Development of a double-antibody sandwich ELISA for quantification of mutated EPSPS gene expression in rice.

Glyphosate resistance is a critically important trait for genetically modified (GM) crops. Mutation of the rice EPSPS gene results in a high level of glyphosate resistance, presenting significant potential for the development of glyphosate-tolerant crops. The resistance of rice to glyphosate is correlated with the expression levels of resistance genes. Therefore, developing a convenient, stable, and sensitive method for quantifying the OsmEPSPS protein is crucial for the development of glyphosate-resistant crops. We developed a double-antibody sandwich quantitative ELISA (DAS-ELISA) using a specific monoclonal antibody (mAb) for OsmEPSPS capture and an HRP-conjugated anti-OsmEPSPS rabbit polyclonal antibody (pAb). The method could be used to detect OsmEPSPS within a linear range of 16-256 ng/mL with robust intra- and inter-batch duplicability (%CV values: 0.17 %-7.24 %). OsmEPSPS expression in the transgenic rice lines (54.44-445.80 µg/g) was quantified using the DAS-ELISA. Furthermore, the expression of the OsmEPSPS gene was validated through Western blotting. This study demonstrated the reliability and stability of the DAS-ELISA for OsmEPSPS detection in GM rice.

pH-sensitive and redox-responsive poly(tetraethylene glycol) nanoparticle-based platform for cancer treatment.

Effective drug delivery with precise tumour targeting is crucial for cancer treatment. To address the challenges posed by the specificity and complexity of the tumour microenvironment, we developed a poly(tetraethylene glycol)-based disulfide nanoparticle (NP) platform and explored its potential in cancer treatment, focusing on drug loading and controlled release performance. Poly(tetraethylene glycol) NPs were characterised using nuclear magnetic resonance spectroscopy, mass spectrometry, and ultraviolet-visible spectroscopy. Additionally, we evaluated physicochemical properties, including dynamic light scattering, zeta potential analysis, drug loading capacity (DLC), and drug loading efficiency (DLE). The impact of NPs on the mouse colorectal cancer cell line (CT26) and NIH3T3 cells was assessed using a cytotoxicity assay, live/dead staining assay, flow cytometry, and confocal fluorescence microscopy. The experimental results align with the expected chemical structure and physicochemical properties of poly(tetraethylene glycol) NPs. These NPs exhibit high DLE (78.7%) and DLC (12%), with minimal changes in particle size over time in different media.In vitroexperiments revealed that the NPs can induce significant cytotoxicity and apoptosis in CT26 cells. Cellular uptake notably increases with increasing concentration and exposure time. The confocal microscopic analysis confirmed the effective distribution and accumulation of NPs within cells. In conclusion, poly(tetraethylene glycol) NPs hold promise for improving drug-delivery efficiency, offering potential advancements in cancer treatment.

Insight into the transcriptional regulation of key genes involved in proline metabolism in plants under osmotic stress.

Proline biosynthesis and catabolism pathways are executed by powerful action of specific enzymes that are subjected to environmental fluctuations at the transcriptional level. Previous researches have demonstrated that osmotic stress-induced upstream events can affect the expression of proline metabolism-related genes, which results in adjustable free proline accumulation to protect plant cells from severe damage. Here, we mainly describe the mechanisms for how some key factors, such as transcription factors, ABA (abscisic acid), Ca2+, MAPK cascades, CK (cytokinin) and phospholipase, in a phosphorylated manner, vividly function in the transcriptional regulation of proline metabolism under osmotic stress. These mechanisms reveal that sustaining of proline homeostasis is an efficient way for plants to adapt to osmotic stress.

Concurrent chemoradiotherapyof different radiation doses and different irradiation fields for locally advanced thoracic esophageal squamous cell carcinoma: A randomized, multicenter, phase III clinical trial.

BACKGROUND: Concurrent chemoradiotherapy (CCRT) is the standard treatment for locally advanced esophageal squamous cell carcinoma (ESCC). However, the optimal radiotherapy regimen, particularly in terms of total dose and planned range of irradiation field, remains unclear. This phase III clinical trial aimed to compare the survival benefits between different radiation doses and different target fields. METHODS: This trial compared two aspects of radiation treatment, total dose and field, using a two-by-two factorial design. The high-dose (HD) group received 59.4 Gy radiation, and the standard-dose (SD) group received 50.4 Gy. The involved field irradiation (IFI) group and elective nodal irradiation (ENI) group adopted different irradiation ranges. The participants were assigned to one of the four groups (HD+ENI, HD+IFI, SD+ENI and SD+IFI). The primary endpoint was overall survival (OS), and the secondary endpoints included progression-free survival (PFS). The synergy indexwas used to measure the interaction effect between dose and field. RESULTS: The interaction analysis did not reveal significant synergistic effects between the dose and irradiation field. In comparison to the target field, patients in IFI or ENI showed similar OS (hazard ratio [HR] = 0.99, 95% CI: 0.80-1.23, p = 0.930) and PFS (HR = 1.02, 95% CI: 0.82-1.25). The HD treatment did not show significantly prolonged OS compared with SD (HR = 0.90, 95% CI: 0.72-1.11, p = 0.318), but it suggested improved PFS (25.2 months to 18.0 months). Among the four groups, the HD+IFI group presented the best survival, while the SD+IFI group had the worst prognosis. No significant difference in the occurrence of severe adverse events was found in dose or field comparisons. CONCLUSIONS: IFI demonstrated similar treatment efficacy to ENI in CCRT of ESCC. The HD demonstrated improved PFS, but did not significantly improve OS. The dose escalation based on IFI (HD+IFI) showed better therapeutic efficacy than the current recommendation (SD+ENI) and is worth further validation.

Challenges and innovations in CAR-T cell therapy: a comprehensive analysis.

Recent years have seen a marked increase in research on chimeric antigen receptor T (CAR-T) cells, with specific relevance to the treatment of hematological malignancies. Here, the structural principles, iterative processes, and target selection of CAR-T cells for therapeutic applications are described in detail, as well as the challenges faced in the treatment of solid tumors and hematological malignancies. These challenges include insufficient infiltration of cells, off-target effects, cytokine release syndrome, and tumor lysis syndrome. In addition, directions in the iterative development of CAR-T cell therapy are discussed, including modifications of CAR-T cell structures, improvements in specificity using multi-targets and novel targets, the use of Boolean logic gates to minimize off-target effects and control toxicity, and the adoption of additional protection mechanisms to improve the durability of CAR-T cell treatment. This review provides ideas and strategies for the development of CAR-T cell therapy through an in-depth exploration of the underlying mechanisms of action of CAR-T cells and their potential for innovative modification.

A Cullin 5-based complex serves as an essential modulator of ORF9b stability in SARS-CoV-2 replication.

The ORF9b protein, derived from the nucleocapsid's open-reading frame in both SARS-CoV and SARS-CoV-2, serves as an accessory protein crucial for viral immune evasion by inhibiting the innate immune response. Despite its significance, the precise regulatory mechanisms underlying its function remain elusive. In the present study, we unveil that the ORF9b protein of SARS-CoV-2, including emerging mutant strains like Delta and Omicron, can undergo ubiquitination at the K67 site and subsequent degradation via the proteasome pathway, despite certain mutations present among these strains. Moreover, our investigation further uncovers the pivotal role of the translocase of the outer mitochondrial membrane 70 (TOM70) as a substrate receptor, bridging ORF9b with heat shock protein 90 alpha (HSP90α) and Cullin 5 (CUL5) to form a complex. Within this complex, CUL5 triggers the ubiquitination and degradation of ORF9b, acting as a host antiviral factor, while HSP90α functions to stabilize it. Notably, treatment with HSP90 inhibitors such as GA or 17-AAG accelerates the degradation of ORF9b, leading to a pronounced inhibition of SARS-CoV-2 replication. Single-cell sequencing data revealed an up-regulation of HSP90α in lung epithelial cells from COVID-19 patients, suggesting a potential mechanism by which SARS-CoV-2 may exploit HSP90α to evade the host immunity. Our study identifies the CUL5-TOM70-HSP90α complex as a critical regulator of ORF9b protein stability, shedding light on the intricate host-virus immune response dynamics and offering promising avenues for drug development against SARS-CoV-2 in clinical settings.

The long-term efficacy of eltrombopag in children with immune thrombocytopenia.

Immune thrombocytopenia (ITP) is the most common autoimmune disorder characterized by decreased platelet counts and impaired platelet production. Eltrombopag has been demonstrated to be safe and effective for children with ITP. It is reported eltrombopag can achieve a sustained response off treatment. However, data on its overall efficacy and safety profile are scarce in children. This study aimed to investigate the long-term efficacy of eltrombopag in children with ITP. Treatment overall response (OR), complete response (CR), response (R), durable response (DR), no response (NR), treatment free remission (TFR), and relapse rate, were assessed in 103 children with ITP during eltrombopag therapy. The OR rate, CR rate, R rate, DR rate, NR rate, TFR rate, and relapse rate were 67.0%, 55.3%, 11.7%, 56.3%, 33.0%, 60%, 36.2%, respectively. Importantly, we discovered that newly diagnosed ITP patients showed a higher DR rate, TFR rate and lower relapse rate compared to persistent and chronic ITP patients. Furthermore, the CR rate, DR rate, and TFR rate of 5 patients under six months were 100%. None of them suffered relapse. The most common adverse event (AEs) was hepatotoxicity (7.77%). Our study highlighted the critical role of eltrombopag as the second-line treatment in children with ITP who were intolerant to first-line therapy.

A Coupled System of Ni3S2 and Rh Complex with Biomimetic Function for Electrocatalytic 1,4-NAD(P)H Regeneration.

NAD(P)H cofactor is a critical energy and electron carrier in biocatalysis and photosynthesis, but the artificial reduction of NAD(P)+ to regenerate bioactive 1,4-NAD(P)H with both high activity and selectivity is challenging. Herein, we found that a coupled system of a Ni3S2 electrode and a Rh complex in an electrolyte (denoted as Ni3S2-Rh) can catalyze the reduction of NAD(P)+ to 1,4-NAD(P)H with superior activity and selectivity. The optimized selectivity in 1,4-NADH can be up to 99.1%, much higher than that for Ni3S2 (80%); the normalized activity of Ni3S2-Rh is about 5.8 times that of Ni3S2 and 13.2 times that of the Rh complex. The high performance of Ni3S2-Rh is attributed to the synergistic effect between metal sulfides and Rh complex. The NAD+ reduction reaction proceeds via a concerted electron-proton transfer (CEPT) mechanism in the Ni3S2-Rh system, in which Ni3S2 acts as a proton and electron-transfer mediator to accelerate the formation of Rh hydride (Rh-H), and then the Rh-H regioselectively transfers the hydride to NAD+ to form 1,4-NADH. The artificial system Ni3S2-Rh essentially mimics the functions of ferredoxin-NADP+ reductase in nature.

Identification of α-Glucosidase-Inhibitors in Edgeworthia gardneri (Wall.) Meisn. Using UPLC-Q-TOF-MS/MS Analysis.

Edgeworthia gardneri (Wall.) Meisn., a member of the genus Edgeworthia in the family Thymelaeaceae, has long been applied as an edible and medicinal plant in China. E. gardneria has a hypoglycemic effect and is used to prepare daily drinks for the prevention and treatment of diabetes. However, the hypoglycemic substances involved remain unknown. The present study aimed to screen the α-glucosidase-inhibitors of E. gardneri and analyze its chemical profile using a ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) method. As a result, the ethyl acetate fraction (EAF) had significant α-glucosidase-inhibitory and antioxidant activities but did not show an α-amylase-inhibitory activity. A total of 67 compounds were identified in the EAF by UPLC-Q-TOF-MS/MS analysis; among them, 48 compounds were first discovered in the genus Edgeworthia. Additionally, five flavonoids, namely, isoorintin, secoisolaricirinol, tiliroside, chrysin, and kaempferol, had α-glucosidase-inhibitory activities. Rutin had a α-amylase-inhibitory activity. Daphnoretin, a kind of coumarin, has α-glucosidase and α-amylase-inhibitory activities. These findings enrich the chemical library of E. gardneria. EAF has a selective α-glucosidase-inhibitory activity, and flavonoids and coumarins may be the active components of EAF. E. gardneria has important value for developing multiple-target hypoglycemic drugs.

The Role of Noncoding RNA in the Transmission and Pathogenicity of Flaviviruses.

Noncoding RNAs (ncRNAs) constitute a class of RNA molecules that lack protein-coding capacity. ncRNAs frequently modulate gene expression through specific interactions with target proteins or messenger RNAs, thereby playing integral roles in a wide array of cellular processes. The Flavivirus genus comprises several significant members, such as dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV), which have caused global outbreaks, resulting in high morbidity and mortality in human populations. The life cycle of arthropod-borne flaviviruses encompasses their transmission between hematophagous insect vectors and mammalian hosts. During this process, a complex three-way interplay occurs among the pathogen, vector, and host, with ncRNAs exerting a critical regulatory influence. ncRNAs not only constitute a crucial regulatory mechanism that has emerged from the coevolution of viruses and their hosts but also hold potential as antiviral targets for controlling flavivirus epidemics. This review introduces the biogenesis of flavivirus-derived ncRNAs and summarizes the regulatory roles of ncRNAs in viral replication, vector-mediated viral transmission, antiviral innate immunity, and viral pathogenicity. A profound comprehension of the interplay between ncRNAs and flaviviruses will help formulate efficacious prophylactic and therapeutic strategies against flavivirus-related diseases.

Thioredoxin-1 decreases alpha-synuclein induced by MPTP through promoting autophagy-lysosome pathway.

Parkinson's disease (PD) is characterized by the formation of Lewy body in dopaminergic neurons in the substantia nigra pars compacta (SNpc). Alpha-synuclein (α-syn) is a major component of Lewy body. Autophagy eliminates damaged organelles and abnormal aggregated proteins. Thioredoxin-1 (Trx-1) is a redox regulating protein and plays roles in protecting dopaminergic neurons against neurotoxicity induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). However, the relationship between Trx-1 and α-syn in PD is still unknown. In the present study, the movement disorder and dopaminergic neurotoxicity in MPTP-treated mice were improved by Trx-1 overexpression and were aggravated by Trx-1 knockdown in the SNpc in mice. The expression of α-syn was increased in the SNpc of MPTP-treated mice, which was inhibited by Trx-1 overexpression and was exacerbated in Trx-1 knockdown mice. Autophagosomes was increased under electron microscope after MPTP treatment, which were recovered in Trx-1 overexpressing mice and were further increased in Trx-1 knockdown in the SNpc in mice. The expressions of phosphatase and tensin homolog deleted on chromosome ten (PTEN)-induced putative kinase 1 (PINK1), Parkin, LC3 II and p62 were increased by MPTP, which were blocked in Trx-1 overexpressing mice and were further increased in Trx-1 knockdown mice. Cathepsin D was decreased by MPTP, which was restored in Trx-1 overexpressing mice and was further decreased in Trx-1 knockdown mice. The mRFP-GFP-LC3 green fluorescent dots were increased by 1-methyl-4-phenylpyridinium (MPP+) and further increased in Trx-1 siRNA transfected PC12 cells, while mRFP-GFP-LC3 red fluorescent dots were increased in Trx-1 overexpressing cells. These results indicate that Trx-1 may eliminate α-syn in PD mice through potentiating autophagy-lysosome pathway.

Effects of sodium-glucose cotransporter-2 (SGLT-2) inhibitors on serum uric acid levels in patients with chronic kidney disease: a systematic review and network meta-analysis.

Elevated serum uric acid levels are an independent predictor of occurrence and development of chronic kidney disease (CKD) and are strongly associated with prognosis. Several clinical trials have demonstrated the benefits of sodium-glucose cotransporter-2 (SGLT-2) inhibitors. To evaluate and rank the effects and safety of various SGLT-2 for serum uric acid levels in patients with CKD. We performed a systematic PubMed, Embase, Scopus, and Web of Science search, including studies published before July 1, 2023. Two researchers independently extracted data on study characteristics and outcomes and assessed study quality using the Cochrane Collaboration's risk of bias tool 2. The gemtc package of R software was used to perform network meta-analysis within a Bayesian framework. The primary outcome was serum uric acid levels, and the secondary outcome was adverse events. Effect sizes are reported as standardized mean differences (SMDs), risk ratio (RR), and 95% CI, respectively. The certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria. Eight RCTs (9367 participants) were included in this meta-analysis. The results of the paired meta-analysis showed that SGLT-2 inhibitors significantly reduced serum uric acid levels in patients with CKD compared with the placebo group (SMD -0.22; 95% CI -0.42 to -0.03; GRADE: low). Pooled analysis of any adverse events reported in the included studies showed similar incidence rates in the SGLT-2 inhibitor and placebo groups (RR: 0.99; 95% CI 0.97 to 1.00; p=0.147; GRADE: high). Subgroup analysis showed a statistically significant difference only for tofogliflozin. Further network meta-analysis showed that dapagliflozin 10 mg and ipragliflozin 50 mg may be the most effective in reducing uric acid levels. SGLT-2 inhibitors significantly reduced serum uric acid levels in patients with CKD, and dapagliflozin 10 mg and ipragliflozin 50 mg may be the optimal dosages. SGLT-2 inhibitors hold great promise as an antidiabetic therapeutic option for patients with CKD who have elevated serum uric acid levels. PROSPERO registration number: CRD42023456581.

Proposal for the classification of sinomenine alkaloids.

The chemical structure of sinoacutine is formed by a phenanthrene nucleus and an ethylamine bridge. Because it has a similar parent structure to morphine, it is subdivided into morphinane. At present, all reports have pointed out that the basic skeleton of morphine alkaloids is salutaridine (the isomer of sinoacutine), which is generated by the phenol coupling reaction of (R)-reticuline. This study shows that the biosynthetic precursors of sinoacutine and salutaridine are different. In this paper, the sinoacutine synthetase (SinSyn) gene was cloned from Sinomenium acutum and expressed SinSyn protein. Sinoacutine was produced by SinSyn catalyzed (S)-reticuline, according to the results of enzyme-catalyzed experiments. The optical activity, nuclear magnetic resonance, and mass spectrum of sinoacutine and salutaridine were analyzed. The classification and pharmacological action of isoquinoline alkaloids were discussed. It was suggested that sinoacutine should be separated from morphinane and classified as sinomenine alkaloids.

Sneddon's syndrome concurrent with cerebral venous sinus thrombosis: A case report.

BACKGROUND: This report delves into the diagnostic and therapeutic journey undertaken by a patient with Sneddon's syndrome (SS) and cerebral venous sinus thrombosis (CVST). Particular emphasis is placed on the comprehensive elucidation of SS's clinical manifestations, the intricate path to diagnosis, and the exploration of potential underlying mechanisms. CASE SUMMARY: A 26-year-old woman presented with recurrent episodes of paroxysmal unilateral limb weakness accompanied by skin mottling, seizures, and cognitive impairment. Digital subtraction angiography revealed CVST. Despite negative antiphospholipid antibody results, skin biopsy indicated chronic inflammatory cell infiltration. The patient was treated using anticoagulation, antiepileptic therapy, and supportive care, which resulted in symptom improvement. The coexistence of SS and CVST is rare and the underlying pathophysiology remains uncertain. This case underscores the challenge in diagnosis and highlights the need for early clinical differentiation to facilitate accurate assessment and prompt intervention. CONCLUSION: This article has reported and analyzed the clinical data, diagnosis, treatment, and prognosis of a case of SS with CVST and reviewed the relevant literature to improve the clinical understanding of this rare condition.

A new biphenanthrene with cytotoxic activity from Liparis nervosa (Thunb.) Lindl.

2,7,2'-Trihydroxy-3,4,4'7'-tetramethoxy-1,1'-biphenanthrene (1), a previously undescribed biphenanthrene, and five known phenanthrenes, i.e. 2,5-dihydroxy-4-methoxy-9,10-dihydroxyphenanthrene (2), 2,4-dihydroxy -7-methoxy-9,10-dihydroxyphenanthrene (3), 7-hydroxy-2-methoxy-phenanthrene-1,4-dione (4), 7-hydroxy-2-methoxy-9,10-dihydro-phenanthrene-1,4-dione (5), and 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,1'-biphenanthrene (6) were isolated from the whole plant (stems, leaves, roots and fruits) of Liparis nervosa (Thunb.) Lindl., which is a medicinal plant of the genus Liparis in the Orchidaceae family. The structures of isolates were identified using spectroscopic methods, including NMR and mass spectrometry. Additionally, the cytotoxic potency of all the isolates against human lung cancer A549 cell line was evaluated by an MTT assay. All the isolated compounds showed cytotoxic activities with IC50 values in the range of 10.20 ± 0.81 to 42.41 ± 2.34 µM. The obtained data highlight the importance of L. nervosa as a source of natural lead compounds for cancer therapy.

Olfactory bulb neurogenesis depending on signaling in the subventricular zone.

Olfaction is a crucial sense that is essential for the well-being and survival of individuals. Olfactory bulb (OB) is the first olfactory relay station, and its function depends on newly generated neurons from the subventricular zone (SVZ). These newly born neurons constantly migrate through the rostral migratory stream to integrate into existing neural networks within the OB, thereby contributing to olfactory information processing. However, the mechanisms underlying the contribution of SVZ adult neurogenesis to OB neurogenesis remain largely elusive. Adult neurogenesis is a finely regulated multistep process involving the proliferation of adult neural stem cells (aNSCs) and neural precursor cells, as well as the migration and differentiation of neuroblasts, and integration of newly generated neurons into preexisting neuronal circuitries. Recently, extensive studies have explored the mechanism of SVZ and OB neurogenesis. This review focused on elucidating various molecules and signaling pathways associated with OB neurogenesis dependent on the SVZ function. A better understanding of the mechanisms underlying the OB neurogenesis on the adult brain is an attractive prospect to induce aNSCs in SVZ to generate new neurons to ameliorate olfactory dysfunction that is involved in various diseases. It will also contribute to developing new strategies for the human aNSCs-based therapies.

Preharvest 24-epibrassinolide treatment prolongs harvest duration and shelf life in sweet corn.

Sweet corn is perishable and have limited harvest duration and shelf life due to their quality deterioration. Reactive oxygen species (ROS) are one of the most predominant factors for maintaining quality of sweet corn during and after harvest. Brassinosteroids (BRs) can enhance the activity of antioxidant enzymes and decrease the ROS level in plants. In this study, we found that a bioactive BR (24-epibrassinolide, EBR) treatment before harvest markedly inhibited change of quality indicators (MDA content, weight loss rate, and soluble sugar content) during and after harvest. Further analysis revealed that EBR promoted the activity and transcriptions of antioxidant enzymes, maintaining lower ROS level in kernels. Meanwhile, exogenous EBR increased the expression level of genes controlling sucrose transport in sweet corn kernels. Bioinformatics and binding analysis identified that BR transcription factor ZmBES1/ZmBZR1-10 might potentially bind to and upregulate transcriptions of antioxidant enzyme genes including SOD and POD genes, and sucrose transport-related genes including SUT and SWEET genes. These results indicated that exogenous application of EBR ameliorates quality during and after harvest by improving the antioxidant capacity and photosynthetic assimilates accumulation rate of sweet corn, thus prolonging harvest duration and shelf life in sweet corn.

Transcriptomic and Metabolomic Investigation on Leaf Necrosis Induced by ZmWus2 Transient Overexpression in Nicotiana benthamiana.

WUSCHEL (WUS) is a crucial transcription factor in regulating plant stem cell development, and its expression can also improve genetic transformation. However, the ectopic expression of WUS always causes pleiotropic effects during genetic transformation, making it important to understand the regulatory mechanisms underlying these phenomena. In our study, we found that the transient expression of the maize WUS ortholog ZmWus2 caused severe leaf necrosis in Nicotiana benthamiana. We performed transcriptomic and non-target metabolomic analyses on tobacco leaves during healthy to wilted states after ZmWus2 transient overexpression. Transcriptomic analysis revealed that ZmWus2 transformation caused active metabolism of inositol trisphosphate and glycerol-3-phosphate, while also upregulating plant hormone signaling and downregulating photosystem and protein folding pathways. Metabolomic analysis mainly identified changes in the synthesis of phenylpropanoid compounds and various lipid classes, including steroid synthesis. In addition, transcription factors such as ethylene-responsive factors (ERFs), the basic helix-loop-helix (bHLH) factors, and MYBs were found to be regulated by ZmWus2. By integrating these findings, we developed a WUS regulatory model that includes plant hormone accumulation, stress responses, lipid remodeling, and leaf necrosis. Our study sheds light on the mechanisms underlying WUS ectopic expression causing leaf necrosis and may inform the development of future genetic transformation strategies.

PECTIN METHYLESTERASE INHIBITOR18 functions in stomatal dynamics and stomatal dimension.

Pectin methylesterification in guard cell (GC) walls plays an important role in stomatal development and stomatal response to external stimuli, and pectin methylesterase inhibitors (PMEIs) modulate pectin methylesterification by inhibition of pectin methylesterase (PME). However, the function of PMEIs has not been reported in stomata. Here, we report the role of Arabidopsis (Arabidopsis thaliana) PECTIN METHYLESTERASE INHIBITOR18 in stomatal dynamic responses to environmental changes. PMEI18 mutation increased pectin demethylesterification and reduced pectin degradation, resulting in increased stomatal pore size, impaired stomatal dynamics, and hypersensitivity to drought stresses. In contrast, overexpression of PMEI18 reduced pectin demethylesterification and increased pectin degradation, causing more rapid stomatal dynamics. PMEI18 interacted with PME31 in plants, and in vitro enzymatic assays demonstrated that PMEI18 directly inhibits the PME activity of PME31 on pectins. Genetic interaction analyses suggested that PMEI18 modulates stomatal dynamics mainly through inhibition of PME31 on pectin methylesterification in cell walls. Our results provide insight into the molecular mechanism of the PMEI18-PME31 module in stomatal dynamics and highlight the role of PMEI18 and PME31 in stomatal dynamics through modulation of pectin methylesterification and distribution in GC walls.