation. Elevated endogenous ABA levels and ABA/ACC ratios were associated with increased TKW and grain-filling of Zn, Mn, Ca and Mg, and inhibited K in wheat grains. However, the effects of ACC were diametrically opposite. These results provide a basis for wheat grain biofortification to alleviate human malnutrition. Full article

In the temperate zone of Europe, plants flowering in early spring or at high elevation risk that their reproductive organs are harmed by episodic frosts. Focusing on flowers of two mountain and three early-flowering colline to montane distributed species, vulnerability to ice formation and ice management strategies using infrared video thermography were investigated. Three species had ice susceptible flowers and structural ice barriers, between the vegetative and reproductive organs, that prevent ice entrance from the frozen stems. Structural ice barriers as found in Anemona nemorosa and Muscari sp. have not yet been described for herbaceous species that of Jasminum nudiflorum corroborates findings for woody species. Flowers of Galanthus nivalis and Scilla forbesii were ice tolerant. For all herbs, it became clear that the soil acts as a thermal insulator for frost susceptible below ground organs and as a thermal barrier against the spread of ice between individual flowers and leaves. Both ice barrier types presumably promote that the reproductive organs can remain supercooled, and can at least for a certain time-period escape from effects of ice formation. Both effects of ice barriers appear significant in the habitat of the tested species, where episodic freezing events potentially curtail the reproductive success. Full article

(1) Background: Oenothein B, a cyclic dimeric ellagitannin present in various medicinal plants, has been reported to exert diverse effects that are beneficial for the treatment and prevention of diseases, including cancer and infections. We recently showed that oenothein B also functions in the brain because its oral administration to systemic inflammatory model mice reduced inflammatory responses in the brain and suppressed abnormal behavior. (2) Results: The present in vivo results demonstrated that oenothein B activated extracellular signal-regulated kinase 2 and cAMP response element-binding protein in the brain, both of which play important roles in synaptic transmission and learning/memory in the central nervous system (CNS). (3) Conclusions: These results suggest that oenothein B exerts neuroprotective effects on the CNS by not only its anti-inflammatory activity but also by enhancing neuronal signaling pathways. Full article

Hexaploid tritordeum is the amphiploid derived from the cross between the wild barley Hordeum chilense and durum wheat. This paper reviews the main advances and achievements in the last two decades that led to the successful development of tritordeum as a new crop. In particular, we summarize the progress in breeding for agronomic performance, including the potential of tritordeum as a genetic bridge for wheat breeding; the impact of molecular markers in genetic studies and breeding; and the progress in quality and development of innovative food products. The success of tritordeum as a crop shows the importance of the effective utilization of plant genetic resources for the development of new innovative products for agriculture and industry. Considering that wild plant genetic resources have made possible the development of this new crop, the huge potential of more accessible resources, such as landraces conserved in gene banks, goes beyond being sources of resistance to biotic and abiotic stresses. In addition, the positive result of tritordeum also shows the importance of adequate commercialization strategies and demonstrative experiences aimed to integrate the whole food chain, from producers to end-point sellers, in order to develop new products for consumers. Full article

Lantana camara L. (Verbenaceae) is native to tropical America and has been introduced into many other countries as an ornamental and hedge plant. The species has been spreading quickly and has naturalized in more than 60 countries as an invasive noxious weed. It is considered to be one of the world’s 100 worst alien species. L. camara often forms dense monospecies stands through the interruption of the regeneration process of indigenous plant species. Allelopathy of L. camara has been reported to play a crucial role in its invasiveness. The extracts, essential oil, leachates, residues, and rhizosphere soil of L. camara suppressed the germination and growth of other plant species. Several allelochemicals, such as phenolic compounds, sesquiterpenes, triterpenes, and a flavonoid, were identified in the extracts, essential oil, residues, and rhizosphere soil of L. camara. The evidence also suggests that some of those allelochemicals in L. camara are probably released into the rhizosphere soil under the canopy and neighboring environments during the decomposition process of the residues and as leachates and volatile compounds from living plant parts of L. camara. The released allelochemicals may suppress the regeneration process of indigenous plant species by decreasing their germination and seedling growth and increasing their mortality. Therefore, the allelopathic property of L. camara may support its invasive potential and formation of dense monospecies stands. Full article

Wheat is one of the most important staple foods in temperate regions and is in increasing demand in urbanizing and industrializing countries such as China. Enhancing yield potential to meet the population explosion around the world and maintaining grain quality in wheat plants under climate change are crucial for food security and human nutrition. Global warming resulting from greenhouse effect has led to more frequent occurrence of extreme climatic events. Elevated atmospheric CO₂ concentration (eCO₂) along with rising temperature has a huge impact on ecosystems, agriculture and human health. There are numerous studies investigating the eCO₂ and heatwaves effects on wheat growth and productivity, and the mechanisms behind. This review outlines the state-of-the-art knowledge regarding the effects of eCO₂ and heat stress, individually and combined, on grain yield and grain quality in wheat crop. Strategies to enhance the resilience of wheat to future warmer and CO₂-enriched environment are discussed. Full article

Eastern Mountain Avens (Geum peckii Pursh, Rosaceae) is a globally rare and endangered perennial plant found only at two coastal bogs within Digby County (Nova Scotia, Canada) and at several alpine sites in the White Mountains of New Hampshire (USA). In Canada, the G. peckii population has declined over the past forty years due in part to habitat degradation. We investigated the culturable foliar fungi present in G. peckii leaves at five locations with varying degrees of human impact within this plant species’ Canadian range. Fungal identifications were made using ITS rDNA barcoding of axenic fungal cultures isolated from leaf tissue. Differences in foliar fungal communities among sites were documented, with a predominance of Gnomoniaceae (Class: Sordariomycetes, Phylum: Ascomycota). Habitats with more human impact showed lower endophytic diversities (10–16 species) compared to the pristine habitat (27 species). Intriguingly, several fungi may represent previously unknown taxa. Our work represents a significant step towards understanding G. peckii’s mycobiome and provides relevant data to inform conservation of this rare and endangered plant. Full article

We investigated the impact of Bacillus thuringiensis as seed treatment and application with silicon on lettuce plants exposed to salinity levels (4 dS m⁻¹ and 8 dS m⁻¹). Results revealed that leaves number, head weight, total yield, relative water content (RWC), and chlorophyll a and b declined considerably due to two salinity levels. Oxidative stress markers, i.e., hydrogen peroxide (H₂O₂), superoxide (O₂⁻), and lipid peroxidation (MDA) dramatically augmented in stressed plants. On the other hand, leaves number, total yield, RWC, and chlorophyll a, b in stressed lettuce plants were considerably enhanced because of the application of Si or B. thuringiensis. In contrast, EL%, MDA, and H₂O₂ were considerably reduced in treated lettuce plants with Si and B. thuringiensis. In addition, the treatment with Si and B. thuringiensis increased head weight (g) and total yield (ton hectare-1), and caused up-regulation of proline and catalase, superoxide dismutase, peroxidase, and polyphenol oxidase activity in lettuce leaves under salinity conditions. Full article

European pear rust is an important disease; however, the relationship between its causal pathogen Gymnosporangium sabinae (Dicks.) Oerst. and host Pyrus communis L. is poorly understood. In this study, disease severity was measured, and leaf samples were collected over three years, and their leaf water content; leaf area; leaf mass per area; and epidermis, mesophyll, and vascular tissue width and stomatal density were measured and compared between susceptible and resistant genotypes for each year. Most genotypes either showed consistent disease symptoms or showed no symptoms during the study in terms of their susceptibility. A correlation between disease severity and mesophyll tissue thickness, and stomatal density and differences between several morphological parameters were found depending on the genotype’s susceptibility. The study showed that the following pear morphological traits were stable between the years: water content, leaf mass per area, spongy mesophyll thickness, phloem thickness, and stomatal density. When selecting for breeding, we found that candidates for traits that discern susceptible genotypes from resistant were mesophyll layer width, stomatal density, epidermis width, and xylem tissue width. Full article

Understanding the genetic architecture of drought tolerance is of great importance for overcoming the negative impact of drought on wheat yield. Earlier, we discovered the critical role of chromosome 2A for the drought-tolerant status of wheat spring cultivar Saratovskaya 29. A set of 92 single-chromosome recombinant double haploid (SCRDH) lines were obtained in the genetic background of Saratovskaya 29. The lines carry fragments of chromosome 2A from the drought-sensitive cultivar Yanetzkis Probat. The SCRDH lines were used to identify regions on chromosome 2A associated with the manifestation of physiological and agronomical traits under distinct water supply, and to identify candidate genes that may be associated with adaptive gene networks in wheat. Genotyping was done with Illumina Infinium 15k wheat array using 590 SNP markers with 146 markers being polymorphic. In four identified regions of chromosome 2A, 53 out of 58 QTLs associated with physiological and agronomic traits under contrasting water supply were mapped. Thirty-nine candidate genes were identified, of which 18 were transcription factors. The region 73.8–78.1 cM included the largest number of QTLs and candidate genes. The variation in SNPs associated with agronomical and physiological traits revealed among the SCRDH lines may provide useful information for drought related marker-assisted breeding. Full article

In recent years, silver nanoparticles (AgNPs) are increasingly used in various industries due to their antibacterial properties, which lead to an increase in pollution of the environment and soil ecosystems. However, the ecological effects of soil pollution by AgNPs were poorly studied than that with AgNPs of other metal-based NPs. The aim of this study is to assess the influence of AgNPs on the biological properties of Haplic Chernozem. Silver was introduced into the soil in the form of AgNPs with a concentration of 0.5; 1; 5; 10; 50, and 100 mg/kg in laboratory conditions. The influence of AgNPs on the biological properties of Haplic Chernozem was assessed 30 days after contamination. The degree of reduction in biological properties depends on the AgNPs concentration in the soil. This study showed that the sensitivity to contamination by AgNPs in the total number of bacteria and enzymatic activity was more than that in the abundance of bacteria of the genus Azotobacter. The integrated index of biological state (IIBS) of Haplic Chernozem was decreased by contamination with AgNPs. Silver nanoparticles in the concentration of 10 mg/kg caused a decrease in the indicator by 13% relative to the control. It also decreased IIBS by doses of 50 and 100 mg/kg by 22 and 27% relative to the control. All used biological indicators could be used for biomonitoring, biodiagnosis, bioindication, and regulation of ecological condition of soil contamination by AgNPs. Full article

Extreme temperature events as a consequence of global climate change result in a significant decline in rice production. A two-year phytotron experiment was conducted using three temperature levels and two heating durations to compare the effects of heat stress at booting, flowering, and combined (booting + flowering) stages on the production of photosynthates and yield formation. The results showed that high temperature had a significant negative effect on mean net assimilation rate (MNAR), harvest index (HI), and grain yield per plant (YPP), and a significant positive effect under treatment T₃ on mean leaf area index (MLAI) and duration of photosynthesis (DOP), and no significant effect on biomass per plant at maturity (BPP_M), except at the flowering stage. Negative linear relationships between heat degree days (HDD) and MNAR, HI, and YPP were observed. Conversely, HDD showed positive linear relationships with MLAI and DOP. In addition, BPP_M also showed a positive relationship with HDD, except at flowering, for both cultivars and Wuyunjing-24 at combined stages. The variation of YPP in both cultivars was mainly attributed to HI compared to BPP_M. However, for biomass, from the first day of high-temperature treatment to maturity (BPP_T-M), the main change was caused by MNAR followed by DOP and then MLAI. The projected alleviation effects of multiple heat stress at combined stages compared to single-stage heat stress would help to understand and evaluate rice yield formation and screening of heat-tolerant rice cultivars under current scenarios of high temperature during the rice-growing season. Full article

The impact of warming on the phenology of grapevine (Vitis vinifera L.) in conditions of central Europe was evaluated at the locality of Dolné Plachtince in the Slovakian wine region. In Welschriesling and Pinot Blanc model varieties, the onset of phenophases as defined in the BBCH scale over the period of 1985 to 2018 was observed. Based on the data obtained, the influence of the average and average maximum temperature and GDD on the onset of phenophases was evaluated. The results observed indicate earlier budburst by five to seven days, earlier beginning of flowering by 7 to 10 days, earlier berry softening by 18 days, and harvest dates advanced by 8 to 10 days on average. In both varieties, the highest influence of the average monthly temperature in March on budburst, the highest influence of the average monthly temperature and the average maximum temperature in May on the beginning of flowering, and the highest statistically significant influence of the average maximum temperature in June on the softening of berries was found. Warming observed in moderate climate conditions of northern wine regions in central Europe (Slovakia) has not yet caused changes in the grapevine phenology stable enough to require serious adaptation measures. Full article

The investigation about the leaf wounding effect on plant physiological procedures and on leaf pigments content will contribute to the understanding of the plants’ responses against this abiotic stress. During the experiment, some physiological parameters such as photosynthesis, transpiration and stomatal conductance as well as the chlorophyll and anthocyanin leaf contents of Ocimum basilicum, Salvia officinalis, and Mentha piperita plants were measured for about 20–40 days. All the measurements were conducted on control and wounded plants while in the latter, they were conducted on both wounded and intact leaves. A wide range of responses was observed in the wounded leaves, that is: (a) immediate decrease of the gas exchange parameters and long-term decrease of almost all the measured variables from O. basilicum, (b) immediate but only short-term decrease of the gas exchange parameters and no effect on pigments from M. piperita, and (c) no effect on the gas exchange parameters and decrease of the pigments content from S. officinalis. Regarding the intact leaves, in general, they exhibited a similar profile with the control ones for all plants. These results imply that the plant response to wounding is a complex phenomenon depending on plant species and the severity of the injury. Full article

In Iraq, in 2019, there were about 1.4 million Internally Displaced Persons (IDP); medical treatments were often interrupted. The feasibility of using Hibiscus sabdariffa (HS) decoction to curb hypertension was evaluated. A multicentric comparative pilot intervention for 121 participants with high blood pressure (BP) (≥140/90 mmHg) was conducted. Participants of the intervention group (with or without conventional medication) received HS decoction on a dose regimen starting from 10 grams per day. BP was measured five times over six weeks. The major active substances were chemically quantified. Results: After 6 weeks, 61.8% of participants from the intervention group (n = 76) reached the target BP < 140/90 mmHg, compared to 6.7% in the control group (n = 45). In the intervention group, a mean (±SD) reduction of 23.1 (±11.8) mmHg and 12.0 (±11.2) for systolic and diastolic BP, respectively, was observed, while in the control group the reduction was 4.4 (±10.2)/3.6 (±8.7). The chemical analysis of the starting dose indicated a content of 36 mg of total anthocyanins and 2.13 g of hibiscus acid. The study shows the feasibility of using HS decoction in IDP’s problematic framework, as hibiscus is a safe, local, affordable, and culturally accepted food product. Full article

Under the effects of climate change, it is becoming increasingly common to observe excessively fast grape sugar accumulation while phenolic and flavour development are lagging behind. The aim of this research was to quantify the impacts of three different leaf removal techniques on the canopy architecture and ripening of Cabernet Sauvignon trained in a sprawl trellis system. Treatments were performed at veraison (~14 °Brix) and included (i) control; (ii) leaf plucking in the bunch zone; (iii) leaf plucking the top two-thirds of shoots, apical to the bunches; and (iv) shoot trimming. On the date of harvest, no significant difference in total soluble solids was observed between treatments. Other results including the effect of the treatments on fruit acidity, anthocyanins, phenolics, and tannins were somewhat inconclusive. While various other studies have shown the potential of leaf removal to achieve slower grape sugar accumulation without affecting the concentration of anthocyanins, phenolics, and tannins, the results of this study do not indicate a decrease in the rate of grape sugar accumulation as a result of the investigated defoliation techniques. Given the cost of implementing these treatments, the results of this study do not support the use of these methods for the purpose of delaying fruit ripening in a hot Australian climate. Full article

Cherry blossom (Prunus yedoensis) petals are used as ingredients in many cosmetics. However, despite their use in numerous products, the exact function of cherry blossom petals in cosmetics is unclear. Therefore, we need evidence-based studies to support the labeling claims that are made in cherry blossom products in the cosmetics industry. We investigated the skin anti-aging potential of non-enzymatic softening cherry blossom extract (NES-CBE) in this study. The extract desalinated, to improve its quality such that it can be used as a functional material for the skin. The anti-wrinkle effect of NES-CBE was investigated on human keratinocytes (HaCaT cells) under solar UV (sUV) light exposure. We found that NES-CBE reduced the sUV-induced matrix metalloproteinase (MMP)-1 expression and modulated the transactivation of the activator protein (AP)-1. Furthermore, NES-CBE suppressed the phosphorylation of MEK1/2 and ERK proteins, indicating its regulation of sUV-induced MAPK signaling. Additionally, we observed NES-CBE reduced MMP-1 protein expression in a human skin equivalent model. Taken together, these results suggest that NES-CBE reduces sUV-induced MMP-1 protein expression through reducing AP-1 transactivation via regulation of the MEK1/2-ERK pathway. Full article

Intercropping systems could be a potential source of nutrient-rich forage production in cool climates on podzolic soils common in boreal ecosystems. In this study, we evaluated the effects of corn–soybean intercropping (IC) on the nutritional quality of forage. Two silage corn varieties were cultivated as monocropping (MC) or were intercropped with three forage soybean varieties using a randomized complete block design. IC significantly increased the crude protein (22%) and decreased the acid detergent (14%) and neutral detergent (6%) fibers. Forage net energy, total digestible nutrients, ash, dry matter intake, digestible dry matter and relative feed value were also significantly increased (p ≤ 0.05) in the IC treatments compared to corn MC. The macro and micro nutrients were higher in IC than corn MC. Intercropping increased the omega 3 fatty acid (FA) contents (67%) compared to corn MC. IC also increased the active microbial community in the plant root zone, which may contribute to the improvement in forage nutritional quality because the active soil microbial community composition showed significant correlations with soluble sugars, soluble proteins and potassium contents of the forage. These results demonstrate that corn–soybean IC could be a suitable cropping system to increase the nutritional quality of forage cultivated on podzols in boreal climates. The resultant forage has the potential to be a source of high-value animal feed for livestock production in cool climate regions of the world. Full article

The chemical profile, antiproliferative, antioxidant and antiphytoviral activities of the species Hypericum perforatum ssp. veronense (Schrank) H. Lindb. (Clusiaceae) were investigated. Free volatiles were isolated and the chemical composition was determined in the lipophilic fraction (essential oil) and for the first time in the water fraction (hydrosol). The aim is to provide phytochemical data for H. perforatum ssp. veronense useful for distinguishing ssp. veronense from ssp. angustifolium, as there are taxonomic disagreements between them and the composition of the secretory products may be helpful in this respect. In the essential oil, the most abundant compounds identified were α-pinene and n-nonane, while in the hydrosol, myrtenol, carvacrol and α-pinene were the most abundant. Overall, the class of monoterpenes and oxygenated monoterpenes dominated in the EO and hydrosol samples. The essential oil showed high antioxidant activity, in contrast to the antiproliferative activity, where the hydrosol showed exceptional activity against three cancer cell lines: Hela (cervical cancer cell line), HCT116 (human colon cancer cell line) and U2OS (human osteosarcoma cell line). Both the essential oil and hydrosol showed antiphytoviral activity against tobacco mosaic virus infection on the local host plants. This is the first report dealing with biological activities of hydrosol of H. perforatum ssp. veronense, and the obtained results suggest that this traditional medicinal plant is a valuable source of volatiles with promising antiproliferative, antioxidant and antiphytoviral activities. Full article

The distribution of viruses in eastern Australian field garlic was evaluated. Detection assays were developed that involved generic RT-PCR for viruses in the Allexivirus, Carlavirus and Potyvirus genera followed by virus-specific colorimetric dot-blot hybridization. Assays targeted the potyviruses (onion yellow dwarf virus (OYDV), shallot yellow stripe virus (SYSV), and leek yellow stripe virus (LYSV)), the carlaviruses (garlic common latent virus (GCLV) and shallot latent virus (SLV)), and the allexiviruses (garlic viruses A, B, C, X (GarVA, -B, -C, -X) and shallot virus X (ShVX)). Virus incidence in crops was consistently high, with most plants infected with at least one virus from each genus. OYDV, LYSV, SLV, and GCLV were commonly detected. Three of the four allexiviruses were in all districts surveyed but varied in incidence, whereas ShVX and SYSV were not detected. There was no association between virus species complement and bulb size, indicating size is not a good predictor of the virus status of planting material. The variation of virus incidence across different Australian growing districts and in different cultivars implies multiple introductions of viruses rather than spread within the country. The genetic diversity observed within coat protein sequences of some virus species also supports multiple separate introductions. Full article

Bacterial endophytes constitute an essential part of the plant microbiome and are described to promote plant health by different mechanisms. The close interaction with the host leads to important changes in the physiology of the plant. Although beneficial bacteria use the same entrance strategies as bacterial pathogens to colonize and enter the inner plant tissues, the host develops strategies to select and allow the entrance to specific genera of bacteria. In addition, endophytes may modify their own genome to adapt or avoid the defense machinery of the host. The present review gives an overview about bacterial endophytes inhabiting the phytosphere, their diversity, and the interaction with the host. Direct and indirect defenses promoted by the plant–endophyte symbiont exert an important role in controlling plant defenses against different stresses, and here, more specifically, is discussed the role against biotic stress. Defenses that should be considered are the emission of volatiles or antibiotic compounds, but also the induction of basal defenses and boosting plant immunity by priming defenses. The primed defenses may encompass pathogenesis-related protein genes (PR family), antioxidant enzymes, or changes in the secondary metabolism. Full article

Toluene is an industrial raw material and solvent that can be found abundantly in our daily life products. The amount of toluene vapor is one of the most important measurements for evaluating air quality. The evaluation of toluene scavenging ability of different plants has been reported, but the mechanism of plant response to toluene is only partially understood. In this study, we performed RNA sequencing (RNA-seq) analysis to detect differential gene expression in toluene-treated and untreated leaves of Ardisiapusilla. A total of 88,444 unigenes were identified by RNA-seq analysis, of which 49,623 were successfully annotated and 4101 were differentially expressed. Gene ontology analysis revealed several subcategories of genes related to toluene response, including cell part, cellular process, organelle, and metabolic processes. We mapped the main metabolic pathways of genes related to toluene response and found that the differentially expressed genes were mainly involved in glycolysis/gluconeogenesis, starch and sucrose metabolism, glycerophospholipid metabolism, carotenoid biosynthesis, phenylpropanoid biosynthesis, and flavonoid biosynthesis. In addition, 53 transcription factors belonging to 13 transcription factor families were identified. We verified 10 differentially expressed genes related to metabolic pathways using quantitative real-time PCR and found that the results of RNA-seq were positively correlated with them, indicating that the transcriptome data were reliable. This study provides insights into the metabolic pathways involved in toluene response in plants. Full article

Taro is important for its nutritional content, medicinal use, and bioethanol production. The aim of the present study was to compare different semi-automated bioreactors (SABs) during in vitro multiplication of C. esculenta. The SABs used were temporary immersion bioreactors (TIBs), SETIS™ bioreactors and ebb-and-flow bioreactors; semi-solid culture medium was used as a control treatment. At 30 d of culture, different developmental variables, determination of chlorophyll, stomatal content, and survival percentage during acclimatization were evaluated. SABs increased the shoot multiplication rate relative to the semi-solid medium; however, the SETIS™ bioreactor showed the highest shoot production, with 36 shoots per explant, and the highest chlorophyll content. The stomatal index was higher in the semi-solid medium compared to the SABs, while the percentage of closed stomata was higher in the SABs than in the semi-solid culture medium. The survival rate during acclimatization showed no differences among the culture systems assessed, obtaining survival rates higher than 99%. In conclusion, the SETIS™ bioreactor showed the highest multiplication rate; however, other bioreactor alternatives are available for semi-automation and cost reduction for micropropagation of C. esculenta. Full article

Manganese, as one of the xenobionts, belongs to the group of heavy metals, which, in high concentrations, can negatively affect the development of plants. In small concentrations, it is necessary for plants for normal growth and development. It is present in soils and is available to plants to varying degrees. In acidic soils, it often acts as a toxic element, and plants do not develop well and can even die. Screening major crops for manganese tolerance is essential. Based on the analysis of the collection of barley (Hordeum L., Poaceae), the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) presented data that manganese-tolerant varieties and samples are concentrated in western and northern countries with a wide distribution of soils with low pH levels and high contents of mobile manganese. It follows from the diagnostic results that the maximum number of barley genotypes resistant to manganese is concentrated in Sweden, Finland, the northwestern and northern regions of the CIS countries, and the Russian Federation. In most cases, the samples tolerant to Al showed resistance to Mn as well, which is of great interest for further study of the mechanisms of plant resistance to these stressors. As a rule, samples from the northern territories—zones of distribution of acidic soils—were highly resistant. In this case, the role of the species belonging to the sample was leveled out. The highlighted areas (Scandinavia (Finland, Sweden), northern and northwestern regions of Russia, Belarus, and the Baltic countries) are sources of germplasm valuable for selection for acid resistance of barley. Full article

In the present paper, we focused our attention on Cinnamomum camphora (L.) J. Presl. (Lauraceae), studied at three levels: (i) micromorphological, with the analysis of the secretory structures and a novel in-depth histochemical characterization of the secreted compounds; (ii) phytochemical, with the characterization of the essential oils from young stems, fruits, and leaves, subjected to different conservation procedures (fresh, dried, stored at −20 °C, stored at −80 °C) and collected in two different years; (iii) bioactive, consisting of a study of the potential antibacterial activity of the essential oils. The micromorphological investigation proved the presence of secretory cells characterized by a multi-layered wall in the young stems and leaves. They resulted in two different types: mucilage cells producing muco-polysaccharides and oil cells with an exclusive terpene production. The phytochemical investigations showed a predominance of monoterpenes over sesquiterpene derivatives; among them, the main components retrieved in all samples were 1,8-cineole followed by α-terpineol and sabinene. Conservation procedures seem to only influence the amounts of specific components, i.e., 1,8-cineole and α-terpineol, while analyses on each plant part revealed the presence of some peculiar secondary constituents for each of them. Finally, the evaluation of the antibacterial activity of the essential oil showed a promising activity against various microorganisms, as Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa. In conclusion, we combined a micromorphological and phytochemical approach of the study on different plant parts of C. camphora, linking the occurrence of secretory cells to the production of essential oils. We compared, for the first time, the composition of essential oils derived from different plant matrices conserved with different procedures, allowing us to highlight a relation between the conservation technique and the main components of the profiles. Moreover, the preliminary antibacterial studies evidenced the potential activity of the essential oils against various microorganisms potentially dangerous for plants and humans. Full article

The present study aimed to analyze the differences in the tolerance of fava bean (Vicia faba cv. Aštar) roots to cadmium in nitrate—Cd(NO₃)₂—and chloride—CdCl₂—solutions. The physiological and biochemical parameters were assessed. The tested doses of Cd (50, 100, 150 and 300 mg/L) did not influence the germination of seeds. However, considerable growth inhibition and dehydration were observed after 96 h incubation. The thickness of roots and rupture of cell membranes increased along with the increasing concentration of the metal in the solution. At a Cd dose of 300 mg/L, irrespective of the solution used, increased nitrogen concentration and no change in sodium content were observed. The content of magnesium increased due to the dose of 100 mg/L (cadmium nitrate) and the content of calcium increased due to the dose of 300 mg/L (in either nitrate or chloride). The correlation analyses pointed to a possible effect of nitrates in the applied solutions on the accumulation of Cd and some minerals in the roots of the given variety of fava bean. This may be important for both research and agricultural practice. The identification of crops with high tolerance to cadmium, as well as knowledge about the mechanisms of ion interactions at the soil solution–plant level, is important in terms of such crops’ use in the process of the remediation of cadmium-contaminated soils coupled with food production. Full article

Vitellaria paradoxa C. F. Gaertn is widely used in African traditional medicine as an anti-inflammatory remedy to treat rheumatism, gastric problems, diarrhea, and dysentery. The phytochemical investigation of the ethyl acetate extract of V. paradoxa stem bark collected in Burkina Faso led to the isolation of eight known and two triterpenes undescribed to date (7 and 10), in the free alcohol form or as acetyl and cinnamyl ester derivatives. The stereostructures of the new compounds were elucidated using HR-ESIMS and 1D and 2D NMR data. The isolated compounds were evaluated in vitro for their inhibitory effect on nitrite levels on murine macrophages J774 stimulated with the lipopolysaccharide (LPS). Among all the compounds tested, lupeol cinnamate (3) and betulinic acid (5) showed a beneficial effect in reducing nitrite levels produced after LPS stimulation. Full article

Salt stress adversely affects the growth and productivity of crops. However, reports suggest that the application of various micronutrients could help the plant to cope with this stress. Hence, the objective of the study was to examine the effect of exogenous application of Zinc (Zn) on salt tolerance in Vigna radiata (L.) Wilczek (mungbean). Mungbean is considered to be an economically important crop and possess a strategic position in Southeast Asian countries for sustainable crop production. It is rich in quality proteins, minerals and vitamins. Three weeks old grown seedlings were subjected to NaCl (150 mM and 200 mM) alone or with Zn (250 µM). After 21 days of treatment, plants were harvested for investigating morphological, physiological and biochemical changes. We found that the Zn application mitigates the negative effect upon plant growth to a variable extent. This may be attributed to the increased shoot and root length, improved chlorophyll and carotenoid contents, enhanced total soluble sugar (TSS), total soluble protein (TSP) and proline accumulation, decreased H₂O₂ content and increased enzymatic antioxidant activities. Zn’s application improved the performance of the enzymes such as phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) of the secondary metabolism, which resulted in the improvement of total phenol and flavonoids. The antioxidant activities such as 1,1diphenyl 2-picryl hydrazine (DPPH) and ferrous reducing antioxidant power assay (FRAP) of the plants also showed improved results in their salt only treatments. Furthermore, hydrogen peroxide (H₂O₂) and superoxide radical (SOD) scavenging activity were also improved upon the application of 250 µM zinc. Thus, Zn application in low doses offers promising potential for recovering plants suffering from salinity stress. In conclusion, we assume that zinc application improved salt tolerance in mungbean through the improvement of various physiological and photochemical processes which could prove to be useful in nutrient mediated management for crop improvement. Full article

Whole-genome doubling (polyploidy) is common in angiosperms. Several studies have indicated that it is often associated with molecular, physiological, and phenotypic changes. Mounting evidence has pointed out that micro-RNAs (miRNAs) may have an important role in whole-genome doubling. However, an integrative approach that compares miRNA expression in polyploids is still lacking. Here, a re-analysis of already published RNAseq datasets was performed to identify microRNAs’ precursors (pre-miRNAs) in diploids (2x) and tetraploids (4x) of five species (Arabidopsis thaliana L., Morus alba L., Brassica rapa L., Isatis indigotica Fort., and Solanum commersonii Dun). We found 3568 pre-miRNAs, three of which (pre-miR414, pre-miR5538, and pre-miR5141) were abundant in all 2x, and were absent/low in their 4x counterparts. They are predicted to target more than one mRNA transcript, many belonging to transcription factors (TFs), DNA repair mechanisms, and related to stress. Sixteen pre-miRNAs were found in common in all 2x and 4x. Among them, pre-miRNA482, pre-miRNA2916, and pre-miRNA167 changed their expression after polyploidization, being induced or repressed in 4x plants. Based on our results, a common ploidy-dependent response was triggered in all species under investigation, which involves DNA repair, ATP-synthesis, terpenoid biosynthesis, and several stress-responsive transcripts. In addition, an ad hoc pre-miRNA expression analysis carried out solely on 2x vs. 4x samples of S. commersonii indicated that ploidy-dependent pre-miRNAs seem to actively regulate the nucleotide metabolism, probably to cope with the increased requirement for DNA building blocks caused by the augmented DNA content. Overall, the results outline the critical role of microRNA-mediated responses following autopolyploidization in plants. Full article

The gene flow mediated by unreduced gametes between diploid and tetraploid plants of the Medicagosativa-coerulea-falcata complex is pivotal for alfalfa breeding. Sexually tetraploidized hybrids could represent the best way to exploit progressive heterosis simultaneously derived from gene diversity, heterozygosity, and polyploidy. Moreover, unreduced gametes combined with parthenogenesis (i.e., apomixis) would enable the cloning of plants through seeds, providing a unique opportunity for the selection of superior genotypes with permanently fixed heterosis. This reproductive strategy has never been detected in the genus Medicago, but features of apomixis, such as restitutional apomeiosis and haploid parthenogenesis, have been reported. By means of an original case study, we demonstrated that sexually tetraploidized plants maintain apomeiosis, but this trait is developmentally independent from parthenogenesis. Alfalfa meiotic mutants producing unreduced egg cells revealed a null or very low capacity for parthenogenesis. The overall achievements reached so far are reviewed and discussed along with the efforts and strategies made for exploiting reproductive mutants that express apomictic elements in alfalfa breeding programs. Although several studies have investigated the cytological mechanisms responsible for 2n gamete formation and the inheritance of this trait, only a very small number of molecular markers and candidate genes putatively linked to unreduced gamete formation have been identified. Furthermore, this scenario has remained almost unchanged over the last two decades. Here, we propose a reverse genetics approach, by exploiting the genomic and transcriptomic resources available in alfalfa. Through a comparison with 9 proteins belonging to Arabidopsis thaliana known for their involvement in 2n gamete production, we identified 47 orthologous genes and evaluated their expression in several tissues, paving the way for novel candidate gene characterization studies. An overall view on strategies suitable to fill the gap between well-established meiotic mutants and next-generation genomic resources is presented and discussed. Full article