Machine Learning-Based Approach to Predict Last-Minute Cancellation of Pediatric Day Surgeries.

The last-minute cancellation of surgeries profoundly affects patients and their families. This research aimed to forecast these cancellations using EMR data and meteorological conditions at the time of the appointment, using a machine learning approach. We retrospectively gathered medical data from 13 440 pediatric patients slated for surgery from 2018 to 2021. Following data preprocessing, we utilized random forests, logistic regression, linear support vector machines, gradient boosting trees, and extreme gradient boosting trees to predict these abrupt cancellations. The efficacy of these models was assessed through performance metrics. The analysis revealed that key factors influencing last-minute cancellations included the impact of the coronavirus disease 2019 pandemic, average wind speed, average rainfall, preanesthetic assessments, and patient age. The extreme gradient boosting algorithm outperformed other models in predicting cancellations, boasting an area under the curve value of 0.923 and an accuracy of 0.841. This algorithm yielded superior sensitivity (0.840), precision (0.837), and F1 score (0.838) relative to the other models. These insights underscore the potential of machine learning, informed by EMRs and meteorological data, in forecasting last-minute surgical cancellations. The extreme gradient boosting algorithm holds promise for clinical deployment to curtail healthcare expenses and avert adverse patient-family experiences.

The Abundant and Unique Transcripts and Alternative Splicing of the Artificially Autododecaploid London Plane (Platanus × acerifolia).

Transcription and alternative splicing (AS) are now appreciated in plants, but few studies have examined the effects of changing ploidy on transcription and AS. In this study, we showed that artificially autododecaploid plants of London plane (Platanus × acerifolia (Aiton) Willd) had few flowers relative to their hexaploid progenitors. Transcriptome analysis based on full-length Oxford Nanopore Technologies (ONTs) and next-generation sequencing (NGS) revealed that the increased ploidy level in P. × acerifolia led to more transcribed isoforms, accompanied by an increase in the number of isoforms per gene. The functional enrichment of genes indicated that novel genes transcribed specifically in the dodecaploids may have been highly correlated with the ability to maintain genome stability. The dodecaploids showed a higher number of genes with upregulated differentially expressed genes (DEGs) compared with the hexaploid counterpart. The genome duplication of P. × acerifolia resulted mainly in the DEGs involved in basic biological pathways. It was noted that there was a greater abundance of alternative splicing (AS) events and AS genes in the dodecaploids compared with the hexaploids in P. × acerifolia. In addition, a significant difference between the structure and expression of AS events between the hexaploids and dodecaploids of Platanus was found. Of note, some DEGs and differentially spliced genes (DSGs) related to floral transition and flower development were consistent with the few flower traits in the dodecaploids of P. × acerifolia. Collectively, our findings explored the difference in transcription and AS regulation between the hexaploids and dodecaploids of P. × acerifolia and gained new insight into the molecular mechanisms underlying the few-flower phenotype of P. × acerifolia. These results contribute to uncovering the regulatory role of transcription and AS in polyploids and breeding few-flower germplasms.

Quality Evaluation of Wild Germplasm of Chinese Prickly Ash (Zanthoxylum bungeanum Maxim) from Qinling Mountains at Different Elevations Based on HPLC-Fingerprint.

Wild Chinese prickly ash resources provide a valuable genetic resource for Zanthoxylum bungeanum Maxim improvement and breeding. The Qinling Mountains was an abundant source for wild Chinese prickly ash. In this study, the phenolic and flavonoid compounds of wild germplasm resources from different altitudes and six cultivated varieties were analyzed by high performance liquid chromatography (HPLC). The chromatograms of them were essentially consistent, although their chemical composition contents were greatly different. The thirty samples were divided into three categories through the hierarchical clustering analysis. Catechin, hyperoside and quercitrin were considered to be key compounds for the quality evaluation, and by contrast, the wild samples with an altitude of 2300±50 m (Group IV) had the highest content of key compounds, and presented stronger antioxidant activity and antibacterial ability, indicating that these wild samples could be identified as the excellent breeding resources. This is the first time to evaluate the quality of wild Chinese prickly ash at different altitudes in Qinling Mountains. These excellent wild germplasm resources provided substantial potential accessions for use directly in Chinese prickly ash breeding programs.

Knockdown of Yes-Associated Protein Induces the Apoptosis While Inhibits the Proliferation of Human Periodontal Ligament Stem Cells through Crosstalk between Erk and Bcl-2 Signaling Pathways.

Objective: The purpose of this study was to provide an insight into the biological effects of knockdown Yes-associated protein (YAP) on the proliferation and apoptosis of human periodontal ligament stem cells (h-PDLSCs). Methods: Immunofluorescence and Western blot were used to evaluate Hippo-YAP signaling expression level. Enhanced green fluorescence protein lentiviral vector was constructed to down-regulate YAP in h-PDLSCs. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were used to detect the interfering efficiency of YAP expression. The proliferation activity was detected by EdU staining. Analysis of apoptosis in h-PDLSCs was done through Annexin V-APC staining, while cell cycle analysis was detected by flow cytometry. Cellular senescence was analyzed by ß-galactosidase activity detection. The expression of elements in signaling pathways related with proliferation and apoptosis was detected by Western blot. Results: YAP was located in nucleus and cytoplasm. After the lentivirus transfection, the expression of YAP mRNA and protein was significantly reduced (P<0.001). When YAP was knocked down, the proliferation activity of h-PDLSCs was inhibited; the early & late apoptosis rates increased; the proportion of cells in G1 phases increased (P<0.05), while that in G2 and S phase decreased (P<0.05); cellular senescence was accelerated (P<0.01); ERK and its target proteins P-P90RSK and P-MEK were reduced while Bcl-2 family members increased. Conclusion: Knockdown of YAP inhibits the proliferation activity and induces apoptosis of h-PDLSCs with the involvement of Hippo pathway and has a crosstalk between Erk and Bcl-2 signaling pathways.

Investigation on the IL-18 -607A/C and -137C/G on the susceptibility of ischemic stroke.

OBJECTIVE: We conducted a case-control study with 322 cases and 322 controls to assess the role of the two common SNPs in the promoter of IL-18 gene. METHODS: Polymerase chain reaction restriction fragment length of polymorphism (PCR-RFLP) was taken to genotype -607A/C and -137C/G in the promoter of the IL-18 gene. RESULTS: By comparing cases and control subjects, we found that IS cases were more likely to have higher BMI, higher proportion of hypertension, and have higher proportion of smokers and drinkers. We found that IL-18 -607CC genotype (OR=1.70, 95% CI=1.03-2.81) and C allele (OR=1.26, 95% CI=1.01-1.58) were significantly more frequent in IS patients when compared with AA genotype. We did not find significant association between IL-18 -607A/C gene polymorphism and BMI, hypertension, smoking and drinking on the risk of IS. CONCLUSION: Our study suggests that polymorphisms in IL-18 -607A/C can influence the development of IS, and this gene polymorphism is associated with risk of IS in a Chinese population.

Characterizing the complete chloroplast genome of the Impatiens davidii (Balsaminaceae).

Impatiens davidii Franch, 1886 is a rare ornamental flower used in gardens and has high economic value. In this study, we characterized the chloroplast genome of I. davidii and analyzed its phylogenetic relationship with other Impatiens species. The length of the complete chloroplast genome sequence of I. davidii is 152,214 bp, with a GC content of 36.9%. The chloroplast genome shows a typical quadripartite structure with a pair of inverted repeats (IRs) of 25,634 bp, separated by one large single copy (LSC) region of 83,128 bp and one small single copy (SSC) region of 17,818 bp. We annotated 125 genes, of which there were 85 protein-coding genes, 32 tRNA genes, and 8 rRNA genes. The Bayesian phylogenetic tree strongly supports that I. davidii has a close phylogenetic relationship with a group including I. piufanensis and I. alpicola.

PaNAC089 is a membrane-tethered transcription factor (MTTF) that modulates flowering, chlorophyll breakdown and trichome initiation.

Flowering and senescence are essential developmental stages of green plants, which are governed by complex molecular regulatory networks. However, the connection between flowering regulation and senescence regulation in London plane tree (Platanus acerifolia ) remains unknown. In this study, we identified a gene PaNAC089 from London plane tree, which encodes a membrane-tethered transcription factor (MTTF) belonging to the NAC (NAM, ATAF1/2, CUC2) transcription factor family. We investigated the functions of PaNAC089 in the regulation of flowering and senescence through the analysis of expression profiles and transgenic phenotypes. Heterologous overexpression of ΔPaNAC089 delayed flowering and inhibited chlorophyll breakdown to produce dark green rosette leaves in Arabidopsis . In addition, the trichome density of rosette leaves was decreased in transgenic lines. In ΔPaNAC089 overexpression plants, a series of functional genes with inhibited expression were identified by quantitative real-time polymerase chain reaction (qRT-PCR), including genes that regulate flowering, chlorophyll decomposition, and trichome initiation. Furthermore, Δ PaNAC089 directly binds to the promoter of CONSTANS (CO ) and NON-YELLOWING2 (NYE2 ) in the yeast one-hybrid assay. Consistent with this, luciferase (LUC) transient expression assays also showed that Δ PaNAC089 could inhibit the activity of NYE2 . To summarise, our data suggests that PaNAC089 is an MTTF that modulates flowering, chlorophyll breakdown and trichome initiation.

Dioscin inhibits SCC15 cell proliferation via the RASSF1A/MST2/YAP axis.

Dioscin, an extract from traditional Chinese herbal plants, displays various biological and pharmacological effects on tumors, including inhibition of cell proliferation and induction of DNA damage. However, the effects of dioscin on oral squamous cell carcinoma (OSCC) cells are not completely understood. The present study aimed to evaluate the impact of dioscin on OSCC cell proliferation. Cell Counting Kit­8 and 5­ethynyl­2'­deoxyuridine incorporation assays were performed to assess cell proliferation. Flow cytometry was conducted to detect alterations in the cell cycle and cell apoptosis. Western blotting and coimmunoprecipitation were performed to determine protein expression levels. In SCC15 cells, dioscin treatment significantly induced cell cycle arrest, increased apoptosis and inhibited proliferation compared with the control group. Mechanistically, the tumor suppressor protein Ras association domain­containing protein 1A (RASSF1A) was activated and oncoprotein yes­associated protein (YAP) was phosphorylated by dioscin. Furthermore, YAP overexpression and knockdown reduced and enhanced the inhibitory effects of dioscin on SCC15 cells, respectively. In summary, the results demonstrated that, compared with the control group, dioscin upregulated RASSF1A expression in OSCC cells, which resulted in YAP phosphorylation, thus weakening its transcriptional coactivation function, enhancing cell cycle arrest and apoptosis, and inhibiting cell proliferation. The present study indicated that dioscin may serve as a therapeutic agent for OSCC.

Chemotaxonomic variation in volatile component contents and their correlation between climate factors in Chinese prickly ash peels (Zanthoxylum bungeanum Maxim.).

In this study, we analyzed the characteristics of volatile compounds of Chinese prickly ash peels with different climate conditions and their correlation. The data revealed that the contents of limonene and linalool in peels from southwest and northwest regions were higher, and the aroma was stronger, while the contents of ß-myrcene and (E)-ocimene in them from north, east and central China were higher, and the spicy flavor was heavier. Hierarchical cluster analysis demonstrated that the classification had geographical continuity. Through the correlation analysis and path analysis, it was found that the contents of volatile compounds were closely related to the climatic factors. The influence of wind speed and annual average temperature on volatile substances was greater than that of annual average precipitation and annual sunshine duration. This enriched the effect of climatic factors on the accumulation of volatile substances, and promoted the agriculture practices in area having similar climate conditions.

YKT6, as a potential predictor of prognosis and immunotherapy response for oral squamous cell carcinoma, is related to cell invasion, metastasis, and CD8+ T cell infiltration.

Metastasis and immune suppression account for the poor prognosis of oral squamous cell carcinoma (OSCC). YKT6 is a member of the soluble NSF attachment protein receptor (SNARE) family, and the effect of YKT6 in OSCC remains elusive. The purpose of this study was to explore promising prognostic and immune therapeutic candidate biomarkers for OSCC and to understand the expression pattern, prognostic value, immune effects, and biological functions of YKT6. Genes correlated with tumor metastasis and CD8 + T cell levels were identified by weighted gene coexpression network analysis (WGCNA). Next, YKT6 was analyzed through differential expression, prognostic and machine learning analyses. The molecular and immune characteristics of YKT6 were analyzed in independent cohorts, clinical specimens, and in vitro. In addition, we investigated the role of YKT6 at the pan-cancer level. The results suggested that the red module in WGCNA, as a hub module, was associated with lymph node (LN) metastasis and CD8 + T cell infiltration. Upregulation of YKT6 was found in OSCC and linked to adverse prognosis. A nomogram model containing YKT6 expression and tumor stage was constructed for clinical practice. The aggressive and immune-inhibitory phenotypes showed YKT6 overexpression, and the effect of YKT6 on OSCC cell invasion and metastasis in vitro was observed. Moreover, the low expression of YKT6 was correlated with high CD8 + T cell levels and potential immunotherapy response in OSCC. Similar results were found at the pan-cancer level. In total, YKT6 is a promising candidate biomarker for prognosis, molecular, and immune characteristics in OSCC.

San Huang Decoction Targets Aurora Kinase A to Inhibit Tumor Angiogenesis in Breast Cancer.

San Huang Decoction (SHD), a Chinese herb formula, has been popularly prescribed in the clinical treatment of patients suffering from breast cancer. The aim of this study was to explore the anti-angiogenic effects of SHD in breast cancer and explain the underlying mechanism. Transwell and Matrigel assays showed that SHD reduced human umbilical vein endothelial cell migration and tubule formation and ELISA and qRT-PCR assays demonstrated its mediation of vascular endothelial growth factor (VEGF) expression. siRNA silencing of aurora kinase A (AURKA) produced results similar to those obtained by inhibition of AURKA with SHD. In addition, a chorioallantoic membrane assay was carried out to directly examine the effect of SHD on breast cancer anti-angiogenesis and immunofluorescence and immunohistochemical staining analysis showed that SHD reduced the expression of CD31, AURKA, and VEGF in a xenograft model. Furthermore, SHD regulated extracellular signal-regulated kinase expression in breast cancer cells, which was examined by western blotting. In conclusion, our findings indicated that SHD treatment mimicked the decrease in tumor neovascularization in breast cancer cells after the siRNA-mediated knockdown of AURKA. Thus, SHD may inhibit tumor angiogenesis in breast cancer by targeting AURKA and downregulating the ERK signaling pathway.

Effect of YAP on an Immortalized Periodontal Ligament Stem Cell Line.

OBJECTIVE: To establish an immortalized human periodontal ligament stem cell line (hPDLSC) and investigate whether and how YAP mediates the establishment of the stem cell line. METHODS: Primary hPDLSCs were cultured and transfected with lentivirus containing the telomerase reverse transcriptase (TERT) gene. The expression of TERT was detected via the polymerase chain reaction (PCR) and real-time quantitative PCR (RT-PCR). Flow cytometry was employed to detect surface markers of hPDLSCs and TERT-hPDLSCs. The cell counting kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) methods were used to examine the proliferation ability of the cells. Flow cytometry and TUNEL staining were employed to examine the cell apoptosis rate. The ß-galactosidase staining assay was used to assess the rate of cell senescence. The osteogenic differentiation ability of the cells was detected via alkaline phosphatase (ALP) staining and Alizarin red staining assays. BALB/c mice were employed to determine the tumorigenicity of TERT-hPDLSCs. The expression levels of YAP and other proteins in the Hippo signaling pathway were detected by Western blotting. Verteporfin was used to inhibit the binding of YAP to the downstream target gene TEAD. RESULTS: TERT-hPDLSCs showed stable high expression of TERT, even at the thirtieth passage after transfection with lentivirus containing the TERT gene. Compared with primary hPDLSCs, TERT-hPDLSCs exhibited a stronger proliferation ability and lower cell apoptosis and senescence rates while maintaining the same osteogenetic differentiation ability as primary hPDLSCs. The transfection of hPDLSCs with lentivirus containing the TERT gene did not lead to tumorigenesis in nude mice. The Hippo signaling pathway was inactivated in TERT-hPDLSCs compared to hPDLSCs. When treated with verteporfin, the proliferation of TERT-hPDLSCs decreased, while the apoptosis and senescence rates of these cells increased. However, TERT-hPDLSCs still showed a stronger proliferation ability and lower cell apoptosis and senescence rates than hPDLSCs treated with verteporfin at the same concentration. CONCLUSIONS: Overexpression of TERT in hPDLSCs resulted in the successful establishment of an immortalized periodontal ligament stem cell line. TERT may regulate the biological characteristics of hPDLSCs through the Hippo/YAP signaling pathway. hPDLSCs could be a feasible resource for stem cell research and a promising resource for stem cell therapy.

Protective effects of Polygonatum sibiricum polysaccharide on acute heart failure in rats 1.

PURPOSE: To investigate the protective effects of Polygonatum sibiricum polysaccharide (PSP) on acute heart failure (AHF) in rats. METHODS: Sixty rats were randomly divided into control, model, and low-, middle- and high-dose PSP groups, 12 rats in each group. The low-, medium- and high-dose PSP groups were intragastrically administrated with 100, 200 and 400 mg/kg PSP for 5 days, respectively. On the sixth day, the AHF model was established by intraperitoneal injection of adriamycin. After 24h, the cardiac function, serum biochemical indexes, myocardial ATPase and succinate dehydrogenase levels and apoptosis related protein expressions were determined. RESULTS: Compared with model group, in high-dose PSP group the heart rate, left ventricular systolic pressure, ±dp/dtmax, serum superoxide dismutase level, myocardial Na+-K+-ATPase, Ca2+-Mg2+-ATPase and succinate dehydrogenase levels and myocardial Bcl-2 and Caspase-3 protein expression levels were significantly increased (P<0.05), the left ventricular end diastolic pressure, serum cTnI, CK-MB, TNF-α, IL-6, malondialdehyde and nitric oxide levels and myocardial Bax and cleaved Caspase-3 protein expression levels were significantly decreased (P<0.05). CONCLUSIONS: Polysaccharide can prevent the acute heart failure induced by adriamycin. The mechanism may be related to its anti-oxidative stress, anti-inflammation and inhibition of cardiac myocyte apoptosis.

Epigallocatechin-3-gallate affects the proliferation, apoptosis, migration and invasion of tongue squamous cell carcinoma through the hippo-TAZ signaling pathway.

The purpose of the present study was to investigate the mechanism by which epigallocatechin­3­gallate (EGCG) inhibits the biological behaviors of the tongue squamous cell carcinoma (TSCC) through the Hippo­tafazzin (TAZ) signaling pathway and to provide insights into molecular targeted therapy in TSCC. CAL27 and SCC15 cells were treated with different concentrations of EGCG for 24 h. Cell proliferation was determined using Cell­Counting Kit­8 and EdU assays. Cell apoptosis was evaluated by flow cytometry. Cell migration and invasion were measured using scratch and Transwell assays, respectively. Furthermore, protein levels of associated target genes were detected using a western blot assay. It was demonstrated that EGCG affected biological behaviors of CAL27 and SCC15 cells in concentration­ and time­dependent manners. In addition, EGCG decreased the protein levels of TAZ, LATS1, MOB1 and JNK. Overexpression of TAZ alleviated the effect of EGCG on CAL27 cells. Furthermore, the combination of EGCG and simvastatin inhibited the proliferation, migration and invasion, and promoted apoptosis significantly compared with single treatment in CAL27 cells. The results of the present study suggested that EGCG affects proliferation, apoptosis, migration and invasion of TSCC through the Hippo­TAZ signaling pathway.

C-MYC and BCL-2 mediate YAP-regulated tumorigenesis in OSCC.

Transcriptional co-activator Yes-associated protein (YAP) is a key oncogene in mammalian cells. The present understanding of YAP in oral squamous cells carcinoma (OSCC) remains unclear. The purpose of this study is to investigate the effects of YAP on proliferation and apoptosis in OSCC and the molecular mechanism. The results showed the expression level of YAP was higher in OSCC tissues than that in adjacent normal tissues. Knockdown of YAP in CAL27 cell lines prohibited cell proliferation while augmented apoptosis. Conversely, overexpression of YAP protected cells from apoptosis and promoted cell proliferation. Moreover, C-MYC and BCL-2 mRNA and protein levels were altered due to the differential expression of YAP. Subsequent Verteporfin treatment in CAL27 cells revealed that the transcription and translation of BCL-2 and C-MYC both decreased. In a tumor xenograft model, knockdown of YAP suppressed tumor growth of CAL27 in vivo, while YAP overexpression promoted the tumor growth. These results suggest that YAP is a crucial regulator that exerts pro-proliferation and anti-apoptosis effects in OSCC through actions affecting the cell cycle and intrinsic apoptotic signaling. Thus YAP could potentially serve as a valuable molecular biomarker or therapeutic target in the treatment of OSCC.

Propofol protects hippocampal neurons from apoptosis in ischemic brain injury by increasing GLT-1 expression and inhibiting the activation of NMDAR via the JNK/Akt signaling pathway.

Ischemic brain injury (IBI) can cause nerve injury and is a leading cause of morbidity and mortality worldwide. The neuroprotective effects of propofol against IBI have been previously demonstrated. However, the neuroprotective effects of propofol on hippocampal neurons are not yet entirely clear. In the present study, models of IBI were established in hypoxia-exposed hippocampal neuronal cells. Cell viability assay and apoptosis assay were performed to examine the neuroprotective effects of propofol on hippocampal neurons in IBI. A significant decrease in cell viability and a significant increase in cell apoptosis were observed in the IBI group compared with the control group, accompanied by a decrease in glial glutamate transporter-1 (GLT­1) expression as determined by RT-qPCR and western blot analysis. The effects of IBI were reversed by propofol treatment. The siRNA-mediated knockdown of GLT­1 in the hypoxia-exposed hippocampal neuronal cells led to an increase in cell apoptosis, Jun N-terminal kinase (JNK) activation and N-methyl-D­aspartate (NMDA) receptor (NR1 and NR2B) activation, as well as to a decrease in cell viability and a decrease in Akt activation. The effects of RNA interference-mediated GLT­1 gene silencing on cell viability, JNK activation, NMDAR activation, cell apoptosis and Akt activation in the hippocampal neuronal cells were slightly reversed by propofol treatment. The JNK agonist, anisomycin, and the Akt inhibitor, LY294002, both significantly blocked the effects of propofol on hippocampal neuronal cell viability and apoptosis in IBI. The decrease in JNK activation and the increase in Akt activation caused by GLT­1 overexpression were reversed by NMDA. Collectively, our findings suggest that propofol treatment protects hippocampal neurons against IBI by enhancing GLT­1 expression and inhibiting the activation of NMDAR via the JNK/Akt signaling pathway.

San Huang Decoction downregulates Aurora kinase A to inhibit breast cancer cell growth and enhance chemosenstivity to anti-tumor drugs.

Our study aimed to explore whether San Huang Decoction (SHD) inhibited the development of breast cancer by regulating Aurora A. Human breast cancer cell lines MCF-7 and MDA-MB-231 were cultured and SHD extract was prepared. Cell growth assay and apoptosis analysis were respectively performed to detect the effects of SHD on breast cancer cells. In addition, the effects of SHD on the expression of Aurora A and p53 were determined by RT-PCR and western blot. Besides, we used Aurora A siRNA to knock down Aurora A. We then co-administrated SHD and tamoxifen or epirubicin to detect the effect of SHD on chemosensitivity to tamoxifen or epirubicin. SHD treatment significantly inhibited cell growth in a dose-dependent manner. Moreover, SHD treatment resulted in a marked decrease in Aurora A expression and obvious increase in p53 expression. In addition, knockdown of Aurora A induced cell growth inhibition, which was similar to the effect of SHD treatment. Besides, SHD exerted an additive effect on cell growth inhibition and apoptosis induction when breast cancer cells were co-administration of SHD with tamoxifen or epirubicin. Our study indicates that SHD treatment may inhibit cell growth and enhance chemosenstivity to other anti-tumor drugs in breast cancer via down-regulation of Aurora A.

Hydrogen Sulfide-Mediated Polyamines and Sugar Changes Are Involved in Hydrogen Sulfide-Induced Drought Tolerance in Spinacia oleracea Seedlings.

Hydrogen sulfide (H2S) is a newly appreciated participant in physiological and biochemical regulation in plants. However, whether H2S is involved in the regulation of plant responses to drought stress remains unclear. Here, the role of H2S in the regulation of drought stress response in Spinacia oleracea seedlings is reported. First, drought stress dramatically decreased the relative water content (RWC) of leaves, photosynthesis, and the efficiency of PSII. Moreover, drought caused the accumulation of ROS and increased the MDA content. However, the application of NaHS counteracted the drought-induced changes in these parameters. Second, NaHS application increased the water and osmotic potential of leaves. Additionally, osmoprotectants such as proline and glycinebetaine (GB) content were altered by NaHS application under drought conditions, suggesting that osmoprotectant contributes to H2S-induced drought resistance. Third, the levels of soluble sugars and polyamines (PAs) were increased differentially by NaHS application in S. oleracea seedlings. Moreover, several genes related to PA and soluble sugar biosynthesis, as well as betaine aldehyde dehydrogenase (SoBADH), choline monooxygenase (SoCMO), and aquaporin (SoPIP1;2), were up-regulated by H2S under drought stress. These results suggest that H2S contributes to drought tolerance in S. oleracea through its effect on the biosynthesis of PAs and soluble sugars. Additionally, GB and trehalose also play key roles in enhancing S. oleracea drought resistance.