OsbZIP1 regulates phosphorus uptake and nitrogen utilization, contributing to improved yield.

Increasing nutrient uptake and use efficiency in plants can contribute to improved crop yields and reduce the demand for fertilizers in crop production. In this study, we characterized a rice mutant, 88n which showed long roots under low nitrogen (N) or phosphorus (P) conditions. Low expression levels of N transporter genes were observed in 88n root, and total N concentration in 88n shoots were decreased, however, C concentrations and shoot dry weight in 88n were comparable to that in WT. Therefore, 88n showed high nitrogen utilization efficiency (NUtE). mRNA accumulation of Pi transporter genes was higher in 88n roots, and Pi concentration and uptake activity were higher in 88n than in WT. Therefore, 88n also showed high phosphorus uptake efficiency (PUpE). Molecular genetic analysis revealed that the causal gene of 88n phenotypes was OsbZIP1, a monocot-specific ortholog of the A. thaliana bZIP transcription factor HY5. Similar to the hy5 mutant, chlorophyll content in roots was decreased and root angle was shallower in 88n than in WT. Finally, we tested the yield of 88n in paddy fields over 3 years because 88n mutant plants showed higher PUpE and NUtE activity and different root architecture at the seedling stage. 88n showed large panicles and increased panicle weight/plant. Taken together, a mutation in OsbZIP1 could contribute to improved crop yields.

A rice PHD-finger protein OsTITANIA, is a growth regulator that functions through elevating expression of transporter genes for multiple metals.

Essential metal absorption for plant growth is mediated predominantly by metal-specific transporters, with expression that responds to the environmental or cellular conditions of specific metals. Differing from metal-specific regulation, we describe a constitutively expressed transcription factor that regulates the transport of several metals in rice. We characterized the rice mutant LOW CADMIUM 5 (LC5), which exhibited reduced growth and accumulation of essential metals (e.g., copper [Cu], zinc [Zn] and manganese [Mn]) in shoots. LC5 was dwarf and developed less tillers than the wild type, but the structure of vasculature was apparently normal. Molecular genetic analysis revealed that the causal gene of LC5 is an ortholog of the transcriptional regulator Arabidopsis thaliana TITANIA (TTA), known as a transcriptional regulator. Expression analyses demonstrated that the OsTTA gene encodes a nucleus-localized protein containing a plant homeodomain-finger (PHD-finger) domain and is expressed ubiquitously in rice plants. RNA sequencing and quantitative PCR analyses revealed that the mRNA accumulation of transporter genes for essential metals, including iron (Fe), Zn, or Mn, were substantially lower in LC5 roots than in the wild type. Unlike known transcription factors of metal transport regulation, OsTTA transcript accumulation was not affected by metal availability. In addition, the growth defect of LC5 was partially rescued by Fe, Zn, or Mn supplementation, respectively. Taken together, OsTTA is a constitutively expressed regulator of multiple metal transporter genes responsible for essential metals delivery to shoots for their normal growth.

Comparison of the analgesic efficacy of ultrasound-guided rectus sheath block and local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children.

BACKGROUND: Ultrasound-guided rectus sheath block and local anesthetic infiltration are the standard options to improve postoperative pain for children undergoing surgery with a midline incision. However, there is no study comparing the effect of ultrasound-guided rectus sheath block with local anesthetic infiltration for children undergoing laparoscopic surgery. AIMS: The aim of this trial was to compare the onset of ultrasound-guided rectus sheath block with that of local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children. METHODS: We performed an observer-blinded, randomized, prospective trial. Enrolled patients were assigned to either an ultrasound-guided rectus sheath block group or a local anesthetic infiltration group. The ultrasound-guided rectus sheath block group (n = 17) received ultrasound-guided rectus sheath block with 0.2 ml·kg-1 of 0.375% ropivacaine per side in the posterior rectus sheath compartment. The local anesthetic infiltration group (n = 17) received local anesthetic infiltration with 0.2 ml·kg-1 of 0.75% ropivacaine. The Face, Legs, Activity, Cry, and Consolability (FLACC) pain scores were recorded at 0, 30, 60 min after arrival at the postanesthesia care unit. RESULTS: Of the 37 patients enrolled in this study, 34 completed the study protocol. A significant difference in the pain scale between the ultrasound-guided rectus sheath block group and local anesthetic infiltration group was found at 0 min (median: 0, interquartile range [IQR]: 0-1.5, vs median: 1, IQR 0-5, confidence interval of median [95% CI]: 0-3, P = 0.048), but no significant difference was found at 30 min (median: 1, IQR: 0-4 vs median: 6, IQR: 0-7, 95% CI: 0-5, P = 0.061), or 60 min (median: 0, IQR: 0-2 vs median: 1, IQR: 0-3, 95% CI: -1 to 1, P = 0.310). No significant difference was found in anesthesia time between the ultrasound-guided rectus sheath block and local anesthetic infiltration groups. No procedure-related complications were observed in either group. CONCLUSION: Ultrasound-guided rectus sheath block is a quicker way to control postoperative pain for pediatric patients undergoing laparoscopic extraperitoneal closure than local anesthetic infiltration, and thus may provide a clinical benefit.

Exogenous Boron supplementation partially rescues fertilization defect of osbor4 mutant.

Arabidopsis thaliana BOR1 is the first boron (B) transporter identified in the living systems. In the rice genome, there are four AtBOR1-like genes, OsBOR1, 2, 3 and 4. We have previously demonstrated that OsBOR4 is a B efflux transporter gene specifically expressed in rice pollen. OsBOR4 heterozygous lines showed abnormal segregation ratio, suggesting the significance of OsBOR4 in rice pollen tube germination/elongation process. To obtain further insights into the mechanisms underlying fertilization defects by osbor4 mutations, we examined if the mutant pollen exhibits morphological changes. The cross section of the pollen of the mutant was similar to those of the wild type. We also determined B concentrations in brown rice of three osbor4 mutants and found that B levels were comparable. These results suggest that osbor4 mutation does not affect B transport to pollen and seeds. We then examined if exogenous B supplementation can rescue segregation defect of osbor4. As reported previously, a OsBOR4 heterozygous lines showed abnormal segregation rate under the normal growth condition in this present study, too. Importantly, this abnormality in segregation was partially rescued by application of six-times higher B concentration to roots, providing further evidence that the fertilization defect of osbor4 is due to the defect in B transport process. Taken together we propose that osbor4 causes defect in B transport process during pollen germination to fertilization.

Roles of pollen-specific boron efflux transporter, OsBOR4, in the rice fertilization process.

Arabidopsis thaliana BOR1 was the first boron (B) transporter identified in living systems. There are four AtBOR1-like genes, OsBOR1, 2, 3 and 4, present in the rice genome. We characterized the activity, expression and physiological function of OsBOR4. OsBOR4 is an active efflux transporter of B. Quantitative PCR analysis and OsBOR4 promoter-green fluorescent protein (GFP) fusion revealed that OsBOR4 was both highly and specifically expressed in pollen. We obtained five Tos17 insertion mutants of osbor4. The pollen grains were viable and development of floral organs was normal in the homozygous osbor4 mutants. We observed that in all Tos17 insertion lines tested, the frequency of osbor4 homozygous plants was lower than expected in the progeny of self-fertilized heterozygous plants. These results establish that OsBOR4 is essential for normal reproductive processes. Pollen from osbor4 homozygous plants elongated fewer tubes on wild-type stigmas, and tube elongation of mutant pollen was less efficient compared with the wild-type pollen, suggesting reduced competence of osbor4 mutant pollen. The reduced competence of mutant pollen was further supported by the crosses of independent Tos17-inserted alleles of OsBOR4. Our results suggest that OsBOR4, a boron efflux transporter, is required for normal pollen germination and/or tube elongation.

Magnetic field-based delivery of human CD133⁺ cells promotes functional recovery after rat spinal cord injury.

STUDY DESIGN: Experimental animal study of spinal cord injury (SCI), using a cell delivery system. OBJECTIVE: To investigate the therapeutic effects of transplantation of peripheral blood-derived CD133 cells, with a magnetic delivery system in a rat SCI model. SUMMARY OF BACKGROUND DATA: There are no reports on intrathecal transplantation of peripheral blood-derived CD133 cells, with a magnetic cell delivery system to treat SCI. METHODS: Magnetically isolated peripheral blood-derived CD133 cells were used as the cell source. Contusion SCI was induced by an Infinite Horizon impactor in athymic nude rats. CD133 cells or phosphate-buffered saline was administered via a lumbar puncture immediately after SCI, and a magnetic field was applied to rats for 30 minutes. Animals were analyzed at specific times after transplantation by several methods to examine cell tracking, functional recovery, and histological angiogenesis and neurogenesis. RESULTS: A combination of cell transplantation and application of a magnetic field at the site of injury caused significant functional recovery. Transplantation of the cells alone in the absence of the magnetic field showed no effect beyond that observed in control rats. CONCLUSION: The combination of intrathecal transplantation of CD133 cells and application of a magnetic field at the site of injury is a possible therapeutic strategy to treat rat SCI and may therefore find application in clinical settings.