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In this research, eight local mung bean (Vigna radiata) varieties were analyzed for their performance against two levels of CdCl2 solution (0.3 and 0.5 mM) alone and priming with gibberellic acid (GA3) (100 μM), salicylic acid (SA) (50 μM) and proline (5 mM) solution prior to Cd exposure. Mung bean seedlings were analyzed for disturbance in cytological, morphological, biochemical and enzymatic parameters under cadmium stress. For cytological studies, 48 h grown mung bean seedlings root tips were used to prepare slides and studied for percent mitotic index (MI%) and to calculate percent C-mitosis, laggard, sticky and fragmented chromosomes, pictures were captured by a Nikon camera (DS-Fi 1 Japan) attached with a microscope. One-week grown mung seedlings were studied for growth traits, malondialdehyde (MDA), protein, proline and antioxidant enzymes. ANOVA and DMR test of this research revealed that all the tested mung bean varieties and treatments were significantly different regarding mitotic index and number of chromosomal aberrations. Both the Cd treatments exhibited increased total chromosomal aberrations with different types and a maximum decrease in MI%. In pretreated samples, GA3, SA and proline serve as mitigating agents that reduce mutagenic effects of Cd in mung bean by increasing MI% and decreasing chromosomal aberrations as compared to non-pretreated samples. Both the Cd treatments showed a decrease in all growth traits. Total proteins were also found to be significantly reduced in a dose-dependent manner in all genotypes. Cd treatment increased the activities of all antioxidant enzymes tested. Cd caused oxidative damage as indicated by elevated levels of MDA content in treated samples in comparison to control. Proline content levels were also high in Cd treated seedlings indicating stress. Results demonstrated that pretreatment with phytohormones and proline before Cd were found to improve all morphological parameters, by altering antioxidant enzymes activities along with a decrease in MDA and proline contents as well. It was further noticed that the performance of GA3 was better at 0.3 mM Cd treatment while SA was found to be a good mitigating agent at 0.5 mM Cd stress in all tested mung bean varieties. This research concluded less deleterious effects of Cd on AZRI-2006 while more sensitivity to NM-51 towards Cd. Priming with phytohormones and proline is a user-friendly, economical, and simple mitigation strategy to reduce Cd toxicity in plants and get better yield from contaminated lands.

Plant photosynthesis and biomass production are closely associated traits but critical to unfavorable environmental constraints such as salinity and drought. The relationships among stress tolerance, photosynthetic mechanisms, biomass and ethanol yield were assessed in Phragmites karka. The growth parameters, leaf gas exchange and chlorophyll fluorescence of P. karka were studied when irrigated with the control and 100 and 300 mM NaCl in a nutrient solution and water deficit conditions (drought, at 50% water holding capacity). The plant shoot fresh biomass was increased in the low NaCl concentration; however, it significantly declined in high salinity and drought. Interestingly the addition of low salinity increased the shoot biomass and ethanol yield. The number of tillers was increased at 100 mM NaCl in comparison to the control treatment. High salinity increased the photosynthetic performance, but there were no significant changes in drought-treated plants. The saturated irradiance (Is) for photosynthesis increased significantly in low salinity, but it declined (about 50%) in high salt-stressed and (about 20%) in drought-treated plants compared to the control. The rates of dark respiration (Rd) and compensation irradiance (Ic) were decreased significantly under all treatments of salinity and drought, with the exception of unchanged Rd values in the control and drought treatments. A-Ci curve analyses revealed a significant improvement in the Jmax, Vc, max, and triose-phosphate utilization (TPU) at lower salinity levels but decreased at 300 mM NaCl and drought treatments compared to the control. In the chlorophyll fluorescence parameters (Fv/Fm, maximum photochemical quantum yield of PSII, and Y(NO)), the non-photochemical yields were not affected under the salt and drought treatments, although an effective photochemical quantum yield (YII) and electron transport rate (ETR) were significantly enhanced in water deficit compared to control plants. P. karka regulates an efficient photosynthesis mechanism to grow in saline and arid areas and can therefore be used as a sustainable biofuel crop.

ObjectivesThe high salinization stress to seedling is the substantial ecological problem in the ongoing era. It negatively influences the growth that retard mitotic division by enhancing aberrations in nuclear chromatin. In the light of these views, the current work was designed to investigate the response of Vigna seedlings root tip cells to the presence of NaCl ions.Materials and methodsNM-92 and NM19-19 seeds were imbibed separately in distilled water for 24 h and allowed to grow into 0, 50, 150, 250, and 350 mM NaCl solution for 24 h. Excised root tips were stained, and slides were scored at 100× objective for the mitotic index (MI) and chromosomal aberrations.ResultsOur data demonstrated that as NaCl molarity increased, the MI was declined along with various chromatin abnormalities. The 150 mM of NaCl showed more lagging (69%) of chromosomes during anaphase in NM19-19. The highest stickiness at metaphase stage (68%) was found in 250 mM NaCl in variety NM19-19. However, both varieties were differed non-significantly for c-mitosis that was recorded 99% at 350 mM NaCl concentration.ConclusionsThe NaCl ions toxicity induced various cytological anomalies in seedling roots that adversely affect the growth of Vigna seedlings.

Due to urbanization and industrialization, heavy metals have become the common environmental pollutant throughout the world. Chromosomal studies are one of the important tools to estimate the genome damaging property of these metals. This research was done to analyze the genotoxic effects of metals such as cadmium (Cd), nickel (Ni), mercury (Hg), lead (Pb) and copper (Cu) in mung bean (Vigna radiata) root tips. The experiment was set in such a way that mild metal treatment (0.01 mM) was given before respective high metal treatments (0.1 and 0.5 mM) separately, with the aim to know whether low/mild metals can alleviate metal tolerance in mung bean seedlings. Results demonstrated that metals treatment resulted in growth and mitotic index reduction. Among all the tested metals, Cd was found to cause more negative effect on growth of mung bean seedlings with length of 6.12 cm and 13.41% mitotic Index (MI) with the highest total aberrations (27.91%) at 0.5 mM Cd. Positive correlation was found between mitotic index and seedling length while a negative correlation was recorded between chromosomal aberrations with mitotic index and seedling length. Among these abnormalities C-mitosis, sticky chromosomes, and disturb metaphase were the most common aberrations irrespective of the metal. Furthermore, it was also observed that seed priming with respective mild metal concentration improves the seedling length, MI, and reduces the effect of metal stress by lowering the chromosomal aberrations in both 0.1 mM and 0.5 mM concentrations as compared to metal stress alone.

A study of wall bound invertases in different tissues of mung bean cultivar has been undertaken. In young and mature leaves, acid as well as alkaline invertase activity was prominent. Senescent leaves showed the presence of alkaline invertase only. During flowering and fruiting, flowers and pods both posses acid invertase activity at initial stages of development whereas closed flower and mature pods showed the presence of alkaline invertase. Present results revealed that the young tissues of mung bean required acid invertase activity for their growth and development where hexoses were rapidly utilized with rapid sucrose hydrolysis. In mature and senescent tissues the appearance of alkaline invertase indicate the involvement of enzymes in the storage of sucrose. During present investigations, isozymes of invertases were studied by eluting them in sucrose solution of their respective pH optima after performing 7.5% polyacrylamide gel electrophoresis. Each tissue appears to possess wall bound invertases with predominance of a different activity in each case.

Azo dyes are consisted of nitrogen and carbon atom having R-N= N-R' functional group in which Rs is usually aryl. The delocalization of aryl gives vivid colors such as red, orange, and yellow. It is usually produced by an electrophilic substitution reaction of an aryl diazotization with acetoacetic amide or aromatic amines (Clarke and Kirner, 1941), which are well documented carcinogenic and mutagenic agents (Khan et al., 2020).Several studies have been conducted on the nature and characterization of azo dyes which presented a higher level of cytotoxicity on plants cells, severe allergic reactions in humans, and even cancer in lab-tested animals than any other synthetic FCAs (Rangan and Barcelous, 2009;Micic et al., 2014;Kaur et al., Abstract | The frequent use of meal and beverages having food color additives (FCAs) may cause mutation in humans' proto-oncogenes which leads to carcinogenicity. The current findings aimed to evaluate the genotoxic impact of widely used azo FCAs on the cell cycle by using onion as a model plant. The study was designed in a complete randomized design where the grown onion roots were exposed to 0%, 0.001%, 0.01%, 0.1%, and 1% concentration of FCA for 120 hours for macroscopic and 36 h for microscopic evaluation. The onion root tips morpho-physiology was severely affected as the concentration of FCAs increased. The macroscopic analysis manifested that allura red had 95% broken-ended extremely thin and transparent root tips at 1% concentration. In the microscopic analysis, FCAs induced eight different kinds of chromosomal aberrations in which allura red significantly induced the highest frequencies of abnormal prophase, sticky metaphase, c-mitosis, sticky anaphase, and laggard anaphase at each concentration. While, dislocated metaphase, forwarded anaphase, and bridge anaphase were only found in sunset yellow, tartrazine, and fast green, respectively. The use of evaluated FCAs especially allura red in foodstuff, cosmetics, and skincare products can cause cancer in humans.

Heavy metals are notoriously toxic pollutants which can potentially harm living beings and are serious health hazards. The aim of the present study was to assess the levels of cadmium (Cd) and nickel (Ni) throughout the year in the urban areas of the densely populated industrial city of Faisalabad in eight commonly raised ornamental tree species with phytoremediation potential. High levels of Cd and Ni were recorded in all study areas, with spatio-temporal heterogeneity. Heavy metal uptake varied among plant species with Cd and Ni in soil ranging between 6.78–8.57 mgkg−1 and 46.31–55.85 mg kg−1 respectively. Plant species accumulated 6.73–8.98 mg kg−1 Cd and 26.42–52.50 mg kg−1 Ni with Conocarpus erectus, Dalbergia sissoo and Bismarckia nobilis showing higher accumulation potential than others. Dalbergia sissoo accumulated the highest levels of Ni and was shown to a good bio-indicator for this metal. The highest accumulation of Cd was recorded in Conocarpus erectus (9 mg kg−1), followed by Dalbergia sissoo (8.2 mg kg−1) and Bismarckia nobilis (8.1 mg kg−1) while the leaves of Azadirachta indica retained the lowest (6.3 mg kg−1) Cd levels. The highest levels of metals were accumulated by all species during the summer season while the second highest were observed in the autumn season. The study revealed that ornamental species can help in minimizing heavy metal pollution as well as providing green space in urban settings for maintaining a clean and healthy environment.