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Dietary lithium stimulates female fecundity in Drosophila melanogaster
Dietary lithium (0.1–5 mM LiCl) improved the lithium status of the female fruit fly Drosophila melanogaster and substantially increased egg production. These findings were accompanied by alterations in mRNA levels of genes encoding proteins involved with chorion formation and yolk protein biosynthesis, which are essential steps in Drosophila oogenesis. (Image created with BioRender.com).
Abstract
The trace element lithium exerts a versatile bioactivity in humans, to some extend overlapping with in vivo findings in the model organism Drosophila melanogaster. A potentially essential function of lithium in reproduction has been suggested since the 1980s and multiple studies have since been published postulating a regulatory role of lithium in female gametogenesis. However, the impact of lithium on fruit fly egg production has not been at the center of attention to date. In the present study, we report that dietary lithium (0.1–5.0 mM LiCl) substantially improved life time egg production in D. melanogaster w 1118 females, with a maximum increase of plus 45% when supplementing 1.0 mM LiCl. This phenomenon was not observed in the insulin receptor mutant InR E19 , indicating a potential involvement of insulin-like signaling in the lithium-mediated fecundity boost. Analysis of the whole-body and ovarian transcriptome revealed that dietary lithium affects the mRNA levels of genes encoding proteins related to processes of follicular maturation. To the best of our knowledge, this is the first report on dietary lithium acting as an in vivo fecundity stimulant in D. melanogaster, further supporting the suggested benefit of the trace element in female reproduction.
Morphological and pathological characterization of Colletotrichum species causing anthracnose of litchi leaves in Guangxi, China
Abstract
Litchi (Litchi chinensis Sonn.) is an evergreen subtropical fruit tree native to southern China. Litchi is vulnerable to a wide range of diseases affecting yield and fruit quality. Anthracnose is one of the main diseases during the period of growth and storage, which has a serious impact on the quality and production of litchi. In December 2020 to May 2021, typical anthracnose symptoms were observed on litchi leaves in different orchards in Qinzhou City, Guangxi Province, Southern China. According to colony features, conidial and appressorial morphology, and sequence analysis of several genomic regions (internal transcribed spacer (ITS) region, chitin synthase (chs-1), actin (act), calmodulin (cal), glyceraldehyde-3-phosphate dehydrogenase (gapdh), β-tubulin (tub2) and the intergenic region of apn2 and MAT1-2-1 (ApMat)), 44 isolates were obtained, and 26 were identified as three Colletotrichum species: C. fructicola (50%), C. siamense (42.31%), C. gigasporum (7.69%). The pathogenicity tests were performed with conidial suspension and mycelia plugs to inoculate wounded litchi seedlings. The results of pathogenicity tests showed that the virulence of C. gigasporum was the weakest, and the virulence of C. fructicola was the strongest. This is the first report of C. gigasporum causing anthracnose of litchi worldwide.
Greater variation in boreal plant community composition and community‐level traits at local‐ than regional‐scale
We explored variation in plant community processes in sites spanning the latitudinal extent of the boreal biome of western North America. We found that the majority of variation in plant community composition and functional traits occurred within sites, suggesting that local-scale environmental gradients were more strongly driving plant community dynamics than the regional-scale climatic gradient across our sites.
Abstract
Questions
Rapid climate change in northern latitudes is expected to influence plant functional traits of the whole community (community-level traits) through species compositional changes and/or trait plasticity, limiting our ability to anticipate climate warming impacts on northern plant communities. We explored differences in plant community composition and community-level traits within and among four boreal peatland sites and determined whether intra- or interspecific variation drives community-level traits.
Location
Boreal biome of western North America.
Methods
We collected plant community composition and functional trait data along dominant topoedaphic and/or hydrologic gradients at four peatland sites spanning the latitudinal extent of the boreal biome of western North America. We characterized variability in community composition and community-level traits of understorey vascular and moss species both within (local-scale) and among sites (regional-scale).
Results
Against expectations, community-level traits of vascular plant and moss species were generally consistent among sites. Furthermore, interspecific variation was more important in explaining community-level trait variation than intraspecific variation. Within-site variation in both community-level traits and community composition was greater than among-site variation, suggesting that local environmental gradients (canopy density, organic layer thickness, etc.) may be more influential in determining plant community processes than regional-scale gradients.
Conclusions
Given the importance of interspecific variation to within-site shifts in community-level traits and greater variation of community composition within than among sites, we conclude that climate-induced shifts in understorey community composition may not have a strong influence on community-level traits in boreal peatlands unless local-scale environmental gradients are substantially altered.
Role of Nigella sativa in Preventing Oxidative Stress Damage Using Planaria as Model Organism
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Exploring the therapeutic potential of naturally occurring piceatannol in non‐communicable diseases
The natural stilbene Piceatannol is having a promising therapeutic potential for the prevention and treatment of a wide variety of complex human diseases like asthma, cancer, diabetes, and so forth.
Abstract
Piceatannol is a naturally occurring hydroxylated resveratrol analogue that can be found in a variety of fruits and vegetables. It has been documented to have a wide range of beneficial effects, including anti-inflammatory, antioxidant, anti-aging, anti-allergic, antidiabetic, neuroprotective, cardioprotective, and chemopreventive properties. Piceatannol has significantly higher antioxidant activity than resveratrol. Piceatannol has been shown in preclinical studies to have the ability to inhibit or reduce the growth of cancers in various organs such as the brain, breast, lung, colon, cervical, liver, prostate, and skin. However, the bioavailability of Piceatannol is comparatively lower than resveratrol and other stilbenes. Several approaches have been reported in recent years to enhance its bioavailability and biological activity, and clinical trials are required to validate these findings. This review focuses on several aspects of natural stilbene Piceatannol, its chemistry, and its mechanism of action, and its promising therapeutic potential for the prevention and treatment of a wide variety of complex human diseases.
Effect of environmental factors, fungicide sensitivity, and pathogenicity of Fusarium spp. associated with fruit rot of melon
Abstract
Fusarium rot is one of the main postharvest diseases of melons, directly interfering with the quality and commercial use of the fruit. The purpose of this study was to assess the effect of environmental factors (temperature, pH and salinity) and the pathogenicity of four Fusarium species (F. falciforme, F. kalimantanense, F. pernambucanum and F. sulawesiense) belonging to three different species complexes on disease development on melon, as well as the in vitro and in vivo sensitivity of these species to the fungicides azoxystrobin + fludioxonil, imazalil and thiabendazole. The results showed optimum fungal growth temperatures from 24.5 to 27.2°C, and optimum pH from 6.10 to 8.37 for all Fusarium species. NaCl concentrations (250–1000 mM) significantly reduced in vitro mycelial growth for all isolates. All species were pathogenic to melon plants and fruit, with an isolate of F. falciforme being the most aggressive, causing the highest disease severity in plants and fruit (43.3% and 62.5%, respectively). The isolate of F. sulawesiense tested showed high in vitro sensitivity to two fungicides (azoxystrobin + fludioxonil and imazalil), with EC50 values below 1 mg/L of a.i. Fruit inoculated with the selected isolates of F. falciforme and F. pernambucanum showed a reduction in the disease severity on the peduncle when treated with the fungicide thiabendazole (9.0% and 4.0%, respectively). Azoxystrobin + fludioxonil was responsible for the lowest disease severity in the epicarp caused by the same isolates (0.0% and 2.5%, respectively). These results are relevant to improve management strategies for diseases of melon caused by Fusarium spp.
Issue Information
Journal of Phytopathology, Volume 171, Issue 10, Page i-iii, October 2023.
Powdery mildew of chayote (Sechium edule) caused by Podosphaera xanthii race 2 in Brazil
Abstract
The causal agent of chayote (Sechium edule) powdery mildew (PM) was identified in Brazil. Microscopic examinations revealed hyaline and ovoid conidia, borne in chains and displaying distinctive extra-vacuolar fibrosin bodies. Morphology agreed to the standard description of the anamorph of Podosphaera xanthii. To confirm this identification, genomic DNA was extracted from field isolates and used in PCR assays with ITS primers. Amplicons were Sanger-sequenced and the nucleotide alignments of all isolates displayed identity levels above 97% with P. xanthii isolates in GenBank database. Phylogenetic analyses indicated only P. xanthii isolates as the PM-inducing pathogens in chayote. Inoculation assays were performed using chayote, zucchini and a set of muskmelon differential cultigens for determination of the physiological races of P. xanthii. All chayote isolates were pathogenic to chayote and zucchini seedlings. Five isolates were also pathogenic to the muskmelon cultigens ‘Hale's Best Jumbo’, ‘Védrantais’, ‘PMR-45’ and ‘Edisto 47’, whereas ‘PMR-5’ was asymptomatic during the experimental period. The virulence profile of chayote-infecting isolates allowed their classification as P. xanthii race 2. To the best of our knowledge, this is the first worldwide report of P. xanthii race 2 in chayote. This report has relevant epidemiological and disease management implications, allowing more sustainable chayote cultivation under tropical and subtropical conditions.
Identification of Clonostachys rogersoniana as a causal agent of sisal leaf blight disease in South China
Abstract
A novel strain of leaf blight disease affecting sisal leaves was discovered at the Hongshan farm of Yulin City, Guangxi Province, in 2022. Ten fungal isolates were identified in the infected sisal leaves and classified into six categories (22GX3-1 to 6). Pathogenicity testing revealed that only 22GX3-2 and two morphologically similar isolates induced symptoms similar to those detected in the field. Based on morphological analysis and nucleotide sequencing of the internal transcribed spacer (ITS) of the rRNA gene, translation elongation factor 1 alpha (TEF1) and tubulin beta chain 2 (TUB2) genes, the fungal isolate 22GX3-2 was identified as Clonostachys rogersoniana. To the best of our knowledge, this is the first study reporting sisal leaf blight caused by Clonostachys rogersoniana.