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Frontiers in Plant Science 2024Arsenate, a metalloid, acting as an analog to phosphate, has a tendency to accumulate more readily in plant species, leading to adverse effects.
INTRODUCTION
Arsenate, a metalloid, acting as an analog to phosphate, has a tendency to accumulate more readily in plant species, leading to adverse effects.
METHODS
In the current study, sunflower seedlings were exposed to 25, 50 and 100 ppm of the arsenic.
RESULTS
Likewise, a notable reduction (p<0.05) was observed in the relative growth rate (RGR) by 4-folds and net assimilation rate (NAR) by 75% of when subjected to arsenic (As) stress. Nevertheless, the presence of , a plant growth-promoting rhizobacterium with As tolerance, yielded an escalation in the growth of within As-contaminated media. facilitated the conversion of As into a form accessible to plants, thereby, increasing its uptake and subsequent accumulation in plant tissues. encouraged the enzymatic antioxidant systems (Superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT)) and non-enzymatic antioxidants (flavonoids, phenolics, and glutathione) in seedlings following substantial As accumulation. The strain also induced the host plant to produce osmolytes like proline and sugars, mitigating water loss and maintaining cellular osmotic balance under As-induced stress. rectified imbalances in lignin content, reduced high malonaldehyde (MDA) levels, and minimized electrolyte leakage, thus counteracting the toxic impacts of the metal.
CONCLUSION
The strain exhibited the capability to concurrently encourage plant growth and remediate Ascontaminated growth media through 2-folds rate of biotransformation and bio-mobilization.
PubMed: 38952849
DOI: 10.3389/fpls.2024.1391348 -
Frontiers in Plant Science 2024Melatonin (N-acetyl-5-methoxytryptamine) is a molecule implicated in multiple biological functions, but exerts contrasting effects on plants owing to concentration...
INTRODUCTION
Melatonin (N-acetyl-5-methoxytryptamine) is a molecule implicated in multiple biological functions, but exerts contrasting effects on plants owing to concentration differences. Hydroxyindole O-methyltransferase (HIOMT), which catalyzes the last step of melatonin synthesis, plays a crucial role in this context.
METHODS
Transgenic switchgrass overexpressing with different melatonin levels displayed distinct morphological changes in a concentration-dependent manner. In this study, we divided the transgenic switchgrass into two groups: melatonin-moderate transgenic (MMT) plants and melatonin-rich transgenic (MRT) plants. To determine the concentration-dependent effect of melatonin on switchgrass growth and stress resistance, we conducted comparative morphological, physiological, omics and molecular analyses between MMT, MRT and wild-type (WT) plants.
RESULTS
We found that overexpression, with moderate melatonin levels, was crucial in regulating switchgrass growth through changes in cell size rather than cell number. Moderate levels of melatonin were vital in regulating carbon fixation, stomatal development and chlorophyll metabolism. Regarding salt tolerance, melatonin with moderate levels activated numerous defense (e.g. morphological characteristics, anatomical structure, antioxidant enzymatic properties, non-enzymatic capacity and Na/K homeostasis). Additionally, moderate levels of overexpression were sufficient to increase lignin content and alter monolignol compositions with an increase in the S/G lignin ratio.
DISCUSSION
Taken together, overexpression in switchgrass with different melatonin levels resulted in morphological, anatomical, physiological and molecular changes in a concentration-dependent manner, which characterized by stimulation at low doses and inhibition at high doses. Our study presents new ideas and clues for further research on the mechanisms of the concentration-dependent effect of melatonin.
PubMed: 38952842
DOI: 10.3389/fpls.2024.1379756 -
Physiologia Plantarum 2024Under changing climatic conditions, plants are simultaneously facing conflicting stresses in nature. Plants can sense different stresses, induce systematic ROS signals,...
Under changing climatic conditions, plants are simultaneously facing conflicting stresses in nature. Plants can sense different stresses, induce systematic ROS signals, and regulate transcriptomic, hormonal, and stomatal responses. We performed transcriptome analysis to reveal the integrative stress response regulatory mechanism underlying heavy metal stress alone or in combination with heat and drought conditions in pitaya (dragon fruit). A total of 70 genes were identified from 31,130 transcripts with conserved differential expression. Furthermore, weighted gene co-expression network analysis (WGCNA) identified trait-associated modules. By integrating information from three modules and protein-protein interaction (PPI) networks, we identified 10 interconnected genes associated with the multifaceted defense mechanism employed by pitaya against co-occurring stresses. To further confirm the reliability of the results, we performed a comparative analysis of 350 genes identified by three trait modules and 70 conserved genes exhibiting their dynamic expression under all treatments. Differential expression pattern of genes and comparative analysis, have proven instrumental in identifying ten putative structural genes. These ten genes were annotated as PLAT/LH2, CAT, MLP, HSP, PB1, PLA, NAC, HMA, and CER1 transcription factors involved in antioxidant activity, defense response, MAPK signaling, detoxification of metals and regulating the crosstalk between the complex pathways. Predictive analysis of putative candidate genes, potentially governing single, double, and multifactorial stress response, by several signaling systems and molecular patterns. These findings represent a valuable resource for pitaya breeding programs, offering the potential to develop resilient "super pitaya" plants.
Topics: Gene Expression Regulation, Plant; Gene Regulatory Networks; Fruit; Vanadium; Stress, Physiological; Caragana; Plant Proteins; Protein Interaction Maps; Gene Expression Profiling; Droughts; Transcriptome; Cactaceae
PubMed: 38952344
DOI: 10.1111/ppl.14416 -
Physiologia Plantarum 2024Phytophthora root rot (PRR), caused by Phytophthora medicaginis, is a major soil-borne disease of chickpea in Australia. Breeding for PRR resistance is an effective...
Phytophthora root rot (PRR), caused by Phytophthora medicaginis, is a major soil-borne disease of chickpea in Australia. Breeding for PRR resistance is an effective approach to avoid significant yield loss. Genetic resistance has been identified in cultivated chickpea (Cicer arietinum) and in the wild relative C. echinospermum, with previous studies identifying independent genetic loci associated with each of these sources. However, the molecular mechanisms associated with PRR resistance are not known. RNA sequencing analysis employed in this study identified changes in gene expression in roots of three chickpea genotypes grown hydroponically, early post-infection with P. medicaginis zoospores. Analyses of differentially expressed genes (DEG) identified the activation of a higher number of non-specific R-genes in a PRR-susceptible variety than in the resistant genotypes, suggesting a whole plant resistance response occurring in chickpea against the pathogen. Contrasting molecular changes in signaling profiles, proteolysis and transcription factor pathways were observed in the cultivated and wild Cicer-derived resistant genotypes. DEG patterns supported a hypothesis that increased root elongation and reduced adventitious root formation limit the pathogen entry points in the genotype containing the wild Cicer source of PRR resistance. Candidate resistance genes, including an aquaporin and a maltose transporter in the wild Cicer source and GDSL esterases/lipases in the cultivated source of resistance, were oppositely regulated. Increased knowledge of these genes and pathways will improve our understanding of molecular mechanisms controlling PRR resistance in chickpea, and support the development of elite chickpea varieties through molecular breeding approaches.
Topics: Cicer; Phytophthora; Plant Diseases; Disease Resistance; Gene Expression Regulation, Plant; Sequence Analysis, RNA; Plant Roots; Genotype
PubMed: 38952339
DOI: 10.1111/ppl.14412 -
Advanced Science (Weinheim,... Jul 2024Phase transitions are typically quantified using order parameters, such as crystal lattice distances and radial distribution functions, which can identify subtle changes...
Phase transitions are typically quantified using order parameters, such as crystal lattice distances and radial distribution functions, which can identify subtle changes in crystalline materials or high-contrast phases with large structural differences. However, the identification of phases with high complexity, multiscale organization and of complex patterns during the structural fluctuations preceding phase transitions, which are essential for understanding the system pathways between phases, is challenging for those traditional analyses. Here, it is shown that for two model systems- thermotropic liquid crystals and a lyotropic water/surfactant mixtures-graph theoretical (GT) descriptors can successfully identify complex phases combining molecular and nanoscale levels of organization that are hard to characterize with traditional methodologies. Furthermore, the GT descriptors also reveal the pathways between the different phases. Specifically, centrality parameters and node-based fractal dimension quantify the system behavior preceding the transitions, capturing fluctuation-induced breakup of aggregates and their long-range cooperative interactions. GT parameterization can be generalized for a wide range of chemical systems and be instrumental for the growth mechanisms of complex nanostructures.
PubMed: 38952077
DOI: 10.1002/advs.202402464 -
ACS Nano Jul 2024Nanotechnology has demonstrated significant potential to improve agricultural production and increase crop tolerance to abiotic stress including exposure to heavy...
Nanotechnology has demonstrated significant potential to improve agricultural production and increase crop tolerance to abiotic stress including exposure to heavy metals. The present study investigated the mechanisms by which aloe vera extract gel-biosynthesized (AVGE) selenium nanoparticles (Se NPs) alleviated cadmium (Cd)-induced toxicity to rice ( L.). AVGE Se NPs, chemically synthesized bare Se NPs, and NaSeO as an ionic control were applied to Cd-stressed rice seedlings via root exposure in both hydroponic and soil systems. Upon exposure to AVGE Se NPs at 15 mg Se/L, the fresh root biomass was significantly increased by 100.7% and 19.5% as compared to Cd control and conventional bare Se NPs. Transcriptional analyses highlighted that AVGE Se NPs activated stress signaling and defense related pathways, including glutathione metabolism, phenylpropanoid biosynthesis and plant hormone signal transduction. Specifically, exposure to AVGE Se NPs upregulated the expression of genes associated with the gibberellic acid (GA) biosynthesis by and 4.79- and 3.29-fold as compared to the Cd-alone treatment and the untreated control, respectively. Importantly, AVGE Se NPs restored the composition of the endophyte community and recruit of beneficial species under Cd exposure; the relative abundance of was significantly increased in roots, shoots, and the rhizosphere soil by 0.73-, 4.58- and 0.37-fold, respectively, relative to the Cd-alone treatment. Collectively, these findings highlight the significant potential of AVGE Se NPs to enhance plant growth and to minimize the Cd-induced toxicity in rice and provide a promising nanoenabled strategy to enhance food safety upon crop cultivation in contaminated agricultural soils.
PubMed: 38952034
DOI: 10.1021/acsnano.4c04215 -
Nature Communications Jun 2024Argonaute proteins are the central effectors of RNA-guided RNA silencing pathways in eukaryotes, playing crucial roles in gene repression and defense against viruses and...
Argonaute proteins are the central effectors of RNA-guided RNA silencing pathways in eukaryotes, playing crucial roles in gene repression and defense against viruses and transposons. Eukaryotic Argonautes are subdivided into two clades: AGOs generally facilitate miRNA- or siRNA-mediated silencing, while PIWIs generally facilitate piRNA-mediated silencing. It is currently unclear when and how Argonaute-based RNA silencing mechanisms arose and diverged during the emergence and early evolution of eukaryotes. Here, we show that in Asgard archaea, the closest prokaryotic relatives of eukaryotes, an evolutionary expansion of Argonaute proteins took place. In particular, a deep-branching PIWI protein (HrAgo1) encoded by the genome of the Lokiarchaeon 'Candidatus Harpocratesius repetitus' shares a common origin with eukaryotic PIWI proteins. Contrasting known prokaryotic Argonautes that use single-stranded DNA as guides and/or targets, HrAgo1 mediates RNA-guided RNA cleavage, and facilitates gene silencing when expressed in human cells and supplied with miRNA precursors. A cryo-EM structure of HrAgo1, combined with quantitative single-molecule experiments, reveals that the protein displays structural features and target-binding modes that are a mix of those of eukaryotic AGO and PIWI proteins. Thus, this deep-branching archaeal PIWI may have retained an ancestral molecular architecture that preceded the functional and mechanistic divergence of eukaryotic AGOs and PIWIs.
Topics: Argonaute Proteins; Humans; RNA Interference; Archaea; RNA, Small Interfering; Archaeal Proteins; Cryoelectron Microscopy; MicroRNAs; Evolution, Molecular; Phylogeny
PubMed: 38951509
DOI: 10.1038/s41467-024-49452-1 -
Journal of Agricultural and Food... Jul 2024Peanut southern blight, caused by the soil-borne pathogen , is a widespread and devastating epidemic. Frequently, it is laborious to effectively control by...
Peanut southern blight, caused by the soil-borne pathogen , is a widespread and devastating epidemic. Frequently, it is laborious to effectively control by labor-intensive foliar sprays of agrochemicals due to untimely find. In the present study, seed treatment with physcion (PHY) at doses of 0.08, 0.16, and 0.32 g AI kg seed significantly improved the growth and photosynthetic activity of peanuts. Furthermore, PHY seed treatment resulted in an elevated enzymatic activity of key enzymes in peanut roots, including peroxidase, superoxide dismutase, polyphenol oxidase, catalase, lipoxygenase, and phenylalanine ammonia-lyase, as well as an increase in callus accumulation and lignin synthesis at the infection site, ultimately enhancing the root activity. This study revealed that PHY seed treatment could promote the accumulation of reactive oxygen species, salicylic acid (SA), and jasmonic acid (JA)/ethylene (ET) in peanut roots, while also decreasing the content of malondialdehyde levels in response to infection. The results were further confirmed by transcriptome data and metabolomics. These findings suggest that PHY seed treatment activates the plant defense pathways mediated by SA and JA/ET in peanut roots, enhancing the resistance of peanut plants to . In short, PHY is expected to be developed into a new plant-derived immunostimulant or fungicide to increase the options and means for peanut disease control.
PubMed: 38950526
DOI: 10.1021/acs.jafc.4c02519 -
PloS One 2024A trademark's image is usually the first type of indirect contact between a consumer and a product or a service. Companies rely on graphical trademarks as a symbol of...
A trademark's image is usually the first type of indirect contact between a consumer and a product or a service. Companies rely on graphical trademarks as a symbol of quality and instant recognition, seeking to protect them from copyright infringements. A popular defense mechanism is graphical searching, where an image is compared to a large database to find potential conflicts with similar trademarks. Despite not being a new subject, image retrieval state-of-the-art lacks reliable solutions in the Industrial Property (IP) sector, where datasets are practically unrestricted in content, with abstract images for which modeling human perception is a challenging task. Existing Content-based Image Retrieval (CBIR) systems still present several problems, particularly in terms of efficiency and reliability. In this paper, we propose a new CBIR system that overcomes these major limitations. It follows a modular methodology, composed of a set of individual components tasked with the retrieval, maintenance and gradual optimization of trademark image searching, working on large-scale, unlabeled datasets. Its generalization capacity is achieved using multiple feature descriptions, weighted separately, and combined to represent a single similarity score. Images are evaluated for general features, edge maps, and regions of interest, using a method based on Watershedding K-Means segments. We propose an image recovery process that relies on a new similarity measure between all feature descriptions. New trademark images are added every day to ensure up-to-date results. The proposed system showcases a timely retrieval speed, with 95% of searches having a 10 second presentation speed and a mean average precision of 93.7%, supporting its applicability to real-word IP protection scenarios.
Topics: Intellectual Property; Humans; Information Storage and Retrieval; Databases, Factual; Algorithms; Image Processing, Computer-Assisted
PubMed: 38950045
DOI: 10.1371/journal.pone.0304915 -
Obstetrics and Gynecology Jul 2024
Topics: Humans; Female; Transgender Persons; Male; Transsexualism; Gonadal Steroid Hormones
PubMed: 38949553
DOI: 10.1097/AOG.0000000000005610