Background: Cymbidium faberi Rolfe is an ornamental orchid of high economic value, however, an efficient genetic transformation system has not yet been reported for this species. Aims: This study aimed to establish an Agrobacterium tumefaciens-mediated genetic transformation system for C. faberi and to optimize the key factors affecting transformation performance. Methods: Rhizomes, calli, and inflorescences were used as explants. The pCAMBIA3301-EGFP vector was introduced using Agrobacterium strain GV3101. Explant type, pre-culture duration, bacterial density (OD600), infection time, co-cultivation period, and antibiotic selection were systematically optimized. Putative transformants were screened by green fluorescence and verified by polymerase chain reaction (PCR). Results: Calli pre-cultured for 3 d were the most suitable recipient material. The optimal transformation conditions were an Agrobacterium suspension of OD600 = 0.2, infection for 5 min, and co-cultivation for 2 d; under these conditions, explant survival reached 72.22%. Two independent transgenic plantlets with stable integration of the enhanced green fluorescent protein gene were obtained and confirmed by PCR. Conclusions: This study provides an Agrobacterium-mediated transformation protocol for C. faberi and offers a technical basis for molecular breeding and gene function studies in this orchid.
Background: Protocorm-like bodies (PLBs) represent a major morphogenic pathway in orchids and are characterized by cellular reprogramming, tissue differentiation, and developmental reorganization. Although PLB formation is widely explored for orchid micropropagation, endopolyploidy dynamics during PLB morphogenesis remain poorly understood. Aims: This study aimed to characterize endopolyploidy patterns and evaluate nuclear DNA content maintenance during PLB morphogenesis and plant regeneration in Cattleya tigrina. Methods: Basal leaf explants were cultured under PLB-inducing conditions in vitro. Morphological and histological analyses were performed throughout PLB development, while nuclear DNA content was estimated by flow cytometry in leaf regions, PLBs at successive developmental stages, and regenerated plants. Results: The leaf base was the most responsive region for PLB induction, showing intense cell proliferation and meristematic activity. Flow cytometric profiles consistently revealed 2C, 4C, and 8C nuclear DNA peaks, indicating endopolyploidy in somatic tissues. PLBs exhibited transient shifts in ploidy distribution during active proliferation phases, particularly at intermediate developmental stages, when 4C nuclei became predominant. Regenerated plants maintained nuclear DNA contents comparable to the original explants. Conclusions: Endopolyploidy is an intrinsic and developmentally regulated feature of PLB morphogenesis in Cattleya tigrina. PLB-mediated regeneration maintained overall nuclear DNA content under the evaluated in vitro conditions.
Background: Stem base rot disease poses a serious threat to the Cyclocodon lancifolius industry, yet its causal agent remains unidentified. Aims: In this study, we aimed to identify the pathogenic fungi responsible for this disease and to screen for effective biocontrol strains against the causal agent. Methods: We isolated and identified the fungal pathogen from the stem base of diseased plants and confirmed its pathogenicity by fulfilling Koch's postulates. Multilocus sequence analysis identified the pathogen as Stemphylium lycopersici. Results: An antagonistic strain, Bacillus subtilis YHYS1, exhibited significant inhibition (51.8%) of S. lycopersici growth in a plate confrontation assay. Volatile compound analysis further confirmed the fungistatic potential of YHYS1. These findings highlight the promise of YHYS1 as an eco-friendly alternative to chemical fungicides for controlling stem base rot disease in C. lancifolius caused by S. lycopersici. Conclusions: Our characterization of this novel disease in C. lancifolius has elucidated the pathogenic features of Stemphylium species, an essential yet understudied group of plant pathogens. These findings provide valuable references for the diagnosis and control of diseases affecting C. lancifolius.
Background: RAB Guanine Nucleotide Dissociation Inhibitors (RAB GDIs) are important vesicle transport regulators in eukaryotes, participating in the functional cycle of RAB GTPases by stabilizing their non-active GDP-conformation. Aims: We address the importance of the three Arabidopsis thaliana RAB GDI paralogs by genetic and developmental analyses and put these results into the seed plants evolution context. Methods: We use methods of genetics, microscopy, and phylogenetics. Results: Our genetic analyses of Arabidopsis T-DNA insertional mutants confirm recent CRISPR alleles data indicating lethality of double gdi1 gdi2 mutants, and our microscopic data point to embryo development arrest in double mutant seeds. We also confirm the involvement of GDI2 and GDI3 in pollen tube growth. Moreover, our data show that GDI1 also contributes to proper pollen function. Our phylogenetic analysis reveals independent diversification of RAB GDIs in Gymnosperms and Angiosperms, with early specialization of an Angiosperm reproduction- and gametophyte-related clade. Conclusions: In Arabidopsis, RAB GDI1 and 2 are important for the vegetative growth while RAB GDI2 and 3 are vital for reproduction. Evolution of the RAB GDI family reflects the evolution of seed plants.
Background: Many concerns have been raised about the extensive use of agrochemicals and their impacts on environment and soil. Some serious issues include increased soil salinization, toxicity and decrease in soil microbial biodiversity. Biostimulants have emerged as a promising ecofriendly alternative to agrochemicals. Humic substances (HSs) are biostimulants with many beneficial effects in plants physiology and productivity. Aims: This review aims to synthesize current evidence on the role of HSs in supporting sustainable agriculture that improves crop productivity while maintaining good soil health in changing environmental conditions. Methods: Relevant studies related to HSs and their effects on soil fertility, plant growth, stress tolerance and hormonal regulation were collected from major scientific databases including Scopus, Web of Science, and Google Scholar. The main outcomes of these studies were extracted and analyzed to provide an overview of the available evidence. Results: The literature shows that the integration of HSs into agricultural practices improves soil structure, increases water retention, maintains healthy microbial diversity and enhances plant productivity. Conclusions: This review highlights the importance of using HSs in enhancing soil health and plant physiology. However, further studies are required to integrating new technologies and diversify HSs sources, plants species, and different environments.
Background: Idesia polycarpa var. vestita Diels is an oil-bearing woody plant of significant economic value. Aims: To accelerate the propagation of its elite germplasm, this study aimed to establish an efficient and stable in vitro rapid propagation system using one-year-old stem segments from elite plants. Methods: Young stem explants were disinfected with 75% ethanol for 40 s, followed by 0.1% HgCl2 for 6 min. MS or 1/2 MS served as basal media, and various combinations of plant growth regulators were tested for axillary bud induction, proliferation, and rooting. Results: The optimal disinfection protocol yielded a 38.10% survival rate. The best axillary bud induction medium was MS + 1.5 mg/L 6-BA + 0.05 mg/L NAA + 0.08 mg/L TDZ, achieving 100% induction. For proliferation, MS + 1.5 mg/L 6-BA + 0.06 mg/L NAA + 0.01 mg/L TDZ (proliferation coefficient 5.81) was optimal. Rooting was best with 1/2 MS + 0.3 mg/L IAA + 0.1 mg/L NAA (100% rooting, 14 roots/plant). Conclusions: This study established a reliable micropropagation system for Idesia polycarpa var. vestita, providing technical support for the efficient production of high-quality seedlings.
Background and aims: Tire wear microplastics (TWMs) are emerging environmental contaminants, but their ecological risks to agricultural systems remain poorly understood. Methods: Rice seedlings were exposed to 0, 10, 100, and 1 000 mg L-1 TWMs for 10 days. Growth parameters, chlorophyll fluorescence, and antioxidant enzyme activities were measured. Results: TWMs promoted growth; exposure to 1 000 mg L-1 TWMs increased plant height and root length by 8.06% and 57.38%, respectively. Chlorophyll fluorescence analysis revealed that TWMs significantly suppressed rETRmax by 32.53 - 43.62% and altered qP and NPQ. TWMs inhibited Y(NPQ) while enhancing Y(NO) loss, indicating impaired photoprotective dissipation and aggravated photodamage. TWMs also inhibited SOD, POD, CAT, and APX activities in both leaves and roots, with root CAT and APX decreasing by up to 37.35% and 40.34%, reflecting a direct impairment of the antioxidant defense system. Conclusions: Rice seedlings achieve TWM-induced short-term growth at the expense of compromised photosynthetic efficiency and antioxidant defense, leading to an unsustainable compensatory state. This study provides physiological evidence for assessing TWMs phytotoxicity in agricultural systems.
Background: In the last decades, vacuum infiltration had been applied for the Agrobacterium-mediated transient expression of foreign gene in plants. However, the relevant influencing factors have not been fully studied yet. Aims: This study aimed to evaluate the effects of vacuum infiltration pressure, time of vacuum infiltration, concentration of Agrobacterium tumefaciens (A. tumefaciens), and incubation time post infiltration on the transient expression of foreign gene in leaves of Nicotiana benthamiana (N. benthamiana). Methods: Two A. tumefaciens strains, LBA4404 and EHA105, carrying a reporter gene of green fluorescent protein (GFP), were used to infiltrate leaves of N. benthamiana via vacuum infiltration. The changes of GFP expression with changes of vacuum infiltration pressure, time of vacuum infiltration, concentration of A. tumefaciens, and incubation time post infiltration were measured. Results: Increase of vacuum pressure from 0.03 to 0.07 MPa increased the GFP expression in the leaves infiltrated with either LBA4404 or EHA105, and the vacuum pressure at 0.07 MPa made almost all of area of the infiltrated leaf express GFP. The increase of the time of vacuum infiltration from 10 to 20 min significantly enhanced the GFP expression in either the LBA4404 or EHA105-infected leaves. Among the different concentrations of Agrobacterium (from OD600 0.1 to 0.9), the concentrations of LBA4404 strain suspension at OD600 0.5 and EHA105 strain suspension at OD600 0.3, respectively, were most effective concentrations for enhancing the GFP expression in the infected leaves. The increase of incubation time post infiltration from 2 to 4 days largely enhanced the intensity of GFP expression in the either LBA4404 or EHA105-infected leaves. However, further increase of incubation time post infiltration from 4 to 6 days decreased the GFP expression in the infected leaves. Conclusions: Vacuum infiltration pressure/time, concentration of A. tumefaciens, and the incubation time post infiltration were important factors affecting the level of transient expression by vacuum infiltration. Optimizing these factors is essential for improving the level of transient expression of foreign gene by vacuum infiltration.
Background: The tomato brown rugose fruit virus (Tobamovirus fructirugosum, ToBRFV) is an emerging tobamovirus that has quickly become a significant obstacle to the production of tomatoes and peppers worldwide. It is now classified as a regulated quarantine pathogen. Effective containment requires rapid, reliable, inexpensive, and safe diagnostic protocols for routine screening in laboratories and production systems. Aims: We aimed to thoroughly evaluate integrated molecular and serological diagnostic methods for ToBRFV and develop biosafe positive controls suitable for high-throughput and decentralized applications. Methods: We evaluated the following methods: conventional RT-PCR, one-enzyme RTX-PCR, immunocapture RT-PCR, recombinase polymerase amplification, loop-mediated isothermal amplification with colorimetric detection, Western blotting, dot blot, and tissue blot immunoassay. The non-infectious positive control was prepared using the GoldenBraid 3.0 cloning system. We developed a single-seed assay that enables direct testing of tomato seed stocks. Results: Among the evaluated molecular methods, RTX-PCR was particularly advantageous due to its minimal sample handling, reduced cost, and ability to bypass RNA extraction. The tissue blot immunoassay enabled high-throughput, low-cost screening of hundreds of samples per day using only basic equipment. Although ToBRFV was frequently detected in seeds harvested from infected plants, no systemic infection was observed in progeny seedlings, confirming the low rate of true vertical transmission. A non-infectious positive control was prepared and successfully employed in molecular methods. Conclusions: Our findings provide an integrated diagnostic framework combining molecular, serological, and biosafety tools to effectively monitor and contain ToBRFV in commercial production and phytosanitary settings.
Background and aims: There appears to be a strong correlation between the rapid proliferation of shrubs in the alpine grassland of the Qinghai-Tibet Plateau and the root exudates of these plants. The dynamics of root exudates during shrub development, however, have been the subject of few investigations. Methods: This work examined Lonicera thibetica, a plant found on the eastern edge of the Qinghai-Tibet Plateau. It focused on the root systems of 5-, 10-, 15-, and 20-year-old L. thibetica plants and how their primary organic acid components changed with the seasons and other circumstances. Results: The findings revealed that the primary components of acid secretion in the roots of L. thibetica were oxalic acid, lactic acid, and tartaric acid; of these, oxalic acid made up over 50% of the total organic acid content. The levels of these organic acids often dropped as shrubs got older, and their seasonal dynamics exhibited a parabolic shift pattern, typically peaking during the robust development stage. According to regression analysis, soil moisture was the primary determinant of the concentration of organic acids produced by alpine shrub roots, suggesting that soil moisture played a crucial role in the secretion process. Conclusions: The physiological dynamics of roots and the mechanisms that regulate them throughout the expansion of alpine shrubs can be better understood thanks to this work.
Background: Rapid and objective characterisation of viral accumulation requires methods combining fast detection and temporal resolution. Aims: Develop a two-phase approach for screening sugar beet genotypes for beet yellows virus (BYV) accumulation dynamics. Methods: Phase 1 employed one-enzyme RTX-PCR for rapid BYV detection, followed by single-time-point RT-qPCR at 30 days post-inoculation (dpi) to screen ten genotypes. Phase 2 performed time-course RT-qPCR at six time points (10-60 dpi) on two contrasting genotypes selected from Phase 1, with assay performance validated by a standard curve. Results: One-enzyme RTX-PCR confirmed BYV infection, enabling quantification; single-time-point RT-qPCR at 30 dpi showed a 5.7-fold titre range (5.6 x 10(7) to 3.2 x 10(8) copies), while time-course RT-qPCR revealed distinct trajectories, relatively resistant GZs1 increased gradually (similar to 5.0 x 10(5) at 10 dpi to 1.7 - 2.3 x 10(7) at 40 - 60 dpi) whereas susceptible Masaryk rose rapidly early (similar to 3.1 x 10(6) at 10 dpi) and peaked at 3.7 x 10(7) by 40 dpi, dynamics not captured by single-time-point measurements; standard curve metrics indicated high assay quality (R-2 = 0.9976; efficiency = 103%). Conclusions: This two-phase method combines speed with precision for effective genotype comparison. It reveals BYV accumulation dynamics that are not captured by single-point assays.
Background: Platycladus orientalis L. is a drought-tolerant conifer valued for its ornamental and medicinal properties. However, efficient regeneration systems for this species remain limited, hindering its propagation and conservation. Aims: The aim of this study was to develop a reliable protocol for indirect organogenesis of Platycladus orientalis under in vitro conditions, evaluating the influence of explant type, culture medium, light exposure, and pretreatment on regeneration efficiency. Methods: Cotyledon, hypocotyl, and radicle explants were cultured on different media formulations. The effects of light and darkness during callus induction and shoot elongation were compared. Seeds underwent or avoided vernalization and scarification treatments to assess their influence on germination and callus formation. Results: Cotyledon explants achieved the highest callus induction rate, reaching 74.06%, particularly under dark conditions. Exposure to light during elongation significantly enhanced callus proliferation and shoots differentiation. Quoirin and LePoivre medium promoted the greatest number of adventitious shoots, with an average of 7.9 shoots per explant, while other media tested showed lower effectiveness. Germination was higher in non-vernalized and non-scarified seeds cultured in Quoirin and LePoivre medium. Conclusions: The established protocol enables efficient indirect organogenesis and shoot regeneration of Platycladus orientalis using cotyledon explants and Quoirin and LePoivre medium. The finding provides a valuable tool for clonal propagation and conservation of this species, supporting both ornamental cultivation and the preservation of its genetic resources.
Background: Tomato plants exposed to salinity stress may experience dynamic changes in root growth and cell wall (CW) composition and structure. Aims: Here, we determined the CW composition and cation-exchange capacity (CEC) of two tomato cultivars (Daniela, salt-tolerant and Naomi, salt-sensitive) as well as their growth and root characteristics. Methods: Seedlings of the tomato cultivars were exposed to six NaCl plus CaCl2 concentrations hydroponically, root growth and CW chemical composition were measured. Results: The root growth of Naomi was adversely (P <= 0.05) reduced at the elongation zone, but there was little change in the chemical composition of the CW under salinity. A marked reduction occurred in the CW-constituting polysaccharides of Naomi relative to Daniela, whether at the 8.00 dS m-1 NaCl treatment or its combination with CaCl2. For both root zones, CW viscosity was better enhanced under NaCl and CaCl2 combinations, but the contents of uronic acid across the CW constituents increased under sole treatment with CaCl2 at the mature root zone of Naomi. The root CW CEC increased (P <= 0.05) with increases in the ionic concentration of the external solution. Salt concentrations at 8.0 dS m-1 NaCl or 8.0 dS m-1 NaCl + CaCl2 increased (P <= 0.05) the CEC of the CW, especially for Daniela. Conclusions: The overall results showed that CaCl2 could enhance some tolerance in CW polysaccharides of tomato under salinity stress. The salt-tolerant Daniela with higher CW and ionic contents had superior stability in cell structure under salt stress.
Image-derived phenotyping at individual plant level can provide more accurate and more comprehensive information than manual measuring for quantitative traits related to canopy growth in field environment. Aims of this study were to: (i) assess smartphone image-derived canopy parameter at early stage of sunflower, and (ii) to evaluate performance of predictive models for morphological and biomass traits related to canopy growth using smartphone image-derived parameter. Original top-view image datasets taken with a smartphone camera were processed, and necessary information was extracted with image analysis software developed using fuzzy c-means clustering algorithm. Canopy cover rate per plant (CCR) was not only the relative value but also image-derived phenotyping feature. CCR were significantly and positively correlated (r ≧ 0.90; **P < 0.01) with plant height, total leaf area per plant, plant dry mass, aboveground plant dry and leaf dry mass, respectively. Ground measured and predicted values from linear regression model for plant height, total leaf area per plant, plant dry mass, aboveground total dry mass, leaf dry mass per plant with CCR showed an accurate prediction with high coefficients of determination (R ) of more than 0.8063, respectively. The present study documented the robustness of predictive models using several metrics.
Michelia chapensis Dandy, a rare and endangered evergreen woody species of the genus Michelia (Magnoliaceae), is endemic to China, with only scattered natural communities (Zhou et al., 2023). First reported from Lechang City, Guangdong Province in 1929 (Dandy, 1929), it is mainly distributed across southern China, with smaller populations in Vietnam (Sima et al., 2020). Valued for its fragrant flowers, medicinal properties, timber, and strong adaptability to diverse soil and climatic conditions (Ao, 1986; Chen et al., 2005; Wang et al., 2009; Liu et al., 2018; Zhou et al., 2023), M. chapensis also plays an important role in providing ecosystem services in both natural and urban environments (Cao et al., 2011; Chen, 2020).
Tomato spotted wilt virus (TSWV; species Orthotospovirus tomatomaculae, family Tospoviridae) (Kuhn et al., 2023), is a negative strand RNA-virus containing envelope structures, which makes it unique among plant viruses (de Haan et al., 1991). TSWV ranks among the most destructive plant viruses worldwide. First described in Australia in 1919, TSWV has since attained a global distribution, infecting over 1 000 plant species across more than 85 families, including key agricultural crops such as tomato (Solanum lycopersicum), pepper (Capsicum annuum), groundnut (Arachis hypogaea), and various ornamentals (Parrella et al., 2003; Pappu et al., 2009). Infected plants typically exhibit chlorotic or necrotic spots, wilting, stunted growth, and in severe cases, complete crop failure, resulting in considerable economic losses, particularly in Solanaceous and Asteraceous crops (Roselló et al., 1996; Latham and Jones, 1998).
Over the past few decades, rice (Oryza sativa L.) has remained a fundamental staple crop and a primary nutritional energy source for nearly 3.5 billion people worldwide, particularly in Asia. With the global population projected to reach 9.6 billion by 2050, rice production must significantly increase to meet the escalating food demand. However, salinity stress poses a major abiotic challenge that severely hampers plant growth and productivity. Soil salinization, driven by climate change and rising temperatures, leads to an excessive accumulation of salts in the soil (Sári et al., 2023). This phenomenon disrupts plant physiology through water deficit, cytotoxic effects of Na⁺ and Cl⁻ ion accumulation, and nutrient imbalances (Isayenkov and Maathuis, 2019). In coastal regions, salinity stress is further intensified by seawater intrusion into groundwater reserves (Muhardi et al., 2020), while in arid and semi-arid areas, low rainfall limits salt leaching, resulting in excessive salt accumulation (Karolinoerita and Yusuf, 2020). Exposure to salinity stress induces the overproduction of reactive oxygen species (ROS), a group of highly reactive free radicals that can damage essential cellular components, including DNA, proteins, lipids, and pigments, ultimately impairing plant function (Ghosh et al., 2021). To mitigate these detrimental effects, plants activate various adaptive responses (Huong et al., 2020), including the upregulation of antioxidant enzyme systems (Jan et al., 2019), which play a crucial role in ROS scavenging and oxidative stress alleviation. These responses involve both well-developed enzymatic and non-enzymatic scavenging pathways or detoxification systems to counter the destructive effects of ROS that include the enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and so forth (Hasanuzzaman et al., 2011).
Virus-induced gene silencing (VIGS) using self-replicating viral vectors is a powerful technique for analysing plant genes and proteins. Conversely, analysing gene silencing provides insights into the infectivity, replication, movement and stability of viral vectors. This study investigates the VIGS of phytoene desaturase gene (PDS) in different Nicotiana species using a vector based on apple latent spherical virus (ALSV, species Cheravirus mali, ICTV 2023). The ALSV genome consists of RNA1 and RNA2, which were cloned separately into plasmids using the GoldenBraid 3.0 system and transformed into two Agrobacterium strains. A third plasmid containing p19, a known gene silencing suppressor, was also introduced. These threeAgrobacterium cultures are traditionally grown separately and then inoculated together (as a mixture) in plants. Here, we describe a novel All-in-One system in which RNA1, RNA2 and p19 are co-expressed in plants after inoculation of a single Agrobacterium strain. A RT-qPCR analysis comparing both methods revealed that PDS expression is significantly different in the early phase of inoculation (6 dpi), but becomes statistically similar at later time points. The All-in-One approach therefore enables efficient co-expression of multiple targets, minimises variations in gene expression and reduces handling complexity, space requirements and costs compared to conventional co-inoculation methods.
Sulfur dioxide (SO2) is a potential signaling molecule, playing a crucial role in regulating multiple physiological processes in organisms. In the present study, we investigate the impact of SO2 on the germination rate of wheat seed subjected to drought stress. Drought stress was stimulated using polyethylene glycol 6000, and the findings revealed that SO2 pretreatment significantly enhanced the germination rate of wheat grain. Additionally, SO2 pretreatment resulted in increased levels of reducing sugars and soluble proteins, as well as elevated amylase activity. Furthermore, SO2 pretreatment of wheat grain significantly reduced the content of superoxide anion, hydrogen peroxide, and malondialdehyde, while increasing the activities of peroxidase (POD), ascorbate peroxidase and catalase. Additionally, SO2 pretreatment was associated with a decrease in lipoxygenase activity and an increase in the levels of endogenous hydrogen sulfide. Principal component analysis revealed that POD is the most influential factor in the seed germination process. These findings suggest that SO2 pretreatment may enhance the germination of wheat grain under drought conditions by facilitating the mobilization of storage materials and improving antioxidant capacity during the germination phase.
