Ploidy Level Research Articles

Adaptive laboratory evolution for acetic acid-tolerance matches sourdough challenges with yeast phenotypes

Acetic acid tolerance of Saccharomyces cerevisiae is an important trait in sourdough fermentation processes, where the accumulation of acid by the growth of lactic acid bacteria reduces the yeast metabolic activity. In this work, we have carried out adaptive laboratory evolution (ALE) experiments in two sourdough isolates of S. cerevisiae exposed to acetic acid, or alternatively to acetic acid and myriocin, an inhibitor of sphingolipid biosynthesis that sped-up the evolutionary adaptation. Evolution approaches resulted in acetic tolerance, and surprisingly, increased lactic susceptibility. Four evolved clones, one from each parental strain and evolutionary scheme, were selected on the basis of their potential for CO2 production in sourdough conditions. Among them, two showed phenotypic instability characterized by strong lactic sensitivity after several rounds of growth under unstressed conditions, while two others, displayed increased constitutive acetic tolerance with no loss of growth in lactic medium. Genome sequencing and ploidy level analysis of all strains revealed aneuploidies, which could account for phenotypic heterogeneity. In addition, copy number variations (CNVs), affecting specially to genes involved in ion transport or flocculation, and single nucleotide polymorphisms (SNPs) were identified. Mutations in several genes, ARG82, KEX1, CTK1, SPT20, IRA2, ASG1 or GIS4, were confirmed as involved in acetic and/or lactic tolerance, and new determinants of these phenotypes, MSN5 and PSP2, identified.

Phenotyping and identification of target traits for de novo domestication of wheat wild relatives

AbstractDe novo domestication—the modification of domestication genes in crop wild relatives via genome editing—is an approach for harnessing the beneficial genetic diversity of crop wild relatives. A prerequisite for de novo domestication is phenotyping to identify genetic materials suitable for cultivation in the respective environment. Taxa from the wheat genepool (Triticum aestivum, Triticum durum, Triticum monococcum) are a staple food; these taxa comprise wild relatives of different ploidy levels. The diploid Triticum boeoticum and Triticum urartu and the tetraploid Triticum dicoccoides and Triticum araraticum harbor desirable traits such as high grain quality and abiotic and biotic stress tolerance. Hence, they are candidates for de novo domestication. Here, we grew 111 wild wheats and 38 landraces originating predominantly from the Fertile Crescent and six modern wheat cultivars in a field in Giessen, Germany, to evaluate their environmental adaptability to the central European climate and to identify potential candidates and target traits for de novo domestication. We demonstrate that several wild taxa are suitable for cultivation in the central European environment and that they have distinct characteristics that need to be modified during de novo domestication. The normalized difference vegetation index and the thermal time to heading and flowering indicated excellent adaptability of some wheat wild relatives to central European conditions. The values of yield parameters such as grain weight per plant, number of tillers, and thousand kernel weight were lower in the wild wheats than in the landraces. Therefore, these traits should be targeted for improvement during the de novo domestication of wild wheats.

Investigating the effects of whole genome duplication on phenotypic plasticity: implications for the invasion success of giant goldenrod Solidago gigantea

Polyploidy commonly occurs in invasive species, and phenotypic plasticity (PP, the ability to alter one's phenotype in different environments) is predicted to be enhanced in polyploids and to contribute to their invasive success. However, empirical support that increased PP is frequent in polyploids and/or confers invasive success is limited. Here, we investigated if polyploids are more pre‐adapted to become invasive than diploids via the scaling of trait values and PP with ploidy level, and if post‐introduction selection has led to a divergence in trait values and PP responses between native‐ and non‐native cytotypes. We grew diploid, tetraploid (from both native North American and non‐native European ranges), and hexaploid Solidago gigantea in pots outside with low, medium, and high soil nitrogen and phosphorus (NP) amendments, and measured traits related to growth, asexual reproduction, physiology, and insects/pathogen resistance. Overall, we found little evidence to suggest that polyploidy and post‐introduction selection shaped mean trait and PP responses. When we compared diploids to tetraploids (as their introduction into Europe was more likely than hexaploids) we found that tetraploids had greater pathogen resistance, photosynthetic capacities, and water‐use efficiencies and generally performed better under NP enrichments. Furthermore, tetraploids invested more into roots than shoots in low NP and more into shoots than roots in high NP, and this resource strategy is beneficial under variable NP conditions. Lastly, native tetraploids exhibited greater plasticity in biomass accumulation, clonal‐ramet production, and water‐use efficiency. Cumulatively, tetraploid S. gigantea possesses traits that might have predisposed and enabled them to become successful invaders. Our findings highlight that trait expression and invasive species dynamics are nuanced, while also providing insight into the invasion success and cyto‐geographic patterning of S. gigantea that can be broadly applied to other invasive species with polyploid complexes.

Automated estimation of stomatal number and aperture in haskap (Lonicera caerulea L.).

This study developed the reliable Mask R-CNN model to detect stomata in Lonicera caerulea. The obtained data could be utilized for evaluating some characters such as stomatal number and aperture area. The native distribution of haskap (Lonicera caerulea L.), a small-shrub species, extends through Northern Eurasia, Japan, and North America. Stomatal observation is important for plant research to evaluate the physiological status and to investigate the effect of ploidy levels on phenotypes. However, manual annotation of stomata using microscope software or ImageJ is time consuming. Therefore, an efficient method to phenotype stomata is needed. In this study, we used the Mask Regional Convolutional Neural Network (Mask R-CNN), a deep learning model, to analyze the stomata of haskap efficiently and accurately. We analyzed haskap plants (dwarf and giant phenotypes) with the same ploidy but different phenotypes, including leaf area, stomatal aperture area, stomatal density, and total number of stomata. The R-square value of the estimated stomatal aperture area was 0.92 and 0.93 for the dwarf and giant plants, respectively. The R-square value of the estimated stomatal number was 0.99 and 0.98 for the two phenotypes. The results showed that the measurements obtained using the models were as accurate as the manual measurements. Statistical analysis revealed that the stomatal density of the dwarf plants was higher than that of the giant plants, but the maximum stomatal aperture area, average stomatal aperture area, total number of stomata, and average leaf area were lower than those of the giant plants. A high-precision, rapid, and large-scale detection method was developed by training the Mask R-CNN model. This model can help save time and increase the volume of data.

Development of genomic resources for Rhodes grass (Chloris gayana), draft genome and annotated variant discovery.

Genomic resources for grasses, especially warm-season grasses are limited despite their commercial and environmental importance. Here, we report the first annotated draft whole genome sequence for diploid Rhodes grass (Chloris gayana), a tropical C4 species. Generated using long read nanopore sequencing and assembled using the Flye software package, the assembled genome is 603 Mbp in size and comprises 5,233 fragments that were annotated using the GenSas pipeline. The annotated genome has 46,087 predicted genes corresponding to 92.0% of the expected genomic content present via BUSCO analysis. Gene ontology terms and repetitive elements are identified and discussed. An additional 94 individual plant genotypes originating from three diploid and two tetraploid Rhodes grass cultivars were short-read whole genome resequenced (WGR) to generate a single nucleotide polymorphism (SNP) resource for the species that can be used to elucidate inter- and intra-cultivar relationships across both ploidy levels. A total of 75,777 high quality SNPs were used to generate a phylogenetic tree, highlighting the diversity present within the cultivars which agreed with the known breeding history. Differentiation was observed between diploid and tetraploid cultivars. The WGR data were also used to provide insights into the nature and evolution of the tetraploid status of the species, with results largely agreeing with the published literature that the tetraploids are autotetraploid.

Genome-material costs and functional trade-offs in the autopolyploid Solidago gigantea (giant goldenrod) series.

Increased genome-material costs of N and P atoms inherent to organisms with larger genomes have been proposed to limit growth under nutrient scarcities and to promote growth under nutrient enrichments. Such responsiveness may reflect a nutrient-dependent diploid versus polyploid advantage that could have vast ecological and evolutionary implications, but direct evidence that material costs increase with ploidy level and/or influence cytotype-dependent growth, metabolic, and/or resource-use trade-offs is limited. We grew diploid, autotetraploid, and autohexaploid Solidago gigantea plants with one of four ambient or enriched N:P ratios and measured traits related to material costs, primary and secondary metabolism, and resource-use. Relative to diploids, polyploids invested more N and P into cells, and tetraploids grew more with N enrichments, suggesting that material costs increase with ploidy level. Polyploids also generally exhibited strategies that could minimize material-cost constraints over both long (reduced monoploid genome size) and short (more extreme transcriptome downsizing, reduced photosynthesis rates and terpene concentrations, enhanced N-use efficiencies) evolutionary time periods. Furthermore, polyploids had lower transpiration rates but higher water-use efficiencies than diploids, both of which were more pronounced under nutrient-limiting conditions. N and P material costs increase with ploidy level, but material-cost constraints might be lessened by resource allocation/investment mechanisms that can also alter ecological dynamics and selection. Our results enhance mechanistic understanding of how global increases in nutrients might provide a release from material-cost constraints in polyploids that could impact ploidy (or genome-size)-specific performances, cytogeographic patterning, and multispecies community structuring.

Estimativa da ploidia e pré-seleção de autotetraploides de bananeira após indução da poliploidia in vitro

ABSTRACT This study aimed to evaluate the efficiency of the parameters fresh leaf mass and stomatal density in the estimation of ploidy and pre-selection of putative banana autotetraploids. Young plants of the diploid cultivar Ouro (AA), previously subjected to in vitro polyploidization with the antimitotic amiprofos-methyl - APM (0, 10, 20, 30, 40, and 60 µM L-1) and colchicine (2.5 mM L-1) were evaluated for survival, height, number of leaves, pseudostem diameter, leaf disc fresh mass, and stomatal density. Ploidy was determined by flow cytometry in a random sample of 200 plants to find the relationship between the genomic content and the analyzed variables. Spearman’s correlation analysis showed a strong correlation (0.84**) between leaf disc fresh mass and tetraploid plants, as well as an absence of significant correlation between stomatal density and ploidy levels. Thus, the pre-selection of plants was carried out using a reference value of leaf disc fresh mass and resulted in 688 plants pre-selected as putative tetraploids. Among them, 318 were confirmed as tetraploids, 291 as diploids, and 79 as mixoploids after flow cytometry analysis. The pre-selection efficiency was 46.2% of tetraploid plants from the total pre-selected. The results indicate that the use of leaf disc fresh mass is a simple, practical, and promising method to estimate ploidy when a high number of plants is obtained in in vitro banana polyploidization studies, reducing the total number of plants to have confirmed ploidy.

Autotetraploid Origin of Chinese Cherry Revealed by Chromosomal Karyotype and In Situ Hybridization of Seedling Progenies.

Polyploidy is considered a driving force in plant evolution and diversification. Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don], an economically important fruit crop native to China, has evolved at the tetraploid level, with a few pentaploid and hexaploid populations. However, its auto- or allo-polyploid origin remains unclear. To address this issue, we analyzed the ploidy levels and rDNA chromosomal distribution in self- and open-pollinated seedling progenies of tetraploid and hexaploid Chinese cherry. Genomic in situ hybridization (GISH) analysis was conducted to reveal the genomic relationships between Chinese cherry and diploid relatives from the genus Cerasus. Both self- and open-pollinated progenies of tetraploid Chinese cherry exhibited tetraploids, pentaploids, and hexaploids, with tetraploids being the most predominant. In the seedling progenies of hexaploid Chinese cherry, the majority of hexaploids and a few pentaploids were observed. A small number of aneuploids were also observed in the seedling progenies. Chromosome 1, characterized by distinct length characteristics, could be considered the representative chromosome of Chinese cherry. The basic Chinese cherry genome carried two 5S rDNA signals with similar intensity, and polyploids had the expected multiples of this copy number. The 5S rDNA sites were located at the per-centromeric regions of the short arm on chromosomes 4 and 5. Three 45S rDNA sites were detected on chr. 3, 4 and 7 in the haploid complement of Chinese cherry. Tetraploids exhibited 12 signals, while pentaploids and hexaploids showed fewer numbers than expected multiples. Based on the GISH signals, Chinese cherry demonstrated relatively close relationships with C. campanulata and C. conradinae, while being distantly related to another fruiting cherry, C. avium. In combination with the above results, our findings suggested that Chinese cherry likely originated from autotetraploidy.

Clonal In Vitro Propagation as a Tool for Production of High Quality Planting Material of Helichrysum italicum (Asteraceae)

Helichrysum italicum (immortelle), Asteraceae, is a perennial plant species with increasing market demand for its essential oil possessing anti-inflammatory, antibacterial, and antioxidant properties. The present study deals with clonal in vitro propagation of high-productive immortelle individuals. In vitro culture was initiated from stem tips on basal MS medium and sub-cultured several times on the same medium or on media supplemented with activated charcoal or with different plant growth regulators. Plants differed by their height, ramification, in vitro rooting, and callus formation. The highest propagation rate of 13.5±4.2 new shoots per explant, along with spontaneous rooting, was noticed in spring on the control MS medium. About 180 plants were successfully ex vitro adapted first in a phytotron, then in a greenhouse, and 14 were transferred outdoor in the ex situ collection where they acclimatized and bloomed in the first season. The nuclear DNA amount in 65 individuals was measured by flow cytometry, and no deviations in the ploidy level were detected. The results suggest the genome of the in vitro obtained plants is stable. Essential oil was extracted by water distillation from two pooled samples, one for the mother plants and another one for the ex vitro adapted plants. The main components identified by GC/MS in both samples were α-pinene, nerol acetate, and γ-curcumene. The results proved that the method of the in vitro clonal propagation is reliable for obtaining of numerous true-to-type plants in a short time, by direct organogenesis of high-productive individuals of H. italicum.

Embryo Rescue in Plant Breeding.

Embryo rescue (ER) techniques are among the oldest and most successful in vitro tissue culture protocols used with plant species. ER refers to a series of methods that promote the development of an immature or lethal embryo into a viable plant. Intraspecific, interspecific, or intergeneric crosses allow the introgression of important alleles of agricultural interest from wild species, such as resistance or tolerance to abiotic and biotic stresses or morphological traits in crops. However, pre-zygotic and post-zygotic reproductive barriers often present challenges in achieving successful hybridization. Pre-zygotic barriers manifest as incompatibility reactions that hinder pollen germination, pollen tube growth, or penetration into the ovule occurring in various tissues, such as the stigma, style, or ovary. To overcome these barriers, several strategies are employed, including cut-style or graft-on-style techniques, the utilization of mixed pollen from distinct species, placenta pollination, and in vitro ovule pollination. On the other hand, post-zygotic barriers act at different tissues and stages ranging from early embryo development to the subsequent growth and reproduction of the offspring. Many crosses among different genera result in embryo abortion due to the failure of endosperm development. In such cases, ER techniques are needed to rescue these hybrids. ER holds great promise for not only facilitating successful crosses but also for obtaining haploids, doubled haploids, and manipulating the ploidy levels for chromosome engineering by monosomic and disomic addition as well substitution lines. Furthermore, ER can be used to shorten the reproductive cycle and for the propagation of rare plants. Additionally, it has been repeatedly used to study the stages of embryonic development, especially in embryo-lethal mutants. The most widely used ER procedure is the culture of immature embryos taken and placed directly on culture media. In certain cases, the in vitro culture of ovule, ovaries or placentas enables the successful development of young embryos from the zygote stage to maturity.

The effects of high concentration of bicarbonate applications on kiwifruit genotypes with different ploidy levels on some growth parameters of leaves

The effects of high concentration of bicarbonate applications on kiwifruit genotypes with different ploidy levels on some growth parameters of leaves

Genomic content of wheat has a higher influence than plant domestication status on the ability to interact with Pseudomonas plant growth-promoting rhizobacteria.

Plant evolutionary history has had profound effects on belowground traits, which is likely to have impacted the ability to interact with microorganisms, but consequences on root colonization and gene expression by plant growth-promoting rhizobacteria (PGPR) remain poorly understood. Here, we tested the hypothesis that wheat genomic content and domestication are key factors determining the capacity for PGPR interaction. Thus, 331 wheat representatives from eight Triticum or Aegilops species were inoculated under standardized conditions with the generalist PGPR Pseudomonas ogarae F113, using an autofluorescent reporter system for monitoring F113 colonization and expression of phl genes coding for the auxinic inducing signal 2,4-diacetylphloroglucinol. The interaction with P. ogarae F113 was influenced by ploidy level, presence of genomes AA, BB, DD, and domestication. While root colonization was higher for hexaploid and tetraploid species, and phl expression level higher for hexaploid wheat, the diploid Ae. tauschii displayed higher phl induction rate (i.e., expression:colonisation ratio) on roots. However, a better potential of interaction with F113 (i.e., under non-stress gnotobiotic conditions) did not translate, after seed inoculation, into better performance of wheat landraces in non-sterile soil under drought. Overall, results showed that domestication and especially plant genomic content modulate the PGPR interaction potential of wheats.

Antimicrobial and Hepatoprotective Activity of Different Cytotypes of Taraxacum officinale from the Indian Himalayas

ABSTRACT Three cytotypes (2×), (3×), and (4×) of Taraxacum officinale (Dandelion) from the Lahaul-Spiti region of Himachal Pradesh, India, were examined for their phytochemical composition and antimicrobial and hepatoprotective properties. The diploid cytotype had the highest concentration of cichoric acid (1.20% w/w), followed by the triploid and tetraploid cytotypes (0.21 and 0.14% w/w, respectively). The cichoric acid content decreased with increasing ploidy level. The ethanol extract of leaves from diploid cytotype exhibited the highest antibacterial activities against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa. As shown by the reduction in the activity of marker enzymes (AST, ALT, and ALP) and the restoration of total protein, bilirubin levels, and liver weight, the hepatoprotective activity was the greatest in the diploid cytotype. Although polyploidy is a key factor in plant evolution, it does not always have the same impact on secondary metabolites.

Correlations among chromosome numbers, nuclear DNA contents and climatic variables of South American Cactaceae in a phylogenetic context

Abstract Cactaceae are American members of arid and semi-arid regions and are also present in tropical forests and temperate climates. The taxonomy is complex owing to large morphological variability, and polyploidy is a significant mechanism in cactus speciation associated with geographical and environmental range expansions. In South America, Cactaceae have a wide distributional range and provide an informative model in which to examine the correlation between ploidy levels and genome sizes with geographical and bioclimatic variables. We tested whether ploidy levels and DNA contents are related to elevation and the 19 WorldClim variables, and we mapped chromosome numbers and amounts of DNA on a molecular phylogeny to interpret their evolution. We performed Pearson correlation tests between the response variables and each climatic variable and used a multivariate analysis to assess the pattern of variation among variables and chromosome numbers. Our data suggest that polyploidy had independent origins within each subfamily. Chromosome numbers were related to variables associated with temperature, whereas DNA contents were related mostly to precipitation. A negative correlation was observed between the amount of DNA in one chromosome set and the increase in the ploidy level. Based on the results, the small genome can be considered ecologically important as an adaptation to higher temperatures and droughts.

Integrative taxonomy supports the recognition of four taxa in the Notholaena trichomanoides complex (Pteridaceae) in Cuba

Abstract With nearly 40 species, the fern genus Notholaena has its evolutionary centre in the deserts of Mexico and the southwestern United States. Previous studies have focused on assessing the monophyly of the genus and the patterns of farina evolution, but little attention has been given to species complexes. Notholaena trichomanoides s.l. is endemic to the Greater Antilles, growing on all four islands. Although at least two varieties have been described, many authors have hesitated to recognize them and have treated this complex as only one taxon. A multivariate morphometric analysis including 80 representatives of N. trichomanoides from the Greater Antilles allowed us to recognize four morphological groups. Twenty individuals from seven populations representing all these morphological groups were sampled in Cuba. Differences among the four lineages were supported by molecular phylogenetics (including three plastid and two nuclear markers), molecular species delimitation, morphology and geological preferences. Ploidy levels inferred using spore sizes calibrated by chromosome counts revealed the existence of diploid and tetraploid lineages within the complex. Time-calibrated trees suggest that the divergence of the common ancestral populations of N. trichomanoides s.l. and those of its sister taxon N. ekmanii occurred between the Middle Miocene and the Miocene–Pliocene boundary followed by a recent diversification within the complex, ranging between the Middle Pliocene and the Middle Pleistocene.

Abstract B015: Understanding cell heterogeneity in single-cell renal cell carcinoma datasets

Abstract Studying the heterogeneity in RCC may provide insights for improved diagnosis and treatment. Cell heterogeneity may be reflected at the mRNA level, and cell deconvolution tools like CIBERSORT have been used to decipher cell-specific signals in bulk RNA interrogation. Single-cell RNA seq technologies (scRNA-seq) enable dissecting cell heterogeneity in tumor samples further. An exploratory scRNA-seq study was conducted on three subtypes of RCC: 2 samples of clear cell RCC (ccRCC1 and ccRCC2), 1 sample of type-2 papillary RCC (pRCC), and 1 sample of chromophobe RCC (chRCC) (Su et al., 2021). This study provided valuable insights, such as delineating new tumor markers and predicting drug responses. As we advance our understanding of scRNA-seq, additional tools allow annotating of more cell types and exploring ploidy levels. Here we reanalyze this dataset further to illustrate the tumor microenvironment heterogeneity in RCC samples. We downloaded the datasets (GSE152938) from Gene Expression Omnibus and reprocessed the data using Seurat. The cellular composition and ploidy levels were explored using Azimuth and CopyKAT. A total of 30261 high-quality single-cell transcriptomic information of the RCC samples were obtained for the downstream analysis. The RCC subtypes showed both intra and inter-tumoral heterogeneity. Within the clear cell carcinomas, the ccRCC2 sample showed about 63.57% immune cell infiltration compared to 45.68% in ccRCC1. Rare subpopulations of 0.86% fibroblast and 0.81% mast cells were observed only in ccRCC1. In contrast, 1.56% of B cells were observed only in ccRCC2. Using an improved cell deconvolution algorithm, we identified natural killer T cells, neutrophils, and plasma cells in the ccRCC samples that were not reported in the original publication. We also identified five subtypes of endothelial cells (instead of the two reported in the original article) which may further our understanding of angiogenesis and immune regulation in these ccRCC samples. Our analysis showed that the macrophages in the ccRCC and pRCC samples are predominantly M2 macrophages. In the chRCC sample, we also identified 0.2% B cells and 2.19% M2 macrophage subpopulations, which may further illuminate the immune landscape of the chRCC tumor microenvironment. We found the ccRCC sample to be the most immune-rich with about 56.49% immune infiltration, followed by the pRCC (46.88% infiltration) and chRCC (8.86% infiltration) samples. In the combined ccRCC samples, three of the four ccRCC cell clusters were predominantly diploids (85.6%, 97.8%, and 60%, respectively), whereas only one showed a higher proportion of aneuploidy (95.8%). Further studies with a larger sample are required to validate these observations. This reanalysis of previously published data may enrich the results of the original manuscript and provide additional information about the tumor microenvironment of these RCC subtypes. We will integrate these findings with our more extensive collection of scRNA-seq at our institution, for further interrogating and validating these results. Citation Format: Sadia Islam Kana, Lucas A. Salas. Understanding cell heterogeneity in single-cell renal cell carcinoma datasets [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr B015.

Allelopathic Interactions of Solanum stramonifolium Jacq. Might Be Used for Meloidogyne incognita Management

The root-knot nematode (RKN) Meloidogyne incognita infects a large host range causing enormous agricultural losses. Although the control of this pest is mainly based on the use of chemical pesticides, natural alternatives are currently being largely considered, especially the use of plant-derived molecules, as allelochemicals and plant extracts. Solanum stramonifolium is a plant of the Solanaceae family and has been studied for its potential to control RKN, either by the use aqueous extracts of its seeds, or due to its immunity to nematode penetration. Our studies demonstrate that S. stramonifolium has an efficient defense mechanism against RKN completely preventing its penetration into its root system. Additionally, the compounds exuded by this plant in the soil can affect nematode infection in nearby grown Nicotiana benthamiana (-89% biomass for treatment I respectively, and -61% and +57% of galls for the treatments and Solanum lycopersicum (-79% biomass for treatment I, and -83% of galls for the treatments I and II). Herein, external (ED, < 3.5 kDa) and internal (ID, > 3.5 kDa) dialysates were prepared from the extract of S. stramonifolium seeds. Arabidopsis thaliana Col-0 inoculated with RKN treated with the dialysates showed a reduced gall diameter in 45% and 35% for ED and ID respectively. Additionally, a significant reduction in biomass was observed in germinated seeds after treatment with ID. In addition, Arabidopsis roots showed changes in their ploidy levels when treated with ED and ID, compared to the untreated control, indicating its effect on endoreduplicating cells. Finally, a partial identification of glycoalkaloids present in the ED and root extracts may help to explain plant immunity to root-knot nematode infection. Results obtained shed light on the defense mechanisms of S. stramonifolium against M. incognita, its allelopathic potential in co-cultivated plants and its biotechnological potential of dialysates obtained from its seeds, representing a strong alternative to the management of RKN in conventional agriculture.

Conserved chamber-specific polyploidy maintains heart function in Drosophila.

Developmentally programmed polyploidy (whole-genome duplication) of cardiomyocytes is common across evolution. Functions of such polyploidy are essentially unknown. Here, in both Drosophila larvae and human organ donors, we reveal distinct polyploidy levels in cardiac organ chambers. In Drosophila, differential growth and cell cycle signal sensitivity leads the heart chamber to reach a higher ploidy/cell size relative to the aorta chamber. Cardiac ploidy-reduced animals exhibit reduced heart chamber size, stroke volume and cardiac output, and acceleration of circulating hemocytes. These Drosophila phenotypes mimic human cardiomyopathies. Our results identify productive and likely conserved roles for polyploidy in cardiac chambers and suggest that precise ploidy levels sculpt many developing tissues. These findings of productive cardiomyocyte polyploidy impact efforts to block developmental polyploidy to improve heart injury recovery.

Cultivar-dependent phenotypic and chemotypic responses of drug-type Cannabis sativa L. to polyploidization.

Cannabis sativa L. is a plant with a wide range of potential medicinal applications. In recent years, polyploidy has gained attention as a potential strategy for rapidly improving C. sativa, which, unlike other modern crops, has not yet benefitted from this established biotechnological application. Currently, no reports on high THCA and CBDA drug-type polyploid cultivars have been published. Moreover, it still needs to be clarified if different cultivars react similarly to polyploidization. For these reasons, we set out to evaluate and compare the phenotype and chemotype of three high Δ9-tetrahydrocannabinolic acid (THCA) and one high cannabidiolic acid (CBDA) drug-type cultivars in their diploid, triploid and tetraploid state through agronomic and metabolomic approaches. Our observations on plant morphology revealed a significant increase in plant height and leaf size with increasing ploidy levels in a cultivar-dependent manner. In contrast, cannabinoids were negatively affected by polyploidization, with the concentration of total cannabinoids, THCA, CBDA and cannabigerolic acid (CBGA) decreasing significantly in higher ploidy levels across all four cultivars. Headspace analysis of volatiles revealed that total volatile content decreased in triploids. On the other hand, tetraploids reacted differently depending on the cultivars. Two THCA dominant cultivars showed an increase in concentrations, while in the other two cultivars, concentrations decreased. Additionally, several rare compounds not present in diploids appeared in higher ploidy levels. Moreover, in one high THCA cultivar, a couple of elite tetraploid genotypes for cannabinoid and volatile production were identified, highlighting the role of cultivar and genotypic variability as an important factor in Cannabis sativa L. polyploids. Overall, our observations on plant morphology align with the giga phenotype observed in polyploids of other plant species. The decrease in cannabinoids and volatiles production in triploids have relevant implications regarding their commercial use. On the other hand, this study found that tetraploidization is a suitable approach to improve Cannabis sativa L. medicinal potential, although the response is cultivar and genotype-dependent. This work lays the ground for further improving, evaluating and harnessing Cannabis sativa L. chemical diversity by the breeding, biotechnological and pharmaceutical sectors.

Genome size, genetic diversity, and phenotypic variability imply the effect of genetic variation instead of ploidy on trait plasticity in the cross-pollinated tree species of mulberry.

Elucidation of genome size (GS), genetic and phenotypic variation is the fundamental aspect of crop improvement programs. Mulberry is a cross-pollinated, highly heterozygous tree eudicot, and comprised of huge ploidy variation with great adaptability across the world. However, because of inadequate information on GS, ploidy-associated traits, as well as the correlation between genetic and phenotypic variation hinder the further improvement of mulberry. In this present research, a core set of 157 germplasm accessions belonging to eight accepted species of Morus including promising functional varieties were chosen to represent the genetic spectrum from the whole germplasm collection. To estimate the GS, accessions were subjected to flow cytometry (FCM) analysis and the result suggested that four different ploidies (2n = 2x, 3x, 4x, and 6x) with GS ranging from 0.72±0.005pg (S-30) to 2.89±0.015pg (M. serrata), accounting~4.01 fold difference. The predicted polyploidy was further confirmed with metaphase chromosome count. In addition, the genetic variation was estimated by selecting a representative morphologically, diverse population of 82 accessions comprised of all ploidy variations using simple sequence repeats (SSR). The estimated average Polymorphism Information Content (PIC) and expected heterozygosity showed high levels of genetic diversity. Additionally, three populations were identified by the model-based population structure (k = 3) with a moderate level of correlation between the populations and different species of mulberry, which imply the effect of genetic variation instead of ploidy on trait plasticity that could be a consequence of the high level of heterozygosity imposed by natural cross-pollination. Further, the correlation between ploidies, especially diploid and triploid with selected phenotypic traits was identified, however, consistency could not be defined with higher ploidy levels (>3x). Moreover, incite gained here can serve as a platform for future omics approaches to the improvement of mulberry traits.