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The misfolding and aggregation of superoxide dismutase 1 (SOD1) and its mutants has been implicated in amyotrophic lateral sclerosis (ALS). In this study, we have created three peptide conjugates with the antioxidant pentacyclic terpene celastrol and examined their interactions with SOD1 and its mutants A4V and G93A. The peptides YYIVS, MPDAHL, and GSGGL are derived from natural sources and are known for their inherent antioxidant properties. Docking studies revealed that most conjugates showed strong binding with the metal binding and electrostatic loops as well as the β1, β5, and β6 hydrophobic core of SOD1. The conjugates were synthesized and self‐assembled into nanoassemblies. Surface plasmon resonance studies further confirmed the binding interactions of the nanoassemblies with the SOD1 proteins. The nanoassemblies were found to internalize into HEK293T cells. The HEK 293T cells were then transfected with GFP fused WT (Wild Type), A4V and G93A SOD1 mutants. Flow cytometry revealed that treatment with celastrol‐peptide nanoassemblies, affected the fluorescence of the SOD1 protein, implying their role in modulating SOD1, particularly for the mutants. N–Acetyl–Leu–Leu–Norleucinal (ALLN) induced SOD1 aggregation was also affected upon treatment with the nanoassemblies. These results suggest that the nanoassemblies may potentially modulate the activity and structure of SOD1. [ABSTRACT FROM AUTHOR]

After successfully performing Agrobacterium-mediated CRISPR-Cas9-based gene editing in plants, isolation of the Cas9 T-DNA is essential for the stable inheritance of induced mutations. Here, we report a simple technique that allows the isolation of Cas9-free mutants, eliminating the need for outcrossing or other intricate methods. This method is based on the ability of Basta-sensitive Arabidopsis thaliana seedlings, which generally perish, to recover and grow once transplanted to Basta-free growth media. By growing gene-edited heterozygous populations of single-locus insertion Basta-resistant plants on Basta selection media, plants lacking the Cas9 T-DNA can be identified. These pale-looking plants lacking Cas9 are then rescued on media lacking the Basta to recover Cas9-free plants. The ability of seedlings to recover from Basta selection was also studied in camelina, canola, and wheat. All three crops showed different recovery rates, with wheat demonstrating the highest recovery once transplanted from Basta to normal growth media. In summary, our findings demonstrate that by harnessing the recovery capability of Basta-sensitive seedlings, we can effectively identify and rescue plants lacking the Cas9 T-DNA, enabling the isolation of Cas9-free mutants in Arabidopsis and potentially extending to other crops. [ABSTRACT FROM AUTHOR]

Summary: Mutations play a pivotal role in shaping the trajectory and outcomes of a species evolution and domestication. Maize (Zea mays) has been a major staple crop and model for genetic research for more than 100 yr. With the arrival of site‐directed mutagenesis and genome editing (GE) driven by the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), maize mutational research is once again in the spotlight. If we combine the powerful physiological and genetic characteristics of maize with the already available and ever increasing toolbox of CRISPR‐Cas, prospects for its future trait engineering are very promising. This review aimed to give an overview of the progression and learnings of maize screening studies analyzing forward genetics, natural variation and reverse genetics to focus on recent GE approaches. We will highlight how each strategy and resource has contributed to our understanding of maize natural and induced trait variability and how this information could be used to design the next generation of mutational screenings. [ABSTRACT FROM AUTHOR]

The voltage-dependent potassium channels (Kv channels) show several different types of inactivation. N-type inactivation is a fast inactivating mechanism, which is essentially an open pore blockade by the amino-terminal structure of the channel itself or the auxiliary subunit. There are several functionally discriminatable slow inactivation (C-type, P-type, U-type), the mechanism of which is supposed to include rearrangement of the pore region. In some Kv1 channels, the actual inactivation is brought about by coupling of N-type and C-type inactivation (N-C coupling). In the present study, we focused on the N-C coupling of the Aplysia Kv1 channel (AKv1). AKv1 shows a robust N-type inactivation, but its recovery is almost thoroughly from C-type inactivated state owing to the efficient N-C coupling. In the I8Q mutant of AKv1, we found that the inactivation as well as its recovery showed two kinetic components apparently correspond to N-type and C-type inactivation. Also, the cumulative inactivation which depends on N-type mechanism in AKv1 was hindered in I8Q, suggesting that N-type inactivation of I8Q is less stable. We also found that Zn 2 + specifically accelerates C-type inactivation of AKv1 and that H382 in the pore turret is involved in the Zn 2 + binding. Because the region around Ile 8 (I8) in AKv1 has been suggested to be involved in the pre-block binding of the amino-terminal structure, our results strengthen a hypothesis that the stability of the pre-block state is important for stable N-type inactivation as well as the N-C coupling in the Kv1 channel inactivation. [ABSTRACT FROM AUTHOR]

This review explores the production of the fungal polysaccharide pullulan by mutants and natural isolates of Aureobasidium species using strain improvement. Pullulan is a neutral polysaccharide gum whose structure is a maltotriose-containing glucan. This polysaccharide gum has applications in the fields of food, pharmaceuticals, biomedical and wastewater treatment. The strain improvement of Aureobasidium species has focused on the pullulan production process, including the isolation of strains exhibiting reduced pigmentation, polysaccharide overproduction, the production of pullulan with variable molecular weight, and increased osmotolerant strains promoting pullulan production at high carbon source concentrations and pullulan production on hemicellulosic substrates. The majority of studies have emphasized the isolation of reduced pigmentation and pullulan hyperproducer strains since the goal of large-scale commercial pullulan production is to synthesize non-pigmented polysaccharides. A promising area of strain improvement is the isolation of strains that synthesize authentic pullulan from hemicellulosic substrates. If strain improvement in this area is successful, the goal of commercially producing pullulan at a competitive cost will eventually be achieved. [ABSTRACT FROM AUTHOR]

Moringa is renowned as the miracle tree for its versatile applications in food, medicine, plant growth stimulation, animal feed, and its nutritional, pharmacological, and biotechnological potential. Initially, the mutation was induced by treating the seeds with gamma rays (100 Gy, 200Gy and 300 Gy) and Ethyl methane sulphonate (EMS) at 0.15%, 0.20% and 0.25%. Based on continuous evaluation of mutants from M1 to M3 generation, four selected mutant families: 15-1-09, 35-1-62, 35-1-63 and 35-1-68, with 15 mutants from each family were studied to identify high-performing mutants alongside PKM 1 Moringa. Principal component analysis (PCA) of 12 morphological traits for each mutant family revealed five principal components with eigenvalues exceeding one, collectively explaining 78.19, 74.88, 79.85 and 83.80% of the total variability from the mutant families 15-1-09, 35-1-63, 35-1-62, and 35-1-68 respectively. The analysis highlighted that foliage density, apex shape of the first leaf blade, leaf shape, and plant growth habit exhibited the highest variation, while the remaining traits showed lower variability. Through Agglomerative Hierarchical Clustering (AHC) and Principal Component Analysis (PCA), the genotypes 15-1-09-39, 35-1-62-72, 35-1-62-73, 35-1-68-79, and 35-1-63-06 emerged as the most diverse genotypes based on seedling hypocotyls colour, young shoot colour and petiole: anthocyanin colouration of the axis and branches. Hence, through this study, the identified diverse genotypes for specific traits of interest can be included in the moringa breeding programs for crop improvement. [ABSTRACT FROM AUTHOR]

Proteome analyses of two contrasting mutant lines and their parent revealed responsive proteins in salt stress. The tandem mass spectrometry analysis resulted in identification of 67 proteins involved in various molecular processes including defense to oxidative stresses. The results demonstrated that total upregulated proteins were similar in sensitive and tolerant mutants (20), but downregulated proteins were significantly higher in sensitive line. Similarly, downregulated proteins were equal in tolerant mutant and wild type (23), though upregulated proteins were much higher than their parent. Although, tolerant, sensitive and their parent had partially the same pattern of protein regulations in protein folding and oxidative stress proteins, they were absolutely different in regulation of photosynthesis and carbohydrate proteins. Even, tolerant mutant showed lower up regulation intensity in some oxidative stress proteins than wild-type parent. Protein–protein interaction (PPI) maps revealed core protein roles in regulating salt tolerance mechanisms in mutant lines and their wild-type parent. PPI maps were created with two algorithms including K-mean and MCL clusters to discover protein–protein interactions. By employing PPI, we found 4 core proteins including Peptidyl-prolyl cis–trans isomerase, 70 kDa heat shock protein, Ferredoxin and 2-Cys peroxiredoxin that were involved in protein folding and oxidative stress pathways. These core proteins can regulate a wide range of molecular processes like carbohydrates metabolism, photosynthesis and ATP synthesis. As a result, tolerant mutant would regulate salt tolerance due to efficient and ordered protein–protein interactions. Further studies are needed to illuminate the importance of ordered protein–protein interactions leading to salt tolerance. [ABSTRACT FROM AUTHOR]

Summary: Interactions between plants and microorganisms are pivotal for plant growth and productivity. Several plant molecular mechanisms that shape these microbial communities have been identified. However, the importance of nitric oxide (NO) produced by plants for the associated microbiota remains elusive.Using Arabidopsis thaliana isogenic mutants overproducing NO (nox1, NO overexpression) or down‐producing NO (i.e. nia1nia2 impaired in the expression of both nitrate reductases NR1/NIA1 and NR2/NIA2; the 35s::GSNOR1 line overexpressing nitrosoglutathione reductase (GSNOR) and 35s::AHB1 line overexpressing haemoglobin 1 (AHB1)), we investigated how altered NO homeostasis affects microbial communities in the rhizosphere and in the roots, soil microbial activity and soil metabolites.We show that the rhizosphere microbiome was affected by the mutant genotypes, with the nox1 and nia1nia2 mutants causing opposite shifts in bacterial and fungal communities compared with the wild‐type (WT) Col‐0 in the rhizosphere and roots, respectively. These mutants also exhibited distinctive soil metabolite profiles than those from the other genotypes while soil microbial activity did not differ between the mutants and the WT Col‐0.Our findings support our hypothesis that changes in NO production by plants can influence the plant microbiome composition with differential effects between fungal and bacterial communities. [ABSTRACT FROM AUTHOR]

Kalmegh is one of the most widely used medicinal herbs in tropical Asian countries because it contains many therapeutic compounds among them andrographolide and neo-andrographolide are two major bioactive compounds that have a variety of therapeutic properties. In this crop, only prevailing variability was used for cultivation and other research. The attempt was very limited or nil for the creation of new variability and stability assessment. The present study was undertaken to create new genetic variability in kalmegh and to assess the stability of newly generated mutants. The cultivar CIM-Megha was treated with different doses of gamma rays and a total of 47 mutant lines were tested throughout the course of three different years (2019, 2020, and 2021) to determine the stability of mutants over three years for andrographolide and neo-andrographolide content (%). Biplot analyses using additive main effect and multiplicative interaction (AMMI) and genotype-genotype-environment (GGE) were performed. Using pooled analysis of variance (ANOVA), it was found that there was a significant genotype by environment interaction (GEI) for both components. Moreover, mutants showed significant GEI for both andrographolide and neo-andrographolide in the AMMI ANOVA. The mutants 4, 16, 21, 23, 28, 40, and 5 were found to be stable for andrographolide content, whereas the mutants 7, 32, 20, and 36 were found to be stable for neo-andrographolide content based on the AMMI-1 biplot. According to GGE biplots, mutant 4 was found to be a reasonably excellent performer with stability for andrographolide content, and mutant 14, which produced a significant amount of neo-andrographolide, was found to be the most stable. [ABSTRACT FROM AUTHOR]

This review explores the production of the fungal polysaccharide pullulan by mutants and natural isolates of Aureobasidium species using strain improvement. Pullulan is a neutral polysaccharide gum whose structure is a maltotriose-containing glucan. This polysaccharide gum has applications in the fields of food, pharmaceuticals, biomedical and wastewater treatment. The strain improvement of Aureobasidium species has focused on the pullulan production process, including the isolation of strains exhibiting reduced pigmentation, polysaccharide overproduction, the production of pullulan with variable molecular weight, and increased osmotolerant strains promoting pullulan production at high carbon source concentrations and pullulan production on hemicellulosic substrates. The majority of studies have emphasized the isolation of reduced pigmentation and pullulan hyperproducer strains since the goal of large-scale commercial pullulan production is to synthesize non-pigmented polysaccharides. A promising area of strain improvement is the isolation of strains that synthesize authentic pullulan from hemicellulosic substrates. If strain improvement in this area is successful, the goal of commercially producing pullulan at a competitive cost will eventually be achieved.

Background: The emergence and spread of multidrug-resistant Staphylococcus aureus strains demonstrates the urgent need for new antimicrobials. Xanthorrhizol, a plant-derived sesquiterpenoid compound, has a rapid killing effect on methicillin-susceptible strains and methicillin-resistant strains of S. aureus achieving the complete killing of staphylococcal cells within 2 min using 64 µg/mL xanthorrhizol. However, the mechanism of its action is not yet fully understood. Methods: The S. aureus cells treated with xanthorrhizol were studied using optical diffraction tomography. Activity of xanthorrhizol against the wild-type and mscL null mutant of S. aureus ATCC 29213 strain was evaluated in the time-kill assay. Molecular docking was conducted to predict the binding of xanthorrhizol to the SaMscL protein. Results: Xanthorrhizol treatment of S. aureus cells revealed a decrease in cell volume, dry weight, and refractive index (RI), indicating efflux of the cell cytoplasm, which is consistent with the spontaneous activation of the mechanosensitive MscL channel. S. aureus ATCC 29213mscL was significantly more resistant to xanthorrhizol than was the wild-type strain. Xanthorrhizol had an enhanced inhibitory effect on the growth and viability of exponentially growing S. aureus ATCC 29213mscL cells overexpressing the SaMscL protein and led to a noticeable decrease in their viability in the stationary growth phase. The amino acid residues F5, V14, M23, A79, and V84 were predicted to be the residues of the binding pocket for xanthorrhizol. We also showed that xanthorrhizol increased the efflux of solutes such as K+ and glutamate from S. aureus ATCC 29213mscL cells overexpressing SaMscL. Xanthorrhizol enhanced the antibacterial activity of the antibiotic dihydrostreptomycin, which targets the MscL protein. Conclusion: Our findings indicate that xanthorrhizol targets the SaMscL protein in S. aureus cells and may have important implications for the development of a safe antimicrobial agent. [ABSTRACT FROM AUTHOR]

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SARS-CoV-2 Omicron has the largest number of mutations among all the known SARS-CoV-2 variants. The presence of these mutations might explain why Omicron is more infectious and vaccines have lower efficacy to Omicron than other variants, despite lower virulence of Omicron. We recently established a long-term in vivo replication model by infecting Calu-3 xenograft tumors in immunodeficient mice with parental SARS-CoV-2 and found that various mutations occurred majorly in the spike protein during extended replication. To investigate whether there are differences in the spectrum and frequency of mutations between parental SARS-CoV-2 and Omicron, we here applied this model to Omicron. At 30 days after infection, we found that the virus was present at high titers in the tumor tissues and had developed several rare sporadic mutations, mainly in ORF1ab with additional minor spike protein mutations. Many of the mutant isolates had higher replicative activity in Calu-3 cells compared with the original SARS-CoV-2 Omicron virus, suggesting that the novel mutations contributed to increased viral replication. Serial propagation of SARS-CoV-2 Omicron in cultured Calu-3 cells resulted in several rare sporadic mutations in various viral proteins with no mutations in the spike protein. Therefore, the genome of SARS-CoV-2 Omicron seems largely stable compared with that of the parental SARS-CoV-2 during extended replication in Calu-3 cells and xenograft model. The sporadic mutations and modified growth properties observed in Omicron might explain the emergence of Omicron sublineages. However, we cannot exclude the possibility of some differences in natural infection. [ABSTRACT FROM AUTHOR]

A series of novel sulfone derivatives were synthesized and screened in vitro for their cytotoxicity and antifungal activity with annotated primary mechanism of action (MOA). We prioritized sulfones with high (4-(bromodichloromethylsulfonyl)benzoic acid 4, 4-(difluoromethylsulfonyl)benzoic acid 12), little (3-[4-(bromodichloromethylsulfonyl)phenyl]propanoic acid 8, difluoromethyl 4-methylphenyl sulfone 11, 4-(difluoromethylsulfonyl)benzoic acid 12), or no cytotoxicity of 4-(4-(dichloromethylsulfonyl)benzoic acid 3) and 3-[4-(dichloromethylsulfonyl)phenyl]propanoic acid 7 against mammalian cell lines. 3 was found to be the most potent sulfone against Candida albicans (Rlog=7.25 at 128–256 µg/mL). The mutation in the CNB1 gene (1) increased the sensitivity of the C. albicans biofilm to 3; (2) reduced ergosterol production and therefore generated higher susceptibility to 4. Sulfone 4 at 128 µg/mL increased cellular RH-123 fluorescence in the wild-type cells of C. albicans, except CNB1/cnb1∆. Moreover, the uptake of sulfones into the cell was unaffected regardless of the presence or absence of RH-123, and the uptake of sulfones was strictly cell/strain dependent. Both RH123 and sulfones cumulatively competed with one another for access to transporters. Calcineurin played a role in this mechanism. [ABSTRACT FROM AUTHOR]

Abstract The misfolding and aggregation of superoxide dismutase 1 (SOD1) and its mutants has been implicated in amyotrophic lateral sclerosis (ALS). In this study, we have created three peptide conjugates with the antioxidant pentacyclic terpene celastrol and examined their interactions with SOD1 and its mutants A4V and G93A. The peptides YYIVS, MPDAHL, and GSGGL are derived from natural sources and are known for their inherent antioxidant properties. Docking studies revealed that most conjugates showed strong binding with the metal binding and electrostatic loops as well as the β1, β5, and β6 hydrophobic core of SOD1. The conjugates were synthesized and self‐assembled into nanoassemblies. Surface plasmon resonance studies further confirmed the binding interactions of the nanoassemblies with the SOD1 proteins. The nanoassemblies were found to internalize into HEK293T cells. The HEK 293T cells were then transfected with GFP fused WT (Wild Type), A4V and G93A SOD1 mutants. Flow cytometry revealed that treatment with celastrol‐peptide nanoassemblies, affected the fluorescence of the SOD1 protein, implying their role in modulating SOD1, particularly for the mutants. N–Acetyl–Leu–Leu–Norleucinal (ALLN) induced SOD1 aggregation was also affected upon treatment with the nanoassemblies. These results suggest that the nanoassemblies may potentially modulate the activity and structure of SOD1.

After successfully performing Agrobacterium-mediated CRISPR-Cas9-based gene editing in plants, isolation of the Cas9 T-DNA is essential for the stable inheritance of induced mutations. Here, we report a simple technique that allows the isolation of Cas9-free mutants, eliminating the need for outcrossing or other intricate methods. This method is based on the ability of Basta-sensitive Arabidopsis thaliana seedlings, which generally perish, to recover and grow once transplanted to Basta-free growth media. By growing gene-edited heterozygous populations of single-locus insertion Basta-resistant plants on Basta selection media, plants lacking the Cas9 T-DNA can be identified. These pale-looking plants lacking Cas9 are then rescued on media lacking the Basta to recover Cas9-free plants. The ability of seedlings to recover from Basta selection was also studied in camelina, canola, and wheat. All three crops showed different recovery rates, with wheat demonstrating the highest recovery once transplanted from Basta to normal growth media. In summary, our findings demonstrate that by harnessing the recovery capability of Basta-sensitive seedlings, we can effectively identify and rescue plants lacking the Cas9 T-DNA, enabling the isolation of Cas9-free mutants in Arabidopsis and potentially extending to other crops.

Abstract Thermophilic endo-chitinases are essential for production of highly polymerized chitooligosaccharides, which are advantageous for plant immunity, animal nutrition and health. However, thermophilic endo-chitinases are scarce and the transformation from exo- to endo-activity of chitinases is still a challenging problem. In this study, to enhance the endo-activity of the thermophilic chitinase Chi304, we proposed two approaches for rational design based on comprehensive structural and evolutionary analyses. Four effective single-point mutants were identified among 28 designed mutations. The ratio of (GlcNAc)3 to (GlcNAc)2 quantity (DP3/2) in the hydrolysates of the four single-point mutants undertaking colloidal chitin degradation were 1.89, 1.65, 1.24, and 1.38 times that of Chi304, respectively. When combining to double-point mutants, the DP3/2 proportions produced by F79A/W140R, F79A/M264L, F79A/W272R, and M264L/W272R were 2.06, 1.67, 1.82, and 1.86 times that of Chi304 and all four double-point mutants exhibited enhanced endo-activity. When applied to produce chitooligosaccharides (DP ≥ 3), F79A/W140R accumulated the most (GlcNAc)4, while M264L/W272R was the best to produce (GlcNAc)3, which was 2.28 times that of Chi304. The two mutants had exposed shallower substrate-binding pockets and stronger binding abilities to shape the substrate. Overall, this research offers a practical approach to altering the cutting pattern of a chitinase to generate functional chitooligosaccharides. Graphical abstract

To provide an updated summary of recent advances in the application of gamma irradiation to elicit secondary metabolism and for induction of mutations in plant cell and organ cultures for the production of industrially important specialized metabolites (SMs). Research on the application of gamma radiation with plants has contributed a lot to microbial decontamination of seeds, and the promotion of physiological processes such as seed germination, seedling vigor, plant growth, and development. Various studies have demonstrated the influence of gamma rays on the morphology, physiology, and biochemistry of plants. Recent research efforts have also shown that low-dose gamma (5–100 Gy) irradiation can be utilized as an expedient solution to alleviate the deleterious effect of abiotic stresses and to obtain better yields of plants. Inducing mutagenesis using gamma irradiation has also evolved as a better option for inducing genetic variability in crops, vegetables, medicinal and ornamentals for their genetic improvement. Plant SMs are gaining increasing importance as pharmaceutical, therapeutic, cosmetic, and agricultural products. Plant cell, tissue, and organ cultures represent an attractive alternative to conventional methods of procuring useful SMs. Among the varied approaches the elicitor-induced in vitro culture techniques are considered an efficient tool for studying and improving the production of SMs. This review focuses on the utilization of low-dose gamma irradiation in the production of high-value SMs such as phenolics, terpenoids, and alkaloids. Furthermore, we present varied successful examples of gamma-ray-induced mutations in the production of SMs. [ABSTRACT FROM AUTHOR]

The emergence of SARS-CoV-2 triggered a global health emergency, causing > 7 million deaths thus far. Limited early knowledge spurred swift research, treatment, and vaccine developments. Implementation of public health measures such as, lockdowns and social distancing, disrupted economies and strained healthcare. Viral mutations highlighted the need for flexible strategies and strong public health infrastructure, with global collaboration crucial for pandemic control. (i) Revisiting diagnostic strategies, (ii) adapting to the evolving challenge of the virus, (iii) vaccines against new variants, (iv) vaccine hesitancy in the light of the evolving disease, (v) treatment strategies, (vi) hospital preparedness for changing clinical needs, (vii) global cooperation and data sharing, (viii) economic implications, and (ix) education and awareness- keeping communities informed. The COVID-19 crisis forced unprecedented adaptation, emphasizing public health readiness, global unity, and scientific advancement. Key lessons highlight the importance of adaptability and resilience against uncertainties. As the pandemic evolves into a 'new normal,' ongoing vigilance, improved understanding, and available vaccines and treatments equip us for future challenges. Priorities now include proactive pandemic strategies, early warnings, supported healthcare, public education, and addressing societal disparities for better health resilience and sustainability. [ABSTRACT FROM AUTHOR]

N-glycosylation is one of the most common and most complex posttranslational modifications of proteins, playing a key role in their folding, quality control, and degradation, and it also influences activity, transport, localization, and interaction with other proteins. Moreover, N-glycosylation modulates many important biological processes, including growth, development, and morphogenesis and is involved in stress signaling processes. Moreover, while the role of N-glycosylation in general and the functions of individual N‑glycans in mammalian cells have been well studied, the studies of this process in plants lag significantly behind. The review summarizes the available information about the N-glycosylation process of proteins, the biosynthetic pathway and functions of various N-glycans in plants in the context of growth, development, and the influence of external factors. Emphasis is placed on the main points that must be taken into account when studying this process in plants, and the possibilities of practical use of the acquired knowledge for glycoengineering of plant proteins are discussed. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is one of the most abundant polyester materials used in daily life and it is also one of the culprits of environmental pollution. ICCG (F243I/D238C/S283C/Y127G) is a quadruple mutant of leaf-branch compost cutinase (LCC) displaying outstanding performance in hydrolyzing PET and holding a great potential in further applications. Substrate concentration is one of the important factors affecting the catalytic degradation efficiency. The conventional fast equilibrium theory holds that the degradation rate reaches the maximum and tends to be stable with the increase of substrate concentration, however, in practice, too much substrate will inhibit the catalytic reaction. In this study, the substrate inhibitory effect of PET plastic particles with different particle sizes on ICCG was evaluated. Combined with kinetic constant analysis, the optimal PET particle size was determined to be 300 μm. Meanwhile, several mutants (Y95K, M166S and H218S) of ICCG were obtained by site-directed mutagenesis. The effect of substrate concentration on mutant was studied under the condition of optimal reaction particle size. This study provides a strategy for obtaining high-efficiency PET degradation mutants and a new possibility of environmentally friendly plastic degradation. [ABSTRACT FROM AUTHOR]

Bagasse, the residue left after extracting juice from sugarcane stalks, is rich in lignocellulosic biomass. The lignin present in this plant biomass is the key factor that hinders the efficient extraction of ethanol from the bagasse. In the current study, γ-irradiated sugarcane mutants were evaluated for variation in lignin content and its corresponding caffeic acid-O-methyl transferase (COMT) gene. The acetyl bromide method was used to estimate lignin content in sugarcane mutants. PCR-based cloning of the COMT gene was performed in low lignin mutants as well as control plants in E. coli (strain DH5α) to understand the mechanism of variation at the molecular level. The Sanger sequencing for cloned gene was performed to check variation in gene sequence. In comparison to the control (21.5%), the mutant plants' lignin content ranged from 13 to 28%. The Sanger sequencing revealed approximately the same length of the gene from mutants as well as a control plant. In comparison to the reference gene, the mutated gene showed SNPs and indels in different regions, which may have an impact on lignin content. Therefore, γ-irradiated mutagenesis is an acceptable approach to develop novel mutants of sugarcane with low lignin content to enhance bioethanol production from waste material using bioprocess technology. [ABSTRACT FROM AUTHOR]

Thermophilic endo-chitinases are essential for production of highly polymerized chitooligosaccharides, which are advantageous for plant immunity, animal nutrition and health. However, thermophilic endo-chitinases are scarce and the transformation from exo- to endo-activity of chitinases is still a challenging problem. In this study, to enhance the endo-activity of the thermophilic chitinase Chi304, we proposed two approaches for rational design based on comprehensive structural and evolutionary analyses. Four effective single-point mutants were identified among 28 designed mutations. The ratio of (GlcNAc)3 to (GlcNAc)2 quantity (DP3/2) in the hydrolysates of the four single-point mutants undertaking colloidal chitin degradation were 1.89, 1.65, 1.24, and 1.38 times that of Chi304, respectively. When combining to double-point mutants, the DP3/2 proportions produced by F79A/W140R, F79A/M264L, F79A/W272R, and M264L/W272R were 2.06, 1.67, 1.82, and 1.86 times that of Chi304 and all four double-point mutants exhibited enhanced endo-activity. When applied to produce chitooligosaccharides (DP ≥ 3), F79A/W140R accumulated the most (GlcNAc)4, while M264L/W272R was the best to produce (GlcNAc)3, which was 2.28 times that of Chi304. The two mutants had exposed shallower substrate-binding pockets and stronger binding abilities to shape the substrate. Overall, this research offers a practical approach to altering the cutting pattern of a chitinase to generate functional chitooligosaccharides. [ABSTRACT FROM AUTHOR]

BackgroundThe emergence and spread of multidrug-resistant Staphylococcus aureus strains demonstrates the urgent need for new antimicrobials. Xanthorrhizol, a plant-derived sesquiterpenoid compound, has a rapid killing effect on methicillin-susceptible strains and methicillin-resistant strains of S. aureus achieving the complete killing of staphylococcal cells within 2 min using 64 μg/mL xanthorrhizol. However, the mechanism of its action is not yet fully understood.MethodsThe S. aureus cells treated with xanthorrhizol were studied using optical diffraction tomography. Activity of xanthorrhizol against the wild-type and mscL null mutant of S. aureus ATCC 29213 strain was evaluated in the time-kill assay. Molecular docking was conducted to predict the binding of xanthorrhizol to the SaMscL protein.ResultsXanthorrhizol treatment of S. aureus cells revealed a decrease in cell volume, dry weight, and refractive index (RI), indicating efflux of the cell cytoplasm, which is consistent with the spontaneous activation of the mechanosensitive MscL channel. S. aureus ATCC 29213ΔmscL was significantly more resistant to xanthorrhizol than was the wild-type strain. Xanthorrhizol had an enhanced inhibitory effect on the growth and viability of exponentially growing S. aureus ATCC 29213ΔmscL cells overexpressing the SaMscL protein and led to a noticeable decrease in their viability in the stationary growth phase. The amino acid residues F5, V14, M23, A79, and V84 were predicted to be the residues of the binding pocket for xanthorrhizol. We also showed that xanthorrhizol increased the efflux of solutes such as K+ and glutamate from S. aureus ATCC 29213ΔmscL cells overexpressing SaMscL. Xanthorrhizol enhanced the antibacterial activity of the antibiotic dihydrostreptomycin, which targets the MscL protein.ConclusionOur findings indicate that xanthorrhizol targets the SaMscL protein in S. aureus cells and may have important implications for the development of a safe antimicrobial agent.

The lack of effective treatment options for an increasing number of cancer cases highlights the need for new anticancer therapeutic strategies. Immunotherapy mediated by Salmonella enterica Typhimurium is a promising anticancer treatment. Candidate strains for anticancer therapy must be attenuated while retaining their antitumor activity. Here, we investigated the attenuation and antitumor efficacy of two S. enterica Typhimurium mutants, ΔtolRA and ΔihfABpmi, in a murine melanoma model. Results showed high attenuation of ΔtolRA in the Galleria mellonella model, and invasion and survival in tumor cells. However, it showed weak antitumor effects in vitro and in vivo. Contrastingly, lower attenuation of the attenuated ΔihfABpmi strain resulted in regression of tumor mass in all mice, approximately 6 days after the first treatment. The therapeutic response induced by ΔihfABpmi was accompanied with macrophage accumulation of antitumor phenotype (M1) and significant increase in the mRNAs of proinflammatory mediators (TNF-α, IL-6, and iNOS) and an apoptosis inducer (Bax). Our findings indicate that the attenuated ΔihfABpmi exerts its antitumor activity by inducing macrophage infiltration or reprogramming the immunosuppressed tumor microenvironment to an activated state, suggesting that attenuated S. enterica Typhimurium strains based on nucleoid-associated protein genes deletion could be immunotherapeutic against cancer.

This article analyzes the complete corpus of live-action X-Men movies for their depictions of genetics and otherness. The researchers watched and qualitatively coded all thirteen movies produced by 20th Century Fox that take place in the same shared cinematic universe, beginning with X-Men (2000) and ending with The New Mutants (2020). The X-Men movies are unusual summer blockbusters since they explore genetic topics through their central characters, mutants, who are genetically different from their non-mutant peers. Mutants in the films evoke a plurality of analogies, such as mutant-as-Black and mutant-as-queer. These intersecting metaphors build upon a core of genetic difference to create a versatile but limited picture of prejudice, solidarity, and otherness. [ABSTRACT FROM AUTHOR]

Plastid-encoded RNA polymerase (PEP) forms a multisubunit complex in operating chloroplasts, where PEP subunits and a sigma factor are tightly associated with 12 additional nuclear-encoded proteins. Mutants with disrupted genes encoding PEP-associated proteins (PAPs) provide unique tools for deciphering mutual relationships among phytohormones. A block of chloroplast biogenesis in Arabidopsis pap mutants specifying highly altered metabolism in white tissues induced dramatic fluctuations in the content of major phytohormones and their metabolic genes, whereas hormone signaling circuits mostly remained functional. Reprogramming of the expression of biosynthetic and metabolic genes contributed to a greatly increased content of salicylic acid (SA) and a concomitant decrease in 1-aminocyclopropane-1-carboxylic acid (ACC) and oxophytodienoic acid (OPDA), precursors of ethylene and jasmonic acid, respectively, in parallel to reduced levels of abscisic acid (ABA). The lack of differences in the free levels of indole-3-acetic acid (IAA) between the pap mutants and wild-type plants was accompanied by fluctuations in the contents of IAA precursors and conjugated forms as well as multilayered changes in the expression of IAA metabolic genes. Along with cytokinin (CK) overproduction, all of these compensatory changes aim to balance plant growth and defense systems to ensure viability under highly modulated conditions. [ABSTRACT FROM AUTHOR]

We recently established a long‐term SARS‐CoV‐2 infection model using lung‐cancer xenograft mice and identified mutations that arose in the SARS‐CoV‐2 genome during long‐term propagation. Here, we applied our model to the SARS‐CoV‐2 Delta variant, which has increased transmissibility and immune escape compared with ancestral SARS‐CoV‐2. We observed limited mutations in SARS‐CoV‐2 Delta during long‐term propagation, including two predominant mutations: R682W in the spike protein and L330W in the nucleocapsid protein. We analyzed two representative isolates, Delta‐10 and Delta‐12, with both predominant mutations and some additional mutations. Delta‐10 and Delta‐12 showed lower replication capacity compared with SARS‐CoV‐2 Delta in cultured cells; however, Delta‐12 was more lethal in K18‐hACE2 mice compared with SARS‐CoV‐2 Delta and Delta‐10. Mice infected with Delta‐12 had higher viral titers, more severe histopathology in the lungs, higher chemokine expression, increased astrocyte and microglia activation, and extensive neutrophil infiltration in the brain. Brain tissue hemorrhage and mild vacuolation were also observed, suggesting that the high lethality of Delta‐12 was associated with lung and brain pathology. Our long‐term infection model can provide mutant viruses derived from SARS‐CoV‐2 Delta and knowledge about the possible contributions of emergent mutations to the properties of new variants. [ABSTRACT FROM AUTHOR]

Dioscorea is an important group of species in the world cultivated as a food source with an eatable tuber rich in carbohydrates, minerals, saponins and pigments in some varieties, making them a functional food. Dioscorea genus is cultivated in Africa, Asia and parts of South America. Dioscoreaceae has six genus and close to 850 species, the most abundant genus is Dioscorea with 650 species. In Mexico 65 species have been reported to date, the most important one being D. sparsiflora as it is used as food. The common name given to Dioscorea sparsiflora collectively is camote de cerro and its nutritional value is similar to other tubers. Its natural habitat is the large gullies, generally living among tangled bushes and trees and on top of them. As a natural resource it is over exploited from September to May. It has been noticed that fruits and seeds can be damaged by beetles jeopardizing the recovery of native populations. Crop yield is the result of good management as this reduces physiological disorders and promotes optimal morphological development. Besides its nutritional value, increasing yield is important as several other aspects can be taken advantage of, like using the light energy reaching its leaves, due to plants' capacity to intercept and transform it into chemical energy. Photosynthetic capacity is related to tuber yield. Camote the cerro has a specific demand of light intensity at each stage of its development and this can impact yield, length and width. As it develops on the ground it is important to find methodologies allowing for optimal growth. It has been reported that form and size of furrow or mound has an impact on yield. Specifically for D. sparsiflora, the form of the container where it is planted has an effect on tuber yield.To find out which factors improve D. sparsiflora yield, different light intensities (26000, 18000 and 14000 lx), three shade periods (60, 90 and 180 d), and five types of containers were evaluated in two accessions (751 and 112). Tuber weight was higher at 18000 lx (6.9 t ha-1) and a higher yield was obtained when cultivated for 60 d of shading (33 t ha-1). The container was rectangular (40 t ha-1). Accession 751 presented the highest averages of weight and diameter (43 t ha-1 and 73 mm, respectively). Breeding is one of the alternatives that has been considered in all crops as it can improve species characteristics, like yield, adaptability to environmental conditions, and increase in important chemical compounds. Among breeding alternatives, crossbreeding is considered a traditional alternative; another way of breeding is through mutagenesis induction with chemical and physical agents that can be a way to obtain variations not commonly found in the species. Before carrying out cross breeding some factors had to be considered, ploidy is one of them and could be a barrier limiting crossbreeding. All Dioscorea species have been reported polyploidies. Using cytogenetic characterization several levels of ploidies were observed in D. sparsiflora for native accessions from different areas of Jalisco: 2n, 3n, 4n and 6n. This was carried out placing the ends of roots in a 2mM 8-hidroxiquinoleine solution; a solution of acetic alcohol was used for fixing; chromosomes were tinted with acetoorcein. Findings showed that ploidy level is related to chloroplast number in stomata and stomata width. An alternative for producing hybrid plants in D. sparsiflora has been carrying pollen to feminine flowers. In these hybrids, tuber yield has been poor in the first life cycles, but it is possible to find variations among different hybrids. Hybrids were obtained using females and males from the 11 variations of the State of Jalisco. They were placed in two different environments (greenhouse and shade house). Greenhouse hybrids had a greater percentage of success (32%). Trying to get better genetic characteristics, D. sparsiflora and D. alata plants propagated in vitro were radiated with different dosages of Gamma rays and then acclimated to greenhouse conditions. To know if there were differences with treatments, mini tubers were weighed and measured. Results showed that D. sparsiflora resisted all dosages; those treated with 30 Gy and higher radiation treatments had the greatest size. For D. alata, seedlings radiated with 50 and 60 Gy did not survive. The highest number of mini tubers obtained were those radiated with 10 Gy, but the biggest ones were from mini tubers radiated with 20 Gy. These morphological changes in mini tubers could be considered variations due to a genetic change caused by Gamma radiation and the researched alternatives could be used for agricultural purposes in D. sparsiflora domestication process, obtaining the resource and not damaging wild populations. [ABSTRACT FROM AUTHOR]

This manuscript aimed for the generation of γ-irradiation derived mutants of potato genotype PAU/RR-1501 possessing desirable processing traits. Nodal cuttings from virus-free explants were established on basal MS medium and irradiated with different doses (0, 5, 10 and 20 Gy) of γ-irradiation. The 5 and 10 Gy treated plantlets were multiplied and used for micro-tuber induction. Harvested micro-tubers were planted in pots for the selection and evaluation of mutants in M1V2 generation. Four weeks post-treatment, plantlets (5 Gy) showed enhanced growth as compared to the control while 20 Gy treatment exhibited completely ceased shoot growth. The highest number and weight of mini-tubers per plant was recorded for 10 Gy followed by 5 Gy treatment as compared to control. The γ-irradiation treatments caused changes in the skin color and shape of M1V2 tubers. Under the 5 Gy treatment 49.9% of clones produced exhibited cream and 8.53% brown skin color. Nine putative mutants were identified in genotype PAU/RR-1501 exhibiting promising processing traits. [ABSTRACT FROM AUTHOR]

The coastal region of Lebak-Banten is an area with a relatively high population of buffalo. The forage requirement has relied on existing forage with low productivity and quality. The study aimed to investigate the physiological, morphological, and nutritional response of mutant benggala grass in the coastal area and to develop salt-tolerant forage crops with high productivity and nutritive value for livestock. The research was conducted in the Binuangeun coastal area, Muara Village, Wanasalam District, Lebak Regency, located at 6°50'34.4"S and 105°53'23.4"E. This study used a completely randomized block design with a factorial arrangement with 5 replications. The first factor consisted of 4 benggala grass mutants: mutant 12, 18, 36, 56, and a control. The second factor was the location or distance of the planting plots from the coastline (FC), consisting of L1: 50 m FC, L2: 75 m FC, L3: 100 m FC, and L4: 500 m FC, representative of low, moderate, and high salinity levels, and no saline. Observations were made during the dry and rainy seasons. The results showed that mutants 12 and 36 had higher fresh forage production during the rainy season, while mutant 36 had the highest forage production at the L1 location (high salinity conditions) during the dry season. Mutant 12 had higher crude protein values at the L2 location (moderate salinity) than the other mutants and locations (salinity levels) during the dry season. Meanwhile, mutant 18 at the L2 location (moderate salinity) had the highest crude protein value during the rainy season. In addition, mutant 12 had a high proline value at the L1 location (high salinity stress) as a plant adaptation response to salinity stress. The study suggests that mutants 12 and 36 have great potential to be developed into new salttolerant forage crop cultivars and can be grown in coastal areas of Lebak-Banten. [ABSTRACT FROM AUTHOR]

Aldehyde dehydrogenase (ALDH), a common oxidoreductase in organisms, is an aldehyde scavenger involved in various metabolic processes. However, its function in different pathogenic fungi remains unknown. Fusarium graminearum causes Fusarium head blight in cereals, which reduces grain yield and quality and is an important global food security problem. To elucidate the pathogenic mechanism of F. graminearum, seven genes encoding ALDH were knocked out and then studied for their function. Single deletions of seven ALDH genes caused a decrease in spore production and weakened the pathogenicity. Furthermore, these deletions altered susceptibility to various abiotic stresses. FGSG_04194 is associated with a number of functions, including mycelial growth and development, stress sensitivity, pathogenicity, toxin production, and energy metabolism. FGSG_00139 and FGSG_11482 are involved in sporulation, pathogenicity, and SDH activity, while the other five genes are multifunctional. Notably, we found that FGSG_04194 has an inhibitory impact on ALDH activity, whereas FGSG_00979 has a positive impact. RNA sequencing and subcellular location analysis revealed that FGSG_04194 is responsible for biological process regulation, including glucose and lipid metabolism. Our results suggest that ALDH contributes to growth, stress responses, pathogenicity, deoxynivalenol synthesis, and mitochondrial energy metabolism in F. graminearum. Finally, ALDH presents a potential target and theoretical basis for fungicide development. [ABSTRACT FROM AUTHOR]

The current study was carried out at Nuclear Institute of Agriculture, Tandojam to assess ten mungbean mutants together with one check cultivar in two separate cropping seasons. The findings revealed that all mutants, with the exception of the branches per plant, had significantly different examined traits. By characterizing ten variables, including plant height (cm), number of branches/plant, number of seeds per pod, grain yield per plot (g/plot), grain weight per plant, pod length (cm), pods per plant, days to flowering, above ground biological weight per plot (g/plot) and days to maturity, the results could considerably differentiate between low and high producing mutants. Discriminant analysis was used to choose high-yielding genotypes. The discriminant score demonstrated a significant canonical correlation of 0.994** and could account for 98.8 % of differences in mungbean production. According to the results of discriminant function analysis, the most significant features are pod length, days to flowering, plant height and above ground biological weight. The highest discriminant scores were displayed by the genotypes AEM66, AEM27, AEM25 and AEM14, identified as high yielding mutants. The low yielding mungbean mutants, designated Viz, AEM20, AEM30, AEM35, AEM-96, AEM29, AEM40 and AEM32 are those that exhibit the lowest values of the discriminant score. Mungbean cultivation is more successful in the summer than it is in the spring.

Understanding the connection between local and global dynamics can provide valuable insights into enzymatic function and may contribute to the development of novel strategies for enzyme modulation. In this work, we investigated the dynamics at both the global and local (active site) levels of Shikimate Kinase (SK) through microsecond time-scale molecular dynamics (MD) simulations of the holoenzyme in the product state. Our focus was on the wild-type (WT) enzyme and two mutants (R116A and R116K) which are known for their reduced catalytic activity. Through exploring the dynamics of these variants, we gained insights into the role of residue R116 and its contribution to overall SK dynamics. We argue that the connection between local and global dynamics can be attributed to local frustration near the mutated residue which perturbs the global protein dynamics.

The morbidostat is a bacteria culture device that progressively increases antibiotic drug concentration. It is used to study the evolutionary pathway. In this article, we construct mathematical models for the morbidostat. First we consider the case of no mutations, we study limiting systems and obtain criteria for the large time behavior of the solutions. From the theoretical results and numerical simulations, we conclude that there are two competitive exclusion states of either wild type or mutant type as the threshold parameter $ U $ varies. There are three cases, wild type bacteria excludes all mutants; a mutant dominates in the competition; oscillation between the above two states. Next we study the systems of forward mutations and forward-backward mutations. Then we apply a result of pertubation for globally stable state.

This article analyzes the complete corpus of live-action X-Men movies for their depictions of genetics and otherness. The researchers watched and qualitatively coded all thirteen movies produced by 20th Century Fox that take place in the same shared cinematic universe, beginning with X-Men (2000) and ending with The New Mutants (2020). The X-Men movies are unusual summer blockbusters since they explore genetic topics through their central characters, mutants, who are genetically different from their non-mutant peers. Mutants in the films evoke a plurality of analogies, such as mutant-as-Black and mutant-as-queer. These intersecting metaphors build upon a core of genetic difference to create a versatile but limited picture of prejudice, solidarity, and otherness.

The coastal region of Lebak-Banten is an area with a relatively high population of buffalo. The forage requirement has relied on existing forage with low productivity and quality. The study aimed to investigate the physiological, morphological, and nutritional response of mutant benggala grass in the coastal area and to develop salt-tolerant forage crops with high productivity and nutritive value for livestock. The research was conducted in the Binuangeun coastal area, Muara Village, Wanasalam District, Lebak Regency, located at 6°50’34.4”S and 105°53’23.4”E. This study used a completely randomized block design with a factorial arrangement with 5 replications. The first factor consisted of 4 benggala grass mutants: mutant 12, 18, 36, 56, and a control. The second factor was the location or distance of the planting plots from the coastline (FC), consisting of L1: 50 m FC, L2: 75 m FC, L3: 100 m FC, and L4: 500 m FC, representative of low, moderate, and high salinity levels, and no saline. Observations were made during the dry and rainy seasons. The results showed that mutants 12 and 36 had higher fresh forage production during the rainy season, while mutant 36 had the highest forage production at the L1 location (high salinity conditions) during the dry season. Mutant 12 had higher crude protein values at the L2 location (moderate salinity) than the other mutants and locations (salinity levels) during the dry season. Meanwhile, mutant 18 at the L2 location (moderate salinity) had the highest crude protein value during the rainy season. In addition, mutant 12 had a high proline value at the L1 location (high salinity stress) as a plant adaptation response to salinity stress. The study suggests that mutants 12 and 36 have great potential to be developed into new salt-tolerant forage crop cultivars and can be grown in coastal areas of Lebak-Banten.

The ease and throughput of single-cell genomics have steadily improved, and its current trajectory suggests that surveying single-cell populations will become routine. We discuss the merger of quantitative genetics with single-cell genomics and emphasize how this synergizes with advantages intrinsic to plants. Single-cell population genomics provides increased detection resolution when mapping variants that control molecular traits, including gene expression or chromatin accessibility. Additionally, single-cell population genomics reveals the cell types in which variants act and, when combined with organism-level phenotype measurements, unveils which cellular contexts impact higher-order traits. Emerging technologies, notably multiomics, can facilitate the measurement of both genetic changes and genomic traits in single cells, enabling single-cell genetic experiments. The implementation of single-cell genetics will advance the investigation of the genetic architecture of complex molecular traits and provide new experimental paradigms to study eukaryotic genetics. [ABSTRACT FROM AUTHOR]

The effects of high-intensity light on the pigment content, photosynthetic rate, and fluorescence parameters of photosystem II in high-pigment tomato mutants (hp 3005) and low-pigment mutants (lp 3617) were investigated. This study also evaluated the dry weight percentage of low molecular weight antioxidant capacity, expression patterns of some photoreceptor-regulated genes, and structural aspects of leaf mesophyll cells. The 3005 mutant displayed increased levels of photosynthetic pigments and anthocyanins, whereas the 3617 mutant demonstrated a heightened content of ultraviolet-absorbing pigments. The photosynthetic rate, photosystem II activity, antioxidant capacity, and carotenoid content were most pronounced in the high-pigment mutant after 72 h exposure to intense light. This mutant also exhibited an increase in leaf thickness and water content when exposed to high-intensity light, suggesting superior physiological adaptability and reduced photoinhibition. Our findings indicate that the enhanced adaptability of the high-pigment mutant might be attributed to increased flavonoid and carotenoid contents, leading to augmented expression of key genes associated with pigment synthesis and light regulation. [ABSTRACT FROM AUTHOR]