The AP2/ERF transcription factor MdDREB2A regulates nitrogen utilisation and sucrose transport under drought stress.

Drought stress is one of the main environmental factors limiting plant growth and development. Plants adapt to changing soil moisture by modifying root architecture, inducing stomatal closure, and inhibiting shoot growth. The AP2/ERF transcription factor DREB2A plays a key role in maintaining plant growth in response to drought stress, but the molecular mechanism underlying this process remains to be elucidated. Here, it was found that overexpression of MdDREB2A positively regulated nitrogen utilisation by interacting with DRE cis-elements of the MdNIR1 promoter. Meanwhile, MdDREB2A could also directly bind to the promoter of MdSWEET12, which may enhance root development and nitrogen assimilation, ultimately promoting plant growth. Overall, this regulatory mechanism provides an idea for plants in coordinating with drought tolerance and nitrogen assimilation to maintain optimal plant growth and development under drought stress.

Human cytomegalovirus UL49 encodes an early, virion-associated protein essential for virus growth in human foreskin fibroblasts.

Despite recent results of deletion experiments showing that open reading frame (ORF) UL49 of human cytomegalovirus (HCMV) is essential, the expression, function and functional location of its encoded protein remain unknown. We generated an antibody specific for pUL49 to investigate the protein product encoded by the UL49 ORF and identified its function in HCMV-infected host foreskin fibroblasts. A bacterial artificial chromosome (BAC) of HCMV strain Towne (pRV-Towne) and the UL49-deleted mutant pRV-delUL49Towne were used to observe virus growth by plaque assay. Using a UL49-protein-binding antibody, we located pUL49 in the fibroblast cytoplasm. pUL49 exhibited expression kinetics resembling those of the class ß-2 proteins and was detected in the virion tegument. Following deletion of UL49 ORF, the virus failed to replicate, but it could be recovered by addition of pUL49 from pCDNA3.1 (+)-UL49. Our findings indicate that UL49 ORF is essential for HCMV replication in host foreskin fibroblasts.

[A prospective multicenter clinical control trial on treatment of refractory nephrotic syndrome with mycophenolate mofetil in children].

OBJECTIVE: To evaluate the efficacy and safety of mycophenolate mofetil (MMF) plus prednisone on refractory nephrotic syndrome (RNS) in children. METHODS: One hundred and forty-two children with RNS from ten clinical trial centers were divided into two groups: MMF (n=87) and control (n=55). The MMF group patients were administered with oral MMF (30-40 mg/kg daily) for at least 6 months. Afterwards the patients who responded to MMF received another 6 months MMF treatment at a dosage of 10-20 mg/kg daily. The controls were treated with pulse intravenous infusion of cyclophosphamide (CTX) (10 mg/kg daily) for 2 days every 2 weeks for 3 months. Then CTX was administered at a dosage of 500 mg/m2 once a month 4, 7 and 10 months after treatment. While the patients received MMF or CTX treatment, they were treated with oral prednisone (0.5-1 mg/kg daily) for 2 to 3 months, and then the dosage of prednisone was gradually reduced. Urinary protein, liver and renal functions, and side effects of drugs were examined at regular intervals for one year. RESULTS: Of the 87 patients, 58 achieved complete remission, 16 achieved partial remission, 9 achieved early remission and 4 had no response to treatment. In the control group, 35 achieved complete remission, 9 achieved partial remission, 1 achieved early remission and 10 had no response to treatment. The total remission rate in the MMF group (95.4%) was significantly higher than that in the control group (81.8%) (P<0.01). After treatment 67 patients (65.4%) in the MMF group had negative proteinuria compared with 36 patients (65.4%) in the control group (P>0.05). MMF was found to be more effective in reducing proteinuria, and improving hypoproteinemia, oliguria, hyperlipemia, and edema than CTX. MMF was better tolerated with lower incidences of adverse reactions than CTX. CONCLUSIONS: The combined therapy of MMF and prednisone is more effective and tolerable than pulse intravenous infusion of CTX for treatment of RNS in children.