The localization and endogenous content of phytohormones (indole-3-acetic acid, IAA; cytokinins; and abscisic acid, ABA) were studied in proliferating embryogenic cell lines (CLs) of Larix sibirica. Cell elongation, polarization, and polar localization of IAA at one pole of elongated cells were observed during the initiation of embryogenic cultures. In proliferating CLs, intense immunofluorescent staining of the embryonal globule for IAA, zeatin, and ABA was observed, whereas embryonal tubes of the suspensor did not contain hormones. In young, actively proliferating cell lines, IAA content ranged from 495 to 2380 ng g-1 DW, total cytokinins from 54 to 166 ng g-1 DW, and ABA was very low (9-24 ng g-1 DW). During long-term proliferation (11-14 years) or even after only 3 years in some cell lines, IAA increased to 3687ngg-1 DW, total cytokinins changed only slightly, whereas ABA increased to 970 ng g-1 DW. ABA above 300 ng g-1 DW, accompanied by high IAA, was associated with reduced or complete loss of somatic embryo maturation and plantlet regeneration capacity.
Heavy metal pollution of sewage water might have an impact not only on the plant system but also on human health. Lens culinaris Medik.'s chromosomes (2n= 14) were investigated for assessing physicochemical parameters and cytotoxic potential by employing a radicle chromosomal aberration assay. Seeds of lentils were germinated in different sites of sewage water, such as T-1, T-2, T-3, and T-4 (distilled water). The effect of different treatments was analyzed by evaluating the germination rate, mitotic index, radicle length, chromosomal aberrations, and CV in root tips meristematic tissue. The results of the physicochemical analysis showed that the pH is acidic in nature, with heavy metals Fe and Mn in T(1 )sewage water exceeding Indian Standard 0500:2012 permissible limits, while other chemicals Pb, Cl, Cu, Cd, Cr, and Zn are within standard tolerance limits. Compared with the control sample, the results established that the heavy metal-contaminated sewage water can be correlated with significant MI reduction (p<0.01) and an increase in different chromosomal aberrations such as karyorrhexis, bi-nucleate, fragmented chromosome, sticky metaphase, c-metaphase, diagonal anaphase, telophase laggard, ring chromosome, diagonal sticky anaphase, and anaphase bridge in root tip meristems of Lens culinaris Medik., thereby harming the health of living organisms.
Despite the chromosomes of Vicia faba being a prominent cytogenetic model, the status of chromosome analysis in Indian germplasm has been underrepresented. The present study provides a state-of-the-art chromosome preparation for Indian V. faba. The heterochromatic landmarks are visibly demonstrated by the distribution of nucleolar CMA bands and proximal DAPI bands in the M chromosome pair. The present study lays a background in Indian faba bean to delve deeper into the molecular cytogenetic architecture of this crop.
The genus Datura, a member of the economically important Solanaceae family, comprises toxic species distributed worldwide and noted for their diverse pharmacological properties. Despite its significance, the cytogenetic characteristics of Datura remain insufficiently explored, limiting insights into its genomic organization and evolutionary dynamics. In this study, four Iranian populations: three Datura innoxia and one D. stramonium, were investigated to provide a detailed cytogenetic assessment. Karyotype analyses were performed on root tip cells, while nuclear DNA content was quantified using flow cytometry with Solanum lycopersicum cv. Stupicke serving as an internal reference standard. All populations consistently displayed a diploid chromosome number of 2n=2x= 24, confirming chromosomal stability within these taxa. However, significant interpopulation variation was identified in chromosome length, ranging from 2.02 to 3.53 & micro;m, as well as in monoploid genome size, with a mean 1Cx DNA content of 1.82 pg. These results highlight a remarkable constancy in chromosome number alongside variability in genomic DNA content, emphasizing the complex cytogenetic diversity within Datura. The study provides essential baseline data for future genetic, phylogenetic, and evolutionary research, aiding in the understanding of genome organization and species differentiation in this genus.
Plants adapt to abiotic stresses through complex signaling networks, in which the phytohormone abscisic acid (ABA) plays a central role. While the core ABA biosynthesis and signaling modules are well characterized, the spatiotemporal mechanisms enabling rapid and specific molecular interactions within crowded cellular environments have remained elusive. This review comprehensively examines the emerging role of liquid-liquid phase separation (LLPS) as a critical physicochemical signal conversion system in plant environmental stress responses. LLPS facilitates the direct regulation of ABA signaling through the formation of biomolecular condensates, such as stress granules and processing bodies, which spatially sequester specific mRNAs and proteins. Key examples include the stabilization of ABA-biosynthetic mRNAs by DRG9 and the dynamic modulation ofABA-responsive transcripts by N6-methyladenosine (m6A) reader proteins SiYTH1 and ECT8. The review also highlights the regulation of stress responses via osmotic stress sensors, such as SEU and DCP5, and extracellular RALF-pectin condensates, which reprogram the transcriptome and integrate with ABA networks. LLPS bridges physical stress detection, such as molecular crowding, with hormonal control and mRNA fate determination, thereby providing plants with rapid, reversible, and spatially compartmentalized adaptive strategies. Finally, we outline future research directions, emphasizing the need to explore phase separation within core ABA components and the potential applications of LLPS in stress-tolerant crop breeding.
This study presents a comprehensive karyotype analysis of 14 Brassica species including six Us Triangle species and eight Brassica wild relatives (BWRs). Chromosome slides were prepared using cytological techniques to determine chromosome numbers and analyze the karyotypes of all species. Evolutionary patterns were assessed, and cluster analysis was performed based on multiple karyotypic parameters, including chromo-some length, arm ratio, centromeric index, relative length, karyotype type, asymmetry index, etc. The results revealed that the chromosome numbers of the eight wild relatives showed diploidy with 2n=2x= 14, 16, 18, 20, 22, and 24, while among the Us Triangle species, three species were diploid with 2n=2x= 16, 18, and 20, and three species were amphidiploid having 2n=4x= 34, 36, and 38. The karyotypes of these species comprised metacentric, submetacentric, and acrocentric chromosomes and were classified into types 2A, 2B, 3A, and 3B. Karyotype analysis indicated evolutionary trends from symmetrical to asymmetrical chromosome structures, sup-porting diversification and adaptation within the Brassicaceae family. Notably, Brassica fruticulosa and Brassica nigra exhibited comparatively higher karyotype asymmetry index values and average arm ratio values of (q/p). In contrast, Brassica oleracea and Brassica rapa showed the lowest karyotype asymmetry index values and aver-age arm ratio of (q/p). Cluster analysis, based on karyotypic parameters, grouped these 14 species into four major groups. Interactome analysis highlighted strong positive and negative correlations among karyotypic parameters across the species. Overall, this study enhances the understanding of phylogenetic evolution, genetic relation-ships, and chromosomal diversification in Brassica species, providing valuable cytogenetic insights into the Brassicaceae family.
Tumor microenvironment (TME) promotes breast cancer progression through complex cellular interactions. Extracellular vesicles derived from cancer-associated fibroblasts (CAF-EXO) are increasingly being studied as important mediators in this process. Still, their specific roles in the epithelial-mesenchymal transition (EMT) of breast cancer cells have not been fully elucidated. The purpose of this study was to evaluate the potential effects of CAF-EXO on the proliferation, apoptosis, migration, invasion, and EMT of breast cancer cells. MDA-MB-231 cells were treated with normal fibroblast-derived exosomes (HKF-EXO) or CAF-derived exosomes (CAF-EXO), and the effects of the exosomes on cell proliferation (CCK-8), apoptosis (Annexin V/7-AAD), migration/invasion (Transwell), and the expressions of EMT markers (RT-PCR, Western blot) were evaluated. The results showed that compared with the control group, CAF-EXO significantly enhanced the proliferation, migration, and invasion abilities of the cells, while reducing cell apoptosis. The expression of E-cadherin was reduced in MDA-MB-231 cells treated with CAF-EXO, while the expression of N-cadherin and LC3B was increased. These results suggested that exosomes derived from CAF may promote the malignant progression of breast cancer by inducing proliferation, invasion, and EMT of breast cancer cells, thereby providing preliminary evidence for understanding their role in TME remodeling.
The chromosomal karyotype characteristics and phylogenetic relationships within 42 germ-plasm accessions from the genus Rosa L. sect. Chinenses were investigated through an integrative cytogenetic approach. Chromosome structural variation and evolutionary patterns were further assessed by combining karyotype clustering, a phylogenetic tree constructed based on SNPs, and fluorescence in situ hybridization (FISH) targeting ribosomal DNA (rDNA) loci. The analysis revealed that the chromosomes of sect. Chinenses are predominantly characterized by median and submedian centromeres, with low karyotype asymmetry indices, reflecting an overall conserved chromosomal architecture. Karyotype-based clustering offered partial resolution of ploidy levels and phylogenetic affinities among accessions, yet discrepancies were observed when compared with the SNP-derived phylogenetic tree, particularly in the delimitation between the `Ser. Chinenses' and the `Ser. Odoratae.' FISH results demonstrated that the number of 45S rDNA loci corresponded well with ploidy levels, while 5S rDNA loci were mainly localized in the centromeric regions. All accessions exhibited a collinear arrangement of 5S and 45S rDNA signals. In triploid accessions, the chromosomal locus composition mirrored that of R. chinensis var. spontanea, suggesting its potential role as a genomic donor. The combined application of karyotype analysis and rDNA-FISH proved effective in elucidating chromosomal evolutionary features within sect. Chinenses, providing valuable cytogenetic evidence for taxonomic classification and phylogenetic studies in Rosa.
The somatic chromosome numbers were counted in seven species of the subtribe Erantheminae from various localities in China. The chromosome numbers were determined as 2n=2x= 28 in Echinacanthus lofouensis, Ec. longipes and Ec. longzhouensis, 2n=8x= 88 in Eranthemum austrosinense, 2n= 4x= 44 in Er. pulchellum, 2n=2x= 28 in Leptosiphonium venustum and 2n=2x= 28 in Pararuellia glomerata. Combined with existing reports, it is inferred that x= 14 may represent the original basic chromosome number for Echinacanthus and Pararuellia, and x=11 for Eranthemum. The results support the close relationship between Echinacanthus and other genera of Erantheminae. This study enriches the cytogenetic data for seven species and provides a basis for the taxonomy of four genera in terms of chromosomal characteristics.
Sex chromosome-based sex determination (SD) systems have evolved from autosomes in many animals and some plants. Suppression of recombination around the SD locus drives the differentiation of X/Y or Z/W pairs, often resulting in the degeneration of the Y (or W) chromosome. Despite this vulnerability, sexual reproduction remains stable through compensatory mechanisms, one of which is `turnover', the replacement of one sex chromosome system by another. While `turnover' is relatively rare in mammals, it occurs more frequently in fish and amphibians. Recent genomic studies have shown that `turnover' also occurs in plants. In poplar and willow, the duplication and relocation of the SD gene to another autosome suggests `turnover' events. In Silene latifolia, the Y chromosome retains a masculinisation gene (GSFY), whereas the X chromosome harbours a feminisation gene (SlWUS]). As the Y chromosome degenerates, GSFY may be lost. In this scenario, turnover may occur if SlWUS] expression increases as a feminising SD gene, shifting from an XY-type SD system to an X/A-type system. Although further analysis is needed in Silene, these findings suggest that plants may have turnover mechanisms, as in animals, to compensate for the loss of sex chromosomes. Insights into plant turnover emphasise that it is not limited to animals and is a general evolutionary process common to plants and animals.
Cytological investigations were carried out on 87 accessions of Sida species collected from the regions of North India. The study showed the occurrence of six species of Sida in the region, namely, Sida acuta, S. cordata, S. cordifolia, S. keralensis, S. mysorensis, and S. rhombifolia. S. acuta, S. cordifolia, and S. keralensis showed the presence of a gametophytic chromosome number of n= 14, while S. cordata and S. mysorensis showed n= 16 chromosomes. All these species were thus observed to be tetraploid based on x= 7. The accessions of S. rhombifolia were observed to be diploid with n= 7. The phylogenetic analysis showed the prevalence of two genetically distinct clades within the genus. The study provides novel data about the genetic status of Sida from the study area, particularly for S. keralensis.
Homoarginine is a toxic non-protein amino acid that occurs naturally in plants and adversely affects plant growth and development. In this study, it was aimed to investigate the effects of different externally applied L-homoarginine doses (10, 50, and 100mM) on various physiological, cytogenetic, biochemical, and anatomical parameters of onion (Allium cepa L.) bulbs. All L-homoarginine doses caused a decrease in the physiological parameters examined (germination percentage, root length, root number, and fresh weight), a rise in chromosomal aberrations and micronucleus frequency, and a decrease in the mitotic index. L-Homoarginine applications promoted chromosomal aberrations such as cellular budding, accumulation of micronuclei, C-metaphase, chromosomal stickiness, chromatid bridges, vagrant chromosomes, unequal separation of chromosomes, and polar slip in the root meristem cells. In addition, this non-protein amino acid caused an enhancement in the free proline, catalase, superoxide dismutase, and malondialdehyde contents in the root cells of onion bulbs. Moreover, this toxic amino acid revealed some serious damage and changes such as the epidermal and cortex cell deformations, wall thickening in the cortex layer cells, accumulation of some chemical compounds in cortex layer cells, flattening of the cell nuclei, and deformation of the cell nuclei in the anatomical structure of onion roots. In summary, it was concluded that L-homoarginine is an amino acid with inhibitory effects and that the A. cepa test is a useful
We report the first chromosome counts for four species of Begonia sect. Platycentrum, three with 2n= 44 and one with 2n= 66, and reinvestigated the chromosome cytology of two species of the section with chromosome numbers of 2n= 44 and 2n= 60, respectively. The karyotypes of these six species are reported for the first time. Based on these karyotypes, species with 2n= 44 and 2n= 66 are shown to be tetraploids and hexaploid with x=11, respectively, whereas B. formosana (2n= 60) is hypothesized to be an amphidiploid, likely originating from hybridization between a diploid with 2n= 22 (i.e., B. longifolia or B. palmata) and a tetraploid with 2n= 38, which are represented by four species endemic to Taiwan.
Mentha L. is a valuable source for cytological investigations due to its pronounced polymorphism and diverse chromosomal races within species. Chromosome numbers have been studied in many species, but detailed karyotype analysis remains unexplored for the studied species. This study analyzed Mentha arvensis and M. viridis using aceto-orcein and DNA-based fluorochrome staining to elucidate their ploidy and karyotypic variation. The somatic chromosome formulae were 2n=6x=72m in M. arvensis and 2n=3x=36m in M. viridis. M. viridis showed comparatively larger chromosomal lengths, higher CVCI and CVCL values than M. arvensis, indicating greater variation in chromosomal length and centromeric dispersion. The GC-specific stain, chromomycin A3, revealed 5 and 2 CMA+ve chromosomes in M. arvensis and M. viridis, respectively. The AT-specific stain, 4,6-diamidino-2-phenylindole, showed 6 DAPI+ve chromosomes in M. viridis only. This unique banding pattern found in the CMA/DAPI staining highlights the distribution of AT-and GC-rich regions.
Human bone marrow mesenchymal stem cell-derived exosomes (BMSCs-Exos) have shown po-tential as an effective therapeutic tool for the management of colorectal cancer (CRC). Aberrant Wnt pathway activation has been established as a primary mechanism that drives CRC progression. This study aimed to evaluate the potential efficacy of BMSCs-Exos in CRC cell proliferation, migration, and invasion via modula-tion of the Wnt pathway in vitro. Exos were isolated from the supernatant of cultured human BMSCs and char-acterized using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. BMSCs-Exos were introduced to human CRC cell lines (HCT116 and SW480) to detect the effects of BMSCs-Exos on CRC cell proliferation, invasion, migration, and apoptosis by CCK-8, Transwell, and flow cy-tometric assays. Furthermore, the potential mechanism of BMSCs-Exos in regulating these functions of HCT116 and SW480 cells was investigated by quantitative reverse transcription-PCR (RT-qPCR) and Western blotting for the expression levels of the Wnt pathway-related genes. BMSCs-Exo treatment decreased HCT116 and SW480 cell proliferation, migration, and invasion, and potentiated apoptosis of CRC cells. Moreover, mRNA and protein expression patterns of the Wnt pathway-related genes Wnt1, Wnt2, Wnt3, and Wnt3a, as well as protein expression of nuclear beta-catenin, were downregulated in HCT116 and SW480 cells after treatment with BMSCs-Exos. Conversely, the activated Wnt pathway partially offset the regulatory effects of BMSCs-Exos on HCT116 and SW480 cell malignant behaviors and nuclear beta-catenin protein expression. These findings suggest that BMSCs-Exos repress the Wnt pathway with subsequent reduction of beta-catenin nuclear translocation, promot-ing cell apoptosis and thereby attenuating proliferation, migration, and invasion of CRC cells in vitro
Cycas rumphii Miq. (queen sago) is a dioecious gymnosperm of considerable evolutionary and ecological significance. This study provides a comprehensive cytogenetic comparison of male and female C. rumphii through integrated mitotic and meiotic analyses. Mitotic investigation revealed a uniform diploid chromosome complement (2n= 22) in both sexes. Detailed karyotype assessment revealed subtle morphological distinctions, with male plants having heteromorphic sex chromosomes and females having homomorphic karyotypes. Both sexes lack satellite-bearing chromosomes; however, males bear distinct heteromorphic sex chromosome pairs, suggesting a reliable sex-linked chromosomal marker. Meiotic evaluation of male sporocytes revealed normal progression from leptotene to tetrad formation. During diakinesis, 11 ring bivalents were observed with their subsequent equatorial alignment at metaphase, followed by regular segregation at anaphase I and balanced tetrad formation, indicating the absence of meiotic irregularities. According to Stebbins' (1971) asymmetry index, the male C. rumphii karyotype was assigned to the 2A class, showing low asymmetry, while the female counterparts fell into the 2B class, revealing moderate asymmetry, thereby reflecting a subtle intra-karyotype heterogeneity. These findings provide deeper insights into the cytogenetics of C. rumphii, elucidating the chromosomal features underlying sex determination and meiotic stability. These insights offer valuable markers for early sex identification and contribute to conservation strategies aimed at safeguarding the diversity of cycads.
