Rice OsUBR7 modulates plant height by regulating histone H2B monoubiquitination and cell proliferation.

Plant height is an important agronomic trait for lodging resistance and yield. Here, we report a new plant-height-related gene, OsUBR7 in rice (Oryza sativa L.); knockout of OsUBR7 caused fewer cells in internodes, resulting in a semi-dwarf phenotype. OsUBR7 encodes a putative E3 ligase containing a plant homeodomain finger and a ubiquitin protein ligase E3 component N-recognin 7 (UBR7) domain. OsUBR7 interacts with histones and monoubiquitinates H2B (H2Bub1) at lysine148 in coordination with the E2 conjugase OsUBC18. OsUBR7 mediates H2Bub1 at a number of chromatin loci for the normal expression of target genes, including cell-cycle-related and pleiotropic genes, consistent with the observation that cell-cycle progression was suppressed in the osubr7 mutant owing to reductions in H2Bub1 and expression levels at these loci. The genetic divergence of OsUBR7 alleles among japonica and indica cultivars affects their transcriptional activity, and these alleles may have undergone selection during rice domestication. Overall, our results reveal a novel mechanism that mediates H2Bub1 in plants, and UBR7 orthologs could be utilized as an untapped epigenetic resource for crop improvement.

Risk Factors for the Recurrent Herniation After Microendoscopic Discectomy.

BACKGROUND: Microendoscopic discectomy (MED) has been widely accepted for its advantage of minimal injury in the treatment of lumbar disc herniation. Recurrence after successful MED has been reported; however, the risk factors responsible for the MED recurrence were still unclear. METHODS: From April 2005 to April 2016, 111 patients with recurrent herniation after successful MED were included in this retrospective study. Kaplan-Meier methods and Cox regression analysis were used to identify the significant risk factors responsible for MED recurrence. RESULTS: Univariate analysis demonstrated that age (≥50 years old), obesity (body mass index [BMI] ≥25), the treatment period (April 2005 to October 2010), modic change, nonmigrated herniation, and central herniation are identified as the potential risk factors for percutaneous endoscopic lumbar discectomy recurrence. Multivariate analysis suggested that age (≥50 years old), obesity (BMI ≥25), and modic change are identified as the significant risk factors responsible for MED recurrence. CONCLUSIONS: Age (≥50 years old) was the most robust risk factor for MED recurrence. Obesity (BMI ≥25) and modic change were also highly involved in the recurrent herniation after successful MED. Taking these risk factors into consideration before surgery may be instrumental in pursuing a personalized operative method, which may lead to a more satisfactory operative outcome and a relatively lower recurrence rate.