Transcription factors WOX11 and LBD16 function with histone demethylase JMJ706 to control crown root development in rice.

Crown roots are the main components of root systems in cereals. Elucidating the mechanisms of crown root formation is instrumental for improving nutrient absorption, stress tolerance, and yield in cereal crops. Several members of the WUSCHEL-related homeobox (WOX) and lateral organ boundaries domain (LBD) transcription factor families play essential roles in controlling crown root development in rice (Oryza sativa). However, the functional relationships among these transcription factors in regulating genes involved in crown root development remain unclear. Here, we identified LBD16 as an additional regulator of rice crown root development. We showed that LBD16 is a direct downstream target of WOX11, a key crown root development regulator in rice. Our results indicated that WOX11 enhances LBD16 transcription by binding to its promoter and recruiting its interaction partner JMJ706, a demethylase that removes histone H3 lysine 9 dimethylation (H3K9me2) from the LBD16 locus. In addition, we established that LBD16 interacts with WOX11, thereby impairing JMJ706-WOX11 complex formation and repressing its own transcriptional activity. Together, our results reveal a feedback system regulating genes that orchestrate crown root development in rice, in which LBD16 acts as a molecular rheostat.

New insight into comprehensive analysis of INDETERMINATE DOMAIN (IDD) gene family in rice.

The INDETERMINATE DOMAIN (IDD) transcription factor (TF), as a family of plant-specific zinc-finger proteins, regulates a variety of development processes and abiotic stresses in plants. IDD genes have been identified and characterized in other plants, however, the rice IDD family genes have not been investigated at genome-wide. In this study, 15 OsIDD genes were identified in rice genome and phylogenetically classified into two groups. Conserved motifs and potential interaction protein analysis about OsIDD proteins were carried out. Exon-intron structures, cis-acting elements and expression profiles of OsIDD genes were also examined. Exon-intron structures analysis revealed that overall structures of OsIDD genes were relatively conserved although they contained different numbers of introns. Cis-acting elements analysis suggested that most OsIDD gene transcripts could be induced by various abiotic stresses and phytohormones. The expression patterns of OsIDD genes were detected by qRT-PCR under cold and drought conditions, and by exogenous auxin (2,4-D), gibberellin (GA3), and abscisic acid (ABA) treatments, respectively. The results showed that the OsIDDs might play essential roles under abiotic stresses and hormone responses. Distinct expression profiles in tissues/organs suggested that OsIDDs might be involved in different development processes in rice. More interestingly, the prediction of protein-protein interactions (PPIs) revealed OsIDDs could cooperate with some histone modifiers. Yeast two-hybrid assays were performed and confirmed it. Collectively, these results provide a foundation for further elucidation on the molecular mechanisms of OsIDD genes and advance our understanding of their biological function in rice.

[Expression of Ki-67 in chronic lymphocytic leukemia and its clinical significance].

OBJECTIVE: To investigate the expression of nuclear antigen Ki-67 in CLL patients and realationship of Ki-67 expression with other clinical parameters. METHODS: Twenty-Six confirmed cases of CLL were analysised retrospectively. The immhnohistochemical method was carried out to examine the expression of Ki-67 in bone marrow cells, the flow cytometer was used to detect ZAP70 (Zeta chain-associated protein), CD38 and other markers, additionally, a panel of probes RB1 (13q14), ATM (11q22.3), P53 (17p13.1) and CSP12 (+12) FISH were perfomed to detect the cytogenetic abnormalities. RESULTS: Out of 26 patients, 15 cases (57.7%) showed positive expression of Ki-67, 11 cases (42.3%) showed negative expression of Ki-67, the average rate of Ki-67 positive expression was (10.86±7.36)%. The level of Ki-67 did not relate with sex, age, Hb, platelet, ZAP70, ATM. ß2-MG, IgHV and P53, but related to the Rai staging (P=0.01, r=0.517), CD38 (P=0.02, r=0.469), 13q14 (P=0.021, r=-0.48), and there was statistically significant difference (P<0.05). CONCLUSION: The Ki-67 level is higher in progressive stage of CLL and the Ki-67 expression is related with Rai staging, CD38, 13q14. The expression level of Ki-67 may be used as indicator for evaluation of CLL prognosis and guiding treatment for this disease.

[mRNA Expressions of T-bet, GATA-3, ROR γt and Foxp3 in peripheral blood of patients with chronic lymphocytic leukemia in different stages].

OBJECTIVE: This study was to investigate the mRNA expression of T-bet, GATA-3, ROR γt and Foxp3 mRNA in peripheral blood of patients with chronic lymphocytic leukemia (CLL) in different stages and explore their potential role in the pathogenesis and clinical diagnosis. METHODS: A total of 46 newly diagnosed and untreated patients with CLL was chosen as patient group, including 16 patients in the stage of Binet A, 15 in the stage of Binet B, and 15 in the stage of Binet C; 20 healthy persons were selected as controls. The quantitative fluorescence PCR was adopted to detect the mRNA expression of T-bet, GATA-3, RORγt and Foxp3 in peripheral blood mononuclear cell (PBMNC). RESULTS: (1) The expression of T-bet mRNA in patient group was lower than that in normal controls (P < 0.05), while the mRNA expression of GATA-3 mRNA, ROR γt, Foxp3 in CLL patients group were higher than that in normal controls (P < 0.05), and the ratio of T-bet/GATA-3 and RORγt/Foxp3 in CLL in patient group were lower than that in normal controls(P < 0.05); (2) The later the stage, the higher the mRNA expression of GATA-3 and Foxp3. The mRNA expression of GATA-3 in stage Binet B and stage Binet C of CLL patients were higher than that in stage Binet A (P < 0.05),and the mRNA expression of Foxp3 in stage Binet C was higher than that in stage of Binet A and Binet B (P < 0.05); the later the stage, the lower the ratio of T-bet/GATA-3 and RORγt/Foxp3. The ratio of T-bet/GATA-3 in stage of Binet A CLL patients was higher than that in stage Binet C (P < 0.05) and the ratio of RORγt/Foxp3 in stage of Binet A and stage of Binet B were higher than that in stage Binet C (P < 0.05). CONCLUSION: This study found in the level of transcription factors in CLL patients that with the process of disease, the balance shifts from Th1/Th2 and Th17/Treg to Th17 and Treg, and Treg cell may play a critical immunosuppressive role in the development of CLL.