Summary: Liquid crystal monomers (LCMs), the integral components in the manufacture of digital displays, have engendered environmental concerns due to extensive utilization and intensive emission. Despite their prevalence and ecotoxicity, the LCM impacts on plant growth and agricultural yield remain inadequately understood. In this study, we investigated the specific response mechanisms of tobacco, a pivotal agricultural crop and model plant, to four representative LCMs (2OdF3B, 5CB, 4PiMeOP, 2BzoCP) through integrative molecular and physiological approaches. The findings reveal specific impacts, with 4PiMeOP exerting the most pronounced effects, followed by 2BzoCP, 5CB, and 2OdF3B. LCM exposure disrupts the photosynthetic apparatus, exacerbating reactive oxygen species (ROS) levels in leaves, which in turn triggers the upregulation of antioxidative enzymes and the synthesis of antioxidant substances. Additionally, LCMs strongly stimulate the expression of genes involved in abscisic acid (ABA) biosynthesis and signalling pathways. The AI‐assisted meta‐analysis implicates ABA as a critical regulator in the tobacco response to LCMs. Notably, exogenous application of ABA alleviates LCM‐induced toxicities, highlighting the pivotal role of ABA in stress amelioration. Our study provides novel insights into the toxicity and tolerance mechanisms of LCMs in plants, shedding light on both their harmful effects on the ecosystems and potential adaptation responses. This is crucial to develop sustainable agricultural systems by reducing the negative environmental impacts caused by emerging organic pollutants.

As an excellent variety of Camphora glanduliferum, Honganzhang has high essential oil content and can be used as industrial and pharmaceutical raw materials to extract essential oil, which has high development value. In this study, fresh branches and leaves of C. glanduliferum ’Honganzhang’ were used as materials. After extracting C. glanduliferum ’Honganzhang’ essential oils (CGHEO) by steam distillation, gas chromatography-mass spectrometry (GC-MS) was used to analyze its chemical components. On this basis, the antibacterial effect of CGHEO and its potential physiological mechanism were further explored. The results showed that the main components of CGHEO were Cineole (46.57%), α-terpineol (9.93%), Sabinene (8.02%), β-terpinene (6.04%), and α-pinene (4.49%), these compounds can be used in medicine, food and other industries. In terms of antibacterial effect, CGHEO has significant antibacterial effects on three Gram-negative bacteria (Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa), and two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus). CGHEO can reduce Na⁺K⁺-ATPase activity and SDH activity and further interfere with the operation of the bacterial respiratory chain, thereby achieving the effect of inhibiting bacterial reproduction. Based on the main chemical components contained in C. glanduliferum ’Honganzhang’ and its remarkable antibacterial effect, this study is expected to provide a theoretical basis for the wide application of C. glanduliferum ’Honganzhang’ in multiple fields such as medicine, health care, food, and industry.

Polygonatum cyrtonema Hua (P. cyrtonema) is a medicinal plant with high pharmaceutical value. Due to morphological and physiological dormancy mechanisms in P. cyrtonema seeds, natural germination rates remain exceptionally low. This biological constraint necessitates the development of protocols to shorten germination timelines and improve germination efficiency, which are critical requirements for advancing P. cyrtonema breeding programs. In this study, exogenous gibberellin A4 + A7 (GA₄₊₇) was applied to break dormancy in P. cyrtonema seeds. Transcriptomic, hormone metabolomic, and physiological analyses were then employed to investigate the underlying mechanisms. Germination tests revealed that 50 mg·L⁻¹ GA₄₊₇ was the optimal concentration to break dormancy in P. cyrtonema seeds. Transcriptome analysis indicated that exogenous GA₄₊₇ induced the expression of genes involved in GA and ABA biosynthesis and signaling. A total of 19 differential hormone metabolites were identified through hormone metabolomics, with significantly increased levels of active GA₁ and GA₄, but decreased levels of ABA content. These findings were consistent with the up-regulation of transcript levels of GA biosynthesis-related genes and the down-regulation of ABA biosynthesis-related genes, which resulted in an increase in active GA/ABA ratio. At the same time, it was found that exogenous GA₄₊₇ treatment induced sucrose and starch metabolism and pectin catabolic pathways. We measured the relevant physiological indicators and found that the content of soluble sugar and α-amylase activity increased, but the pectin content decreased. These findings establish a theoretical foundation for applying GA₄₊₇ in the standardized production of P. cyrtonema, particularly for accelerating breeding cycles in medicinal germplasm development.

Oxybenzone (OBZ), an organic ultraviolet filter, is an emerging contaminant posing severe threats to ecosystem health. Using tobacco (Nicotiana tabacum) as a model plant, this study investigated the alleviation mechanisms of exogenous silicon (Na₂SiO₃, Si) and bamboo-based biochar (Bc) under OBZ stress. We systematically analyzed physiological and biochemical responses, including phenotypic parameters, reactive oxygen species metabolism, photosynthetic function, chlorophyll synthesis, and endogenous hormone levels. Results reveal that OBZ significantly inhibited tobacco growth and triggered a reactive oxygen species (ROS) burst. Additionally, OBZ disrupted antioxidant enzyme activities and hormonal balance. Exogenous Bc mitigated OBZ toxicity by adsorbing OBZ, directly scavenging ROS, and restoring the ascorbate-glutathione (AsA-GSH) cycle, thereby enhancing photosynthetic efficiency, while Si alleviated stress via cell wall silicification, preferential regulation of root development and hormonal signaling, and repair of chlorophyll biosynthesis precursor metabolism and PSII function. The mechanisms of the two stress mitigators were complementary, Bc primarily relied on physical adsorption and ROS scavenging, whereas Si emphasized metabolic regulation and structural reinforcement. These findings provide practical strategies for simultaneously mitigating organic UV filter pollution and enhancing plant resilience in contaminated soils.

Paulownia fortunei is an important economic tree species that possesses numerous biological and economic traits, such as fast growth, strong stress resistance, and excellent wood properties. The cultivation of this species is pervasive across numerous regions of China. Epicauta ruficeps, a common pest species of P. fortunei, typically consumes the foliage of its host plant. However, there are currently no reported studies on the physiological and biochemical mechanisms underlying P. fortunei response to E. ruficeps feeding. In this study, we discovered that the enhancement of nitrogen assimilation and porphyrin metabolism directly contributes to the maintenance of the steady state of photosynthetic activity in P. fortunei leaves. Meanwhile, E. ruficeps feeding also leads to an increase in the level of reactive oxygen species (ROS) in P. fortunei leaves. As key signaling molecules, the elevated level of ROS activates the antioxidant system and phenylpropanoid metabolism, which in turn results in increased antioxidant enzyme activity, as well as increased contents of antioxidants and lignin. The aforementioned changes have the potential to reduce the degree of membrane lipid peroxidation and enhance the mechanical strength of leaf tissues. Consequently, this can assist in maintaining the steady state of photosynthesis indirectly. In summary, the present study elucidates the physiological and biochemical mechanisms underlying the maintenance of the steady state of photosynthetic activity in P. fortunei after being feeded by E. ruficeps from multiple dimensions. Simultaneously, it lays a theoretical foundation and provides data support for the subsequent comprehensive analysis of the molecular mechanisms involved in P. fortunei response to E. ruficeps feeding.