Methanesulfonate Research Articles

Maintaining the physiological stability during artificial spawning of Liza ramada in captivity

AbstractIn captivity, the physiological condition of mature brood fish has a vital role for a successful artificial spawning. Therefore, the current study aimed to minimize endocrine and metabolic disruptions during routine handling, transportation, and acclimatization during artificial spawning in L. ramada. Here, we determined the impacts of transportation and handling, as well as the acclimation to different salinities on the levels of total thyroxine (T4), triiodothyronine (T3), cortisol, and glucose in the mature L. ramada females. The transportation procedures of cultured mature females of L. ramada without anesthesia induced physiological stress as reflected with a rapid elevation in serum cortisol and glucose concomitant with a decrease in T4 within 3 h. However, the anesthesia protocol and the gradual acclimatization to seawater (24 h) were successful in maintaining baseline concentrations of the measured hormones in mature L. ramada females. The recorded levels of thyroid hormones (T4 and T3) and cortisol proved that 40 mg l−1 of clove oil was superior to anesthetic tricaine methane sulfonate (MS-222). In parallel, clove oil as an anesthetic has a rapid induction time and longer recovery time compared to MS-222 in L. ramada anesthesia. So, the slow acclimation and clove oil anesthesia were crucial during the induction of spawning in L. ramada. Indeed, all injected females were physiologically stable and spawned within the appropriate time consistent with the histological observation of both ovary and liver. Together, these findings recommend that maintaining the physiological stability of broodstock is critical for the successful artificial spawning of mullet.

Photosynthetic characteristics and genetic mapping of a yellow-green leaf mutant jym165 in soybean

BackgroundLeaves are important sites for photosynthesis and can convert inorganic substances into organic matter. Photosynthetic performance is an important factor affecting crop yield. Leaf colour is closely related to photosynthesis, and leaf colour mutants are considered an ideal material for studying photosynthesis.ResultsWe obtained a yellow-green leaf mutant jym165, using ethyl methane sulfonate (EMS) mutagenesis. Physiological and biochemical analyses indicated that the contents of chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll in the jym165 mutant decreased significantly compared with those in Jiyu47 (JY47). The abnormal chloroplast development of jym165 led to a decrease in net photosynthetic rate and starch content compared with that of JY47. However, quality traits analysis showed that the sum of oil and protein contents in jym165 was higher than that in JY47. In addition, the regional yield (seed spacing: 5 cm) of jym165 increased by 2.42% compared with that of JY47 under high planting density. Comparative transcriptome analysis showed that the yellow-green leaf phenotype was closely related to photosynthesis and starch and sugar metabolism pathways. Genetic analysis suggests that the yellow-green leaf phenotype is controlled by a single recessive nuclear gene. Using Mutmap sequencing, the candidate regions related of leaf colour was narrowed to 3.44 Mb on Chr 10.ConclusionsAbnormal chloroplast development in yellow-green mutants leads to a decrease in the photosynthetic pigment content and net photosynthetic rate, which affects the soybean photosynthesis pathway and starch and sugar metabolism pathways. Moreover, it has the potentiality to increase soybean yield under dense planting conditions. This study provides a useful reference for studying the molecular mechanisms underlying photosynthesis in soybean.

Mechanistic insights on stabilization and destabilization effect of ionic liquids on type I collagen fibrils

Tuned assembly of collagen has tremendous applications in the field of biomedical and tissue engineering owing to its targeted biological functionalities. In this study, ionic liquids choline dihydrogen citrate (CDHC) and diethyl methyl ammonium methane sulfonate (AMS) have been used to regulate the self-assembly of collagen at its physiological pH by probing the assembled systems at certain concentration ratios of ionic liquids and the systems were studied using various characterization methods. Due to interaction with collagen, choline dihydrogen citrate causes delay in the collagen fibrillisation process showing no binding interactions with collagen. In contrast, diethyl methyl ammonium methane sulfonate shows crosslinking effect on collagen fibrillisation due to the electrostatic interaction with the tetrahedral hydration shell of collagen moieties. From rheological studies it was observed that the AMS treated collagen fibril at 1:1 % (w/v) has highest linear viscoelastic range, this can bear the stress under high strain compare to native collagen fibril as well as all CDHC composites. For a sustainable biomaterial or bio-scaffold, mechanical property plays pivotal role on it and from our experimental analysis we found certain composites of ionic liquid treated collagen fibrillar assembly which may act as a sustainable biomaterial or bio-scaffold. It was also evolved that, how the structure-function relationship of ionic force modulated fibrillar assembly controlling the mechanical properties of the tuned system. This self-assembled, ionic-liquid treated collagen-fibrillar system would accelerate various force modulated fibrillar network study, for mimicking the ECM and tissue engineering application.

Exogenous Melatonin Reinforces Photosynthesis, Antioxidant Defense and Gene Expression to Ameliorate Na2CO3 Stress in Maize.

Salt stress can seriously affect the growth and development of maize (Zea mays L.), resulting in a great yield loss. Melatonin (MT), an indole hormone, is a potential enhancer of plant tolerance against salt stress. However, the complex mechanisms of MT application in enhancing maize salt tolerance are still unclear. Herein, three-leaf seedlings of salt-susceptible P138 and its salt-resistant ethyl methane sulfonate (EMS)-104 mutant were cultured with or without 150 μM MT application under 0 and 100 mM Na2CO3 treatments for seven days, to systematically explore the response mechanisms of exogenous MT in improving the salt tolerance of maize. The results showed that salt stress triggered an escalation in reactive oxygen species production, enhanced multiple antioxidant enzymes' activities, impaired cellular membrane permeability, inhibited photosynthetic pigment accumulation, and ultimately undermined the vigor and photosynthetic prowess of the seedlings. While suitable MT application counteracted the detrimental impacts of Na2CO3 on seedlings' growth and photosynthetic capacity, the seedling length and net photosynthetic rate of P138 and EMS-104 were increased by 5.5% and 18.7%, and 12.7% and 54.5%, respectively. Quantitative real-time PCR (qRT-PCR) analysis further showed that MT application activated the expression levels of antioxidant enzyme-related genes (Zm00001d025106, Zm00001d031908, Zm00001d027511, and Zm00001d040364) and pigment biosynthesis-related genes (Zm00001d011819 and Zm00001d017766) in both maize seedlings under Na2CO3 stress; they then formed a complex interaction network of gene expression, multiple physiological metabolisms, and phenotype changes to influence the salt tolerance of maize seedlings under MT or Na2CO3 stress. To sum up, these observations underscore that 150 μM MT can alleviate salt injury of maize seedlings, which may provide new insights for further investigating MT regulation mechanisms to enhance maize seedlings' salt resistance.

A Novel SPOTTED LEAF1-1 (SPL11-1) Gene Confers Resistance to Rice Blast and Bacterial Leaf Blight Diseases in Rice (Oryza sativa L.)

Programmed cell death (PCD) plays critical roles in plant immunity but must be regulated to prevent excessive damage. In this study, a novel spotted leaf (spl11-1) mutant was identified from an ethyl methane sulfonate (EMS) population. The SPL11-1 gene was genetically mapped to chromosome 12 between the Indel12-37 and Indel12-39 molecular markers, which harbor a genomic region of 27 kb. Annotation of the SPL11-1 genomic region revealed the presence of two candidate genes. Through gene prediction and cDNA sequencing, it was confirmed that the target gene in the spl11-1 mutant is allelic to the rice SPOTTED LEAF (SPL11), hereafter referred to as spl11-1. Sequence analysis of SPL11 revealed a single bp deletion (T) between the spl11-1 mutant and the ‘Shuangkang77009’ wild type. Moreover, protein structure analysis showed that the structural differences between the SPL11-1 and SPL11 proteins might lead to a change in the function of the SPL11 protein. Compared to the ‘Shuangkang77009’ wild type, the spl11-1 mutant showed more disease resistance. The agronomical evaluation showed that the spl11-1 mutant showed more adverse traits. Through further mutagenesis treatment, we obtained the spl11-2 mutant allelic to spl11-1, which has excellent agronomic traits and more improvement and may have certain breeding prospects in future breeding for disease resistance.

Polyploidy Induction by Sodium Azide and Ethyl Methane Sulfonate in Grape Genotypes

Polyploidy Induction by Sodium Azide and Ethyl Methane Sulfonate in Grape Genotypes

Enhancing floral diversity: A review of mutation breeding techniques in flower crops

Flower crops encompass a wide range of ornamental annuals and perennials that are commercially cultivated for aesthetic appeal of their floral displays. Mutation induction has been used since the early 20th century to increase genetic diversity and develop new flower varieties with improved yield, quality, adaptation and market value. Mutation experiments have successfully created genetic variability and novel phenotypes in diverse floral species. Mutation breeding, which involves the induction of genetic variations via physical and chemical mutagens, has emerged as a vital technique for enhancing ornamental plant traits, such as flower color, shape, disease resistance and stress tolerance. It explores the types and applications of physical mutagens, such as gamma rays and ion beams and chemical mutagens, such as ethyl methane sulfonate (EMS) and sodium azide (SA). This review provides detailed insights into mutation breeding research conducted on major flower crops (e.g., rose, carnation, chrysanthemum and gerbera). This study also highlights achievements in the development of novel flower varieties, highlights the key challenges faced in mutation breeding programs and identifies gaps in research, particularly concerning the comparative efficacy of different mutagens, environmental impacts and genetic stability of mutated varieties. Furthermore, the impact of mutation breeding on the global flower market is discussed, emphasizing its role in expanding trait diversity, catering to niche markets and enhancing the commercial value of flower crops. Mutation breeding offers significant promise in the development of sustainable and climate-resilient ornamental crops that can meet the needs of emerging markets. This review serves as a valuable resource for students, scientists and breeders interested in leveraging mutation breeding for floral crop improvement.

Assessment of the In Vitro Phosphatidylinositol Glycan Class A (PIG-A) Gene Mutation Assay Using Human TK6 and Mouse Hepa1c1c7 Cell Lines.

Gene mutations linked to diseases like cancer may be caused by exposure to environmental chemicals. The X-linked phosphatidylinositol glycan class A (PIG-A) gene, required for glycosylphosphatidylinositol (GPI) anchor biosynthesis, is a key target locus for in vitro genetic toxicity assays. Various organisms and cell lines may respond differently to genotoxic agents. Here, we compared the mutagenic potential of directly genotoxic ethyl methane sulfonate (EMS) to metabolically activated pro-mutagenic polycyclic aromatic hydrocarbons (PAHs). The two classes of mutagens were compared in an in vitro PIG-A gene mutation test using the metabolically active murine hepatoma Hepa1c1c7 cell line and the human TK6 cell line, which has limited metabolic capability. Determination of cell viability is required for quantifying mutagenicity. Two common cell viability tests, the MTT assay and propidium iodide (PI) staining measured by flow cytometry, were evaluated. The MTT assay overestimated cell viability in adherent cells at high benzo[a]pyrene (B[a]P) exposure concentrations, so PI-based cytotoxicity was used in calculations. The spontaneous mutation rates for TK6 and Hepa1c1c7 cells were 1.87 and 1.57 per million cells per cell cycle, respectively. TK6 cells exposed to 600 µM and 800 µM EMS showed significantly higher mutation frequencies (36 and 47 per million cells per cell cycle, respectively). Exposure to the pro-mutagen benzo[a]pyrene (B[a]P, 10 µM) did not increase mutation frequency in TK6 cells. In Hepa1c1c7 cells, mutation frequencies varied across exposure groups (50, 50, 29, and 81 per million cells per cell cycle when exposed to 10 µM B[a]P, 5-methylcholanthrene (5-MC), chrysene, or 16,000 µM EMS, respectively). We demonstrate that the choice of cytotoxicity assay and cell line can determine the outcome of the Pig-A mutagenesis assay when assessing a specific mutagen.

Development and Characterization of a New TILLING Population for Forward and Reverse Genetics in Barley (Hordeum vulgare L.).

Mutagenesis is an important tool in crop improvement and free of the regulatory restrictions imposed on genetically modified organisms. Barley (Hordeum vulgare L.) is a diploid species with a genome smaller than those of other members of the Triticeae crops, making it an attractive model for genetic studies in Triticeae crops. In this study, we report an ethyl methane sulfonate (EMS)-mutagenized population in the Chinese barley landrace TX9425, which is tolerant to both abiotic and biotic stress. A TILLING (Targeting Induced Locus Lesion in Genomes) population consisting of 2000 M2 lines was also constructed based on the CEL I enzyme with subsequent polyacrylamide electrophoresis, which decreased the cost and labor investment. The mutant phenotypes of the M2 and M3 generations were scored and revealed the presence of a wide spectrum of morphological diversity. The population was evaluated by screening for induced mutations in five genes of interest. A detailed analysis was performed for the HvGLR3.5 gene and three mutations were identified by screening in 2000 M2 lines. Two of three mutations displayed tuft and yellow striped leaves compared to the wild type. Altogether, our study shows the efficiency of screening and the great potential of the new TILLING population for genetic studies in the barley crop model system.

A machine learning enhanced EMS mutagenesis probability map for efficient identification of causal mutations in Caenorhabditis elegans.

Chemical mutagenesis-driven forward genetic screens are pivotal in unveiling gene functions, yet identifying causal mutations behind phenotypes remains laborious, hindering their high-throughput application. Here, we reveal a non-uniform mutation rate caused by Ethyl Methane Sulfonate (EMS) mutagenesis in the C. elegans genome, indicating that mutation frequency is influenced by proximate sequence context and chromatin status. Leveraging these factors, we developed a machine learning enhanced pipeline to create a comprehensive EMS mutagenesis probability map for the C. elegans genome. This map operates on the principle that causative mutations are enriched in genetic screens targeting specific phenotypes among random mutations. Applying this map to Whole Genome Sequencing (WGS) data of genetic suppressors that rescue a C. elegans ciliary kinesin mutant, we successfully pinpointed causal mutations without generating recombinant inbred lines. This method can be adapted in other species, offering a scalable approach for identifying causal genes and revitalizing the effectiveness of forward genetic screens.

SPL50 Regulates Cell Death and Resistance to Magnaporthe Oryzae in Rice

BackgroundThe identification of spotted leaf 50 (spl50), a novel lesion mimic mutant (LMM) in rice, provides critical insights into the mechanisms underlying programmed cell death (PCD) and innate immunity in plants.ResultsBased on ethyl methane sulfonate (EMS)-induced mutagenesis, the spl50 mutant mimics hypersensitive responses in the absence of pathogen by displaying spontaneous necrotic lesions after the tillering phase. SPL50, an ARM repeat protein essential for controlling reactive oxygen species (ROS) metabolism and boosting resistance to blast disease, was identified by map-based cloning techniques. This work also demonstrates the detrimental effects of spl50 on photosynthetic efficiency and chloroplast development. The crucial significance of SPL50 in cellular signaling and stress response is shown by its localization to the cytoplasm and constitutive expression in various plant tissues. In light of growing concerns regarding global food security, this study highlights the pivotal role of SPL50 in regulating programmed cell death (PCD) and enhancing the immune response in plants, contributing to strategies for improving crop disease resistance.ConclusionsThe novel identification of the SPL50 gene in rice, encoding an ARM repeat protein, reveals its pivotal role in regulating PCD and innate immune responses independently of pathogen attack.

Evaluation of the Impact of Chemical Mutagens on the Phenological and Biochemical Characteristics of Two Varieties of Soybean (Glycine max L.).

Mutagenic effectiveness and efficiency are the most important factors determining the success of mutation breeding, a coherent tool for quickly enhancing diversity in crops. This study was carried out at Lovely Professional University's agricultural research farm in Punjab, India, during the year 2023. The experimental design followed a randomized complete block design (RCBD) with three replications. The experiment aimed to assess the effect of three chemical mutagens, sodium azide (SA), ethyl methyl sulphonates (EMSs), and methyl methane sulfonate (MMS), at three different concentrations (0.2%, 0.4%, and 0.6%), in SL958 and SL744 soybean varieties to select the mutant exhibiting the highest yield. The data were collected and analysed using a two-way ANOVA test through SPSS software (version 22), and the means were separated using Duncan's multiple range test (DMRT) at the 5% level of significance. Between the two varieties, the highest seed germination percentage (76.0% seedlings/plot) was recorded in SL958 (0.4% SA), while the lowest (30.33% seedlings/plot) was observed in 0.6% MMS as compared to the control (53% and 76% in SL744 and SL958 at 10 days after sowing, respectively). Several weeks after sowing, the average plant height was observed to be higher (37.84 ± 1.32 cm) in SL958 (0.4% SA) and lower (20.58 ± 0.30 cm) in SL744 (0.6% SA), as compared to the controls (SL958: 26.09 ± 0.62 cm and SL744: 27.48 ± 0.74 cm). The average leaf count was the highest (234.33 ± 3.09 tetrafoliate leaves/plant) in SL958 (0.4% SA) while it was the lowest (87 leaves/plant) in 0.6% MMS as compared to the control (SL744 180.00 ± 1.63 and SL958 160.73 ± 1.05). The highest total leaf areas recorded in the SL958 and SL744 M1plants were 3625.8 ± 1.43 cm2 and 2311.03 ± 3.65 cm2, respectively. Seeds of the SL958 variety treated with 0.4% SA resulted in the development of tetrafoliate leaves with a broad leaf base and the maximum yield (277.55 ± 1.37 pods/plant) compared to the narrow pentafoliate leaves obtained through the treatment with EMS. Meanwhile, in the SL744 variety, the same treatment led to tetrafoliate leaves with a comparatively lower yield of 206.54 ± 23.47 pods/plant as compared to the control (SL744 164.33 ± 8.58 and SL958 229.86 ± 0.96). The highest protein content (47.04 ± 0.87% TSP) was recorded in the SL958 (0.4% SA) M2 seeds followed by a content of 46.14 ± 0.64% TSP in the SL744 (0.4% SA) M2 seeds, whereas the lowest content (38.13 ± 0.81% TSP) was found in SL958 (0.6% MMS). Similar observations were recorded for the lipid and fibre content. The 0.4% SA treatment in SL958 proved to be efficient in generating the highest leaf area (tetrafoliate leaves) and a reasonable yield of M1 (the first generation after mutation) plants.

Genome-Wide Identification of Height-Related Genes Using Three Maize Dwarfs and RNA-Seq

Plant height is an important grain yield-associated trait in maize. To date, few genes related to plant height have been characterized in maize. To better understand the genetic mechanisms of plant height in maize, we revealed the transcriptional changes of three dwarf mutants compared to the wild type. By ethyl methane sulfonate treatment of the wild-type maize cultivar PH6WC, we obtained three dwarfs—PH6WCdwarf1 (pd1), PH6WCdwarf2 (pd2), and PH6WCdwarf3 (pd3)—and their plant heights were reduced by 42%, 38%, and 24%, respectively. RNA-Seq data suggested that 1641 differentially expressed genes (DEGs) overlapped with each other among the three dwarfs at the seedling stage. Further analysis showed that the DEGs were divided into four groups with different expression patterns. Functional analysis revealed that these DEGs were commonly enriched in 47 GO terms mainly involved in cytokinesis, hormone, and energy metabolism pathways. Among them, An1, involved in the GA biosynthesis pathway, and mutations in An1 result in reduced plant height. EREB182 encodes ethylene-responsive element binding protein 2, which is critical for internode elongation. Microtubule-related genes Zmtub2, Zmtub3, Zmtub5, Zmtub6, and TUBG2 were commonly enriched among the three comparisons. Previous studies have shown that mutations in microtubule-associated genes cause the dwarf phenotype. However, nearly half of the common DEGs had no functional information, such as Zm00001d000107, Zm00001d000279, etc., implying their novel and specific functions in maize. Overall, this study identifies several potential plant height-related genes and contributes to linking genetic resources with maize breeding.

Antimicrobial Activity of Water-Soluble Silver Complexes Bearing C-Scorpionate Ligands.

The novel hydrosoluble silver coordination polymer [Ag(NO3)(μ-1κN;2κN',N″-TPMOH)]n (1) (TPMOH = tris(1H-pyrazol-1-yl)ethanol) was obtained and characterized. While single crystal X-ray diffraction analysis of compound 1 disclosed an infinite 1D helical chain structure in the solid state, NMR analysis in polar solvents confirmed the mononuclear nature of compound 1 in solution. Compound 1 and the analogue [Ag(μ-1κN;2κN',N″-TPMS)]n (2) (TPMS = tris(1H-pyrazol-1-yl)methane sulfonate) were evaluated with regard to their antimicrobial activities towards the Gram-negative Escherichia coli, Pseudomonas aeruginosa, and Burkholderia contaminans, the Gram-positive Staphylococcus aureus, and the fungal species Candida albicans and Candida glabrata. Compound 1 exhibited minimal inhibitory concentration (MIC) values ranging from 2 to 7.7 µg/mL towards the tested Gram-negative bacteria, 18 µg/mL towards the Gram-positive S. aureus, and 15 and 31 µg/mL towards C. albicans and C. glabrata, respectively. Compound 2 was less effective towards the tested bacteria, with MIC values ranging from 15 to 19.6 µg/mL towards the Gram-negative bacteria and 51 µg/mL towards S. aureus; however, it was more effective against C. albicans and C. glabrata, with MIC values of about 6 µg/mL towards these fungal species. The toxicity of compounds 1 and 2 was assessed by evaluating the survival of the Caenorhabditis elegans model organism to concentrations of up to 100 µg/mL. The value of 50% lethality (LD50) could only be estimated as 73.2 µg/mL for compound 1 at 72 h, otherwise LD50 was >100 µg/mL for both compounds 1 and 2. These results indicate compounds 1 and 2 as novel silver complexes with interesting antimicrobial properties towards bacterial and fungal pathogens.

Proteomic Alterations and Metabolic Pathway Modulations Induced by Methyl Methane Sulfonate Treatment in Response to DNA Damage

Exposure to methyl methane sulfonate (MMS), an alkylating agent, induces DNA damage, increasing cellular and metabolic sensitivity, leading to cellular demise and a delay in the cell cycle. This delay is attributed to changes in global transcription regulation, resulting in significant alterations in the proteome. Numerous studies have focused on transcriptome changes post-MMS treatment. However, cellular proteomic changes remain underexplored. This brief literature review is based on the assessment of studies obtained from several PubMed, Web of Science, and Scopus databases and Google Scholar using specific keywords. The article is based on manuscripts published between 2005 and 2024. Proteomic analysis identified 53 proteins, with 36 upregulated, 10 downregulated statuses, and a few exhibiting no or negligible changes. MMS exposure reflected changes in the phosphorylation status of the carboxy-terminal domain (CTD) of RNA polymerase II (RNAP-II) and a gross change in the transcriptome. Literature also supports the proteome change of the RNAP-II complex and ~1640 peptides, corresponding to 27 interacting proteins and the twelve RNAP-II subunits. The identified proteins were involved in DNA repair and energy pathway modulation. Notably, significant changes were observed in enzymes mostly related to carbohydrate and amino acid metabolism, predominantly, glycolysis, the fate of pyruvate, and the biosynthetic pathways of amino acid metabolism. The available literature supports a co-regulated response to MMS-induced DNA damage involving both DNA repair mechanisms and metabolic pathways.

Is pearl millet (Pennisetum glaucum) a good plant species for ecotoxicological tests?

Various plant species can be selected for environmental testing, including pearl millet (Pennisetum glaucum (L.) R. Br), a globally significant cereal crop. This study aims to assess millet's suitability as a species for ecotoxicological tests, examining (1) germination and initial development dynamics, (2) the minimum seed quantity for reliable sampling, (3) optimal experimental design with replication numbers, (4) suitability of positive control, and (5) the effectiveness of the protocol in evaluating toxic effects of environmental pollutants. Millet exhibited rapid and uniform germination as well as consistent initial seedling development. To establish the minimum number of seeds required for reliable experimentation, germination, and seedling growth were compared across plots containing 10, 25, and 50 seeds. Consequently, 10 seeds per plot were chosen for subsequent experiments to reduce labor and costs while maintaining reliability. To validate the selected experimental design, and to establish a positive control for assays, aluminum was used as a toxic element at concentrations ranging from 10-2 to 10-6 M. While aluminum did not affect the final percentage of germinated seeds, it did exhibit an impact on the Germination Speed Index (GSI). Significant differences in root and aerial growth, and with fresh weight, were observed. The 10-3M concentration was chosen as the positive control as the 10-2 concentration showed extreme toxicity. To assess the applicability of the established protocol in determining the toxic effects of environmental pollutants, millet roots were exposed to the toxic agents atrazine, cadmium, methyl methane sulfonate (MMS), and Spent pot liner (SPL). Millet demonstrated sensitivity and efficiency in response to these tests. In conclusion, millet proves to be an effective species for the toxicological risk assessment of environmental pollutants.

Induction of genetic diversity in gepak kuning soybean cultivar and M.1.1.3 line using ethyl methane sulfonate in M1 generation

Abstract Genetic diversity is the main determining factor in plant breeding activities. Various breeding methods can be used to induce plant variability, including mutation breeding. The chemical mutagen commonly used for mutagenesis is Ethyl Methane Sulfonate (EMS). This study explores the effects of EMS mutagen on the morphological and agronomic diversity of gepak kuning cultivar and M.1.1.3 soybean line. The research was conducted in Tambon Tunong Village, North Aceh District, Indonesia, using a single-factor Randomized Block Completely Design (RCBD). Concentrations of 0%, 0.05%, 0.075%, and 0.1% EMS were tested on the gepak kuning cultivar and M.1.1.3 line. Treating gepak kuning soybeans with EMS significantly impacted various variables, including harvesting age, pod number, seed weight, leaf appearance, and production. Additionally, the treatment resulted in changes in the morphology of the plant, particularly in the shape of its branches. The EMS treatment on M.1.1.3 line also significantly affected various variables like plant height, flowering age, harvesting age, and yield components. However, it led to sterile plants in the line.

Phenotypic characterization of point mutations spanning FHA domain and C-terminal region of Dawdle gene in Arabidopsis

The screening analysis of loss-of-function alleles in Arabidopsis thaliana revealed a mutation in the At3G20550 gene, called DAWDLE (DDL). The mutation in the DDL gene causes pleiotropic phenotypes and reduced the levels of several microRNAs. The DAWDLE gene encodes a protein with a Fork Head-Associated (FHA) domain, found in large range of proteins with significant cellular processes in prokaryotes and eukaryotes. However, it is not completely known whether the FHA domain and C-terminal region of the DDL are necessary for its function. The aim of this study was to determine the function of both regions by conducting a phenotypic analysis of point mutations spanning the FHA domain and C-terminal region in DDL Targeted Induced Local Lesions IN Genome (Tilling) screen was performed in the Columbia erecta-105 background of Arabidopsis resulting in point mutations spanning both regions of DDL. The mutants were phenotypically characterized. Height of the plant, hypocotyl and root length, and fertility were measured. Phenotypic analyses of the mutants revealed ddl phenotypes of varying degrees in different organs. Reduction in fertility and shortening in root, hypocotyl and stem lengths of the Tiller mutant lines suggest that the FHA domain and C-terminal region may require for DDL function in Arabidopsis. Key words: Dawdle, Fork Head-Associated Domain, Targeted Induced Local Lesions in Genome, Ethyl Methane Sulfonate, Arabidopsis

BnaC03.BIN2 regulates plant height by affecting the main inflorescence length and first effective branch height in Brassica napus L.

Rapeseed (Brassica napus L.) is one of the main oil crops in the world, and increasing its yield is of great significance for ensuring the safety of edible oil. Presently, improving rapeseed plant architecture is an effective way to increase rapeseed yield with higher planting density. However, the regulatory mechanism of rapeseed plant architecture is poorly understood. In this study, a dwarf rapeseed mutant dwarf08 (df08) is obtained by ethyl methane sulfonate (EMS)-mutagenesis. The decrease in plant height of df08 is mainly caused by the reduction in main inflorescence length and first effective branch height and controlled by a single semi-dominant gene. The hybrid plants (F1) show a semi-dwarf phenotype. Through map-based cloning and transgenic assay, we confirm that the nonsynonymous single nucleotide variant (SNV) (C to T) in BnaC03.BIN2, which is homologous with Arabidopsis (Arabidopsis thaliana) BIN2, is responsible for the dwarfism of df08. BnaC03.BIN2 interacts with BnaBZR1/BES1 and involves in brassinosteroids (BRs) signal transduction. Proline to Leucine substitution in 284 (P284L) enhances the protein stability of BnaC03.bin2-D, disrupts BRs signal transduction and affects the expression of genes regulating cell division, leading to dwarfism of df08. This study provides a new insight for the mechanism of rapeseed plant height regulation and creates an elite germplasm that can be used for genetic improvement of rapeseed architecture.

Drivers of late Holocene ice core chemistry in Dronning Maud Land: the context for the ISOL-ICE project

Abstract. Within the framework of the Isotopic Constraints on Past Ozone Layer in Polar Ice (ISOL-ICE) project, we present initial ice core results from the new ISOL-ICE ice core covering the last millennium from high-elevation Dronning Maud Land (DML) and discuss the implications for interpreting the stable isotopic composition of nitrogen in ice core nitrate (δ15N(NO3-)) as a surface ultra-violet radiation (UV) and total column ozone (TCO) proxy. In the quest to derive TCO using δ15N(NO3-), an understanding of past snow accumulation changes, as well as aerosol source regions and present-day drivers of their variability, is required. We therefore report here the ice core age–depth model, the snow accumulation and ice chemistry records, and correlation analysis of these records with climate variables over the observational era (1979–2016). The ISOL-ICE ice core covers the last 1349 years from 668 to 2017 CE ± 3 years, extending previous ice core records from the region by 2 decades towards the present and shows excellent reproducibility with those records. The extended ISOL-ICE record of last 2 decades showed a continuation of the methane sulfonate (MSA−) increase from ∼ 1800 to present while there were less frequent large deposition events of sea salts relative to the last millennium. While our chemical data do not allow us to distinguish the ultimate (sea ice or the open ocean) source of sea salt aerosols in DML winter aerosol, our correlation analysis clearly suggests that it is mainly the variability in atmospheric transport and not the sea ice extent that explains the interannual variability in sea salt concentrations in DML. Correlation of the snow accumulation record with climate variables over the observational era showed that precipitation at ISOL-ICE is predominately derived from the South Atlantic with onshore winds delivering marine air masses to the site. The snow accumulation rate was stable over the last millennium with no notable trends over the last 2 decades relative to the last millennium. Interannual variability in the accumulation record, ranging between 2 and 20 cm a−1 (w.e.), would influence the ice core δ15N(NO3-) record. The mean snow accumulation rate of 6.5±2.4 cm a−1 (w.e.) falls within the range suitable for reconstructing surface mass balance from ice core δ15N(NO3-), highlighting that the ISOL-ICE ice core δ15N(NO3-) can be used to reconstruct either the surface mass balance or surface UV if the ice core δ15N(NO3-) is corrected for the snow accumulation influence, thereby leaving the UV imprint in the δ15N(NO3-) ice core record to quantify natural ozone variability.