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Benzoic acid inhibits peach root growth and lateral root emergence by disrupting auxin homeostasis through salicylic acid accumulation.

We established a non-sterile root transformation system in peach seedlings. Using this system, we demonstrated that BA treatment inhibits plant growth and lateral root emergence by SA-mediated disruption of auxin distribution. Allelopathic autotoxins, particularly benzoic acid (BA), are recognized as primary contributors to peach (Prunus persica) replant disease; however, the molecular mechanisms by which BA disrupts root development remain poorly understood. BA treatment significantly reduced stem and root length and inhibited lateral root emergence without affecting lateral root initiation. To investigate the underlying mechanism at cellular resolution, we established a non-sterile Agrobacterium rhizogenes-based root transformation system achieving 27.11% transformation efficiency. Auxin biosynthesis (PpYUC10), influx transport (PpAUX1), and response (PpARF19) genes were markedly downregulated following BA treatment. Transgenic roots expressing the DR5::GUS auxin reporter exhibited reduced DR5 activity in root tips and suppressed expression in tissues surrounding lateral root primordia, indicating impaired auxin signaling at both developmental sites. Hormone profiling revealed a non-significant trend toward reduced auxin metabolites alongside significant accumulation of salicylic acid (SA), an auxin-antagonistic hormone, and its storage conjugate SA 2-O-β-glucoside. Supporting a causal role for SA, exogenous SA phenocopied BA-induced root growth inhibition, whereas co-treatment with IAA or the SA-biosynthesis inhibitor aminoindan-1-phosphonic acid (AIP) significantly rescued lateral root number and root fresh weight. Multi-treatment RNA-seq identified "response to auxin" and "response to salicylic acid" as the most enriched GO terms in BA-treated roots, and AIP treatment restored the expression of key auxin-related genes while reversing BA-induced SA-pathway changes. Together, these findings suggest that BA-induced SA accumulation suppresses auxin biosynthesis, transport, and signaling, thereby inhibiting peach root growth and lateral root emergence. This study elucidates the molecular basis of BA autotoxicity and establishes a transformation platform for functional genomic studies in Prunus.

Indoleacetic Acids

High-efficiency genome-editing, transgene evaluation, and antimicrobial efficacy testing using Citrus medica L. hairy roots.

Huanglongbing (HLB) disease, associated with the fastidious bacterium Candidatus Liberibacter asiaticus (CLas), has a significant impact on citrus production worldwide. Conventional biochemical and genetic evaluation studies to identify potential disease resistance strategies have been mainly hindered due to the inability to culture CLas in a defined medium and the general recalcitrance of Citrus cultivars (grapefruits and oranges) to Agrobacterium-mediated plant transformation. We previously demonstrated the utility of plant hairy roots to co-cultivate CLas. In this study, we developed a hairy root transformation system using citron (Citrus medica L.), which is highly amenable to Rhizobium-mediated hairy root transformation. The explant survival and hairy root transformation efficiencies were up to 100% and 73%, respectively, and transgenic roots can be attained in as little as 30-60 days. We demonstrate the utility of this citron-based hairy root transformation for rapid CRISPR/Cas9-mediated gene editing, transgene evaluation, and antimicrobial efficacy testing. The citron-based hairy root transformation system will significantly help the research community to speed-track the assessment of potential HLB disease resistance strategies.

Citrus

CRISPR/Cas9-mediated knockout of PsLykX gene of pea (Pisum sativum L.) leads to loss of symbiotic nodules.

Pea (Pisum sativum L.) symbiosis with nodule bacteria supplying plants with additional nitrogen is a very specific plant-microbial interaction. Mutual recognition of the partners occurs through perception of bacterial signal molecules (Nod factors) by plant receptors, enabling bacterial entry via root hairs and formation of nitrogen-fixing nodules. The pea gene Sym2, described but not yet cloned, exists in different allelic forms defining the symbiotic specificity, and is therefore thought to encode a Nod factor receptor. The PsLykX gene is a strong candidate for the Sym2, since its alleles coincide with high or low symbiotic specificity; however, to date, no genetic evidence has been obtained for a role of PsLykX in symbiosis. Here, we knocked-out the PsLykX in European pea cultivar Caméor using Agrobacterium-mediated hairy root transformation and CRISPR-Cas9 editing. The roots with editing events confirmed by sequencing lost the ability to form nodules, providing direct functional evidence that PsLykX is essential, at least, for the symbiosis between pea cultivar Caméor and Rhizobium ruizarguesonis RCAM1026.

Pisum sativum

Development of an Efficient Regeneration and Agrobacterium-Mediated Transformation Protocol for Hosta 'Light Star' Using the RUBY Reporter Gene.

Hosta plantaginea is a perennial shade-tolerant herb of the Liliaceae family, with high ornamental and urban greening value. Hosta 'Light Star' is a newly developed ornamental cultivar with yellow-margined leaves and lilac flowers, but no efficient in vitro regeneration or genetic transformation system has been established for this cultivar to date. In this study, we established a highly efficient in vitro regeneration system for Hosta 'Light Star,' and developed an Agrobacterium-mediated genetic transformation protocol using the RUBY visual reporter gene for non-invasive screening of positive transformants. The optimal callus induction medium was MS&#x2009;+&#x2009;2&#xa0;mg/L 6-BA&#x2009;+&#x2009;0.3&#xa0;mg/L NAA&#x2009;+&#x2009;0.05&#xa0;mg/L 2, 4-D, with a callus induction rate of 53.33% for leaf explants (the optimal explant for sterile seedlings). The optimal adventitious bud proliferation medium was MS&#x2009;+&#x2009;2&#xa0;mg/L 6-BA&#x2009;+&#x2009;0.1&#xa0;mg/L NAA, with a proliferation coefficient of 5.87. The optimal rooting medium was 1/2 MS&#x2009;+&#x2009;0.5&#xa0;mg/L NAA&#x2009;+&#x2009;0.5&#xa0;mg/L IBA, with a 100% rooting rate. The optimal transplant substrate was perlite:vermiculite&#x2009;=&#x2009;2:1, with a 100% transplant survival rate after acclimatization. For Agrobacterium-mediated transformation, the optimal infection parameters were as follows: Agrobacterium suspension OD600&#x2009;=&#x2009;0.6, infection time of 10&#xa0;min, and 200&#xa0;&#x3bc;M acetosyringone; the optimal selection conditions were 300&#xa0;mg/L cefotaxime for bacteriostasis and 30&#xa0;mg/L hygromycin for transformant screening. The final stable transformation efficiency was 2.50% (95% CI 1.23-3.77%), with an escape rate of 16.13%. Transgenic plants showed distinct purplish-red coloration in roots, stems, and leaves, with significantly higher betacyanin accumulation than wild-type plants (p&#x2009;<&#x2009;0.05). Stable integration and expression of the RUBY gene were confirmed by PCR, RT-PCR, and RT-qPCR. This study establishes the first efficient regeneration and Agrobacterium-mediated transformation system for Hosta 'Light Star,' and validates the feasibility of the RUBY reporter gene as a visual marker for Hosta transformation. This system provides a solid technical platform for functional genomic studies, CRISPR/Cas9-mediated gene editing, and molecular breeding of ornamental traits in Hosta.

Transformation, Genetic

A stable transformation platform in pomegranate uncovers PgMYB10 as a key regulator of anthocyanin biosynthesis.

An efficient genetic transformation platform enables functional validation of PgMYB10, identifying it as a master regulator governing anthocyanin biosynthesis in pomegranate. Limited availability of stable genetic transformation systems restricts functional genomics research in pomegranate. Here, we established efficient in vitro regeneration and Agrobacterium tumefaciens-mediated transformation systems for 'Taishanhong' pomegranate using stem segment explants. Optimized medium combinations produced high-frequency regeneration: a 93.3% shoot-induction rate on MS medium with 1.5&#xa0;mg/L 6-benzylaminopurine (BAP), 0.6&#xa0;mg/L 1-naphthaleneacetic acid (NAA) and 30.0&#xa0;mg/L adenine sulfate (ADS); a proliferation coefficient of 5.4 on MS medium&#xa0;supplemented with 0.8&#xa0;mg/L BAP and 0.3&#xa0;mg/L indole&#x2011;3&#x2011;butyric acid (IBA); effective shoot-strengthening on MS&#xa0;medium containing 1.2&#xa0;mg/L BAP, 0.3&#xa0;mg/L NAA and 0.2&#xa0;mg/L gibberellic acid (GA&#x2083;); and a rooting rate of 95.3% on half-strength MS medium with 1.5&#xa0;mg/L IBA and 0.5&#xa0;mg/L NAA. For transformation, precultured explants were immersed with A. tumefaciens suspension (OD&#x2086;&#x2080;&#x2080; = 0.8) containing 20.0&#xa0;mg/L acetosyringone (AS) for 30&#xa0;min. After four days of dark co-culture, sequential antibiotic screening with 30&#xa0;mg/L kanamycin and bacteriostatic treatment with 400&#xa0;mg/L timentin yielded a stable average transformation efficiency of 17.5% in 'Taishanhong' pomegranate. Subsequent functional analysis revealed that overexpression of PgMYB10 induced pigment accumulation in leaves and stems. In three independent transgenic lines, maximum anthocyanin content and PgMYB10 transcript levels were 5.4-fold and 27.2-fold higher than in wild-type plants, respectively. Six anthocyanin biosynthetic genes (PgCHS, PgCHI, PgF3H, PgDFR, PgANS, and PgUFGT) were markedly upregulated, demonstrating that PgMYB10 positively controls anthocyanin biosynthesis. This transformation system provides a reliable technical platform for functional genomic studies in pomegranate, and PgMYB10 represents as a promising candidate gene for molecular breeding aimed at improving fruit pigmentation.

Anthocyanins

Establishment of a CRISPR-Cas9 Library for Indica Rice and Identification of OsOPR5 (LOC_Os06g11210) as a Regulator of Root Architecture.

Functional characterization of a large number of rice genes remains a major challenge despite the availability of genome sequences and large-scale transcriptomic datasets. CRISPR-Cas9 library is a powerful approach for high-throughput targeted mutagenesis; however, its application in indica rice cultivars remains limited due to low transformation and regeneration efficiencies. In this study, we developed a CRISPR-Cas9 library targeting 12,000 rice genes and evaluated its utility for functional genomics in the indica cultivar MTU-1010. Sanger sequencing and NGS analysis of the plasmid library revealed high sgRNA coverage and more than 80% accuracy. Transformation of the developed library into the indica cultivar MTU-1010 resulted in a high target editing efficiency, with 90% of analyzed transgenic plants carrying mutations at the intended target site. Functional analysis of one homozygous mutant identified a previously uncharacterized role for OsOPR5 (LOC_Os06g11210), a member of the 12-oxophytodienoate reductase family in root architecture. The opr5 mutants exhibited significant reductions in lateral root number, seminal and crown root number, and root length, demonstrating that OsOPR5 positively regulates root system architecture in rice. Notably, endogenous jasmonic acid (JA) and JA-isoleucine levels were not significantly altered in the mutant, suggesting potential functional specialization or redundancy among rice OPR family members for JA accumulation. The root system architecture is a key determinant of water and nutrient acquisition; our results suggest that OsOPR5 may play an important role in adaptation under adverse environmental conditions. Collectively, this study establishes an efficient genome-editing platform for indica rice and identifies OsOPR5 as a novel regulator of root development.

Oryza

Establishment of an in vitro culture and regeneration protocol for the native Chilean grass Polypogon australis Brong.

Polypogon australis Brong. is a native Chilean grass frequently found colonizing metal-rich mine tailings, yet it lacks an established in vitro regeneration system to support controlled physiological and biotechnological studies. Here, we report a reproducible protocol for seed germination, callus induction, and plant regeneration using coleoptile-mesocotyl explants. Surface-sterilized seeds were germinated on Murashige and Skoog (MS) medium supplemented with sucrose, achieving a cumulative germination percentage of 47.67&#x2009;&#xb1;&#x2009;3.15% after 15 days. The coleoptile-mesocotyl explant proved highly responsive to culture on callus induction medium (CIM) supplemented with dicamba, resulting in a callus induction frequency of 30.55&#x2009;&#xb1;&#x2009;11.96% after 3-5 weeks. Induced calli were predominantly embryogenic, with embryogenic calli representing 65.42&#x2009;&#xb1;&#x2009;8.61% of the total callus population. Embryogenic calli regenerated complete plantlets with a regeneration efficiency of 45.0&#x2009;&#xb1;&#x2009;23.3%. Organogenic structures, including primary shoots and roots, developed directly from embryogenic calli maintained on callus induction medium (CIM) supplemented with dicamba, without transfer to a specialized regeneration medium containing organogenesis-promoting growth regulators. After the initiation of organogenesis, cultures were exposed to a 16&#xa0;h light/8&#xa0;h dark photoperiod while remaining on CIM, and regenerated plantlets were subsequently transferred to MS+10&#xa0;S medium for further growth and elongation. This study establishes the first complete in vitro regeneration system for P. australis, providing a practical framework for future physiological studies, large-scale propagation, genetic transformation, and genome engineering applications in this ecologically relevant native Chilean grass.

Regeneration

Molecular mechanisms of natural de novo shoot organogenesis and their applications.

Natural de novo shoot organogenesis (DNSO) is the spontaneous regeneration of shoots from wound sites outside the shoot apical region through endogenous developmental programs. This regenerative capacity enables plants to recover from severe tissue damage by re-establishing the shoot-root axis. Here, we review current knowledge about the molecular mechanisms of natural DNSO, focusing on transcriptomic and physiological studies in model plants. Accumulating evidence suggests that natural DNSO proceeds through three sequential phases: (i) early wound responses, characterized by the activation of the WIND1-ESR1 module and the establishment of apical-basal auxin asymmetry; (ii) cellular proliferation driven by metabolic and cell-cycle reprogramming; and (iii) cytokinin-mediated establishment of shoot apical meristem identity. We also discuss how these mechanistic insights have been harnessed for practical applications, including tissue culture-free transformation systems such as the cut-dip-budding (CDB) method, and developmental reprogramming strategies that employ ectopic expression of developmental regulator (DR) genes to induce DNSO in otherwise recalcitrant species. Together, these advances illustrate how understanding natural regeneration can guide the development of simplified, broadly applicable plant transformation technologies.

Plant Shoots

Plant-derived and microbial biostimulants in sustainable agriculture: mechanisms, applications, and challenges.

Plant biostimulants have emerged as transformative and sustainable tools for improving crop productivity, resource-use efficiency, and resilience under rapidly intensifying environmental stresses. Unlike conventional agrochemicals, biostimulants function by activating physiological, biochemical, and molecular processes that optimize plant performance without directly supplying nutrients or exerting pesticidal effects. This review comprehensively examines the integrated roles of plant-derived and microbial biostimulants in sustainable agriculture, with particular emphasis on microbial-mediated mechanisms underlying plant stress adaptation and rhizosphere functioning. Plant-derived biostimulants, including seaweed extracts, humic substances, protein hydrolysates, amino acids, and chitosan, enhance nutrient acquisition, root architecture, hormonal regulation, and antioxidant defense systems. More importantly, microbial biostimulants, such as plant growth-promoting rhizobacteria (PGPR), endophytic microorganisms, mycorrhizal fungi, actinomycetes, yeasts, and cyanobacteria, exert multifunctional effects through biological nitrogen fixation, mineral solubilization, phytohormone biosynthesis, volatile signaling, osmolyte accumulation, pathogen suppression, and modulation of stress-responsive genes. These beneficial microorganisms reshape rhizosphere microbial communities, improve nutrient cycling, and enhance plant tolerance to drought, salinity, heat, and heavy metal toxicity. Emerging evidence from genomics, transcriptomics, metabolomics, and microbiome-based investigations has further revealed the molecular networks and signaling pathways governing biostimulant-induced resilience and plant-microbe interactions. Despite their substantial promise, inconsistent field performance, formulation instability, regulatory limitations, and inadequate mechanistic understanding continue to restrict their large-scale adoption. This review highlights recent advances in microbial and plant-derived biostimulants while identifying critical knowledge gaps and future opportunities for precision biostimulant engineering, microbiome manipulation, and climate-resilient crop management. The integration of next generation biostimulant technologies into sustainable agricultural systems may significantly reduce dependence on agrochemicals while improving crop productivity, environmental sustainability, and global food security.

Agriculture

Establishment of an efficient Agrobacterium-mediated genetic transformation protocol for Saccharum officinarum using Black Cheribon as a model genotype.

Efficient Agrobacterium-mediated transformation (AMT) is vital for the biotechnological improvement of sugarcane (Saccharum spp.). Saccharum officinarum is the main ancestor of all modern cultivars, yet little research has been conducted on its AMT system. In this work, an efficient AMT protocol for S. officinarum was developed, with Black Cheribon as the model genotype owing to its superior tissue culture performance and regeneration capacity. The optimized agro-infection protocol comprised the following main parameters: concentration of acetosyringone (AS) in Agrobacterium culture, concentration of AS for infection, Agrobacterium concentration at OD600&#xa0;=&#xa0;0.4, infection time of 30 minutes, vacuum infiltration time of 10 minutes and co-cultivation time of 3 days. To further improve transformation efficiency, 0.5 mg/L thidiazuron and 200 mg/L citric acid were added to the regeneration medium, which enhanced the regeneration of shoots. A modified stage-dependent selection strategy (FlexII) was established by using glufosinate-ammonium at concentrations of 2.0, 1.0, and 0.75 mg/L in the callus proliferation, shoot regeneration, and rooting stages, respectively. This strategy was more successful than the minimum inhibitory concentration-based strategy in S. officinarum transformation. The optimized protocol further boosted the transformation efficiency of Black Cheribon from 1.12% to 7.17%. The resulting transgenic lines were confirmed by PCR amplification of T-DNA regions and immunochromatographic detection of Bar protein expression in primary transformants, respectively. These results provide a sound technical foundation for the functional genomics and biotechnological optimization of S. officinarum germplasm, and may serve as a reference for future transformation studies in other sugarcane germplasm.

Agrobacterium

Novel Mycoparasitic Mechanisms and Colonization Patterns on Poplar Revealed by GFP Tagging of the Biocontrol Fungus Clonostachys reniana.

Clonostachys rosea has long been the primary model for studying mycoparasitism within its genus; however, the potential of other species remains largely unexplored. In this study, we established a PEG-CaCl2-mediated protoplast transformation system for Clonostachys reniana. Our results demonstrate for the first time that this species is amenable to genetic manipulation and produces transformants with genetic stability, providing a reliable platform for functional genomic research in this fungus. Using green fluorescent protein tagging, we achieved stable transformants that retained wild-type physiological traits. Crucially, our data indicated that C. reniana utilizes a distinct mycoparasitic mechanism, which differs from the well-established sequential process of adhesion, coiling, and lysis seen in C. rosea. Confocal and scanning electron microscopy revealed that C. reniana, following initial coiling and invasive structure formation, penetrates the host hyphae of Botryosphaeria dothidea. It then grows longitudinally within the hyphal lumen, absorbing nutrients and eliminating the pathogen from the inside. Furthermore, C. reniana hyphae can colonize the intercellular spaces of the stem periderm in 84K poplar (Populus alba &#xd7; P. glandulosa) while displaying a distinct tissue-specific behavior in the roots by forming a mantle on the root surface resembling that of ectomycorrhizae. These findings establish C. reniana as a highly promising secondary model species within the Clonostachys genus. By uncovering a novel "internal-consumption" mycoparasitic mode, this study expands our understanding of the ecological diversity of biocontrol fungi and provides a powerful genetic toolset for future functional genomic research.

Clonostachys reniana

Experiences of stigma, bias, and communication challenges among pregnant healthcare workers: A systematic review of qualitative evidence.

BACKGROUND: Healthcare work environments are fraught with occupational hazards that can impact pregnant healthcare workers' health as well as patient care. Despite the feminization of healthcare globally, systematic discrimination against pregnant workers persists across diverse healthcare settings and cultural contexts. The intersection of stigma, bias, and communication challenges creates substantial barriers to career advancement and wellbeing. However, no systematic review has synthesized qualitative evidence on how these three constructs interact across healthcare professions and cultural contexts using an integrated theoretical framework. OBJECTIVE: To systematically review and synthesize qualitative evidence on experiences of stigma, bias, and communication challenges among pregnant healthcare workers across different healthcare settings and cultural contexts using an integrated theoretical framework. DESIGN: Systematic review of qualitative studies following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with thematic synthesis. DATA SOURCES: Seven databases were searched from inception to January 2026. REVIEW METHODS: Included qualitative studies were appraised using the Critical Appraisal Skills Programme (CASP) checklist and synthesized through theory-guided thematic synthesis. Confidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation-Confidence in the Evidence from Reviews of Qualitative research (GRADE-CERQual) approach. RESULTS: Fourteen studies encompassing 1223 participants across 17 countries revealed four major themes: (1) professional identity stigma and workplace discrimination through systematic labeling and stereotyping; (2) gender-based institutional bias rooted in masculine organizational logic; (3) multilevel communication failures creating fear-based climates; and (4) individual and collective resistance strategies developed despite constraints. Occupational hazards specific to pregnancy included exposure to infectious diseases, imaging, physical tasks, cleaning products, patient violence, and medication administration. Support from coworkers and supervisors was identified as the most critical facilitator for avoiding hazards and making necessary modifications, while the desire to be 'supernurses' and fear of consequences emerged as significant barriers. These patterns were consistent across healthcare professions, settings, and cultural contexts, with specialty culture and healthcare system type moderating discrimination intensity. Confidence in core findings was rated high using GRADE-CERQual. CONCLUSIONS: Pregnant healthcare workers globally experience interconnected stigma, bias, and communication challenges that are systematically embedded within healthcare organizational structures. These challenges operate synergistically, requiring comprehensive multilevel interventions beyond policy compliance. Healthcare organizations must implement evidence-based strategies addressing stigma reduction, bias interruption, and communication transformation simultaneously to retain skilled workers and ensure quality patient care.

Female

The archaeal roots of eukaryotic life.

Resolving the biological and geological events that led to the origin of eukaryotes is an ongoing challenge in biology. A major step in the evolution of complex cellular life was the merger between an ancestral host cell and a bacterium (that became the mitochondrion) some two billion years ago. Recently, metagenomics has enabled the reconstruction of a broad diversity of genomes, referred to as the Asgard Archaea. The Asgards are monophyletic with eukaryotes on the tree of life. Asgards have an array of genes, previously thought exclusive to eukaryotes, involved in cellular trafficking, the ubiquitin system, endosomal sorting, and cytoskeleton formation, with growing evidence demonstrating the functions of these proteins mirror those in eukaryotes. This gene repertoire suggests that these Archaea are descendants of the archaeal host from which eukaryotes evolved. Increased sampling has revealed that Asgard lineages are metabolically versatile and play key roles in various ecosystems and uncovered evolutionary transitions between Archaea and eukaryotes, such as innovations in eukaryotic defense systems. The positioning of eukaryotes in the Asgards is debated, but eukaryotes appear to branch within the Heimdallarchaeia. Lineages within this group, particularly Hodarchaeales and Kariarchaeaceae, contain a broad repertoire of eukaryote-like traits, including high-energy yielding metabolisms. Observing and studying Asgard interactions with bacterial descendants of mitochondria in a modern setting will transform our understanding of the origin of complex cellular life.

Archaea