Nanoparticles regulate redox metabolism in plants during abiotic stress within hormetic boundaries
Saswati Bhattacharya, Sumanti Gupta, Jayita Saha
The anticancer/cytotoxic effect of a novel gallic acid derivative in non‐small cell lung carcinoma A549 cells and peripheral blood mononuclear cells from healthy individuals and lung cancer patients
This article presents a series of novel derivatives from gallic acid with antioxidant / anticancer properties. These compounds were studied on lymphocytes from healthy individuals and lung cancer patients. Also, gallic acid and its derivatives were examined on non-small cell carcinoma cell line. The anticancer effect of these compounds was revealed which should be confirmed with further future investigations.
Abstract
Gallic acid (GA) is a naturally occurring polyphenol with a strong antioxidant capacity. GA stimulates the apoptosis of cancer cells, thereby suppressing cancer cell invasion. However, the low oral permeability of GA limits its therapeutic use. In order to enhance the antioxidant capacity and oral permeability of GA, a series of compounds analogous to GA were synthesized: 4-methoxybenzenesulfonamide (MBS), 3,4-dimethoxybenzenesulfonamide (DMBS) and 3,4,5-trimethoxybenzenesulfonamide (TMBS). In the new compounds, hydroxyl groups were replaced with various numbers of methoxy groups (stronger electron-donating groups), to increase hydrophobicity and oral permeability compared to GA. In addition, the carboxylic group was replaced with a sulfonyl group (a stronger electron-withdrawing group), to increase the molecular polarity and antioxidative activities of the compounds. The cell counting kit-8 (CCK-8) assay was used to detect the effect of GA, MBS, DMBS, and TMBS on cell proliferation and apoptosis in peripheral blood mononuclear cells (PBMCs) from healthy individuals and non-small cell lung carcinoma A549 cells. Additionally, the comet assay was used to assess the genotoxicity of these compounds in PBMCs from healthy individuals, lung cancer patients, and A549 cells. Compared to untreated cells, TMBS reduced DNA damage more effectively than GA in PBMCs from lung cancer patients and healthy donors. Furthermore, in comparison to GA, TMBS was more cytotoxic in A549 cells. Moreover, TMBS was not cytotoxic in healthy PBMCs, suggesting that TMBS demonstrates therapeutic potential in cancer.
Insights into the antiosteoporotic mechanism of the soy‐derived isoflavone genistein: Modulation of the Wnt/beta‐catenin signaling
Glucocorticoid-induced osteoporosis (GIO) reduces bone formation, osteoblasts differentiation and function, and accelerates osteoblast and osteocyte apoptosis. Genistein induces bone remodeling through Wnt/β-catenin pathway activation in osteoblast and osteocytes. Genistein could represent an interesting new therapeutic approach for the management of GIO patients.
Abstract
Bone remodeling is a process that involves osteoblasts, osteoclasts, and osteocytes, and different intracellular signaling, such as the canonical Wnt/β-catenin pathway. Dysregulations of this pathway may also occur during secondary osteoporosis, as in the case of glucocorticoid-induced osteoporosis (GIO), which accelerates osteoblast and osteocyte apoptosis by reducing bone formation, osteoblast differentiation and function, accelerates in turn osteoblast, and osteocyte apoptosis. Genistein is a soy-derived nutrient belonging to the class of isoflavones that reduces bone loss in osteopenic menopausal women, inhibiting bone resorption; however, genistein may also favor bone formation. The aim of this study was to investigate whether estrogen receptor stimulation by genistein might promote osteoblast and osteocyte function during glucocorticoid challenge. Primary osteoblasts, collected from C57BL6/J mice, and MLO-A5 osteocyte cell line were used to reproduce an in vitro model of GIO by adding dexamethasone (1 μM) for 24 h. Cells were then treated with genistein for 24 h and quantitative Polymerase Chain Reaction (qPCR) and western blot were performed to study whether genistein activated the Wnt/β-catenin pathway. Dexamethasone challenge reduced bone formation in primary osteoblasts and bone mineralization in osteocytes; moreover, canonical Wnt/β-catenin pathway was reduced following incubation with dexamethasone in both osteoblasts and osteocytes. Genistein reverted these changes and this effect was mediated by both estrogen receptors α and β. These data suggest that genistein could induce bone remodeling through Wnt/β-catenin pathway activation.
Cucurbit chlorotic yellows virus, a crinivirus infecting Cannabis sativa plants
Cucurbit chlorotic yellows virus (CCYV-Can), a crinivirus, was transmitted by the whitefly Bemisia tabaci to Cannabis sativa plants causing interveinal chlorosis and leaf yellowing in high-CBD plants.
Abstract
High cannabidiol-containing plants of Cannabis sativa (high-CBD) growing in farms in Israel displayed foliar symptoms of interveinal chlorosis and yellowing, brittleness and occasionally necrosis. These symptoms, which were more apparent in older leaves, resembled those caused by the crinivirus lettuce chlorosis virus (LCV). However, this virus was not detected by reverse transcription (RT)-PCR using specific primer sets. High-throughput sequencing of viral RNA extracted from symptomatic leaves revealed the presence of cucurbit chlorotic yellows virus (CCYV), a crinivirus in the Closteroviridae family. The complete viral genome sequence was obtained using RT-PCR followed by Sanger sequencing. The two CCYV RNA genomic segments shared 99.5%–99.85% nucleotide sequence identity with CCYV isolates from the GenBank. The virus was transmitted from symptomatic cannabis leaves to healthy plants of cannabis and Cucumis sativus ‘King Star’ (cucumber) by the whitefly Bemisia tabaci Middle Eastern Asia Minor 1 (MEAM1) species, causing disease symptoms identical to those of the donor plants. Cannabis-CCYV was also transmitted between infected cucumber plants and cannabis seedlings of unknown genotype. Severe disease symptoms of yellowing and leaf-edge necrosis were observed on high-CBD and high Δ9-tetrahydrocannabinol-containing (high-THC) flowering cannabis plants and were associated with mixed infections of LCV and CCYV. To the best of our knowledge, this is the first report of CCYV infecting C. sativa plants.
QTL mapping and candidate gene analysis of low‐temperature tolerance at the germination stage of soybean
Abstract
When soybean seeds encounter low temperature during germination, the vigour and germination of soybean seeds are affected, which leads to a lack of seedlings and weak seedlings, resulting in yield reduction. In-depth analysis of the genetic mechanism of soybean seed germination tolerance to low-temperature stress and the cultivation of soybean-tolerant varieties is the key to resisting low-temperature stress at the germination stage. In the present study, a chromosome segment substitution line (CSSL) population constructed by wild soybean ZYD00006 and cultivated soybean SN14 was used to map three quantitative trait loci (QTLs). Five candidate genes were obtained by gene annotation, GO enrichment analysis and protein function prediction. The candidate genes were subjected to bioinformatics analysis, qRT-PCR analysis, trypsin activity analysis and soluble protein content analysis. The results showed that the secondary and tertiary structures of the Glyma.09G162700 proteins were mutated. Within 0–72 h, the expression of Glyma.09G162700 in the two materials with different tolerances was consistent, and the change in trypsin activity was consistent with the change in protein expression. Through haplotype analysis, Glyma.09G162700 produced two haplotypes at −2420 bp. The germination rate (GR) and relative germination rate (RGR) of the two haplotypes were significantly different, indicating that the two haplotypes have wide applicability in soybean resources. In summary, Glyma.09G162700 may be a candidate gene for low-temperature tolerance at the germination stage of soybean. These results provide an important theoretical basis and marker information for analysing the mechanism of low-temperature tolerance in soybean germination stage and cultivating low-temperature-tolerant varieties.
Taxonomic revision of Australian Erythrophleum (Fabaceae: Caesalpinioideae) including description of two new species
Russell L. Barrett, Matthew D. Barrett - Volume 36(5)
Vegetation change over 140 years in a sagebrush landscape of the Rio Grande del Norte National Monument, New Mexico, USA
We compared surveys from 1881 with modern vegetation to test for changes in a big sagebrush landscape in a National Monument in New Mexico, USA. We found an increase in sagebrush over 140 years, which contrasts with the sagebrush decline occurring in the Great Basin. These results provide insights into different trends and processes affecting similar vegetation in different regions.
Abstract
Questions
Big sagebrush (Artemisia tridentata) ecosystems across the western United States have experienced many changes in ecosystem dynamics and vegetation composition over the last century due to livestock grazing, non-native species, and changing climate and fire regimes. We conducted the first systematic investigation of historical vegetation composition and vegetation change in a sagebrush landscape in the southwestern United States, asking whether sagebrush or grass dominated the landscape historically?
Location
The Rio Grande del Norte National Monument (RGDN), northern New Mexico, USA.
Methods
We combined General Land Office (GLO) surveys from 1881 with modern vegetation maps, field vegetation surveys, and sagebrush ages from growth ring analysis to test for changes in vegetation in the RGDN over the last 140 years.
Results
We found that big sagebrush presence across the study area increased significantly, from being present on 16% of section lines in 1881 to 79% in 2019, and only three section lines lost sagebrush presence during that period. Concurrently, the number of section lines with low grass index more than doubled since 1881, while moderate and high grass index declined. Grass declined equally in areas where sagebrush increased and areas with no change in sagebrush, suggesting that changes in both vegetation types were catalyzed by external factors, likely including overgrazing. The growth ring analysis of 93 sagebrush revealed a maximum age of 87 years and establishment in every decade since the 1930s, consistent with the GLO results.
Conclusions
The significant vegetation changes in the RGDN over the last century, including an increase of sagebrush, provide important context about the shifting mosaic of grasslands and shrublands relevant to current and future management and ecosystem dynamics.
Cucumber mosaic virus subgroup IA isolates infect four varieties of Nandina domestica in China
Abstract
Cucumber mosaic virus (CMV) subgroup IA isolates were first identified from Nandina domestica plants in Zhejiang province of China by small RNA deep sequencing followed by bioinformatics analysis and was confirmed by RT-PCR amplification, 5′ and 3′ RACE and DNA sequencing. The complete nucleotide sequences of this virus shared the highest sequence similarities (97–98%) with CMV subgroup IA isolate CTL RNA1 and RNA3 (GenBank accession no: EF213023, EF213025) and RP48 RNA2 (KC527727), respectively; and converged with CMV subgroup IA isolates into a branch in phylogenetic tree using full length nucleotide sequences. Pathogenicity test confirmed that this virus can be mechanically transmitted to N. domestica, Nicotiana tabacum and N. benthamiana. All thirty randomly collected samples of four major N. domestica varieties (N. domestica cv. Hong Baoshi, Nana, Fire Power and Xiu Dada) in Lin'an Zhejiang province were positive for CMV subgroup IA. This is the first report of CMV subgroup IA isolate on varieties of N. domestica in China.
From the severity patch to the landscape: Wildfire and spatial heterogeneity in northern Sierra Nevada conifer forests
Habitat mosaics due to shrub establishment in mixed conifer forest after fire creates high spatial heterogeneity at broader scales. However, reburned patches from high to high and low and moderate to low and moderate severities have less spatial heterogeneity. Under climate change-induced increase in wildfire within short return interval, conifer regeneration within large stand-replaced patches is uncertain.
Abstract
Aims
Prolonged fire suppression in conifer forests of the Sierra Nevada Mountain range, California, USA, has led to ingrowth of conifer seedlings, converting the open heterogeneous structure into uniformly dense and layered forest. The threat of a stand-replacing fire has increased because of fuel buildup in combination with rising drought and extreme heat frequency caused by climate change. With such high severity fire, there is also rising concern regarding conifer forest converting to shrublands as severe fire favors the establishment of large shrub patches altering landscape vegetation pattern and heterogeneity. However, a clear understanding of the effects of increased fire severity, size, and frequency on landscape-scale heterogeneity and postfire patch dynamics is lacking, which is critical in implementing restoration and forest management activities. Our aim was to understand multiscale dynamics and spatial heterogeneity patterns of conifer forests and chaparral shrublands due to repeated mixed-severity fire.
Location
A mosaic of burned and unburned patches spanning the boundary of Lassen and Plumas National Forests, CA, USA.
Methods
We used secondary geospatial landcover data classified by cover type before modern fires (1999) and after eight modern fires (2014). We calculated various landscape diversity and fragmentation metrics at patch and landscape scales using FRAGSTATS for comparison before and after fires.
Results
At the fire severity patch scale, high-severity fire reduced vegetation cover type heterogeneity by half, but reburning at low to moderate severity nearly doubled cover type heterogeneity. At the full landscape scale mixed-severity fire, including all burn severities, increased vegetation cover type heterogeneity. Fragmentation indexes confirmed that fire created larger patches of shrub and fragmented patches of conifer forest.
Conclusions
The effects of frequent large fire events on vegetation pattern and heterogeneity vary with the scale of analysis. Hence, heterogeneity and vegetation pattern change need to be evaluated at more than one scale to understand past and future ecological processes before prioritizing management actions for the conifer forests of the Sierra Nevada Mountain range.
Near‐gapless genome assemblies of Williams 82 and Lee cultivars for accelerating global soybean research
Abstract
Complete, gapless telomere-to-telomere chromosome assemblies are a prerequisite for comprehensively investigating the architecture of complex regions, like centromeres or telomeres and removing uncertainties in the order, spacing, and orientation of genes. Using complementary genomics technologies and assembly algorithms, we developed highly contiguous, nearly gapless, genome assemblies for two economically important soybean [Glycine max (L.) Merr] cultivars (Williams 82 and Lee). The centromeres were distinctly annotated on all the chromosomes of both assemblies. We further found that the canonical telomeric repeats were present at the telomeres of all chromosomes of both Williams 82 and Lee genomes. A total of 10 chromosomes in Williams 82 and eight in Lee were entirely reconstructed in single contigs without any gap. Using the combination of ab initio prediction, protein homology, and transcriptome evidence, we identified 58,287 and 56,725 protein-coding genes in Williams 82 and Lee, respectively. The genome assemblies and annotations will serve as a valuable resource for studying soybean genomics and genetics and accelerating soybean improvement.