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.
