Transcriptional factor MdESE3 controls fruit acidity by activating genes regulating malic acid content in apple.

Acidity is a key factor controlling fruit flavor and quality. In a previous study, combined transcriptome and methylation analyses identified a P3A-type ATPase from apple (Malus domestica), MdMa11, which regulates vacuolar pH when expressed in Nicotiana benthamiana leaves. In this study, the role of MdMa11 in controlling fruit acidity was verified in apple calli, fruits, and plantlets. In addition, we isolated an APETALA2 domain-containing transcription factor, designated MdESE3, based on yeast one-hybrid (Y1H) screening using the MdMa11 promoter as bait. A subcellular localization assay indicated that MdESE3 localized to the nucleus. Analyses of transgenic apple calli, fruits, and plantlets, as well as tomatoes, demonstrated that MdESE3 enhances fruit acidity and organic acid accumulation. Meanwhile, chromatin immunoprecipitation quantitative PCR, luciferase (LUC) transactivation assays, and GUS reporter assays indicated that MdESE3 could bind to the ethylene-responsive element (ERE; 5'-TTTAAAAT-3') upstream of the MdMa11 transcription start site, thereby activating its expression. Furthermore, MdtDT, MdDTC2, and MdMDH12 expression increased in apple fruits and plantlets overexpressing MdESE3 and decreased in apple fruits and plantlets where MdESE3 was silenced. The ERE was found in MdtDT and MdMDH12 promoters, but not in the MdDTC2 promoter. The Y1H, LUC transactivation assays, and GUS reporter assays indicated that MdESE3 could bind to the MdtDT and MdMDH12 promoters and activate their expression. Our findings provide valuable functional validation of MdESE3 and its role in the transcriptional regulation of MdMa11, MdtDT, and MdMDH12 and malic acid accumulation in apple.

[Risk factors and prognosis of acute cerebrovascular events at 1 year after hip fracture in elderly patients].

OBJECTIVE: To investigate risk factors of acute cerebrovascular events and effects on the prognosis within 1 year after hip fracture surgery. METHODS: A retrospective analysis was performed on 320 elderly patients with hip fracture treated from July 2017 to December 2020, including 111 males and 209 females, aged from 60 to 101 years old with an average of (79.05±8.48) years old. According to whether acute cerebrovascular events occurred within 1 year after surgery, patients were divided into cerebrovascular events and non-cerebrovascular events group. Clinical data of patients were collected, including age, sex, comorbidities, fracture type, white blood cell count, hemoglobin, albumin, activities of daily living (ADL) score, walking ability, type of anesthesia, type of surgery, and length of hospital stay, Univariate analysis and multivariate Logistic regression were used to analyze the independent risk factors of acute cerebrovascular events within 1 year after hip fracture in elderly patients. ADL, walking ability and mortality were compared between the two groups 1 year after surgery. RESULTS: Acute cerebrovascular events occurred in 38 patients (11.9%) within 1 year after surgery. In the cerebrovascular events group, there were 20 males and 18 females, aged (82.53±7.91) years. In the non-cerebrovascular event group, there were 91 males and 191 females, aged with an average of (78.59±8.46) years old . Univariate analysis showed that acute cerebrovascular events were associated with age (t=2.712, P=0.007), male (χ2=6.129, P=0.013), hypertension (χ2=8.449, P=0.004), arrhythmia (χ2=6.360, P=0.012), stroke history (χ2=34.887, P=0.000), diabetes mellitus (χ2=4.574, P=0.032) and length of hospital stay (t=2.249, P=0.025) were closely related. Multivariate Logistic regression analysis showed age (OR=1.068, P=0.018), male (OR=2.875, P=0.008), arrhythmia (OR=2.722, P=0.017) and stroke history (OR=7.382, P=0.000) was an independent risk factor for acute cerebrovascular events 1 year after surgery. The patients with cerebrovascular events died at 1 year after surgery (11 cases) compared with those without cerebrovascular events (41 cases), and the difference was statistically significant(χ2=5.108, P=0.024). ADL scores of patients with cerebrovascular events at 1 year after operation were (58.70±14.45) points compared with those without cerebrovascular events (67.83±10.45) points, and the difference was statistically significant(t=4.122, P=0.000). Independent walking, assisted walking and bed rest were 3, 17 and 7 cases in cerebrovascular event group, and 54, 174 and 13 cases in non-cerebrovascular event group, respectively;and the difference was statistically significant(χ2=11.030, P=0.003). CONCLUSION: Acute cerebrovascular events were common in elderly patients 1 year after hip fracture. Age, male, arrhythmia and stroke history were independent risk factors for acute stroke. The patients in the cerebrovascular event group had higher mortality and worse self-care ability and walking ability one year after operation.

Combined Profiling of Transcriptome and DNA Methylome Reveal Genes Involved in Accumulation of Soluble Sugars and Organic Acid in Apple Fruits.

Organic acids and soluble sugars are the major determinants of fruit organoleptic quality. Additionally, DNA methylation has crucial regulatory effects on various processes. However, the epigenetic modifications in the regulation of organic acid and soluble sugar accumulation in apple fruits remain uncharacterized. In this study, DNA methylation and the transcriptome were compared between 'Honeycrisp' and 'Qinguan' mature fruits, which differ significantly regarding soluble sugar and organic acid contents. In both 'Honeycrisp' and 'Qinguan' mature fruits, the CG context had the highest level of DNA methylation, and then CHG and CHH contexts. The number and distribution of differentially methylated regions (DMRs) varied among genic regions and transposable elements. The DNA methylation levels in all three contexts in the DMRs were significantly higher in 'Honeycrisp' mature fruits than in 'Qinguan' mature fruits. A combined methylation and transcriptome analysis revealed a negative correlation between methylation levels and gene expression in DMRs in promoters and gene bodies in the CG and CHG contexts and in gene bodies in the CHH context. Two candidate genes (MdTSTa and MdMa11), which encode tonoplast-localized proteins, potentially associated with fruit soluble sugar contents and acidity were identified based on expression and DNA methylation levels. Overexpression of MdTSTa in tomato increased the fruit soluble sugar content. Moreover, transient expression of MdMa11 in tobacco leaves significantly decreased the pH value. Our results reflect the diversity in epigenetic modifications influencing gene expression and will facilitate further elucidating the complex mechanism underlying fruit soluble sugar and organic acid accumulation.