Identification of heat stress-related genomic regions by genome-wide association study in Solanum tuberosum.

The climate crisis impairs yield and quality of crucial crops like potatoes. We investigated the effects of heat stress on five morpho-physiological parameters in a diverse panel of 178 potato cultivars under glasshouse conditions. Overall, heat stress increased shoot elongation and green fresh weight, but reduced tuber yield, starch content and harvest index.

Multi-omics data integration reveals link between epigenetic modifications and gene expression in sugar beet (Beta vulgaris subsp. vulgaris) in response to cold.

Background: DNA methylation is thought to influence the expression of genes, especially in response to changing environmental conditions and developmental changes. Sugar beet (Beta vulgaris ssp. vulgaris), and other biennial or perennial plants are inevitably exposed to fluctuating temperatures throughout their lifecycle and might even require such stimulus to acquire floral competence.

Auxin signaling and vascular cambium formation enable storage metabolism in cassava tuberous roots.

Cassava storage roots are among the most important root crops worldwide, and represent one of the most consumed staple foods in sub-Saharan Africa. The vegetatively propagated tropical shrub can form many starchy tuberous roots from its stem. These storage roots are formed through the activation of secondary root growth processes.

Intratumor Heterogeneity Correlates With Reduced Immune Activity and Worse Survival in Melanoma Patients.

Background: Human malignant melanoma is a highly aggressive, heterogeneous and drug-resistant cancer. Due to a high number of clones, harboring various mutations that affect key pathways, there is an exceptional level of phenotypic variation and intratumor heterogeneity (ITH) in melanoma. This poses a significant challenge to personalized cancer medicine.

Vernalization Alters Sink and Source Identities and Reverses Phloem Translocation from Taproots to Shoots in Sugar Beet.

During their first year of growth, overwintering biennial plants transport Suc through the phloem from photosynthetic source tissues to storage tissues. In their second year, they mobilize carbon from these storage tissues to fuel new growth and reproduction. However, both the mechanisms driving this shift and the link to reproductive growth remain unclear.

Post-transcriptional Regulation of FLOWERING LOCUS T Modulates Heat-Dependent Source-Sink Development in Potato.

Understanding tuberization in the major crop plant potato (Solanum tuberosum L.) is of importance to secure yield even under changing environmental conditions. Tuber formation is controlled by a homolog of the floral inductor FLOWERING LOCUS T, referred to as SP6A.

Gene expression changes elicited by a parasitic B chromosome in the grasshopper Eyprepocnemis plorans are consistent with its phenotypic effects.

Parasitism evokes adaptive physiological changes in the host, many of which take place through gene expression changes. This response can be more or less local, depending on the organ or tissue affected by the parasite, or else systemic when the parasite affects the entire host body. The most extreme of the latter cases is intragenomic parasitism, where the parasite is present in all host nuclei as any other genomic element.

Protein-coding genes in B chromosomes of the grasshopper Eyprepocnemis plorans.

For many years, parasitic B chromosomes have been considered genetically inert elements. Here we show the presence of ten protein-coding genes in the B chromosome of the grasshopper Eyprepocnemis plorans. Four of these genes (CIP2A, GTPB6, KIF20A, and MTG1) were complete in the B chromosome whereas the six remaining (CKAP2, CAP-G, HYI, MYCB2, SLIT and TOP2A) were truncated.

Hybrid apomicts trapped in the ecological niches of their sexual ancestors.

Asexual reproduction is expected to reduce the adaptive potential to novel or changing environmental conditions, restricting or altering the ecological niche of asexual lineages. Asexual lineages of plants and animals are typically polyploid, an attribute that may influence their genetic variation, plasticity, adaptive potential, and niche breadth. The genus Boechera (Brassicaceae) represents an ideal model to test the relative ecological and biogeographic impacts of reproductive mode and ploidy because it is composed of diploid sexual and both diploid and polyploid asexual (i.

Biogeographic variation in genetic variability, apomixis expression and ploidy of St. John's wort (Hypericum perforatum) across its native and introduced range.

Background And Aims: St. John's wort (Hypericum perforatum) is becoming an important model plant system for investigations into ecology, reproductive biology and pharmacology. This study investigates biogeographic variation for population genetic structure and reproduction in its ancestral (European) and introduced (North America) ranges.

Copy number variation in transcriptionally active regions of sexual and apomictic Boechera demonstrates independently derived apomictic lineages.

In asexual (apomictic) plants, the absence of meiosis and sex is expected to lead to mutation accumulation. To compare mutation accumulation in the transcribed genomic regions of sexual and apomictic plants, we performed a double-validated analysis of copy number variation (CNV) on 10 biological replicates each of diploid sexual and diploid apomictic Boechera, using a high-density (>700 K) custom microarray. The Boechera genome demonstrated higher levels of depleted CNV, compared with enriched CNV, irrespective of reproductive mode.

A conserved apomixis-specific polymorphism is correlated with exclusive exonuclease expression in premeiotic ovules of apomictic boechera species.

Apomixis (asexual seed production) is characterized by meiotically unreduced egg cell production (apomeiosis) followed by its parthenogenetic development into offspring that are genetic clones of the mother plant. Fertilization (i.e.

The conserved chimeric transcript UPGRADE2 is associated with unreduced pollen formation and is exclusively found in apomictic Boechera species.

In apomictic Boechera spp., meiotic diplospory leads to the circumvention of meiosis and the suppression of recombination to produce unreduced male and female gametes (i.e.

Novel microRNAs and microsatellite-like small RNAs in sexual and apomictic Boechera species.

Apomixis refers to plant asexual reproduction through seeds that give rise to progeny which are genotypically identical to the maternal parent. It has evolved from many different sexual taxa although the underlying genetic factors remain unknown. Previous analyses of the over-representation of transcription factors, in a comparison of microdissected ovules from apomictic and sexual Boechera, showed that many transcription factor mRNAs possessed microRNA (miRNAs) binding sites, thus pointing to miRNAs as potentially important factors that may be involved in the regulatory switch from sexual to apomictic reproduction.

Analysis of conserved microRNAs in floral tissues of sexual and apomictic Boechera species.

Background: Apomixis or asexual seed formation represents a potentially important agronomic trait whose introduction into crop plants could be an effective way to fix and perpetuate a desirable genotype through successive seed generations. However, the gene regulatory pathways underlying apomixis remain unknown. In particular, the potential function of microRNAs, which are known to play crucial roles in many aspects of plant growth and development, remains to be determined with regards to the switch from sexual to apomictic reproduction.

Selection of reference genes for quantitative real-time PCR expression studies of microdissected reproductive tissues in apomictic and sexual Boechera.

Background: Apomixis, a natural form of asexual seed production in plants, is considered to have great biotechnological potential for agriculture. It has been hypothesised that de-regulation of the sexual developmental pathway could trigger apomictic reproduction. The genus Boechera represents an interesting model system for understanding apomixis, having both sexual and apomictic genotypes at the diploid level.

Isolation and characterization of microsatellite loci from apomictic Hypericum perforatum (Hypericaceae).

Premise Of The Study: Microsatellite markers were developed to study the origins and evolution of apomictic Hypericum perforatum, a polyploid invasive perennial herb indigenous to Europe that produces compounds of medicinal/pharmaceutical importance.

Methods And Results: Eleven primer sets were developed using a non-radioactive protocol. All loci were polymorphic, showing from 2 to 9 alleles per locus.

iso-Kaurenoic acid from Wedelia paludosa D.C.

A recent reinvestigation of aerial parts of Wedelia paludosa D.C. is described and reports, for the first time, the isolation of iso-kaurenoic acid from this species.

Apomictic and sexual ovules of Boechera display heterochronic global gene expression patterns.

We have compared the transcriptomic profiles of microdissected live ovules at four developmental stages between a diploid sexual and diploid apomictic Boechera. We sequenced >2 million SuperSAGE tags and identified (1) heterochronic tags (n = 595) that demonstrated significantly different patterns of expression between sexual and apomictic ovules across all developmental stages, (2) stage-specific tags (n = 577) that were found in a single developmental stage and differentially expressed between the sexual and apomictic ovules, and (3) sex-specific (n = 237) and apomixis-specific (n = 1106) tags that were found in all four developmental stages but in only one reproductive mode. Most heterochronic and stage-specific tags were significantly downregulated during early apomictic ovule development, and 110 were associated with reproduction.

Synthesis and biological evaluation of new podophyllic aldehyde derivatives with cytotoxic and apoptosis-inducing activities.

Several series of nonlactonic podophyllic aldehyde analogues were prepared and evaluated against several human tumor cell lines. They had different combinations of aldehyde, imine, amine, ester, and amide functions at C-9 and C-9' of the cyclolignan skeleton. All the compounds synthesized showed cytotoxicity levels in the microM range and below.

Synthesis and cytotoxic evaluation of 6-(3-pyrazolylpropyl) derivatives of 1,4-naphthohydroquinone-1,4-diacetate.

Several new 6-(3-pyrazolylpropyl) derivatives of 1,4-naphthohydroquinone-1,4-diacetate (NHQ-DA) have been prepared by chemical modifications of the Diels-Alder adduct of alpha-myrcene and 1,4-benzoquinone. All these new compounds and precursors have been evaluated in vitro for their cytotoxicity against cultured human cancer cells of MB-231 breast-adeno carcinoma, A-549 lung carcinoma, and HT-29 colon carcinoma. GI(50) values ranged in and below the micromolar concentration level.

Molecular signatures of apomictic and sexual ovules in the Boechera holboellii complex.

Apomixis, a natural form of asexual seed production in plants, has evolved independently in various taxa, and represents an important potential technology for agriculture. The switch to apomixis is based on de-regulation of developmental pathways originally leading to sexual seed formation. Hybridization and polyploidy, both typical characteristics of asexual plants and animals, are mechanisms that could trigger de-regulation.

Metabolism of prebiotic products containing beta(2-1) fructan mixtures by two Lactobacillus strains.

The capacity of two probiotic strains, isolated from human breast milk, to use several beta(2-1) fructan mixtures as carbon and energy source in in vitro cultures has been tested. Results showed that both strains, Lactobacillus gasseri CECT5714 and Lactobacillus fermentum CECT5716, reached higher growth levels on culture media containing fructooligosaccharide mixtures produced by enzymatic synthesis, compared to those obtained by inulin hydrolysis. Furthermore, the shortest beta(2-1) fructan, kestose, was the only prebiotic compound in the mixtures significantly metabolized in all growth media tested.

Cytotoxic-antineoplastic derivatives of prenyl-1,2-naphthohydroquinone.

Several new prenyl-1,2-naphthohydroquinone derivatives have been prepared by chemical modifications of Diels-Alder products which were obtained from cycloaddition of alpha-myrcene to 1,2-benzoquinone and then evaluated in vitro for their cytotoxic activity against A-549 lung carcinoma, HT-29 colon carcinoma, and MB-231 breast adeno-carcinoma culture cells. Most of them exhibited GI50 values in the microM-concentration level.

Pathological effects of pulmonary vein beta-radiation in a swine model.

Introduction: Atrial fibrillation (AF) may be triggered by ectopic beats originating in sleeves of atrial myocardium entering the pulmonary veins (PVs). PV isolation by means of circumferential ostial or atrial radiofrequency ablation is an effective but also a difficult and long procedure, requiring extensive applications that can have serious potential complications. Our objective was to examine pathological effects of PV beta-radiation, particularly the ability to destroy PV myocardial sleeves without inducing PV stenosis and other unwanted effects, in order to establish its potential feasibility for the treatment of AF.