Potential of utilizing pathogen-derived mycotoxins as alternatives to synthetic herbicides in controlling the noxious invasive plant Xanthium italicum.

Discovery of environmentally friendly agents for controlling alien invasive species (AIS) is challenging and in urgent need as their expansion continues to increase. Xanthium italicum is a notorious invasive weed that has caused serious ecological and economic impacts worldwide. For the purpose of exploring the possibility of utilizing herbicidal mycotoxins to control this species, three compounds, a new compound, curvularioxide (1), a new naturally occurring compound, dehydroradicinin (2), and a known compound, radicinin (3), were isolated via activity-guided fractionation from the secondary metabolites of the pathogenic Curvularia inaequalis, which was found to infect X. italicum in natural habitats. All isolated compounds exhibited potent herbicidal activity on receiver species. It is noteworthy to mention that their effects on X. italicum in our bioassays were equivalent to the commercial herbicide glyphosate. Subsequent morphological analysis revealed that application of radicinin (3) severely hindered X. italicum seedlings' hypocotyl and root development. Malondialdehyde content and the activity of catalase and peroxidase of the seedlings were also significantly different from the control, implying the occurrence of induced oxidative stress. Our results suggest that pathogens infecting invasive plants might be valuable resources for developing safer herbicides for controlling weeds. © 2023 Society of Chemical Industry.

Effectiveness of Continuous Care Interventions in Elderly Patients with High-Risk Pressure Ulcers and Impact on Patients' Activities of Daily Living.

Objective: To explore the influence of continuous care interventions on the incidence of pressure ulcers in elderly patients with high-risk pressure ulcers and their activities of daily living (ADL). Methods: The clinical records of 114 elderly patients at high risk of pressure ulcers (Patients had a Braden pressure ulcer risk score less than or equal to 18 and suffered no pressure pressure ulcers) who attended our hospital from February 2020 to February 2022 were collected for retrospective analysis. Among them, 54 patients treated with conventional nursing interventions were assigned to the control group (CG) (64-91 years old), and the remaining 60 treated with continuous care interventions were assigned to the observation group (OG) (61-91years old). The detection indices and clinical related data were collected from LIS system of our hospital. The self-rating depression scale (SDS) and self-rating anxiety scale (SAS) scores of the two groups were compared before and after the intervention, and the improvement in quality of life and ADL scores were counted. The post-care satisfaction and incidence of pressure ulcers were analyzed, and the caregivers' pressure ulcer care behaviors and pressure ulcer management abilities before and after treatment were compared between both groups of patients. Results: The SAS and SDS scores were lower in the OG (38.33±3.21 and 39.07±4.15) than in the CG (44.74±4.13 and 45.80±3.92) after the intervention (P < .05); quality of life and ADL were higher in the OG (44.07±7.15 and 58.33±6.21) than in the CG (36.20±6.92 and 45.84±6.12) after the intervention (P < .05). The incidence of pressure ulcers in the OG (18.33%) was lower than that in the CG (37.04%) after the intervention (P < .05); total nursing satisfaction in the OG (91.67%) was higher than that in the CG (74.07%) after the intervention (P < .05), and caregivers' pressure ulcer care behaviors and pressure ulcer management abilities of patients in the OG (36.42±2.41 and 44.07±7.15) were higher than those in the CG (29.23±2.50 and 36.20±6.92) after the intervention (P < .05). Conclusion: Continuous care interventions can be promoted for elderly patients with high-risk pressure ulcers outside the hospital, which can reduce the incidence of pressure ulcers, negative emotions, related complications and treatment costs, and improve the effective utilization of medical resources. In the future, continuous care guidelines and training plans can be developed for elderly patients with high-risk pressure ulcers, so as to improve the understanding and application ability of health care providers and nurses on intervention measures.

Chemical composition and phytotoxic activity of the essential oil of Artemisia sieversiana growing in Xinjiang, China.

The chemical profile and phytotoxic activity of the essential oil extracted from Artemisia sieversiana was investigated. In total 17 compounds were identified by GC/MS, representing 99.17% of the entire oil, among which α-thujone (64.46%) and eucalyptol (10.15%) were the most abundant constituents. The major components, their mixture as well as the essential oil exhibited significant phytotoxic activity against Amaranthus retroflexus, Medicago sativa, Poa annua and Pennisetum alopecuroides, with their IC50 values ranged from 1.55 ∼ 6.21 mg/mL (α-thujone), 1.42 ∼ 17.81 mg/mL (eucalyptol), 0.23 ∼ 1.05 mg/mL (the mixture), and 1.89 ∼ 4.69 mg/mL (the essential oil) on the four tested species. The mixture of the major constituents exerted more potent effect compared with each individual compound, indicating the possible involvement of synergistic effect of these two compounds.

The regulatory mechanism of chilling-induced dormancy transition from endo-dormancy to non-dormancy in Polygonatum kingianum Coll.et Hemsl rhizome bud.

KEY MESSAGE: We identified three dormant stages of Polygonatum kingianum and changes that occurred during dormancy transition in the following aspects including cell wall and hormones, as well as interaction among them. Polygonatum kingianum Coll.et Hemsl (P. kingianum) is an important traditional Chinese medicine, but the mechanism of its rhizome bud dormancy has not yet been studied systematically. In this study, three dormancy phases were induced under controlled conditions, and changes occurring during the transition were examined, focusing on phytohormones and the cell wall. As revealed by HPLC-MS (High Performance Liquid Chromatography-Mass Spectrometry) analysis, the endo- to non-dormancy transition was association with a reduced abscisic acid (ABA)/gibberellin (GA3) ratio, a decreased level of auxin (IAA) and an increased level of trans-zeatin (tZR). Transmission electron microscopy showed that plasmodesmata (PDs) and the cell wall of the bud underwent significant changes between endo- and eco-dormancy. A total of 95,462 differentially expressed genes (DEGs) were identified based on transcriptomics, and clustering and principal component analysis confirmed the different physiological statuses of the three types of bud samples. Changes in the abundance of transcripts associated with IAA, cytokinins (CTKs), GA, ABA, brassinolide (BR), jasmonic acid (JA), ethylene, salicylic acid (SA), PDs and cell wall-loosening factors were analysed during the bud dormancy transition in P. kingianum. Furthermore, nitrilase 4 (NIT4) and tryptophan synthase alpha chain (TSA1), which are related to IAA synthesis, were identified as hub genes of the co-expression network, and strong interactions between hormones and cell wall-related factors were observed. This research will provide a good model for chilling-treated rhizome bud dormancy in P. kingianum and cultivation of this plant.