The mechanisms of carotenoid accumulation in yellow-fleshed sweetpotato cultivars are unclear. In this study, we compared the transcriptome profiles of a yellow-fleshed cultivar, Beniharuka (BH) and ...two of its spontaneous white-fleshed mutants (WH2 and WH3) to reveal the genes involved in yellow flesh. As a result of RNA sequencing, a total of 185 differentially expressed genes (DEGs) were commonly detected in WH2 and WH3 compared to BH. Of these genes, 85 DEGs and 100 DEGs were commonly upregulated and downregulated in WH2 and WH3 compared to BH, respectively. g1103.t1, a paralog of zeaxanthin epoxidase (ZEP), was only DEG common to WH2 and WH3 among 38 genes considered to be involved in carotenoid biosynthesis in storage roots. The expression level of g1103.t1 was also considerably lower in five white-fleshed cultivars than in five yellow-fleshed cultivars. Analysis of carotenoid composition in the storage roots showed that the epoxidised carotenoids were drastically reduced in both WH2 and WH3. Therefore, we propose that the ZEP paralog, g1103.t1, may be involved in carotenoid accumulation through the epoxidation of β-carotene and β-cryptoxanthin in sweetpotato.
Purple sweet potatoes are rich in the purple pigment anthocyanin. In recent years, it has been reported that the anthocyanin content of the same variety varies depending on the place of production. ...Therefore, to investigate the effect of soil temperature on the anthocyanin content of sweet potato tuberous roots, two types of covering materials, black and white mulch films, were used in the same field. The vines were planted in May, June and July; the cultivation period was set to 120–180 days and tuberous roots were harvested in September, October and November. The average soil temperature ranged from 22.9 to 26.5°C, with the white mulch having lower soil temperatures than the black mulch. The tuberous root yield increased with longer cultivation periods; the tuberous root yield in the May–November plot with a 180-day cultivation period was about twice that of the June–October and July–November plots with a 120-day cultivation period. The anthocyanin content of the tuberous root was negatively correlated with the average soil temperature; the test plots harvested in November had a higher anthocyanin content than the other test plots. In particular, the anthocyanin content of sweet potato cultivated in white mulch in July–November was about twice that cultivated in May–September. Although the factors that increase the tuberous root yield (prolonged cultivation period) are different from those that increase the anthocyanin content (lower temperature range), the tuberous root yield showed a larger effect on the total anthocyanin yield. Since the cultivation period needs to be prolonged to increase tuberous root yield, it would consequently increase the anthocyanin yield. The quality of the harvest was better under lower soil temperature as it led to an increase in the anthocyanin yield. Therefore, it was suggested that anthocyanin yields could be maximized by extending the growing season and harvesting at lower soil temperatures.
Root hairs of Arabidopsis play significant roles in the absorption of water and several minerals, secretion of acid phosphatases and organic acids, and anchoring of roots.
Summary
Zinc (Zn) depletion adversely affects plant growth. To avoid lethal depletion of cellular Zn, plants have evolved mechanisms to adjust the expression of genes associated with Zn homeostasis, ...the details of which are poorly understood. In the present study, we isolated an Arabidopsis thaliana T‐DNA insertion mutant that exhibited hypersensitivity to Zn depletion. By monitoring root development under Zn‐deficient conditions, we isolated a single mutant lacking the basic‐region leucine‐zipper transcription factor gene bZIP19. To identify proteins whose expression is affected by bZIP19, an iTRAQ‐based quantitative proteomics analysis was performed using microsomal proteins from wild‐type and the bzip19 mutant A. thaliana roots grown on Basal and Zn‐deficient media. Of the 797 proteins identified, expression of two members of the Zrt‐ and Irt‐related protein family, ZIP3 and ZIP9, and three defensin‐like family proteins was markedly induced in wild‐type but not in the bzip19 mutant under Zn‐deficient conditions. Furthermore, selected reaction monitoring and quantitative real‐time PCR revealed that ZIP9 expression is mediated by bZIP19 and may be partly supported by bZIP23, a homolog of bZIP19. Mutant analysis revealed that ZIP9 is involved in uptake of Zn by the roots, and the mutant lacking ZIP9 was significantly more sensitive to Zn depletion than the wild‐type. These results demonstrate that bZIP19 mainly contributes to expression of genes, such as ZIP9, under Zn‐deficient conditions.
Significance Statement
Zinc homeostasis is important for plant growth, but how plants cope with zinc deficiencies is poorly understood. We show that the Arabidopsis transcription factor bZIP19 predominantly contributes zinc deficiency adaptation, in part by affecting expression of the Zrt‐ and Irt‐related protein 9 (ZIP9) Zn transporters.
The micronutrient zinc is essential for all living organisms, but it is toxic at high concentrations. Here, to understand the effects of excess zinc on plant cells, we performed an iTRAQ (for ...isobaric tags for relative and absolute quantification)-based quantitative proteomics approach to analyze microsomal proteins from Arabidopsis (Arabidopsis thaliana) roots. Our approach was sensitive enough to identify 521 proteins, including several membrane proteins. Among them, IRT1, an iron and zinc transporter, and FRO2, a ferric-chela te reductase, increased greatly in response to excess zinc. The expression of these two genes has been previously reported to increase under iron-deficient conditions. Indeed, the concentration of iron was significantly decreased in roots and shoots under excess zinc. Also, seven subunits of the vacuolar H
+
-ATPase (V-ATPase), a proton pump on the tonoplast and endosóme, were identified, and three of them decreased significantly in response to excess zinc. In addition, excess zinc in the wild type decreased V-ATPase activity and length of roots and cells to levels comparable to those of the untreated de-etiolated3-1 mutant, which bears a mutation in V-ATPase subunit Interestingly, excess zinc led to the formation of branched and abnormally shaped root hairs, a phenotype that correlates with decreased levels of proteins of several root hair-defective mutants. Our results point out mechanisms of growth defects caused by excess zinc in which cross talk between iron and zinc homeostasis and V-ATPase activity might play a central role.
Basic concept of JA DEMO fuel cycle Iwai, Yasunori; Edao, Yuki; Kurata, Rie ...
Fusion engineering and design,
20/May , Letnik:
166
Journal Article
Recenzirano
In the JA DEMO, the deuterium-tritium (DT) fuel will be supplied by a combination of gas puff, pellet injection and neutral beam injection. Since the combustion rate of fuel in the JA DEMO is ...approximately 1.7 %, it is necessary to establish the closed deuterium-tritium fuel cycle in the facility for fuel recycling. The fuel cycle for DEMO inevitably differs from that for ITER. Compared to the ITER fuel cycle, which requires high flexibility for fuel supply based on the requirements of plasma experiments, the flexibility required for the fuel cycle decreases in the DEMO reactor. The flow in the fuel cycle becomes steadier. Therefore, the fuel cycle of the DEMO shifts to the continuous processing system. In addition, considering the tritium breeding in the blanket, the fuel cycle must be established so that tritium in the DEMO facility can be balanced. The process components of the fuel cycle that process a large amount of tritium-containing gas are provided with multiple barriers that confine tritium, and the detritiation system processes the confined tritium. The confinement of tritium in the DEMO facility according to nuclear safety regulations is an important safety issue. As a result, the fuel cycle becomes a complex chemical plant. Assuming safety requirements, it is necessary to consider the reduction of the tritium inventory as much as possible at the design stage of the DEMO fuel cycle. The tritium inventory in the fuel cycle is closely related to the requirements to pellet manufacturing and hydrogen isotope separation, and the reduction of the requirements to the hydrogen isotope separation is the major issue in the fuel cycle. For this purpose, it is necessary to minimize the D/T separation based on the concept of direct fuel cycle with the D/T mixture. For the possible shortage in the preparation of the initial loading tritium for the DEMO reactor, it is necessary to design the fuel cycle through dynamic numerical simulation so that the fuel cycle can be started with the minimum initial loading tritium. In the system design of the fuel cycle, it is necessary to support various operation modes from the startup of DT operation to steady operation. The requirements to design the JA DEMO fuel cycle are being investigated in the JA DEMO design activity.
Inhibition of cell division is an active response to DNA damage that enables cells to maintain genome integrity. However, how DNA damage arrests the plant cell cycle is largely unknown. Here, we show ...that the repressor-type R1R2R3-Myb transcription factors (Rep-MYBs), which suppress G2/M-specific genes, are required to inhibit cell division in response to DNA damage. Knockout mutants are resistant to agents that cause DNA double-strand breaks and replication stress. Cyclin-dependent kinases (CDKs) can phosphorylate Rep-MYBs in vitro and are involved in their proteasomal degradation. DNA damage reduces CDK activities and causes accumulation of Rep-MYBs and cytological changes consistent with cell cycle arrest. Our results suggest that CDK suppressors such as CDK inhibitors are not sufficient to arrest the cell cycle in response to DNA damage but that Rep-MYB-dependent repression of G2/M-specific genes is crucial, indicating an essential function for Rep-MYBs in the DNA damage response.Inhibition of cell division maintains genome integrity in response to DNA damage. Here Chen et al. propose that DNA damage causes cell cycle arrest in the Arabidopsis root via Rep-MYB transcription factor-mediated repression of G2/M-specific gene expression in response to reduced cyclin-dependent kinase activity.
Sweet potato shochu oil is one of the by-products of sweet potato shochu production. We investigated the functionality and industrial use of shochu oil as a food-derived raw material. Because of the ...increased incidence of self-consciousness in people owing to thinning hair, in this study, we examined the hair growth-inducing effects of shochu oil. Minoxidil, the only topical medication approved for hair growth treatment in Japan, was used as a control for the evaluation of hair growth-promoting activity of shochu oil. Human follicle dermal papilla cells treated with shochu oil showed upregulated expression of vascular endothelial growth factor in a concentration-dependent manner, indicating that shochu oil induced the activation of the hair growth cycle. In vivo, epidermal treatment with shochu oil also promoted hair growth in C3H mice. More than 35 components were detected in shochu oil via gas chromatography–mass spectrometry. The main components, accounting for 98.5% of shochu oil, were as follows, in order of decreasing concentration: ethyl palmitate, ethyl linoleate, ethyl oleate, ethyl stearate, ethyl caprate, ethyl laurate, ethyl myristate, and ethyl α-linolenate. Among these, ethyl palmitate, ethyl linoleate, and ethyl α-linolenate promoted hair growth in C3H mice. These results indicate that shochu oil can be used as a hair restorer. To the best of our knowledge, this study is the first to demonstrate the hair growth-promoting activity of shochu oil.
We investigated the anthocyanin composition of the purple sweet potato cultivar ‘Churakanasa’. The color tone of the paste was compared by L*, a*, and b* values and ‘Churakanasa’ exhibited a lower b* ...value, which indicates a bluish tint, than ‘Churakoibeni’, a popular cultivar for paste processing in Okinawa. High performance liquid chromatography (HPLC) analysis of the pigment extract showed that the anthocyanin composition of ‘Churakanasa’ was quite different from that of ‘Ayamurasaki’ and ‘Churakoibeni’. The analysis of the aglycone composition revealed that the cyanidin content (%) of ‘Ayamurasaki’ and ‘Churakoibeni’ contained 19.2% and 22.6% of cyanidins and 80.8% and 77.4% of peonidins, respectively. These findings indicate that these cultivars belong to the peonidin type. In contrast, ‘Churakanasa’ contained 86.4% cyanidin, indicating it to be a cyanidin-type cultivar. The steamed sweet potato paste made from ‘Churakanasa’ (cyanidin type cultivar) exhibited a bluer color compared to the peonidin-type cultivars. This observation suggests a direct correlation between the higher cyanidin content and the blue color intensity of the paste. HPLC-MS analysis of the two major HPLC peaks (peak I and II) of ‘Churakanasa’ suggested that the substance in peak I was YGM-0c; cyanidin-3-p-hydroxybenzoyl sophoroside-5-glucoside by mass, whereas peak II was YGM-1a; cyanidin-3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside. ‘Churakanasa’ exhibits unique color and pigment characteristics as it is the only purple sweet potato cultivar that has YGM-0c and -1a as its primary pigments.
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