Reduction of cadmium translocation from roots to shoots in eggplant (Solanum melongena) by grafting onto Solanum torvum rootstock

A survey in Japan showed that approximately 7% of eggplant fruits contain cadmium (Cd) concentrations above the international limit for fruiting vegetables. This study was conducted to develop a method to reduce Cd concentration in eggplant fruits. We determined Cd concentrations in eggplants grown on different rootstocks in Cd-polluted soil, unpolluted soil and nutrient culture. Grafting onto Solanum torvum reduced eggplant fruit Cd concentrations by 63–74% in Cd-polluted soil and unpolluted soil compared with grafting onto Solanum melongena and Solanum integrifolium . Stem and leaf Cd concentrations of scions on S. torvum were approximately 30% of those on S. integrifolium , so Cd translocation from roots to shoots was apparently reduced in plants grafted onto S. torvum . Stem and leaf Cd concentrations of S. torvum were also lower than those of cv. Senryou2 ( S. melongena ) and cv. Daitarou ( S. melongena ); thus, Cd translocation from roots to shoots was also reduced in self-rooted S. torvum plants. The Cd concentration of xylem sap in stems of S. torvum was 22% of that in stems of S. melongena , so the reduced Cd translocation from root to shoot could be accounted for by differential loading of Cd into the xylem in roots. We have developed a practical method for reducing the Cd concentration of eggplant fruits by grafting onto S. torvum rootstock. Further investigation is needed to elucidate the mechanism responsible for the low Cd translocation characteristics of S. torvum .     

Mechanism of salt tolerance in the grass species,Anneurolepidium chinense

The salt-tolerant grass plant, Anneurolepidium chinense, is commonly used for grazing in Northeast China and Inner Mongolia. The plants were grown in water culture and salt tolerance was evaluated in a greenhouse. The plants survived upon exposure to 500 mM NaCI salinity and developed stolons to produce daughter plants. Under 100 and 200 mM NaCI salinity, the plants accumulated mainly K+ to maintain the osmotic pressure of the young leaf blades. Betaine and reducing sugars were also the major constituents of the solutes that accumulated under saline conditions.     

Common reed absorbs K+ more selectively than rice against high Na+/K+ ratio in nutrient solution

The introduction of an active Na⁺ excretion system from salt-tolerant plants in salt-sensitive crop plants might necessitate enhancement of the robustness of K⁺ homeostasis and lead to improved plant growth under salt stress. To address this issue, we compared the acquisition and retention of K⁺ under excess Na⁺ concentrations in the common reed, which possesses excellent Na⁺ excretion ability, and low-Na⁺ excreting rice. Under excess Na⁺ concentrations, common reed maintained constant K⁺ content in all plant parts, whereas K⁺ content in rice decreased with increasing Na⁺ concentration. Preferential uptake of K⁺ against high Na⁺/K⁺ ratio in nutrient solution was approximately 10 times higher in common reed than in rice. The impact of excess Na⁺ on net K⁺ absorption rate of common reed was small. On the other hand, the net K⁺ absorption rate of rice was decreased by excess Na⁺ concentration. However, after the Na⁺ concentration in the nutrient solution was decreased from 50 to 1 mM, K⁺ absorption in rice recovered immediately. Thus, selectivity of K⁺ transporters or channels for K⁺ over Na⁺ in roots could be involved in the differences in K⁺ accumulation in rice and common reed.     

High-resolution Greenland ice core data show abrupt climate change happens in few years

The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.     

Constant transmission of mitochondrial DNA in intergeneric cloned embryos reconstructed from swamp buffalo fibroblasts and bovine ooplasm

Although interspecies/intergeneric somatic cell nuclear transfer (iSCNT) has been proposed as a tool to produce offspring of endangered species, conflict between donor nucleus and recipient cytoplasm in iSCNT embryos has been identified as an impediment to implementation for agricultural production. To investigate the nuclear–mitochondrial interactions on the developmental potential of iSCNT embryos, we analyzed the mtDNA copy numbers in iSCNT embryos reconstructed with water buffalo (swamp type) fibroblasts and bovine enucleated oocytes (buffalo iSCNT). As controls, SCNT embryos were derived from bovine fibroblasts (bovine SCNT). Buffalo iSCNT and bovine SCNT embryos showed similar rates of cleavage and development to the 8‐cell stage (P > 0.05). However, buffalo iSCNT embryos did not develop beyond the 16‐cell stage. Both bovine and buffalo mtDNA content in buffalo iSCNT embryos was stable throughout the nuclear transfer process, and arrested at the 8‐ to 16‐cell stage (P > 0.05). In bovine SCNT embryos that developed to the blastocyst stage, mtDNA copy number was increased (P < 0.05). In conclusion, both the donor cell and recipient cytoplast mtDNAs of buffalo iSCNT embryos were identified and maintained through the iSCNT process until the 8–16‐cell stage. In addition, the copy number of mtDNA per embryo was a useful monitor to investigate nuclear–mitochondrial interactions.     

Different effects of ionic and non-ionic compounds on the freeze denaturation of myofibrils and myosin subfragment-1

The effects of non-ionic (sorbitol, maltose, trehalose) and ionic compounds (Na-glutamate, Na-acetate, Na-sulfate, ammonium sulfate) on freeze denaturation of myosin subfragment-1 (S-1) and of myofibrils were compared. Sugars, Na-glutamate and Na-acetate well suppressed the freeze denaturation of myofibrils as well as S-1 in a concentration dependent manner. Although sulfate suppressed freeze denaturation of S-1 irregularly, it accelerated myofibril denaturation. It was concluded that sulfate salts were useless as cryoprotectant for myofibrils. Stabilization extent by F-actin in frozen storage was much less than that in heating.     

Production of stem cell factor in canine mast cell tumors

Mast cell tumor (MCT) is the most common cutaneous tumor in dogs. We recently revealed that production of stem cell factor (SCF) contributes to the proliferation of neoplastic mast cells in an autocrine/paracrine manner. The aim of the present study was to determine the contribution of the mechanism in clinical MCTs. In consequence, high SCF expression (>10 times compared to HRMC cells) was observed in 5 of 7 MCT samples used in the study regardless of KIT mutation, which was confirmed in immunohistochemical analysis. In addition, production of SCF was observed in Ki-67-positive cells in the MCT xenograft. These results indicate the broad contribution of SCF autocrine/paracrine mechanism on clinical MCTs, providing the rationale for the clinical use of KIT inhibitors regardless of KIT mutation.     

Background data of 2-year-old male and female F344 gpt delta rats

Although gpt delta rats, as reporter gene-transgenic rats, were originally developed for in vivo mutation assays, they have also been used to evaluate chemical carcinogenesis and comprehensive toxicity. Therefore, it is necessary to accumulate background data on carcinogenicity and general toxicity in gpt delta rats. Here, we investigated the background data of 110-week-old male and female F344 gpt delta rats and wild-type rats. There was no effect of reporter gene transfection on animal survival rates and body weights during the experiment. The relative weight of male gpt delta rat adrenals was significantly higher than that of wild-type rats, possibly due to the higher incidence of pheochromocytoma. There were no intergenotype differences in the incidence of nonneoplastic lesions in both sexes, including chronic progressive nephropathy and focus of cellular alteration in the liver, which had a higher incidence in both genotypes. Additionally, the significantly higher incidence of adrenal pheochromocytoma in male gpt delta rats than that in wild-type rats was likely incidental because of the lack of differences in the incidences of preneoplastic (male and female) and neoplastic (female) adrenal lesions in both genotypes. Other neoplastic lesions in both sexes showed no intergenotype differences in incidence rates, although large granular lymphocytic leukemia in the spleen and Leydig cell tumors in the testes of males showed higher incidence rates. Overall, there were no effects of reporter gene transfection on the spectrum of spontaneous lesions in F344 gpt delta rats, thus supporting their applicability in evaluating chemical toxicity and carcinogenicity.