12 results on '"Li, Yimei"'
Search Results
2. Group sequential multi-arm multi-stage survival trial design with treatment selection.
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Wu, Jianrong and Li, Yimei
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CONDITIONAL probability , *INVESTIGATIONAL therapies - Abstract
Multi-arm trials are increasingly of interest because for many diseases; there are multiple experimental treatments available for testing efficacy. Several novel multi-arm multi-stage (MAMS) clinical trial designs have been proposed. However, a major hurdle to adopting the group sequential MAMS routinely is the computational effort of obtaining stopping boundaries. For example, the method of Jaki and Magirr for time-to-event endpoint, implemented in R package MAMS, requires complicated computational efforts to obtain stopping boundaries. In this study, we develop a group sequential MAMS survival trial design based on the sequential conditional probability ratio test. The proposed method is an improvement of the Jaki and Magirr's method in the following three directions. First, the proposed method provides explicit solutions for both futility and efficacy boundaries to an arbitrary number of stages and arms. Thus, it avoids complicated computational efforts for the trial design. Second, the proposed method provides an accurate number of events for the fixed sample and group sequential designs. Third, the proposed method uses a new procedure for interim analysis which preserves the study power. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Household income and health‐related quality of life in children receiving treatment for acute myeloid leukemia: Potential impact of selection bias in health equity research.
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Newman, Haley, Li, Yimei, Huang, Yuan‐Shung V., Elgarten, Caitlin W., Myers, Regina M., Ruiz, Jenny, Zheng, Daniel J., Leahy, Alison Barz, Aftandilian, Catherine, Arnold, Staci D., Bona, Kira, Gramatges, M. Monica, Heneghan, Mallorie B., Maloney, Kelly W., Modi, Arunkumar J., Mody, Rajen J., Morgan, Elaine, Rubnitz, Jeffrey, Winick, Naomi, and Wilkes, Jennifer J.
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INCOME , *QUALITY of life , *ACUTE myeloid leukemia , *HEALTH equity , *CHILD patients - Abstract
Objective: Examine the influence of household income on health‐related quality of life (HRQOL) among children with newly diagnosed acute myeloid leukemia (AML). Design: Secondary analysis of data prospectively collected from pediatric patients receiving treatment for AML at 14 hospitals across the United States. Exposure: Household income was self‐reported on a demographic survey. The examined mediators included the acuity of presentation and treatment toxicity. Outcome: Caregiver proxy reported assessment of patient HRQOL from the Peds QL 4.0 survey. Result: Children with AML (n = 131) and caregivers were prospectively enrolled to complete PedsQL assessments. HRQOL scores were better for patients in the lowest versus highest income category (mean ± SD: 76.0 ± 14 household income <$25,000 vs. 59.9 ± 17 income ≥$75,000; adjusted mean difference: 11.2, 95% CI: 2.2–20.2). Seven percent of enrolled patients presented with high acuity (ICU‐level care in the first 72 h), and 16% had high toxicity (any ICU‐level care); there were no identifiable differences by income, refuting mediating roles in the association between income and HRQOL. Enrolled patients were less likely to be Black/African American (9.9% vs. 22.2%), more likely to be privately insured (50.4% vs. 40.7%), and more likely to have been treated on a clinical trial (26.7% vs. 18.5%) compared to eligible unenrolled patients not enrolled. Evaluations of potential selection bias on the association between income and HRQOL suggested differences in HRQOL may be smaller than observed or even in the opposing direction. Conclusions: While primary analyses suggested lower household income was associated with superior HRQOL, differential participation may have biased these results. Future studies should partner with patients/families to identify strategies for equitable participation in clinical research. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Association of the social disorganization index with time to first septic shock event in children with acute myeloid leukemia.
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Ruiz, Jenny, Li, Yimei, Cao, Lusha, Huang, Yuan‐Shung V., Tam, Vicky, Griffis, Heather M., Winestone, Lena E., Fisher, Brian T., Alonzo, Todd A., Wang, Yi‐Cheng J., Dang, Alice T., Kolb, E. Anders, Glanz, Karen, Getz, Kelly D., Aplenc, Richard, and Seif, Alix E.
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ACUTE myeloid leukemia , *SOCIAL disorganization , *SEPTIC shock , *HEALTH information systems , *CHILD patients - Abstract
Background: Pediatric acute myeloid leukemia (AML) chemotherapy increases the risk of life‐threatening complications, including septic shock (SS). An area‐based measure of social determinants of health, the social disorganization index (SDI), was hypothesized to be associated with SS and SS‐associated death (SS‐death). Methods: Children treated for de novo AML on two Children's Oncology Group trials at institutions contributing to the Pediatric Health Information System (PHIS) database were included. The SDI was calculated via residential zip code data from the US Census Bureau. SS was identified via PHIS resource utilization codes. SS‐death was defined as death within 2 weeks of an antecedent SS event. Patients were followed from 7 days after the start of chemotherapy until the first of end of front‐line therapy, death, relapse, or removal from study. Multivariable‐adjusted Cox regressions estimated hazard ratios (HRs) comparing time to first SS by SDI group. Results: The assembled cohort included 700 patients, with 207 (29.6%) sustaining at least one SS event. There were 233 (33%) in the SDI‐5 group (highest disorganization). Adjusted time to incident SS did not statistically significantly differ by SDI (reference, SDI‐1; SDI‐2: HR, 0.84 [95% confidence interval (CI), 0.51–1.41]; SDI‐3: HR, 0.70 [95% CI, 0.42–1.16]; SDI‐4: HR, 0.97 [95% CI, 0.61–1.53]; SDI‐5: HR, 0.72 [95% CI, 0.45–1.14]). Nine patients (4.4%) with SS experienced SS‐death; seven of these patients (78%) were in SDI‐4 or SDI‐5. Conclusions: In a large, nationally representative cohort of trial‐enrolled pediatric patients with AML, there was no significant association between the SDI and time to SS. Time to first septic shock event was not associated with the social disorganization index (SDI), an area‐based measure of social determination of health, in children with acute myeloid leukemia treated on two Children's Oncology Group trials. Septic shock–associated mortality is rare in children with acute myeloid leukemia, and differences by SDI were not able to be detected. [ABSTRACT FROM AUTHOR]
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- 2024
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5. The association between telemedicine, advance care planning, and unplanned hospitalizations among high‐risk patients with cancer.
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Bange, Erin M., Li, Yimei, Kumar, Pallavi, Doucette, Abigail, Gabriel, Peter, Parikh, Ravi, Li, Eric H., Mamtani, Ronac, and Getz, Kelly D.
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ADVANCE directives (Medical care) , *MACHINE learning , *TELEMEDICINE , *CANCER patients , *HOSPITAL care - Abstract
Background: Despite the widespread implementation of telemedicine, there are limited data regarding its impact on key components of care for patients with incurable or high‐risk cancer. For these patients, high‐quality care requires detailed conversations regarding treatment priorities (advance care planning) and clinical care to minimize unnecessary acute care (unplanned hospitalizations). Whether telemedicine affects these outcomes relative to in‐person clinic visits was examined among patients with cancer at high risk for 6‐month mortality. Methods: This retrospective cohort study included adult patients with cancer with any tumor type treated at the University of Pennsylvania who were newly identified between April 1 and December 31, 2020, to be at high risk for 6‐month mortality via a validated machine learning algorithm. Separate modified Poisson regressions were used to assess the occurrence of advance care planning and unplanned hospitalizations for telemedicine as compared to in‐person visits. Additional analyses were done comparing telemedicine type (video or phone) as compared to in‐person clinic visits. Results: The occurrence of advance care planning was similar between telemedicine and in‐person visits (6.8% vs. 6.0%; adjusted risk ratio [aRR], 1.25; 95% CI, 0.92–1.69). In regard to telemedicine subtype, patients exposed to video encounters were modestly more likely to have documented advance care planning in comparison to those seen in person (7.5% vs. 6.0%; aRR, 1.48; 95% CI, 1.03–2.11). The 3‐month risk for unplanned hospitalization was comparable for telemedicine compared to in‐person clinic encounters (21% vs. 18%; aRR, 1.06; 95% CI, 0.81–1.38). Conclusions: In this study, care delivered by telemedicine, compared to in‐person clinic visits, produced comparable rates of advance care planning conversations without increasing hospitalizations, which suggests that vulnerable patients can be managed safely by telemedicine. In this study, care delivered by telemedicine, compared to in‐person clinic visits, produced comparable rates of advance care planning conversations without increasing hospitalizations, which suggests that vulnerable patients can be managed safely by telemedicine. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Group sequential designs for cancer immunotherapy trial with delayed treatment effect.
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Wu, Jianrong, Li, Yimei, and Zhu, Liang
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TREATMENT delay (Medicine) , *TREATMENT effectiveness , *LOG-rank test , *IMMUNOTHERAPY , *STATISTICAL power analysis - Abstract
Cancer immunotherapy trials are frequently characterized by delayed treatment effects such that the proportional hazards assumption is violated and the log-rank test suffers a substantial loss of statistical power. To increase the efficacy of the trial design, a variety of weighted log-rank tests have been proposed for fixed sample and group sequential trial designs. However, in such a group sequential design, it is often not recommended for futility interim monitoring due to possible delayed treatment effect which could result a high false-negative rate. To resolve this problem, we propose a group sequential design using a piecewise weighted log-rank test which provides an event-driven approach based on number of events after the delayed time. That is, the interim looks will not be conducted until the planned number of events observed after the delay time. Thus, it avoids the possibility of false-negative rate due to the delayed treatment effect. Furthermore, with an event-driven approach, the proposed group sequential design is robust against the underlying survival, accrual and censoring distributions. The group sequential designs using Fleming-Harrington-($$\rho ,\gamma $$ ρ , γ) weighted log-rank test and a new weighted log-rank test are also discussed. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Improving Pediatric Normal Tissue Radiation Dose-Response Modeling in Children With Cancer: A PENTEC Initiative.
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Hua, Chia-Ho, Bentzen, Søren M., Li, Yimei, Milano, Michael T., Rancati, Tiziana, Marks, Lawrence B., Constine, Louis S., Yorke, Ellen D., and Jackson, Andrew
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CHILDHOOD cancer , *MEDICAL dosimetry , *RADIATION , *STATISTICS , *TISSUES - Abstract
The development of normal tissue radiation dose-response models for children with cancer has been challenged by many factors, including small sample sizes; the long length of follow-up needed to observe some toxicities; the continuing occurrence of events beyond the time of assessment; the often complex relationship between age at treatment, normal tissue developmental dynamics, and age at assessment; and the need to use retrospective dosimetry. Meta-analyses of published pediatric outcome studies face additional obstacles of incomplete reporting of critical dosimetric, clinical, and statistical information. This report describes general methods used to address some of the pediatric modeling issues. It highlights previous single- and multi-institutional pediatric dose-response studies and summarizes how each PENTEC taskforce addressed the challenges and limitations of the reviewed publications in constructing, when possible, organ-specific dose-effect models. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Hydroxyurea maintains working memory function in pediatric sickle cell disease.
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Lai, Jesyin, Zou, Ping, Dalboni da Rocha, Josue L., Heitzer, Andrew M., Patni, Tushar, Li, Yimei, Scoggins, Matthew A., Sharma, Akshay, Wang, Winfred C., Helton, Kathleen J., and Sitaram, Ranganatha
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SICKLE cell anemia , *SHORT-term memory , *FUNCTIONAL magnetic resonance imaging , *CEREBRAL circulation , *PARIETAL lobe , *HYDROXYUREA - Abstract
Sickle cell disease (SCD) decreases the oxygen-carrying capacity of red blood cells. Children with SCD have reduced/restricted cerebral blood flow, resulting in neurocognitive deficits. Hydroxyurea is the standard treatment for SCD; however, whether hydroxyurea influences such effects is unclear. A key area of SCD-associated neurocognitive impairment is working memory, which is implicated in other cognitive and academic skills. The neural correlates of working memory can be tested using n-back tasks. We analyzed functional magnetic resonance imaging (fMRI) data of patients with SCD (20 hydroxyurea-treated patients and 11 controls, aged 7–18 years) while they performed n-back tasks. Blood-oxygenation level–dependent (BOLD) signals were assessed during working memory processing at 2 time points: before hydroxyurea treatment and ~1 year after treatment was initiated. Neurocognitive measures were also assessed at both time points. Our results suggested that working memory was stable in the treated group. We observed a treatment-by-time interaction in the right cuneus and angular gyrus for the 2- >0-back contrast. Searchlight-pattern classification of the 2 time points of the 2-back tasks identified greater changes in the pattern and magnitude of BOLD signals, especially in the posterior regions of the brain, in the control group than in the treated group. In the control group at 1-year follow-up, 2-back BOLD signals increased across time points in several clusters (e.g., right inferior temporal lobe, right angular gyrus). We hypothesize that these changes resulted from increased cognitive effort during working memory processing in the absence of hydroxyurea. In the treated group, 0- to 2-back BOLD signals in the right angular gyrus and left cuneus increased continuously with increasing working memory load, potentially related to a broader dynamic range in response to task difficulty and cognitive effort. These findings suggest that hydroxyurea treatment helps maintain working memory function in SCD. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Performance and symptom validity indicators among children undergoing cognitive surveillance following treatment for craniopharyngioma.
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Potter, Brian S, Crabtree, Valerie McLaughlin, Ashford, Jason M, Li, Yimei, Liang, Jia, Guo, Yian, Wise, Merrill S, Skoda, Evelyn S, Merchant, Thomas E, and Conklin, Heather M
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TEST validity , *CRANIOPHARYNGIOMA , *BRAIN tumors , *CHILD patients , *NEUROPSYCHOLOGICAL tests , *EPWORTH Sleepiness Scale - Abstract
Background Performance validity tests (PVTs) and symptom validity tests (SVTs) are essential to neuropsychological evaluations, helping ensure findings reflect true abilities or concerns. It is unclear how PVTs and SVTs perform in children who received radiotherapy for brain tumors. Accordingly, we investigated the rate of noncredible performance on validity indicators as well as associations with fatigue and lower intellectual functioning. Methods Embedded PVTs and SVTs were investigated in 98 patients with pediatric craniopharyngioma undergoing proton radiotherapy (PRT). The contribution of fatigue, sleepiness, and lower intellectual functioning to embedded PVT performance was examined. Further, we investigated PVTs and SVTs in relation to cognitive performance at pre-PRT baseline and change over time. Results SVTs on parent measures were not an area of concern. PVTs identified 0–31% of the cohort as demonstrating possible noncredible performance at baseline, with stable findings 1 year following PRT. Reliable digit span (RDS) noted the highest PVT failure rate; RDS has been criticized for false positives in pediatric populations, especially children with neurological impairment. Objective sleepiness was strongly associated with PVT failure, stressing need to consider arousal level when interpreting cognitive performance in children with craniopharyngioma. Lower intellectual functioning also needs to be considered when interpreting task engagement indices as it was strongly associated with PVT failure. Conclusions Embedded PVTs should be used with caution in pediatric craniopharyngioma patients who have received PRT. Future research should investigate different cut-off scores and validity indicator combinations to best differentiate noncredible performance due to task engagement versus variable arousal and/or lower intellectual functioning. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Thyroid Ultrasound Screening in Childhood Cancer Survivors following Radiotherapy.
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Baran, Julia A., Halada, Stephen, Bauer, Andrew J., Li, Yimei, Isaza, Amber, Patel, Tasleema, Sisko, Lindsay, Ginsberg, Jill P., Kazahaya, Ken, Adzick, N. Scott, and Mostoufi-Moab, Sogol
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CHILDHOOD cancer , *CANCER survivors , *THYROID gland , *IODINE isotopes , *EARLY detection of cancer , *TOTAL body irradiation , *ULTRASONIC imaging , *THYROID nodules - Abstract
Introduction: Childhood cancer survivors (CCS) are at risk for radiotherapy (RT) late effects, including second malignancies. Optimal screening for differentiated thyroid cancer (DTC) in CCS post-RT remains controversial. We assessed the outcome of thyroid ultrasound (US) surveillance in CCS exposed to RT. Methods: 306 CCS were surveilled with thyroid US between 2002–2021. Surveillance was dependent on age at the time of primary diagnosis, interval from receipt of RT, and individual provider. Thyroid US, clinicopathologic features, and outcomes were described. Cutpoints of CCS RT age associated with varying risk of nodule presentation were explored. The selected cutpoints were used to define age categories, which were then used to compare thyroid nodule-related outcomes. Risk factors for thyroid nodule(s) were evaluated using multivariate logistic regression (odds ratio [OR] [95% confidence interval]). Results: The most common CCS diagnoses were leukemia (32%), CNS tumor (26%), and neuroblastoma (18%). Patients received TBI (45%) and/or RT to craniospinal (44%), chest (11%), and neck regions (6%). About 49% (n = 150) of patients had thyroid nodule(s). Forty-four patients underwent surgery, and 28 had DTC: 19 with American Thyroid Association (ATA) low-risk classification, 2 with ATA intermediate-risk, and 7 with ATA high-risk disease. Age cutpoint analyses identified cutpoints 3 and 10; hence, ≤3, >3 to ≤10, and >10 years were used. Of the 9 patients with intermediate- or high-risk disease, 8 were ≤10 years and 1 was >10 years at the time of RT. Female sex (OR = 1.62 [1.13–2.12] p = 0.054) and greater interval between RT and first US (OR = 1.10 [1.04–1.16] p = 0.001) were independent risk factors for nodule presentation. Conclusions: Thyroid US surveillance may be beneficial for CCS exposed to RT at younger ages (≤10 years) for earlier detection of DTC, prior to developing advanced metastatic disease. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Spatial-temporal Bayesian accelerated failure time models for survival endpoints with applications to prostate cancer registry data.
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Wang, Ming, Li, Zheng, Lu, Jun, Zhang, Lijun, Li, Yimei, and Zhang, Liangliang
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SKIN cancer , *PROSTATE cancer , *PROPORTIONAL hazards models , *MARKOV chain Monte Carlo , *LARGE space structures (Astronautics) , *FLEXIBLE structures - Abstract
Prostate cancer is the most common cancer after non-melanoma skin cancer and the second leading cause of cancer deaths in US men. Its incidence and mortality rates vary substantially across geographical regions and over time, with large disparities by race, geographic regions (i.e., Appalachia), among others. The widely used Cox proportional hazards model is usually not applicable in such scenarios owing to the violation of the proportional hazards assumption. In this paper, we fit Bayesian accelerated failure time models for the analysis of prostate cancer survival and take dependent spatial structures and temporal information into account by incorporating random effects with multivariate conditional autoregressive priors. In particular, we relax the proportional hazards assumption, consider flexible frailty structures in space and time, and also explore strategies for handling the temporal variable. The parameter estimation and inference are based on a Monte Carlo Markov chain technique under a Bayesian framework. The deviance information criterion is used to check goodness of fit and to select the best candidate model. Extensive simulations are performed to examine and compare the performances of models in different contexts. Finally, we illustrate our approach by using the 2004-2014 Pennsylvania Prostate Cancer Registry data to explore spatial-temporal heterogeneity in overall survival and identify significant risk factors. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Phytosulfokine promotes fruit ripening and quality via phosphorylation of transcription factor DREB2F in tomato.
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Fang, Hanmo, Zuo, Jinhua, Ma, Qiaomei, Zhang, Xuanbo, Xu, Yuanrui, Ding, Shuting, Wang, Jiao, Luo, Qian, Li, Yimei, Wu, Changqi, Lv, Jianrong, Yu, Jingquan, and Shi, Kai
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Phytosulfokine (PSK), a plant peptide hormone with a wide range of biological functions, is recognized by its receptor PHYTOSULFOKINE RECEPTOR 1 (PSKR1). Previous studies have reported that PSK plays important roles in plant growth, development, and stress responses. However, the involvement of PSK in fruit development and quality formation remains largely unknown. Here, using tomato (Solanum lycopersicum) as a research model, we show that exogenous application of PSK promotes the initiation of fruit ripening and quality formation, while these processes are delayed in pskr1 mutant fruits. Transcriptomic profiling revealed that molecular events and metabolic pathways associated with fruit ripening and quality formation are affected in pskr1 mutant lines and transcription factors are involved in PSKR1-mediated ripening. Yeast screening further identified that DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2F (DREB2F) interacts with PSKR1. Silencing of DREB2F delayed the initiation of fruit ripening and inhibited the promoting effect of PSK on fruit ripening. Moreover, the interaction between PSKR1 and DREB2F led to phosphorylation of DREB2F. PSK improved the efficiency of DREB2F phosphorylation by PSKR1 at the tyrosine-30 site, and the phosphorylation of this site increased the transcription level of potential target genes related to the ripening process and functioned in promoting fruit ripening and quality formation. These findings shed light on the involvement of PSK and its downstream signaling molecule DREB2F in controlling climacteric fruit ripening, offering insights into the regulatory mechanisms governing ripening processes in fleshy fruits. Phytosulfokine promotes fruit ripening and quality formation in tomato by enhancing PHYTOSULFOKINE RECEPTOR1-mediated phosphorylation of DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2F. [ABSTRACT FROM AUTHOR]
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- 2024
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