ABSTRACT
Radish (Raphanus sativus L.) is an economically important vegetable worldwide, but its sustainable production and breeding are highly threatened by blight disease caused by Alternaria brassicae. Melatonin is an important growth regulator that can influence physiological activities in both plants and microbes and stimulate biotic stress resistance in plants. In this study, 0-1500 µM melatonin was exogenously applied to healthy radish seedlings, in vitro incubated A. brassicae, and diseased radish seedlings to determine the effects of melatonin on host, pathogen, and host-pathogen interaction. At sufficient concentrations (0-500 µM), melatonin enhanced growth and immunity of healthy radish seedlings by improving the function of organelles and promoting the biosynthesis of antioxidant enzymes, chitin, organic acid, and defense proteins. Interestingly, melatonin also improved colony growth, development, and virulence of A. brassicae. A strong dosage-dependent effect of melatonin was observed: 50-500 µM promoted host and pathogen vitality and resistance (500 µM was optimal) and 1500 µM inhibited these processes. Significantly less blight was observed on diseased seedlings treated with 500 µM melatonin, indicating that melatonin more strongly enhanced the growth and immunity of radish than it promoted the development and virulence of A. brassicae at this treatment concentration. These effects of MT were mediated by transcriptional changes of key genes as identified by RNA-seq, Dual RNA-seq, and qRT-PCR. The results from this work provide a theoretical basis for the application of melatonin to protect vegetable crops against pathogens.
ABSTRACT
Plasmodiophora brassicae causes a serious threat to cruciferous plants including radish (Raphanus sativus L.). Knowledge on the pathogenic regularity and molecular mechanism of P. brassicae and radish is limited, especially on the metabolism level. In the present study, clubroot-susceptible and clubroot-resistant cultivars were inoculated with P. brassicae Race 4, root hairs initial infection of resting spores (107 CFU/mL) at 24 h post-inoculation and root galls symptom arising at cortex splitting stage were identified on both cultivars. Root samples of cortex splitting stage of two cultivars were collected and used for untargeted metabonomic analysis. We demonstrated changes in metabolite regulation and pathways during the cortex splitting stage of diseased roots between clubroot-susceptible and clubroot-resistant cultivars using untargeted metabonomic analysis. We identified a larger number of differentially regulated metabolites and heavier metabolite profile changes in the susceptible cultivar than in the resistant counterpart. The metabolites that were differentially regulated in both cultivars were mostly lipids and lipid-like molecules. Significantly regulated metabolites and pathways according to the P value and variable important in projection score were identified. Moreover, four compounds, including ethyl α-D-thioglucopyranoside, imipenem, ginsenoside Rg1, and 6-gingerol, were selected, and their anti-P. brassicae ability and effects on seedling growth were verified on the susceptible cultivar. Except for ethyl α-D-thioglucopyranoside, the remaining could inhibit clubroot development of varing degree. The use of 5 mg/L ginsenoside Rg1 + 5 mg/L 6-gingerol resulted in the lowest disease incidence and disease index among all treatments and enhanced seedling growth. The regulation of pathways or metabolites of carbapenem and ginsenoside was further explored. The results provide a preliminary understanding of the interaction between radish and P. brassicae at the metabolism level, as well as the development of measures for preventing clubroot.
ABSTRACT
OBJECTIVE: To determine the effect of comfort nursing in elderly patients with lumbar vertebral compression fractures (LVCFs). METHODS: A total of 194 elderly patients with LVCFs were enrolled, and assigned to two groups based on different nursing intervention methods. Among them, 93 patients were given routine nursing intervention as a control group (CON group), while the rest 101 patients were given comfort nursing as an intervention group (INT group). The visual analog scale (VAS) was adopted to evaluate patients' pain and Japanese Orthopaedic Association score (JOA) to evaluate their dysfunction. In addition, Barthel score was used to evaluate patients' self-care ability, and the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were adopted to score their anxiety and depression. Moreover, the compliance and nursing satisfaction of the two groups were investigated. RESULTS: After nursing, t VAS, SAS, and SDS scores of both groups declined significantly, and these scores of the INT group declined more notably. After nursing, the JOA and Barthel scores of the two groups increased greatly, and both scores of the INT group were significantly higher than those of the CON group. Additionally, the INT group consumed significantly less analgesic drugs and experienced significantly shorter hospital stay than the CON group. Moreover, according to the survey on nursing compliance and nursing satisfaction, the INT group showed significantly higher nursing compliance and nursing satisfaction than the CON group. CONCLUSION: For elderly patients with LVCFs, comfort nursing can effectively relieve their postoperative pain and negative emotion and improve their daily living ability.
