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يعلمك المحادثات الأساسيةُ في الصين. يوضح العديد من مشاهد الحياة الواقعية في الصين. يساعدك في أن تصبح متحدثا طلقا.

Background Styrax tonkinensis (Pierre) Craib ex Hartwich faces challenges in expanding in the south provinces of Yangtze River region due to climate extremes like flood-drought abrupt alternation (FDAA) caused by global warming. Low tolerance to waterlogging and drought restricts its growth in this area. To study its antioxidant system and molecular response related to the peroxisome pathway under FDAA, we conducted experiments on two-year-old seedlings, measuring growth indexes, reactive oxygen species content, antioxidant enzyme activity, and analyzing transcriptomes under FDAA and drought (DT) conditions. Results The physiological results indicated a reduction in water content in roots, stems, and leaves under FDAA conditions. The most significant water loss, amounting to 15.53% was observed in the leaves. Also, ROS accumulation was predominantly observed in leaves rather than roots. Through transcriptome analysis, we assembled a total of 1,111,088 unigenes (with a total length of 1,111,628,179 bp). Generally, SOD1 and CAT genes in S. tonkinensis seedlings were up-regulated to scavenge ROS. Conversely, the MPV17 gene exhibited contrasting reaction with up-regulation in leaves and down-regulation in roots, leading to increased ROS accumulation in leaves. CHS and F3H were down-regulated, which did not play an essential role in scavenging ROS. Moreover, the down-regulation of PYL , CPK and CALM genes in leaves may not contribute to stomatal closure, thereby causing continuous water loss through transpiration. Whereas, the decreased root vigor during the waterlogging phase and up-regulated CPK and CALM in roots posed obstacles to water absorption by roots. Additionally, the DEGs related to energy metabolism, including LHCA and LHCB , were negatively regulated. Conclusions The ROS generation triggered by MPV17 genes was not the main reason for the eventual mortality of the plant. Instead, plant mortality may be attributed to water loss during the waterlogging phase, decreased root water uptake capacity, and continued water loss during the subsequent drought period. This study establishes a scientific foundation for comprehending the morphological, physiological, and molecular facts of S. tonkinensis under FDAA conditions.

Vitamin D deficiency is increasingly common in systemic lupus erythematosus (SLE) patients and is associated with the disease activity and proteinuria. Recently, alterations in metabolism have been recognized as key regulators of SLE pathogenesis. Our objective was to identify differential metabolites in the serum metabolome of SLE with vitamin D deficiency. In this study, serum samples from 31 SLE patients were collected. Levels of 25(OH)D3 were assayed by ELISA. Patients were divided into two groups according to their vitamin D level (20 ng/ml). Untargeted metabolomics were used to study the metabolite profiles in serum by high-performance liquid chromatography-tandem mass spectrometry. Subsequently, we performed metabolomics profiling analysis to identify 52 significantly altered metabolites in vitamin D deficient SLE patients. The area under the curve (AUC) from ROC analyses was calculated to assess the diagnostic potential of each candidate metabolite biomarker. Lipids accounted for 66.67% of the differential metabolites in the serum, highlighted the disruption of lipid metabolism. The 52 differential metabolites were mapped to 27 metabolic pathways, with fat digestion and absorption, as well as lipid metabolism, emerging as the most significant pathways. The AUC of (S)-Oleuropeic acid and 2-Hydroxylinolenic acid during ROC analysis were 0.867 and 0.833, respectively, indicating their promising diagnostic potential. In conclusion, our results revealed vitamin D deficiency alters SLE metabolome, impacting lipid metabolism, and thrown insights into the pathogenesis and diagnosis of SLE.

Cadmium (Cd) stress is increasing at a high pace and is polluting the agricultural land. As a result, it affects animals and the human population via entering into the food chain. The aim of this work is to evaluate the possibility of amelioration of Cd stress through chitosan nanoparticles (CTS-NPs). After 15 days of sowing (DAS), Solanum lycopersicum seedlings were transplanted into maintained pots (20 in number). Cadmium (0.8 mM) was providing in the soil as CdCl2·2.5H2O at the time of transplanting; however, CTS-NPs (100 µg/mL) were given through foliar spray at 25 DAS. Data procured from the present experiment suggests that Cd toxicity considerably reduces the plant morphology, chlorophyll fluorescence, in addition to photosynthetic efficiency, antioxidant enzyme activity and protein content. However, foliar application of CTS-NPs was effective in increasing the shoot dry weight (38%), net photosynthetic rate (45%) and SPAD index (40%), while a decrease in malondialdehyde (24%) and hydrogen peroxide (20%) was observed at the 30 DAS stage as compared to control plants. On behalf of the current results, it is demonstrated that foliar treatment of CTS-NPs might be an efficient approach to ameliorate the toxic effects of Cd.

The global expansion of soil salinization has intensified the need to understand plants’ salt tolerance mechanisms. This study investigates the molecular basis of salt stress responses in Melia azedarach L. and the modulating role of 24-epibrassinolide (EBR) through transcriptomic analysis. While salt stress significantly inhibited seedling growth, EBR application substantially mitigated these effects. Transcriptomic analysis identified 11,747 differentially expressed genes (DEGs) in the salt-treated versus control seedlings (SA vs. CK) comparison, 3786 DEGs in the Salt + EBR-treated versus control seedlings (E1 vs. CK) comparison, and 8019 DEGs in the Salt + EBR-treated versus salt-treated seedlings (E1 vs. SA) comparison. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified the pivotal pathways in salt stress adaptation, such as plant hormone signal transduction, phenylpropanoid biosynthesis, and ribosome pathways. Notably, key regulators such as AUX1, TIR1, IAA, SAUR, PYL, and ABF showed dynamic expression patterns under salt stress and EBR treatment, revealing their critical roles in stress mitigation. Our findings provide novel insights into EBR-mediated salt tolerance, highlighting its potential to modulate phytohormone signaling networks. This study advances both the fundamental knowledge of salt stress adaptation and practical strategies for enhancing plant resilience in saline environments.

Global climate change has led to an increased frequency of extreme weather events, with flooding caused by heavy rainfall posing a significant threat to plant growth and survival. Styrax japonicus, a species of ecological and economic importance, exhibits stronger flooding tolerance compared to its congener Styrax tonkinensis. Endogenous hormonal systems in plants are indispensable for integrating growth dynamics, developmental transitions, and ecological stress perception-transduction pathways. To investigate the response of S. japonicus to flooding stress at both hormonal and molecular levels, this study utilized annual seedlings of S. japonicus as experimental material. Two levels of flooding stress, waterlogging and submergence, were applied to examine the variations in endogenous hormone levels in S. japonicus roots under different stress conditions and durations. Combined with transcriptome sequencing, critical genes associated with hormone-mediated signaling and biosynthetic processes were identified. The results showed that the content of the ethylene precursor ACC exhibited a trend of “increase–decrease–increase”, with an earlier decline under submergence compared to waterlogging stress by approximately 10 days. Abscisic acid content sharply decreased at 5 d, followed by an initial increase and subsequent decrease, with higher ABA levels observed under waterlogging stress than under submergence. GA content significantly decreased after 10 d in both stress conditions. KEGG enrichment analysis revealed that the most prominently enriched pathway for DEGs was plant hormone signal transduction under both waterlogging and submergence stress, with 314 and 370 DEGs identified, respectively. Analysis of common genes indicated their association with ethylene, ABA, auxin, and BRs. After further investigation of DEGs in the ethylene and ABA biosynthesis process, we identified key enzyme genes encoding ACS, ACO, and NCED, which are critical for their biosynthesis.

Salinity is a serious environmental problem following a worsening trend. This study investigates the role of 24-epibrassinolide(EBR) in regulating plant growth and physiological performances, particularly in alleviating the negative effects of salt stress. Melia azedarach L. seedlings from two seed sources, Sheyang (SY) and Xiashu (XS), were exposed to sea salt and treated with different concentrations of EBR within a 60-day period. The results demonstrate that appropriate EBR application improved the seedlings’ stress tolerance by promoting growth and physiological systems. In terms of the relative increment, it showed that a difference of 1.45% and 1.13% in the SY and XS groups was the positive effect of the highest EBR treatment concentration. As for diameter growth, the difference observed was 2.51% and 1.80% for the SY and XS groups, respectively. In all physiological measurements, including the content of photosynthetic pigments, water relations, membrane stability, osmolytes and antioxidant enzymes, significant changes generally observed between salt stress alone and the highest EBR treatment concentration. A better performance was observed in the SY seed source, which is of a coastal nature. These findings contribute to our understanding of Melia azedarach’s adaptation to changing environments and provide potential for further molecular studies as well as valuable insights for forestry, agricultural and ecological research.

This study investigated the physiological and biochemical responses of Styrax japonica Sieb. et Zucc. seedlings to normal water and nutrient management (control group, CK), waterlogging (root submerged, T1), and partial submergence (partial stem submergence, T2) over a period of 25 days. Measurements of root activity, malondialdehyde (MDA) content, hydrogen peroxide (H2O2) content, antioxidant enzyme (SOD, POD, and CAT), and anaerobic respiratory enzyme (LDH, ADH, and PDC) activities were conducted every 5 days. The results showed the following: the seedlings of the control group maintained high root activity and low oxidative damage levels throughout the experiment; under T1 treatment, root activity initially increased but declined, while MDA and H2O2 content gradually increased; T2 seedlings showed little change initially, but root activity briefly increased at Day 20 before rapidly declining. Regarding the antioxidant system, the control group had the highest SOD activity, while seedlings under T1 and T2 treatments exhibited compensatory upregulation of CAT and POD activities (from Day 15 to 20). Additionally, under waterlogging stress, LDH and ADH activities significantly increased, reflecting the activation of anaerobic metabolic pathways, while PDC content continuously decreased, indicating that low-oxygen stress induced the accumulation of LDH and ADH but reduced ethanol fermentation. PCA revealed that the first two principal components explained 61.53% of the total variation, with PC1 (45.76%) reflecting the contrasting relationship between the activation of anaerobic metabolism (increased ADH and LDH activity) and decreased root activity under waterlogging stress, while PC2 (15.77%) primarily captured the responses of oxidative damage (increased MDA) and corresponding antioxidant defense (upregulated CAT and POD activities). Overall, S. japonica seedlings adapt to short-term waterlogging stress by regulating anaerobic respiration and antioxidant systems, but prolonged stress leads to a continued increase in H2O2 and a decline in antioxidant enzyme activities. This study provides experimental evidence and theoretical support for understanding the waterlogging tolerance mechanisms of S. japonica. This experiment provides important information on the adaptive mechanisms of plants under waterlogging stress.

Aim: To predict Rhododendron diversity patterns and identify Rhododendron hotspots and priority areas for their conservation. Location: China. Methods: We predicted the distribution of 212 Rhododendron species by applying a spatially explicit species assemblage modelling (SESAM) framework on a 10 × 10 km grid across China. We evaluated Rhododendron diversity based on species richness, β-diversity and weighted endemism (also known as range-size rarity), and then identified hotspots formed by the top 1%, 5%, 25% and 50% of record-containing grid cells for each diversity metric separately and for the combination of the three diversity metrics. We determined the priority conservation areas for Rhododendrons by overlaying the hotspots with the map of the 2139 nature reserves existing in China, and calculated the percentage of hotspots that is protected. The same analysis was also applied to threatened Rhododendron species. Results: Rhododendron species richness, β-diversity and weighted endemism decrease within China from the south-west to the north-east, mainly along mountain ranges. In total, 12 general hotspots for Rhododendron species are detected, covering 1.4% of China's land area. Five separately discerned hotspots (i.e. southern Chongqing, south-eastern Tibet, north-western Yunnan, south-western Sichuan and northern Guangdong) comprising threatened Rhododendron species largely overlap (86.3%) with the general hotspots, and form priority areas for conservation. However, the remaining hotspots, especially southern Zhejiang and north-eastern Guizhou, need more protection. Main conclusions: To the best of our knowledge, this is the first comprehensive study of Rhododendron diversity patterns across the whole of China in terms of species richness, β-diversity and weighted endemism, thereby offering a sound basis for the conservation of Rhododendrons in China. We demonstrate that as much attention should be paid to the small hotspots in south-western and south-eastern China, as to the largest hotspot (i.e. Mt Hengduan), to achieve conservation of Rhododendrons.

Background Rheumatoid arthritis (RA) is a major public health problem. Unfortunately, there is a scarcity of comprehensive and up-to-date information regarding the burden of RA and its dynamic trends in subsequent years. To examine the changing trends in the global burden of RA and forecast for 2044, which will facilitate the development of strategies tailored to RA burden and provide reference for the development of effective treatment guidelines. Methods Following the general analytical strategy used the Global Burden of Disease Study (GBD) 2019, which included 204 countries, the age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR) and age-standardized disability adjusted of life year (DALY) rate for RA were analyzed. Results The ASIR, ASMR and age-standardized DALY rate for RA in 2019 were 13.001/100,000 (95% UI, 11.833 ~ 14.274), 0.574/100,000 (95% UI, 0.356 ~ 0.793) and 39.565/100,000 (95% UI, 49.529 ~ 30.508), respectively. America had the highest ASIR [18.578(95% UI, 17.147 ~ 20.148)] and age-standardized DALY rate [53.676(95% UI, 40.106 ~ 67.968)] in 2019. Asia had the highest ASMR [0.681(95% UI, 0.802 ~ 0.480)] in 2019. From 1990 to 2019, a significant average annual percentage change (AAPC) in the ASIR was observed in both males [0.237% (95% CI, 0.216 ~ 0.259%)] and females [0.197% (95% CI, 0.141 ~ 0.254%)], AAPC in the ASMR was observed in both males [-0.398% (95% CI, -0.605~-0.191%)] and females [-0.295% (95% CI, -0.424~-0.65%)]. Age effects indicated that the relative risk (RR) of RA-associated incidence and mortality rates increased with age among males and females. The RR of RA increased over time and started to gradually increase from 1990. Cohort effects showed decreases in incidence, mortality and DALY rates in successive birth cohorts. The global incidence of RA would continue to increase in the future, while mortality would continue to decrease. Conclusion The increased risk of RA is dominantly influenced by age effects and period effects and the ethnic area. The results suggest that early identification and treatment of RA is important for reducing the ongoing burden with age, and targeted health education and specific intervention programs should be promoted to control middle-elderly population.