RCB-mediated chlorophagy caused by oversupply of nitrogen suppresses phosphate-starvation stress in plants

Inorganic phosphate (Pi) and nitrogen (N) are essential nutrients for plant growth. We found that a five-fold oversupply of nitrate rescues Arabidopsis (Arabidopsis thaliana) plants from Pi-starvation stress. Analyses of transgenic plants that overexpressed GFP-AUTOPHAGY8 showed that an oversupply of nitrate induced autophagy flux under Pi-depleted conditions. Expression of DIN6 and DIN10, the carbon (C) starvation-responsive genes, was upregulated when nitrate was oversupplied under Pi starvation, which suggested that the plants recognized the oversupply of nitrate as C starvation stress because of the reduction in the C/N ratio. Indeed, formation of Rubisco-containing bodies (RCBs), which contain chloroplast stroma and are induced by C starvation, was enhanced when nitrate was oversupplied under Pi starvation. Moreover, autophagy-deficient mutants did not release Pi (unlike wild-type plants), exhibited no RCB accumulation inside vacuoles, and were hypersensitive to Pi starvation, indicating that RCB-mediated chlorophagy is involved in Pi starvation tolerance. Thus, our results showed that the Arabidopsis response to Pi starvation is closely linked with N and C availability and that autophagy is a key factor that controls plant growth under Pi starvation.

Disturbance of the carbon/nitrogen ratio induces partial chloroplast degradation via autophagy under phosphate starvation and rescues phosphate starvation stress.     

Can Acupuncture Treatment Be Double-Blinded? An Evaluation of Double-Blind Acupuncture Treatment of Postoperative Pain

Blinding protects against bias but the success of blinding is seldom assessed and reported in clinical trials including studies of acupuncture where blinding represents a major challenge. Recently, needles with the potential for double-blinding were developed, so we tested if acupuncture can be double-blinded in a randomized study of sixty-seven patients with acute pain ≥ 3 (0-10 scale following third molar removal) who received active acupuncture with a penetrating needle or placebo acupuncture with a non-penetrating needle. To test if acupuncture was administered double-blind, patients and acupuncturists were asked about perceived treatment allocation at the end of the study. To test if there were clues which led to identification of the treatment, deep dull pain associated with needle application and rotation (termed “de qi” in East Asian medicine), and patients’ pain levels were assessed. Perceived treatment allocation depended on actual group allocation (p < 0.015) for both patients and acupuncturists, indicating that the needles were not successful in double-blinding. Up to 68% of patients and 83% of acupuncturists correctly identified the treatment, but for patients the distribution was not far from 50/50. Also, there was a significant interaction between actual or perceived treatment and the experience of de qi (p = 0.027), suggesting that the experience of de qi and possible non-verbal clues contributed to correct identification of the treatment. Yet, of the patients who perceived the treatment as active or placebo, 50% and 23%, respectively, reported de qi. Patients’ acute pain levels did not influence the perceived treatment. In conclusion, acupuncture treatment was not fully double-blinded which is similar to observations in pharmacological studies. Still, the non-penetrating needle is the only needle that allows some degree of practitioner blinding. The study raises questions about alternatives to double-blind randomized clinical trials in the assessment of acupuncture treatment.     

Auger effects on bromo-deoxyuridine-monophosphate irradiated with monochromatic X-rays around bromine K-absorption edge

Summary In order to study the enhanced effect by Auger cascade, samples of bromo-deoxyuridine-monophosphate (Br-dUMP) in aqueous solutions were irradiated with monochromatic X-rays at 13.49 keV and 13.43 keV, just above and below the K-absorption edge of bromine, using synchrotron radiation as a source. Radiolytic products such as deoxyuridine-monophosphate (dUMP), uracil and bromo-uracil (Br-uracil) were isolated using high performance liquid chromatography. Their amounts were quantitatively analysed as a function of the absorbed dose in the solutions containing Br-dUMP for the energy of the X-rays.G values for these products were calculated on the basis of the absorbed energy. As the results, the ratios of G values of radiolytic products from Br-dUMP between X-rays of 13.49 keV and 13.43 keV were 2.2 for dUMP, 1.02 for Br-uracil and 1.23 for uracil, suggesting clearly the energy dependent enhancement. On the other hand, little significant difference between X-rays of 13.49 keV and 13.43 keV was observed for theG values of uracil released from dUMP irradiated in aqueous solutions. It seemed to confirm that the Auger electrons from K-shell of bromine atoms might play the main role for energy-dependent enhancement at induction of these radiolytic products.     

Reproductive habitat use,body-size structure and spawning season of Cobitis minamorii minamorii in paddy fields and ditches

We surveyed the reproductive ecology of Cobitis minamorii minamorii in paddy fields and ditches. The spatial distribution of females in the spawning season differed from that in the non-spawning season, even in short ditches. Eggs were collected in both ditches and paddy fields, unlike an earlier study demonstrating that no eggs were collected in ditches. The frequency distributions of standard body lengths of males and females were unimodal and bimodal, respectively. The females with a large standard body length were expected to be gravid with higher probability in May.

     

<Emphasis Type="Italic">OsATG10b</Emphasis>, an autophagosome component,is needed for cell survival against oxidative stresses in rice

Autophagy degrades toxic materials and old organelles, and recycles nutrients in eukaryotic cells. Whereas the studies on autophagy have been reported in other eukaryotic cells, its functioning in plants has not been well elucidated. We analyzed the roles of OsATG10 genes, which are autophagy-related. Two rice ATG10 genes - OsATG10a and OsATG10b - share significant sequence homology (about 75%), and were ubiquitously expressed in all organs examined here. GUS assay indicated that OsATG10b was highly expressed in the mesophyll cells and vascular tissue of younger leaves, but its level of expression decreased in older leaves. We identified T-DNA insertional mutants in that gene. Those osatg10b mutants were sensitive to treatments with high salt and methyl viologen (MV). Monodansylcadaverine-staining experiments showed that the number of autophagosomes was significantly decreased in the mutants compared with the WT. Furthermore, the amount of oxidized proteins increased in MV-treated mutant seedlings. These results demonstrate that OsATG10b plays an important role in the survival of rice cells against oxidative stresses.     

Ethanol and Acetaldehyde After Intraperitoneal Administration to Aldh2-Knockout Mice-Reflection in Blood and Brain Levels

This paper reports, for the first time, on the analysis of ethanol (EtOH) and acetaldehyde (AcH) concentrations in the blood and brains of Aldh2-knockout (Aldh2-KO) and C57B6/6J (WT) mice. Animals were administrated EtOH (1.0, 2.0 or 4.0 g/kg) or 4-methylpyrazole (4-MP, 82 mg/kg) plus AcH (50, 100 or 200 mg/kg) intraperitoneally. During the blood tests, samples from the orbital sinus of the eye were collected. During the brain tests, dialysates were collected every 5 min (equal to a 15 µl sample) from the striatum using in vivo brain microdialysis. Samples were collected at 5, 10, 15, 20, 25, 30 and 60 min intervals post-EtOH and -AcH injection, and then analyzed by head-space GC. In the EtOH groups, high AcH levels were found in the blood and brains of Aldh2-KO mice, while only small traces of AcH were seen in the blood and brains of WT mice. No significant differences in EtOH levels were observed between the WT and the Aldh2-KO mice for either the EtOH dose. EtOH concentrations in the brain were comparable to the EtOH concentrations in the blood, but the AcH concentrations in the brain were four to five times lower compared to the AcH concentrations in the blood. In the AcH groups, high AcH levels were found in both WT and Aldh2-KO mice. Levels reached a sharp peak at 5 min and then quickly declined for 60 min. Brain AcH concentrations were almost equal to the concentrations found in the blood, where the AcH concentrations were approximately two times higher in the Aldh2-KO mice than in the WT mice, both in the blood and the brain. Our results suggest that systemic EtOH and AcH administration can cause a greater increase in AcH accumulation in the blood and brains of Aldh2-KO mice, where EtOH concentrations in the Aldh2-KO mice were comparable to the EtOH concentrations in the WT mice. Furthermore, detection of EtOH and AcH in the blood and brain was found to be dose-dependent in both genotypes.