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Results for “plant biology”

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bioRxiv2019

Three criteria of intrinsically theoretical categories in biological system and classification of some medical plants

In classical biology, different taxonomic categories are all decided based on empirical rules established on learning knowledge. In taxonomy, different classification systems are of diversified rules. One biology is often in different categories, although the concepts related to taxonomic categories are the same to each other. Whether there exist some absolute standards to classify biology, and to give unalterable results. This is of greatly scientific meaning. Common and variation, that is heredity and variation are the most elemental information in biology, and exist at multiply biology material levels. In this paper a generalized biological heredity and variation information theory was proposed based on previous works. Three typical heredity and variation models were analyzed by using this theory. They are unique asymmetric variation model, symmetric two variation model and extreme radial variation model. In the maximum information states, two biological constants Pg1 = 0.69 and Pg2=0.61 and a boundary similarity function were obtained. These Pg and Pg function can be defined as the three theoretically taxonomic category criteria of biological system. For 29 samples belonging to four kind plants, their chemical fingerprint -- infrared (IR) fingerprint spectra (FPS) were analyzed depending on the theoretical criteria. The correct classification ratio was 96.6%. The results showed these samples could be ideally classified. A suggestion was proposed that biology should be absolutely classified relying on the three intrinsic theoretical criteria.

plant biology↗

bioRxiv2025

Metagenomes and Metagenome-Assembled Genomes from Microbial Communities in a Biological Nutrient Removal Plant Operated at Hamptons Road Sanitation District (HRSD) with High and Low Dissolved Oxygen Conditions

Aeration in biological nutrient removal (BNR) systems constitutes one of the largest energy demands in water resource recovery facilities (WRRFs). Previous studies have shown that lowering dissolved oxygen (DO) concentrations can sustain effective nitrification and phosphorus removal while substantially reducing energy consumption. However, the microbial mechanisms enabling these low-DO processes remain poorly understood. In this study, we investigated microbial communities associated with reduced DO in a pilot-scale BNR system operated by the Hampton Roads Sanitation District (HRSD). DO was reduced over an 18-month period from 2.5 mg/L to 0.2 mg/L. Metagenomic DNA was obtained from samples from each DO condition then sequenced using PacBio HiFi technology. A total of 316 metagenome-assembled genomes were recovered and after dereplication, 207 were found to be unique. These data augment the metagenomic information related to wastewater treatment under low-DO conditions and provide valuable resources for understanding microbial adaptation to oxygen-limited BNR operation.

genomics↗

bioRxiv2025

Quantitative modelling of biological response dynamics reveals novel patterns in plant volatile signalling

Biological responses to environmental stimuli are inherently dynamic. Recent technological advances enable detailed time-resolved measurements of such responses. However, a standard for quantitative characterisation of dynamics is lacking, thus limiting biological insights and comparisons. We developed an unbiased mathematical model structure that allows for the quantification of biological response curve dynamics without a priori knowledge of underlying biochemical mechanisms. Using the model to quantify the dynamics of stress-induced plant volatiles, we uncover a range of novel patterns in volatile signalling, including i) a strong light-independent impact of the time of day of wounding on the onset, duration and shape of the volatile induction responses, ii) an accentuation of volatile-specific induction curve shapes by herbivory-associated molecular patterns (HAMPs) and iii) independent regulation of the strength and duration of volatile induction across genotypes. The model performs well across biochemically diverse responses, suggesting broad applicability to inducible responses. The model is also robust to partial response curves, low resolution data and complex multi-modal responses arising from overlapping stimuli, enabling identification of priming events from otherwise convoluted curves. As all responses measured conform to a common model structure, yet parameter values diverge markedly, we conclude that biologically meaningful information is ignored when dynamics are not quantified. The presented approach will pave the way to identifying new biological response patterns, and their function, across the tree of life.

plant biology↗

bioRxiv2025

The genome of the vining fern Lygodium microphyllum highlights genomic and functional differences between life phases of an invasive plant

Functional and genomic studies on the differences between gametophyte and sporophyte life phases remain scarce, yet unraveling these dynamics is crucial to understanding the biology of plants and the success of each phase under different environments. Here, we provide a novel reference genome for the highly invasive fern Lygodium microphyllum and compare the transcriptomic and epigenomic landscapes of the gametophyte and sporophyte life phases. We found differential regulation of developmental genes (homeobox and MADS-box clades) and usage of alternative isoforms that may play a role in the genomic determination of the haploid and diploid life stages. We further generated the first base pair-resolution methylome of a fern gametophyte, and determined that methylation patterns are remarkably similar between vegetative tissues despite their morphological and functional differences. By examining the physiological and transcriptomic responses of gametophytes and sporophytes to freezing stress, the most likely abiotic factor preventing further expansion of this invasive species, we show that life phases and tissues use alternative molecular pathways to respond to this stressor, underscoring the need to incorporate both life phases when developing effective mitigation strategies. These new genomic resources fill a gap in our understanding of fundamental plant biology and inform invasive species research. SIGNIFICANCEAll land plants undergo an alternation of generations between haploid gametophyte and diploid sporophyte life phases. How these disparate life phases are generated from a single genome, and the functional implications of these differences for plant success, is largely unknown. Moreover, understanding life-phase-specific differences in rapidly evolving populations, such as invasive species, is critical to developing effective management strategies. We assembled a chromosome-level genome and generated epigenomic and transcriptomic resources from gametophyte and sporophyte phases of the invasive fern Lygodium microphyllum, which is estimated to cost the U.S. more than $2 million annually. We highlight transcriptomic, epigenomic, and physiological variation between life phases and find support for the crucial role of the often overlooked gametophyte in the invasion process.

plant biology↗

bioRxiv2023

Benefits and limits of biological nitrification inhibitors for plant N uptake and the environment

Does root-exudation of biological nitrification inhibitors (BNIs) facilitate nitrogen (N) uptake and reduce pollution by N loss to the environment? We modeled the spatial-temporal dynamics of nitrifiers, ammonium, nitrate, and BNIs around a root and simulated root N uptake and net rhizosphere N loss over the plants life cycle. We determined the sensitivity of N uptake and loss to variation in the parameters, testing a broad range of soil-plant-microbial conditions. An increase in BNI exudation reduces net N loss and, under most conditions, plant N uptake. BNIs decrease uptake in the case of (1) low ammonium concentrations, (2) high ammonium adsorption to the soil, (3) rapid nitrate-or slow ammonium uptake by the plant, and (4) a slowly growing or fast-declining nitrifier population. Bactericidal inhibitors facilitate uptake more than bacteriostatic ones. Some nitrification, however, is necessary to maximize uptake by both ammonium and nitrate transporter systems. Selection for increased BNI exudation should co-select for improved ammonium uptake. BNIs can reduce N uptake, which may explain why not all species exude BNIs but have a generally positive effect on the environment by increasing rhizosphere N retention.

plant biology↗

bioRxiv2025

GO Big or Go Home: A New Gene Ontology Subset that Improves Plant Gene Function Prediction

BackgroundThe availability of gene function prediction datasets helps researchers to consider possible functions for uncharacterized genes for hypothesis generation, candidate gene prioritization, and many other applications. Many such datasets are based on the Gene Ontology (GO) function graph. For plants this can be problematic because the most specific GO terms available are often derived from the biology of non-plant taxa (e.g., functions specific to nerve function would not seem likely to map to plant biological processes given that plants lack nerves). To balance the need for functional specificity while limiting to functions relevant to plant biology, researchers often limit to the GO Slim plant subset, but, by design, that subset consists of very general terms and limits real utility for e.g., specific hypothesis generation. Worse yet, sometimes researchers choose to simply throw out terms if they are not relevant to plant biology (rather than traversing the GO graph to select the most specific term in that hierarchy that is compatible with plant biology). ResultsWe created GO Big, a Gene Ontology subset type, to improve the biological relevance of gene function predictions for taxon-specific biology applications. GO Big plant subsets retain maximal functional specificity for hypothesis generation while limiting to terms applicable to the biology of plants. In brief, we used a curatorial approach to generate two GO Big subsets, a general subset derived from terms with experimentally validated functions across Viridiplantae species, and a species-specific subset for maize (Zea mays ssp. mays). ConclusionAnnotating genes with assignments that better reflect the biology of a taxon can pave the way for more biologically accurate and testable hypotheses for genes of interest. The subsets produced here can help plant biologists limit genome-wide gene function prediction sets to functions possible for plant genes, and the process to generate GO Big subsets is described in detail to enable others to create GO Big subsets for additional taxon sets, including ones for protists, fungi, and other phylogenetic categories.

bioinformatics↗

bioRxiv2025

Metagenomes and Metagenome-Assembled Genomes from Microbial Communities in a Biological Nutrient Removal Plant Operated at Los Angeles County Sanitation District (LACSD) with High and Low Dissolved Oxygen Conditions

Aeration represents one of the largest energy costs in water resource recovery facilities (WRRFs). Previous studies have shown that effective nitrification and phosphorus removal can be maintained in biological nutrient removal (BNR) systems operated under low dissolved oxygen (DO) conditions, significantly reducing energy use. To improve understanding of microbial community adaptation to reduced DO, we analyzed metagenomes and metagenome-assembled genomes (MAGs) from the Pomona WRRF (Los Angeles County Sanitation Districts) before and after a gradual decrease in operating DO from approximately 3.5 mg/L to 0.7 mg/L over 18 months. Metagenomic DNA was isolated from high and low DO samples, then sequenced using PacBio HiFi technology. A total of 492 MAGs were recovered of which 304 were unique after dereplication. These genomes expand current knowledge of microbial community dynamics in low-DO BNR systems and provide valuable genomic resources for understanding microbial adaptation to energy-efficient wastewater treatment processes.

genetics↗

bioRxiv2020

Genome Wide Identification, Characterization and Expression Analysis of Non-Arginine Aspartate Receptor like kinase gene family in Hot pepper under Colletotrichum truncatum stress conditions

Receptor Like kinases (RLKs) are conserved upstream signaling molecules that regulate several biological processes, including plant development and stress adaptation. Non arginine aspartate (non-RD) an important class of RLKs plays a vital role in disease resistance and apoptosis in plants. In present investigation, a comprehensive Insilco analysis for non-RD Kinase gene family including identification, sequence similarity, phylogeny, chromosomal localization, gene structures, gene duplication analysis, promoter analysis and transcript expression profiles were elucidated. In this study twenty six genes were observed on nine out of twelve chromosomes. All these genes were clustered into seven subfamilies under large monophyletic group termed as Interleukin-1 Receptor-Associated Kinase (IRAK) family. Structural diversity in genomic structure among non-RD kinase gene family were identified and presence of pathogen induced cis regulatory elements like STRE, MYC, MYB,W box were found. Expression profiles of genes involved in providing resistance to anthracnose pathogen Colletotrichum truncatum in hot pepper were analyzed at different infective stages in both resistant and susceptible genotypes. Among twenty six genes, CaRLK1 gene belonging to LRRXII subfamily was up regulated under severe stress after infection in resistant genotype PBC-80. This integrative approach has helped us to identify candidate genes involved in disease resistance which would be helpful in future crop improvement programs.

plant biology↗

bioRxiv2020

Creating Clear and Informative Image-based Figures for Scientific Publications

Scientists routinely use images to display data. Readers often examine figures first; therefore, it is important that figures are accessible to a broad audience. Many resources discuss fraudulent image manipulation and technical specifications for image acquisition; however, data on the legibility and interpretability of images are scarce. We systematically examined these factors in non-blot images published in the top 15 journals in three fields; plant sciences, cell biology and physiology (n=580 papers). Common problems included missing scale bars, misplaced or poorly marked insets, images or labels that were not accessible to colorblind readers, and insufficient explanations of colors, labels, annotations, or the species and tissue or object depicted in the image. Papers that met all good practice criteria examined for all image-based figures were uncommon (physiology 16%, cell biology 12%, plant sciences 2%). We present detailed descriptions and visual examples to help scientists avoid common pitfalls when publishing images. Our recommendations address image magnification, scale information, insets, annotation, and color and may encourage discussion about quality standards for bioimage publishing.

bioinformatics↗

bioRxiv2021

The intrinsic chaperone network of Arabidopsis stem cells confers protection against proteotoxic stress

The biological purpose of plant stem cells is to maintain themselves while providing new pools of differentiated cells that form organs and rejuvenate or replace damaged tissues1-3. Protein homeostasis, or proteostasis, is required for cell function and viability4-7. However, the link between proteostasis and plant stem cell identity remains unknown. In contrast to their differentiated counterparts, we find that root stem cells can prevent the accumulation of aggregated proteins even under proteotoxic stress conditions such as heat stress or proteasome inhibition. Notably, root stem cells exhibit enhanced expression of distinct chaperones that maintain proteome integrity. Particularly, intrinsic high levels of the TRiC/CCT chaperonin determine stem cell maintenance and their remarkable ability to suppress protein aggregation. Overexpression of CCT8, a key activator of TRiC/CCT assembly8, is sufficient to ameliorate protein aggregation in differentiated cells and confer resistance to proteotoxic stress in plants. Taken together, our results indicate that enhanced proteostasis mechanisms in stem cells could be an important requirement for plants to persist under extreme environmental conditions and reach extreme long ages. Thus, proteostasis of stem cells could provide insights to design and breed plants tolerant to environmental challenges caused by the climate change.

plant biology↗

bioRxiv2022

Enhanced photosynthetic efficiency for increased carbon assimilation and woody biomass production in hybrid poplar INRA 717-1B4

Increasing CO2 levels in the atmosphere and the resulting negative impacts on climate change have compelled global efforts to achieve carbon neutrality or negativity. Most such efforts focus on carbon sequestration through chemical or physical approaches. We aim to harness the power of synthetic biology to enhance plants natural ability to draw down and sequester carbon, thereby positively affecting climate change. Past decades of scientific progress have shed light on strategies to overcome the intrinsic limitations of carbon drawdown and fixation through photosynthesis, particularly in row crops in hopes of improving agricultural productivity for food security. Incorporating a photorespiration bypass in C3 plants has shown promising results of increased biomass and grain yield. Despite their globally dominant role in atmospheric carbon flux, the drawdown rates of most trees are currently limited by their C3 photosynthetic metabolism, and efforts to improve the photosynthetic capacity of trees, such as by reducing energy loss in photorespiration, are currently lacking. Here, we selected a photorespiration bypass pathway and tested its effectiveness on photosynthetic enhancement in hybrid poplar INRA717-IB4. The design includes a RNAi strategy to reduce the transportation of the photorespiration byproduct, glycolate, out of chloroplast and a shunt pathway to metabolize the retained glycolate back to CO2 for fixation through the Calvin-Benson cycle. Molecular and physiological data collected from two repeated growth experiments indicates that transgenic plants expressing genes in the photorespiration bypass pathway have increased photosynthetic efficiency, leading to faster plant growth and elevated biomass production. One lead transgenic event accumulated 53% more above-ground dry biomass over a five month growth period in a controlled environment. Pilot projects with photosynthesis-enhanced trees in the field are in progress. Our results provide a proof-of-concept for engineering trees to help combat climate change.

plant biology↗

bioRxiv2022

Genotype by microbiome interactions have large effects on growth in Lotus japonicus

Biological interactions between plants and their root microbiomes are pivotal for plant growth. Even though the plant genotype [G], soil microbiome [C], and growth conditions (environment) [E] are core factors shaping the root microbiome, their relationships remain unclear. We disentangled the effects of G, C, E, and their interactions on the Lotus root microbiome and plant growth using a cross-inoculation approach that reconstructed the interactions between nine Lotus accessions and four soil microbiomes under two different environmental conditions. We found that a large proportion of the root microbiome composition was determined by C and E and that G-related (G, G x C, and G x E) effects were significant but small. In contrast, the interactions between G and C had a more pronounced effect on plant shoot growth than C alone. Our findings indicate that most microbiome variations controlled by C have little effect on the plant phenotype, whereas G x C interactions have more significant effects. Plant genotype-dependent interactions with soil microbes warrant more attention in efforts to optimize crop yield and resilience.

plant biology↗

bioRxiv2022

The transcriptional regulator JAZ8 interacts with the C2 protein from geminiviruses and limits the viral infection in Arabidopsis

Jasmonates (JAs) are phytohormones that finely regulate critical biological processes, including plant development and defense. JASMONATE ZIM-DOMAIN (JAZ) proteins are crucial keeping JA-responsive genes in a repressed state. In the presence of JA-Ile, JAZ repressors are ubiquitinated and targeted for degradation by the ubiquitin/proteasome system, allowing the activation of the downstream transcription factors and, consequently, the activation of JA-responsive genes. A growing body of evidence has shown that JA signalling is crucial in defending against plant viruses and their insect vectors. Here, we describe the interaction of C2 proteins from two geminiviruses from the genus Begomovirus, tomato yellow curl Sardinia virus (TYLCSaV) and tomato yellow leaf curl virus (TYLCV), with the transcriptional repressor JAZ8 from Arabidopsis thaliana and its closest orthologue in tomato, SlJAZ9. Both JAZ and C2 proteins colocalize in the nucleus, forming discrete nuclear speckles. Overexpression of JAZ8 did not lead to altered responses to TYLCV infection; however, knock-down of JAZ8 favours the geminiviral infection in plants. Low levels of JAZ8 likely affect the viral infection specifically since JAZ8-silenced plants do not display developmental phenotypes nor present differences in their interaction with the viral insect vector. Our results show that JAZ8 interacts with geminiviral C2 proteins and exerts an anti-geminiviral effect.

plant biology↗

bioRxiv2023

Comparative transcriptomics of Venus flytrap (Dionaea muscipula) across stages of prey capture and digestion

The Venus flytrap, Dionaea muscipula, is perhaps the worlds best-known botanical carnivore. The act of prey capture and digestion along with its rapidly closing, charismatic traps make this species a compelling model for studying the evolution and fundamental biology of carnivorous plants. There is a growing body of research on the genome, transcriptome, and digestome of Dionaea muscipula, but surprisingly limited information on changes in trap transcript abundance over time since feeding. Here we present the results of a comparative transcriptomics project exploring the transcriptomic changes across seven timepoints in a 72-hour time series of prey digestion and three timepoints directly comparing triggered traps with and without prey items. We document a dynamic response to prey capture including changes in abundance of transcripts with Gene Ontology (GO) annotations related to digestion and nutrient uptake. Comparisons of traps with and without prey documented 174 significantly differentially expressed genes at 1 hour after triggering and 151 genes with significantly different abundances at 24 hours. Approximately 50% of annotated protein-coding genes in Venus flytrap genome exhibit change (10041 of 21135) in transcript abundance following prey capture. Whereas peak abundance for most of these genes was observed within 3 hours, an expression cluster of 3009 genes exhibited continuously increasing abundance over the 72-hour sampling period, and transcript for these genes with GO annotation terms including both catabolism and nutrient transport may continue to accumulate beyond 72 hours.

plant biology↗

bioRxiv2023

Mutation of OsCDS5 confers broad-spectrum disease resistance in rice

Phospholipids are important components of biological membranes, participating in various biological processes, including plant development and responses to biotic and abiotic stresses. A previous study showed that mutation of the rice OsCDS5 (CDP-DAG Synthase) gene alters lipid metabolism, causing enhanced abiotic stress responses, yellowing of leaves at the seedling stage and delayed plant development. Here, we observed that the Oscds5 mutant shows enhanced resistance to rice blast, bacterial blight and bacterial leaf streak. Mutation of OsCDS5 promotes production of reactive oxygen species (ROS) and increases the expression level of multiple defense-related genes. Transcriptomic analyses indicate that genes involved in responses to stress, biotic/abiotic stimuli and metabolic processes are highly upregulated and enriched in mutant Oscds5. Metabolomic analyses show that differential metabolites are enriched in the lipid metabolic and tryptophan metabolic pathways. The decreased level of phosphatidylinositol (PI) and increased level of serotonin likely contribute to enhanced disease resistance of the Oscds5 mutant. Taken together, mutation of OsCDS5 enhances abiotic and biotic stress responses, and OsCDS5 may be a promising target in genetic engineering to enhance the resilience of rice to abiotic and biotic stresses simultaneously.

plant biology↗

bioRxiv2025

Non-Thermal Plasma Activated Water is an Effective Nitrogen Fertilizer Alternative for Arabidopsis thaliana

Nitrogen (N) fixation with non-thermal plasmas has been proposed as a sustainable alternative to meet growing N fertilizer demands for agriculture. This technology generates Plasma Activated Water (PAW) with a range of chemical compositions, including different concentrations of nitrate (NO-) and hydrogen peroxide (H2O2), among other compounds. Potential use of PAW as an effective crop fertilizer necessitates a robust understanding of the underlying biology of the plant, which is not yet available. The lack of a unified standard in PAW production and the varying chemical make-up that results from different devices and protocols hampers comparative studies and adoption of this technology. The objective of this study was to compare the efficacy of two PAW solutions with differing concentrations of H2O2 produced from a Radio Frequency (RF) glow discharge plasma source. The effect of these solutions on plant growth, ROS accumulation, gene expression and heat stress response were compared to N-equivalent controls in the model plant Arabidopsis to assess their potential as an alternative N fertilizer. While PAW solutions lacking detectable H2O2 enhanced seedling growth, those containing approximately 0.3 {micro}M of H2O2 did not. ROS accumulation in root tissues was similar between PAW and chemically equivalent solutions, suggesting H2O2 is the primary ROS present in the PAW at the time of treatment. Gene expression studies showed induction of genes involved in N uptake and assimilation in PAW-treated seedlings. Pre- treatment of seedlings with PAW solutions containing H2O2 improved root growth under heat stress which indicates that this treatment may induce plant stress response pathways. Finally, mature plants showed similar growth when fertilized with PAW lacking H2O2 or NO3- control regimes for over 5 weeks indicating equivalency in chemical composition, plant nutrient uptake and utilization. Overall, these results demonstrate that PAW is an effective alternative to NO3- fertilizers for plant cultivation but the levels of H2O2 need to be carefully controlled.

plant biology↗

bioRxiv2025

Divergence of Bowman-Birk Protease Inhibitor Family into seed-specific and environmentally responsive subfamilies in Legume and Soybean: Implication for Legume Seed Composition Improvement.

Bowman-Birk inhibitors (BBI) are an ancient class of serine protease inhibitors originating prior to the emergence of the angiosperms. While BBIs have been preserved in the legume (Fabaceae) and cereal (Poaceae) families, they have been lost in many other divergent lineages. However, their underlying molecular evolution and regulation of BBI remain largely uncharacterized. Our study shows that BBIs in legumes and cereals are encoded by two large and divergent gene families. BBI genes in legumes have further diversified into two subfamilies with distinct gene expression patterns. Genes in one legume BBI subfamily are specifically expressed in seeds while BBI genes in the other legume subfamily and cereal do not have significant expressions in any examined tissues including seed, root, leaf and flower. The soybean BBI gene family shows evidence of expansion via whole genome, segmental and tandem duplication. Protein sequence and structural analysis predicts that functional domains for double-headed inhibitory loops and binding abilities to trypsin and chymotrypsin are largely preserved within the soybean BBI family. The seed-specific subfamily genes are specifically expressed at maturation stages and not at embryogenesis stages. The other, non-seed BBI subfamily genes are highly responsive to a distinct spectrum of signals related to abiotic and biotic stresses. Their specific expression under non-essential biological processes for plant growth and development suggests that, although BBIs have been retained in both cereals and legumes, likely due to their role in enhancing plant fitness under natural selection pressures, they are not involved in core developmental processes. This may explain why BBIs were lost in many divergent plant lineages and support their well-established roles in plant adaptation to environmental stress. Having knocked out the seed-specific BBIs through a CRISPR/Cas9 approach, we have successfully generated soybeans which exhibited 69.4 - 73.7% reduction of trypsin inhibitor activity and 76.4 - 79.4% reduced chymotrypsin inhibitor activity. The edited soybean did not show significant changes in key agronomic traits, supporting that the functions of BBIs are not essential. While BBIs in soybean seeds may have a desirable function in natural selection, they are antinutrients from an applied perspective for their use in feed and food. It provides an opportunity to reduce BBIs in seeds for quality improvement. Our findings provide insights into molecular evolution, regulation, and function of BBI in plants, and successfully demonstrate engineering BBI in seeds to result in production of food and feed of higher nutritional value with minimal impacts on the agronomic performance of the plant.

plant biology↗

bioRxiv2025

Enhanced MicroRNA Accumulation and Gene Silencing Efficiency through Optimized Precursor Base Pairing

MicroRNAs (miRNAs) are endogenous 21-nucleotide small RNAs that direct sequence-specific silencing of complementary messenger RNAs to regulate a wide range of biological processes. In plants, miRNA precursors are processed from imperfect foldback structures by the RNase III enzyme DICER-LIKE1, in coordination with accessory proteins. While mismatches flanking the miRNA/miRNA* duplex in endogenous precursors can strongly influence miRNA accumulation, their impact has not been thoroughly examined in the context of artificial miRNAs (amiRNAs) used for targeted gene silencing in plants. Here, using silencing sensor systems in Nicotiana benthamiana, we systematically investigated how base-pairing at or near DCL1 cleavage sites affects amiRNA production from the recently described minimal shc precursor. Independent pairing of naturally mismatched positions revealed that introducing a G-C pair immediately upstream of the mature amiRNA remarkably enhances amiRNA accumulation and silencing efficiency. This effect was further validated in Arabidopsis transgenic lines targeting endogenous genes and confirmed by deep sequencing, which revealed highly accurate processing and predominant release of the intended amiRNAs, supporting the specificity of the approach. Our findings show that a single structural modification in an amiRNA precursor can significantly enhance the efficacy of amiRNA-mediated gene silencing. This optimized amiRNA platform is well suited for large-scale functional genomics screens and should facilitate the development of next-generation crops with enhanced resilience to environmental stresses. SIGNIFICANCE STATEMENTA large-scale mutational analysis of how base-pairing at or near DCL1 cleavage sites affects artificial microRNA (amiRNA) production from the minimal shc precursor revealed that introducing a single G-C base pair immediately upstream of the first DCL1 cleavage site significantly boosts amiRNA accumulation and gene-silencing efficiency. The incorporation of this structural tweak into a high-efficiency amiRNA platform provides an optimized, highly specific RNAi tool for functional genomics and crop engineering.

plant biology↗