Soil microbes alter plant fitness under competition and drought

Plants exist across varying biotic and abiotic environments, including variation in the composition of soil microbial communities. The ecological effects of soil microbes on plant communities are well known, whereas less is known about their importance for plant evolutionary processes. In particular, the net effects of soil microbes on plant fitness may vary across environmental contexts and among plant genotypes, setting the stage for microbially mediated plant evolution. Here, we assess the effects of soil microbes on plant fitness and natural selection on flowering time in different environments. We performed two experiments in which we grew Arabidopsis thaliana genotypes replicated in either live or sterilized soil microbial treatments, and across varying levels of either competition (isolation, intraspecific competition or interspecific competition) or watering (well‐watered or drought). We found large effects of competition and watering on plant fitness as well as the expression and natural selection of flowering time. Soil microbes increased average plant fitness under interspecific competition and drought and shaped the response of individual plant genotypes to drought. Finally, plant tolerance to either competition or drought was uncorrelated between soil microbial treatments suggesting that the plant traits favoured under environmental stress may depend on the presence of soil microbes. In summary, our experiments demonstrate that soil microbes can have large effects on plant fitness, which depend on both the environment and individual plant genotype. Future work in natural systems is needed for a complete understanding of the evolutionary importance of interactions between plants and soil microorganisms.     

Predicting the success of an invader: Niche shift versus niche conservatism

Invasive species can encounter environments different from their source populations, which may trigger rapid adaptive changes after introduction (niche shift hypothesis). To test this hypothesis, we investigated whether postintroduction evolution is correlated with contrasting environmental conditions between the European invasive and source ranges in the Asian tiger mosquito Aedes albopictus. The comparison of environmental niches occupied in European and source population ranges revealed more than 96% overlap between invasive and source niches, supporting niche conservatism. However, we found evidence for postintroduction genetic evolution by reanalyzing a published ddRADseq genomic dataset from 90 European invasive populations using genotype–environment association (GEA) methods and generalized dissimilarity modeling (GDM). Three loci, among which a putative heat‐shock protein, exhibited significant allelic turnover along the gradient of winter precipitation that could be associated with ongoing range expansion. Wing morphometric traits weakly correlated with environmental gradients within Europe, but wing size differed between invasive and source populations located in different climatic areas. Niche similarities between source and invasive ranges might have facilitated the establishment of populations. Nonetheless, we found evidence for environmental‐induced adaptive changes after introduction. The ability to rapidly evolve observed in invasive populations (genetic shift) together with a large proportion of unfilled potential suitable areas (80%) pave the way to further spread of Ae. albopictus in Europe.     

Large-scale evaluation of candidate genes identifies associations between VEGF polymorphisms and bladder cancer risk

Common genetic variation could alter the risk for developing bladder cancer. We conducted a large-scale evaluation of single nucleotide polymorphisms (SNPs) in candidate genes for cancer to identify common variants that influence bladder cancer risk. An Illumina GoldenGate assay was used to genotype 1,433 SNPs within or near 386 genes in 1,086 cases and 1,033 controls in Spain. The most significant finding was in the 5′ UTR of VEGF (rs25648, p for likelihood ratio test, 2 degrees of freedom = 1 × 10⁻⁵). To further investigate the region, we analyzed 29 additional SNPs in VEGF, selected to saturate the promoter and 5′ UTR and to tag common genetic variation in this gene. Three additional SNPs in the promoter region (rs833052, rs1109324, and rs1547651) were associated with increased risk for bladder cancer: odds ratio (95% confidence interval): 2.52 (1.06–5.97), 2.74 (1.26–5.98), and 3.02 (1.36–6.63), respectively; and a polymorphism in intron 2 (rs3024994) was associated with reduced risk: 0.65 (0.46–0.91). Two of the promoter SNPs and the intron 2 SNP showed linkage disequilibrium with rs25648. Haplotype analyses revealed three blocks of linkage disequilibrium with significant associations for two blocks including the promoter and 5′ UTR (global p = 0.02 and 0.009, respectively). These findings are biologically plausible since VEGF is critical in angiogenesis, which is important for tumor growth, its elevated expression in bladder tumors correlates with tumor progression, and specific 5′ UTR haplotypes have been shown to influence promoter activity. Associations between bladder cancer risk and other genes in this report were not robust based on false discovery rate calculations. In conclusion, this large-scale evaluation of candidate cancer genes has identified common genetic variants in the regulatory regions of VEGF that could be associated with bladder cancer risk.     

Music of metagenomics—a review of its applications,analysis pipeline,and associated tools

Functional & Integrative Genomics - This humble effort highlights the intricate details of metagenomics in a simple, poetic, and rhythmic way. The paper enforces the significance of the...     

Towards ex situ conservation of globally rare Turkish endemic Tripleurospermum fissurale (Asteraceae)

In Vitro Cellular & Developmental Biology - Plant - A rapid and efficient in vitro micropropagation system was developed to conserve Tripleurospermum fissurale (Sosn.) E.Hossain (Asteraceae), a...     

Construction of efficient bioelectrochemical devices: Improved electricity production from cyanobacteria (Leptolyngbia sp.) based on π-conjugated conducting polymer/gold nanoparticle composite interfaces

In this study, gold electrodes (GE) were coated with conducting polymers to obtain a high photocurrent using cyanobacteria from a novel bioelectrochemical fuel cell. For this purpose, 4-(4H-ditiheno[3,2-b:2',3'-d]pyrol-4-yl) aniline and 5-(4H-dithieno[3,2-b:2',3'-d]pyrol-4-yl) napthtalane-1-amine monomers were coated on GE by performing an electropolymerization process. After that, gold nanoparticles (AuNP) were specifically modified by 2-mercaptoethane sulfonic acid and p-aminothiophenol to attach to the electrode surface. The conducting polymers GE coat was modified with functionalized AuNP using a cross-linker. The resulting electrode structures were characterized by cyclic voltammetry and chronoamperometry under on-off illumination using a fiber optic light source. Cyanobacteria Leptolyngbia sp. was added to the GE/conducting polymer/AuNP electrode surface and stabilized by using a cellulose membrane. During the illumination, water was oxidized by the photosynthesis, and oxygen was released. The released oxygen was electrocatalytically reduced at the cathode surface and a 25 nA/cm ² photocurrent was observed in GE/ Leptolyngbia sp. After the electrode modifications, a significant improvement in the photocurrent up to 630 nA/cm ² was achieved.     

Analysis of VEGF gene polymorphisms and serum VEGF protein levels contribution in polycystic ovary syndrome of patients

Vascular endothelial growth factor (VEGF) is a well-known factor in reproductive function and contributes to the pathogenesis of polycystic ovary syndrome (PCOS). Genetic variations in VEGFA gene were suggested to contribute alterations in VEGF secretion and PCOS. This study evaluated the association of VEGFA SNPs with altered VEGF secretion level and PCOS among ethnically-matched control women. This prospective case–control study was conducted from 2016 to 2018 and comprised of 55 women with PCOS and 52 control subjects. ELISA was used to measure VEGF levels; and various other related bio chemicals whereas the genotyping of VEGFA variants was performed through the analysis of nine SNPs of VEGF. PRL, E2, PRGE testosterone and glucose level were found to be insignificantly different. The levels of FSH, LH, LH/FSH, TT, insulin, SHBG and HOMA-IR were significantly higher in the study group. Among the nine tested variants of VEGF SNPs, two SNPs rs3025020 and rs833061, consisted of TT (Recessive and Dominant homozygous, respectively) which were marginally higher in test. The SNP rs1570360 had significantly higher GG allele (32.73%) which was recessive homozygous. There was no significant difference observed in genotype frequencies related to higher value of VEGF. The genotype frequencies for the studied SNPs were in alignment with Hardy–Weinberg equilibrium (HWE). The mean serum VEGF levels got significantly increased in PCOS group. No significant association was found between VEGF genotypes and its serum levels. VEGF levels in rs699947 (AA-major homozygous), rs3025039 (CC-major homozygous) and rs833061 (TT & CC-major & minor homozygous) genotypes were significantly higher in PCOS. The study results evidently proved that the allelic variants in genes may be a factor for PCOS and VEGF serum levels with respect to few SNP variants only. These findings indicated that VEGF may be involved in PCOS status and confirmed the previous association between genetic variants in VEGF, serum level of VEGF protein and PCOS.

     

Free amino acids mimic the anabolic but not the proliferative effect of albumin in OK proximal tubular cells

When plasma proteins leak from circulation into the renal tubular lumen in the proteinuric renal diseases, nephrotoxicity of filtered albumin (and/or molecules bound to it) may be important in the subsequent development of tubulo-interstitial damage which contributes to the progression of the disease. When cultured opossum kidney (OK) proximal tubular cells were exposed to bovine serum albumin for 3 days in vitro, increased cell division ([3H]-thymidine incorporation) and cellular hypertrophy (increased protein/DNA ratio) were observed. Both effects were halved if defatted albumin was used. A trivial explanation for the growth responses is that free fatty acids carried on the albumin, and amino acids generated by intracellular degradation of the albumin, are exerting a non-specific growth effect as metabolic fuels which are oxidized to generate ATP. However, the water-soluble free fatty acid octanoate (1 mmol l(-1)) had no significant effect on protein/DNA ratio and a very variable stimulatory effect on [3H]-thymidine incorporation, whereas an essential amino acid mixture or 1 mmol/l(-1) l-Ala or l-Phe only increased the protein/DNA ratio. Furthermore no carnitine was added to the culture medium. This absence would have impaired mitochondrial transport (and hence oxidation) of long-chain free fatty acids derived from the albumin. l-Phe is also a poor substrate for mitochondrial oxidation in kidney. It is therefore concluded that the growth effects of albumin in OK proximal tubular cells are specific effects of the albumin protein and of the free fatty acids and amino acids derived from it, and not a non-specific effect on metabolic fuel supply.