Sucrose-associated SnRK1a1-mediated phosphorylation of Opaque2 modulates endosperm filling in maize.

During maize endosperm filling, sucrose not only serves as a source of carbon skeletons for storage-reserve synthesis but also acts as a stimulus to promote this process. However, the molecular mechanisms underlying sucrose and endosperm filling are poorly understood. In this study, we found that sucrose promotes the expression of endosperm-filling hub gene Opaque2 (O2), coordinating with storage-reserve accumulation. We showed that the protein kinase SnRK1a1 can attenuate O2-mediated transactivation, but sucrose can release this suppression. Biochemical assays revealed that SnRK1a1 phosphorylates O2 at serine 41 (S41), negatively affecting its protein stability and transactivation ability. We observed that mutation of SnRK1a1 results in larger seeds with increased kernel weight and storage reserves, while overexpression of SnRK1a1 causes the opposite effect. Overexpression of the native O2 (O2-OE), phospho-dead (O2-SA), and phospho-mimetic (O2-SD) variants all increased 100-kernel weight. Although O2-SA seeds exhibit smaller kernel size, they have higher accumulation of starch and proteins, resulting in larger vitreous endosperm and increased test weight. O2-SD seeds display larger kernel size but unchanged levels of storage reserves and test weight. O2-OE seeds show elevated kernel dimensions and nutrient storage, like a mixture of O2-SA and O2-SD seeds. Collectively, our study discovers a novel regulatory mechanism of maize endosperm filling. Identification of S41 as a SnRK1-mediated phosphorylation site in O2 offers a potential engineering target for enhancing storage-reserve accumulation and yield in maize.

Effects of orthodontic treatment on masticatory muscles activity: a meta-analysis.

Context: A comprehensive meta-analysis was carried out to investigate the impact of orthodontics on masticatory muscles.Methods: A thorough search of various databases, including CNKI, Wan Fang, VIP, CBM, MEDLINE, PubMed, Cochrane Library, EMBASE, Web of Science, and Google Scholar, was performed to identify relevant studies on patients undergoing orthodontics or functional corrections. Six case-control studies were finally included in this analysis, which specifically examined the effect of orthodontic treatment on masticatory muscle function.Results: The results revealed that the mean masticatory muscle voltage in patients treated with orthodontics was found to be higher after treatment compared to before treatment [odds ratio (OR)=1.57, 95% confidence interval (CI) (0.57, 2.57), p = 0.002], which could potentially have an impact on masticatory muscle function, particularly in individuals with Class II Division 1 malocclusion.Conclusion: These findings contribute to our understanding of the effects of orthodontic interventions on masticatory muscles, further highlighting the importance of orthodontics in optimising masticatory function.

Establishment of a model to predict the prognosis of pregnancy-related acute kidney injury.

BACKGROUND: Our aim was to investigate the prognostic factors of pregnancy related acute kidney injury (PR-AKI), establish the prognosis prediction model and evaluate predictability with the model. METHODS: Serum creatinine (SCr), placental growth factor (PLGF), endothelin-1 (ET-1), urinary kidney injury molecule-1 (KIM-1), and ß2-microglobulin (ß2-MG) levels in 122 patients with PR-AKI were measured at 1 month, 3 months, 6 months, and 1 year after delivery and the logistic backward stepwise regression method was used to screen the factors associated with the prognosis, establish the model to predict the prognosis of patients 1 year after delivery, and evaluate predictability with the model. RESULTS: 1) At 1 month, 3 months, 6 months, and 1 year after delivery, SCr was not significantly different in the poor prognosis group (P˃0.05); ET-1, KIM-1 and ß2-MG were decreased significantly, and PLGF was significantly increased (P˂0.05); all testing indicators in the good prognosis group were significantly different and returned to normal within 1 year (P˂0.05). By comparing the two groups, there were no significant differences in SCr, PLGF and ß2-MG levels at 1 month after delivery (P˃0.05), while there were significant differences in the remaining testing indicators at each time point (P˂0.05). 2) Logistic backward stepwise regression analysis showed that SCr, KIM-1, ET-1, and time were related to the prognosis of patients with PR-AKI, and the above screening indicators were used to fit the model Logit. CONCLUSIONS: The logistic regression model fitting-effect was good, its accuracy of predicting renal injury prognosis was high. SCr, KIM-1, and ET-1 can be used for PR-AKI screening and are important for monitoring the disease condition of patients, intervention, and evaluation of prognosis.