Chemical Mutagens Research Articles

Relative mutagenic effectiveness and efficiency of chemical mutagens (Caffeine and EMS) and heavy metals [(Pb(NO3)2 and Cd(NO3)2)] in developing chlorophyll and morphological mutants in lentil.

Mutagenic effectiveness and efficiency are the utmost vital indices to determine the effective and efficient mutagenic concentrations for the generation of high frequency of desirable mutation in mutation breeding. Nevertheless, there are meager study are available for employing effective and efficient concentration of caffeine, EMS, Pb(NO3)2 and Cd(NO3)2 for the crop improvement. Thus, the current study was performed to assess the mutagenic effectiveness and efficiency of caffeine, EMS and heavy metals [Pb(NO3)2 Cd(NO3)2] and to determine the genetic variability of M2 and M3 lentil mutant lines. The frequency of different chlorophyll and chromophyll mutation was found highest at moderate and higher concentrations of chemical mutagens and heavy metals in M1 and M2 generation. The highest effectiveness was in 20ppmCd(NO3)2, followed by 20ppm Pb(NO3)2, 0.10% EMS, and 0.10% caffeine. The present investigation also showed lower doses of caffeine, EMS, Pb(NO3)2, and Cd(NO3)2 were more efficient than higher concentrations, and caffeine was found more efficient followed by EMS, Pb(NO3)2, and Cd(NO3)2. Furthermore, a broad spectrum of viable mutations affecting different morphological characters of the plants viz., leaves, plant height, growth habits, flowers, pods, and seeds in M2 and M3 generation were recorded. Ten morphological mutants showing acceptable agronomic and horticultural features were identified, as genetic resources for further breeding.

Cultural, morphological and biochemical properties of Salmonella typhimurium indicator bacteria used in the Ames test and their applicability for the assessment of the test system quality

Introduction. The Ames test has been widely used to study the mutagenicity of chemicals. In view of the implementation of a quality management system in the test facilities, the cultural, morphological and biochemical properties of strains used in the Salmonella/microsome test system were studied. An assessment of their applicability as additional characteristics of quality of the tester strain was made.
 Materials and methods. The study of cultural and morphological characteristics of S. typhimurium strains was carried out using the commercial media. 
 The biochemical properties of S. typhimurium cultures were evaluated using a Vitek-2 system.
 Results. Studies have shown that the procedure of marker verification for confirming the reference properties of tester strains, in addition to evaluation of the spontaneous mutation level and phenotypic characteristics (-his phenotype, the presence or absence of the R-factor plasmids, rfa- and ∆uvrB mutations), can be extended by periodically assessing their biochemical properties. Most of the biochemical characteristics of bacteria of the Salmonella typhimurium serovar are inherent for tester strains. Compared to the wild-type bacteria atypical features of tester strains are a negative reaction in the hydrogen sulfide production test, positive activity of tyrosine arylamidase, the ability to utilize 5-keto-D-gluconate, unstable activity of alpha-galactosidase. Differential selective media used to maintain wild-type Salmonella cultures are not universal for the growth of strains of the Salmonella/microsome test system. When choosing media for cytotoxicity, survival, or sterility assessment, it is necessary to take into consideration the growth characteristics of the Salmonella tester strains on different media: the ability to grow on selective media decreases in the series of Endo-agar > Salmonella Shigella -agar > Bismuth-sulfite agar > Ploskirev’s agar.
 Limitations. The research is limited to the study of cultural, morphological and biochemical characteristics of S. typhimurium, but not Escherichia coli.
 Conclusion. The described cultural and morphological properties of tested strains on different media can be used to assess cytotoxicity/survival of treated cultures performing studies according to OECD 471. The use of additional biochemical markers of authenticity and morphological properties of tester strains will help to ensure the quality of studies using the Ames test in the processes of conservation, reproduction, and routine testing.

Strain improvement of Streptomyces hydrogenans KMF-A1 for Antifungal Metabolite Production

Mangroves are found to be an excellent source for the isolation of novel bioactive metabolite producing microorganisms. Streptomyces hydrogenans KMFA-1, isolated from mangrove soil sample is exclusively known for its potent activity against various pathogenic fungi. The present study is focused on strain improvement of Streptomyces hydrogenans KMFA-1 by physical and chemical mutagens such as ultraviolet irradiation and nitrous acid (HNO2) respectively, for enhancing the production of antifungal metabolite against C. albicans and Pectinotrichum llanense. The parent isolate KMF-A1 produced 20mm inhibition zone diameter of antifungal activity while, the UV mutant designated as UV7, yielded 28mm and the nitrous acid mutant. UV7N4 (KMF-A1) exhibited 30mm inhibition zone diameter. The mutant strain produced improved antifungal activity by 1.5-fold increase with respect to wild strain.

Boosting the Biocontrol Efficacy of Bacillus amyloliquefaciens DSBA-11 through Physical and Chemical Mutagens to Control Bacterial Wilt Disease of Tomato Caused by Ralstonia solanacearum.

Bacterial wilt disease of tomato (Solanum lycopersicum L.), incited by Ralstonia solanacearum (Smith), is a serious agricultural problem in India. In this investigation, chemical mutagenic agents (NTG and HNO2 treatment) and ultraviolet (UV) irradiation have been used to enhance the antagonistic property of Bacillus amyloliquefaciens DSBA-11 against R. solanacearum UTT-25 towards an effective management of tomato wilt disease. The investigation established the fact that maximum inhibition to R. solanacearum UTT-25 was exerted by the derivative strain MHNO2-20 treated with nitrous acid (HNO2) and then by the derivative strain MNTG-21 treated with NTG. The exertion was significantly higher than that of the parent B. amyloliquefaciens DSBA-11. These two potential derivatives viz. MNTG-21, MHNO2-20 along with MUV-19, and a wild derivative strain of B. amyloliquefaciens i.e.,DSBA-11 were selected for GC/MS analysis. Through this analysis 18 major compounds were detected. Among the compounds thus detected, the compound 3-isobutyl hexahydropyrrolo (1,2), pyrazine-1,4-dione (4.67%) was at maximum proportion in the variant MHNO2-20 at higher retention time (RT) of 43.19 s. Bio-efficacy assessment observed a record of minimum intensity (9.28%) in wilt disease and the highest bio-control (88.75%) in derivative strain MHNO2-20-treated plants after 30 days of inoculation. The derivative strain MHNO2-20, developed by treating B. amyloliquefaciens with nitrous acid (HNO2), was therefore found to have a higher bio-efficacy to control bacterial wilt disease of tomato under glasshouse conditions than a wild-type strain.

Effect of Chemical and Physical Mutagens on Vegetative Growth and Flowering of Hibiscus Rosa-sinensis L Plant

Effect of Chemical and Physical Mutagens on Vegetative Growth and Flowering of Hibiscus Rosa-sinensis L Plant

Physical and Chemical Mutagens Induced Mutations in Codiaeum Variegatum var. Mollucanum under Saline Conditions

Physical and Chemical Mutagens Induced Mutations in Codiaeum Variegatum var. Mollucanum under Saline Conditions

Hyper-Production of Biosurfactant by Pseudomonas guguanensis Strain Iraqi ZG.K.M through Random Mutagenesis

Background: With growing environmental concern, interest was increased in research anddevelopment of environmentally friendly substances. Microbial surfactants are nontoxic andbiodegradable bioproducts that are widely used in medical, pharmaceutical, agricultural,industrial, food, cosmetics, and refinery applications. However, the main challenges in theproduction of biosurfactants are the high production cost and the limited yield. The improvementof biosurfactant production depend on many strategies, such as the use of low-cost raw materials,adjusting medium and growth conditions, and the selection of hype-producing strains.Objective: The study was conducted to obtain Pseudomonas guguanensis strain Iraqi ZG.K.Mmutant with higher biosurfactant production, through random mutagenesis.Materials and Methods: Chemical mutagen (acridine orange) in different concentrations andthe physical mutagen (UV irradiation) were used for the production of random mutagenesis inPseudomonas guguanensis strain Iraqi ZG.K.M. The biosurfactant hype-producing strain wasselected depending on CTAB test, E 24 %, and the measurement of surface tension.Results: A clear indication of the efficiency of UV light in producing biosurfactant mutant. Inwhich, a higher E 24 % (78%) and the lowest surface tension (33 mN/m) were recorded withZUVM2 mutant.Conclusion : UV light can successfully used to mutagenize Pseudomonas guguanensis strainIraqi ZG.K.M to obtain hyper-producer mutants of biosurfactant that used in many applications.

Study on the effect of chemical and physical mutagen on seed germination of Indian mustard

Indian mustard [Brassica juncea (L) Czern & coss.] is considered as one of the most important vegetable oil and protein meal crops in the Indian subcontinent. Seeds of Indian Mustard Brassica juncea (L) cultivars Shivani and Pusa Bold were treated with EMS (0.3%) and gamma rays (900-1100 Gy) to study germination and other quantitative traits. Gamma rays as a kind of ionizing radiation represent a physical mutagen that induces mutations and may be effectively used in plant breeding. Ethyl methanesulfonate (EMS) is a chemical extensively used to set off mutations at loci that adjust economically vital traits. During these experiments, we observed seed germination percentage in the M1 generation was highest in Pusa Bold then followed by Shivani. An increase in doses of gamma rays and the concentration of EMS reduced the percentage of germination.

Ethyl Methanesulfonate (EMS) Mutagen Toxicity-Induced DNA Damage, Cytosine Methylation Alteration, and iPBS-Retrotransposon Polymorphisms in Wheat (Triticum aestivum L.)

The use of mutagens in plant breeding is used to create new germplasm, increase agricultural yield, quality, and resistance to diseases and pests. Mutagens are physical or chemical factors that can alter the DNA or RNA structure of an organism, causing mutations above the expected level. One of the most common and potent chemical mutagens is EMS (ethyl-methane sulfonate), which produces point mutations in plants, but to a lesser degree can also cause the loss or deletion of a chromosomal region. This study used inter-primer binding site (iPBS) and coupled restriction enzyme digestion inter-primer binding site (CRED-iPBS) technique analysis to determine the effect of EMS mutagens on methylation rates in wheat genotypes at seedling growth stage. Treatments with five different EMS concentrations (0%; control, 0.1%, 0.2%, 0.3%, and 0.4%) at four different times (0; control, 3, 6, and 9 h) were used. Inter-primer binding site (iPBS) markers were employed to assess genomic instability and cytosine methylation in treated wheat. In seeds treated with EMS at different concentrations and times, the disappearance of regular bands and the formation of new bands due to the effects of the EMS mutagen revealed that genetic diversity exists. The CRED-iPBS analysis revealed that the 3 h + 0.1% EMS treatment produced the highest MspI polymorphism value (19.60%), while the 9 h + 0.1% EMS treatment produced the lowest value (10.90%). The mutagenic effects of EMS treatments had considerable polymorphism on a variety of impacts on the cytosine methylation and genomic instability of wheat. According to the current research, EMS mutagenesis may be a practical method for accelerating breeding programs to produce enough genetic diversity in wheat populations. Mutation-assisted breeding and the subsequent selection of desirable mutants using genetic markers may also be carried out in wheat utilizing an integrated strategy.

Changes in Metabolite Profiling and Expression Levels of Key Genes Involved in the Terpenoid Biosynthesis Pathway in Garden Sage (Salvia officinalis) under the Effect of Hydrazine Hydrate.

Mutagenesis is a highly efficient tool for establishing genetic variation and is widely used for genetic enhancement in various plants. The key benefit of mutation breeding is the prospect of enhancing one or several characteristics of a variety without altering the genetic background. In this study, we exposed the seeds of Salvia officinalis to four concentrations of hydrazine hydrate (HZ), i.e., (0%, 0.1%, 0.2%, and 0.3%) for 6 h. The contents of terpenoid compounds in the S. officinalis plantlets driven from the HZ-treated seeds were determined by GC-MS, which resulted in the identification of a total of 340 phytochemical compounds; 163 (87.48%), 145 (84.49%), 65 (97.45%), and 62 (98.32%), from the four concentrations of HZ (0%, 0.1%, 0.2%, and 0.3%), respectively. Furthermore, we used the qRT-PCR system to disclose the "transcriptional control" for twelve TPS genes related to terpenoid and terpene biosynthesis, namely, SoGPS, SoMYRS, SoNEOD, SoCINS, SoSABS, SoLINS, SoFPPS, SoHUMS, SoTPS6, SoSQUS, SoGGPS, and SoGA2. Altogether, results are likely to ensure some positive relationship between the concentrations of the chemical mutagen HZ used for treating the seeds, the type and amount of the produced terpenes, and the expression of their corresponding genes.

Sodium Azide as a Chemical Mutagen in Wheat (Triticum aestivum L.): Patterns of the Genetic and Epigenetic Effects with iPBS and CRED-iPBS Techniques

Wheat, which is scientifically known as Triticum aestivum L., is a very nutritious grain that serves as a key component of the human diet. The use of mutation breeding as a tool for crop improvement is a reasonably rapid procedure, and it generates a variety that may be used in selective breeding programs as well as functional gene investigations. The present experiment was used to evaluate the potential application of a conventional chemical mutagenesis technique via sodium azide (NaN3) for the germination and seedling growth stage in wheat. Experiments with NaN3 mutagenesis were conducted using four different treatment periods (0, 1, 2, and 3 h) and five different concentrations (0, 0.5, 1, 1.5, and 2 mM). The genomic instability and cytosine methylation of wheat using its seeds were investigated after they were treated. In order to evaluate the genomic instability and cytosine methylation in wheat that had been treated, interprimer binding site (iPBS) markers were used. The mutagenic effects of NaN3 treatments had considerable polymorphism on a variety of impacts on the cytosine methylation and genomic instability of wheat plants. The results of the experiment showed considerable changes in the iPBS profiles produced by the administration of the same treatments at different dosages and at different times. Coupled restriction enzyme digestion interprimer binding site (CRED-iPBS) assays identified changes in gDNA cytosine methylation. The highest polymorphism value was obtained during 1 h + 2 mM NaN3, while the lowest (20.7%) was obtained during 1 h + 1.5 mM NaN3. Results showed that treatments with NaN3 had an effect on the level of cytosine methylation and the stability of the genomic template in wheat plants in the germination stage. Additionally, an integrated method can be used to for mutation-assisted breeding using a molecular marker system in wheat followed by the selection of desired mutants.

The Effect of Colchicine Concentration and Immersion Time on Growth and Morphological Characters of Acacia crassicarpa A. Cunn. Ex Benth In-vitro Explants

The production of polyploidy with a chemical mutagen such as colchicine is one strategy that can be applied to improve the genetic traits and wood properties of acacia trees. The aim of this study was to determine the effects of colchicine at various concentrations and immersion times on the percentage of surviving explants, percentage of rooted explants, and morphological traits of shoot and root A. crassicarpa in-vitro. A completely randomized design (CRD) with two factors was used in this study. The first factor was the concentration of colchicine solution with five levels (0,00%, 0,02%, 0,04%, 0,06%, and 0,08%), and the second factor was the immersion time with three levels (24, 48, and 72 hours). There were fifteen treatment combinations with each treatment repeated three times. Data were analyzed by ANOVA and Duncan’s multiple range test at 5% significance level. The results showed that the treatment combination of colchicine concentration with immersion time showed a significant effect on the percentage of surviving explants, number of leaves, number of shoots and height of A. crassicarpa explants, but did not significantly affect on the number of roots, length of the root and percentage of rooted A. crassicarpa explants.

How flower development genes were identified using forward genetic screens in Arabidopsis thaliana.

In the later part of the 1980s, the time was ripe for identifying genes controlling flower development. In that pregenomic era, the easiest way to do this was to induce random mutations in seeds by chemical mutagens (or irradiation) and to screen thousands of plants for those with phenotypes specifically defective in floral morphogenesis. Here, we discuss the results of premolecular screens for flower development mutants in Arabidopsis thaliana, carried out at Caltech and Monash University, emphasizing the usefulness of saturation mutagenesis, multiple alleles to identify full loss-of-function, conclusions based on multiple mutant analyses, and from screens for enhancer and suppressor modifiers of original mutant phenotypes. One outcome was a series of mutants that led to the ABC floral organ identity model (AP1, AP2, AP3, PI, and AG). In addition, genes controlling flower meristem identity (AP1, CAL, and LFY), floral meristem size (CLV1 and CLV3), development of individual floral organ types (CRC, SPT, and PTL), and inflorescence meristem properties (TFL1, PIN1, and PID) were defined. These occurrences formed targets for cloning that eventually helped lead to an understanding of transcriptional control of the identity of floral organs and flower meristems, signaling within meristems, and the role of auxin in initiating floral organogenesis. These findings in Arabidopsis are now being applied to investigate how orthologous and paralogous genes act in other flowering plants, allowing us to wander in the fertile fields of evo-devo.

Evaluation of mutagenic samples of winter garlic

Relevance. The use of chemical mutagenesis on garlic is relevant for the creation of new forms with stable characteristics, better biochemical qualities, increased yield, for use in breeding practice.Results. The reaction of garlic treated with two chemical mutagens was evaluated: DES (diethyl sulfate) – 0.025; 0.05 and 0.1% (mutants 2, 3 and 4), as well as DMS (dimethyl sulfate) – 0.02; 0.04 and 0.08% solutions (mutants 5, 6 and 7). The aftereffect of chemical mutagens was noted with low and medium variability of signs in the second–fifth generation. According to the low variability of 1.6–9.4%, the height of plants (samples M 3 and 6), the number of leaves (M 5), the height of the false stem (M 3), the diameter of bulbs (M 6), as well as the length of leaves and the weight of bulbs samples M 3, 5 and 6 were distinguished. The effect of mutagens on morphometric signs of garlic were also tracked in the second generation (re-growing from air bulbs), where the parameters of low and medium variability of signs are marked. The majority of samples on 7 signs reflected a low variability of 5.5–10.0% and only 2 mutants showed an average variability of 11.4–16.4%: M 6 in plant height and false stem and M 3 in bulb diameter and yield. The correlation between their value in the 5th generation and in the 2nd generation also revealed strong direct and average connections. High heritability of h2 signs = 0.74–0.99 for DES preparations – 0.05%, VMI – 0.02 and 0.04%, was the most important indicator of the selection of valuable signs.

Optimization of Chemical Mutagen Treatment Techniques and Determination of Absorption Dose in Jasminum auriculatum Ecotype “Muthu Mullai” for Inducing Variation

Background: Chemical mutagenesis is one of the effective tools for the induction of variation in plants. The biological effect of the chemical mutagen on plant tissues is determined by the absorption dose which is calculated by the product of the concentration of the mutagen and the treatment duration. Standardizing the treatment conditions for the best possible mutagenesis is the first prerequisite in chemical mutagenesis. Methods: Five concentrations of EMS (5 mM, 10 mM, 15 mM, 20 mM and 25 mM), three treatment durations (1 hr, 2 hr and 3 hr) and two pre-treatment conditions (soaking in water and non-soaking in water) were taken into consideration in the current study to examine the significance of each factor in regulating the mutation and to determine the unknown value of “Absorption dose” from the known survival rate. Result: The present study revealed that pretreatment with water affected the absorption of EMS into plant tissues and an increase in the EMS concentration and treatment duration decreased the survival rate of the cuttings. The study led to the inference that pretreatment of cuttings of Jasminum auriculatum ecotype Muthu Mullai with water for 2 hours and treatment with EMS at different concentrations of EMS ranging from 5 mM to 30 mM for a duration of 2 hours is suggested for higher mutation frequency.

Influence of ethyl methane sulfonate (EMS) on M3 generations of two genotypes of tomato (Solanum lycopersicum)

Mutation breeding is considered to be economic and efficient in plant improvement, and the use of chemical mutagens such as ethyl methane sulfonate (EMS) can potentially address plant breeding challenges. The aim of this present study is to create variations from existing two genotypes of tomato (Cobra and Roma vf) using a chemical mutagen ethyl methane sulfonate (EMS) in the M3 generation. Variations like increased yield, increase in fruit size and weight, variations in leaf shape, growth habit and fruit colour were conspicuously observed in the two genotypes studied in the M3 generation. In Cobra, variant 3 recorded the highest fruit weight per plant of 1.118kg while 0.318kg was the least and it was recorded by variant 7. Variations in the fruit size are equally observed with some variants producing large fruits while others produce small fruits. Variant 2 had a single fruit weight of about 63g while variant 8 produced small fruit with a single fruit weighing about 27g. There are equally some remarkable variants in Roma vf, variant 2, had a fruit weight of 1.145kg with 56.4g fruits harvested with a single fruit weight of 20.3g. This variant produces lots of many small fruits with a creeping growth habit that makes it behave like an indeterminate variety.

Field Evaluation of In Vitro Derived Mutants of Different Varieties of Banana on Fruit Quality Parameters

A field experiment was conducted on field evaluation of in vitro derived mutants of different varieties of banana during (October–September), 2018–19 and (September–August), 2019–20 at the Department of Fruit Science, College of Horticulture, University of Horticultural Sciences, Bagalkot, Karnataka, India. The one thirty-eight (138) in vitro derived banana mutants both physical and chemical mutagens treated plants along with check were planted. The experiment was laid out in augmented block design with 6 blocks and 26 subplots each block having 23 in vitro mutant lines and three checks. The cultivars used for the experiment were viz., Yelakki bale, Rajapuri bale and Nanjangud rasabale. Among 138 in vitro derived mutants in plant crop, there was no significant difference noted in pulp weight, pulp to peel ratio and fruit firmness. Among different mutants in pulp weight parameter the maximum pulp weight was recorded in NR45Gy-09 (86.45 g), peel weight, RAJ45Gy-14 (20.00 g) pulp to peel ratio YB35Gy-05 (6.70) flavour acceptance, YB40Gy-03 (7.82) fruit firmness, YB40Gy-12 (18.82 N) and shelf life YB40Gy-14 (8.10 days). in ratoon crop, the maximum pulp weight was recorded in NR45Gy-09 (86.45 g), peel weight, RAJ45Gy-14 (25.00 g) pulp to peel ratio, YB35Gy-24 (7.36) flavour acceptance, RAJ45Gy-03 (7.48) fruit firmness, YB40Gy-11 (16.50 N) and shelf life YB45Gy-08 (9.00 days).

Biological (microfloral) factors of influence on cytogenetic stability during chemical mutagenesis

ABSTRACT The article presents the results of a study of chromosomal mutations in residents living in the Aral Sea disaster zone. The present study was designed to evaluate the impact of the combined effect of a chemical mutagen (nickel) and bacterial microflora on the level of chromosomal aberrations (CA) in peripheral blood lymphocytes. This study used classical methods of cell cultivation, methods for determining chromosomal aberrations, a cytomorphological method for assessing epithelial cells, and an atomic absorption method for determining trace elements in the blood. The article shows that with an increase of chemical agent in the blood, the number of cells with features of damage and cells with contamination by microflora increases. Both of these factors cause an increase in the frequency of chromosomal aberrations. The article demonstrates how being exposed to a chemical factor increases chromosomal mutations, and also damages membrane components, which leads to a decrease in the barrier and protective function of the cell, and as a result also affects the level of chromosomal aberrations.

Towards the optimization of genetic polymorphism with EMS-induced mutagenesis in Phaeodactylum tricornutum

Microalgae remain an exciting target for biotechnology as they offer a largely unexploited reservoir of novel and valuable bioactive compounds. Strain improvement programs are an expanding research field aiming to multiply microalgal potential. This study evaluates the genetic diversity created in populations of the diatom Phaeodactylum tricornutum subjected to random mutagenesis. We explored the genetic diversity using genotyping-by-sequencing (GBS) to estimate and compare the impact of the most common chemical mutagen (ethyl methanesulfonate, EMS). Five microalga populations obtained following EMS treatment had survival rates between 1 and 98 %. High genetic diversity was obtained for only one of these P. tricornutum populations, with a survival rate close to 30 %.

Compilation of Groups of Mutagens used to Obtain Optimized Yeast Strains.

Yeasts can be used to process industrial by-products to produce products with higher added value. To optimize the technology, new yeast strains can be created through mutagenesis with improved traits of interests. To achieve this, different mutagens can be used. Mutagens can be divided into physical, chemical, and biological. Each type has its own methodology, operating mechanisms, advantages, and disadvantages. Physical mutagens are the oldest, of which UV radiation is the most used. However, others are less commonly used for yeast mutagenesis due to complicated or unwieldy instrumentation. Chemical mutagens are the most widely used to obtain improved yeast strains. The most recent mutagens to be used under laboratory conditions are biological mutagens. Using the CRISPR/Cas9 system, it is also possible to create targeted changes in previously selected regions of the genome in yeast species.