Many high-yielding rice cultivars with large sink size (total number of spikelet per unit area × mean grain weight) have been developed, but some japonica cultivars developed in Japan often fail to ...attain the expected high yield due to low sink strength of spikelets. Although there is natural variation in sink strength of spikelets among high-yielding cultivars, metabolic factors involved in the natural variation and relationships of sink strength in spikelets with final percentage of filled spikelets are not fully understood. In the present study, we examined cultivar differences in sink strength for superior and inferior spikelets (i.e. earlier fertilizing spikelets with faster growth and later fertilizing ones with slower growth, respectively) in a panicle, using each spikelet at 10 d after the onset of development (10 DAD) when starch accumulation in endosperm was actively proceeding. Nine high-yielding cultivars were used: five japonica-dominant and four indica-dominant cultivars. Cultivar differences were observed in starch contents at 10 DAD in each spikelet type, and indica cultivars had higher starch contents than japonica cultivars in both superior and inferior spikelets. In addition, starch contents at 10 DAD were closely related to percentage of filled grains at maturity in both spikelet types. The activities of sucrose synthase (SUS) and uridine diphosphoglucose pyrophosphorylase (UGP), and the protein levels of phosphorylase 1 (Pho1), were higher in indica than japonica cultivars, and were positively correlated with starch contents at 10 DAD for both superior and inferior spikelets; although metabolic states, revealed from relations between intermediate metabolites and starch contents, differed among spikelet types. Consequently, it was considered that SUS and UGP at the step from sucrose cleavage to adenosine diphosphoglucose synthesis, and Pho1 at the starch biosynthesis step, were key metabolic factors involved in cultivar differences of sink strength (ability to synthesize starch).
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IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Th cells have long been divided into two subsets, Th1 and Th2; however, recently, Th17 and inducible regulatory T (iTreg) cells were identified as new Th cell subsets. Although Th1- and ...Th2-polarizing cytokines have been shown to suppress Th17 and iTreg development, transcriptional regulation of Th17 and iTreg differentiation by cytokines remains to be clarified. In this study, we found that expression of the growth factor independent 1 (Gfi1) gene, which has been implicated in Th2 development, was repressed in Th17 and iTreg cells compared with Th1 and Th2 lineages. Gfi1 expression was enhanced by the IFN-γ/STAT1 and IL-4/STAT6 pathways, whereas it was repressed by the transforming growth factor-β1 stimulation at the promoter level. Over-expression of Gfi1 strongly reduced IL-17A transcription in the EL4 T cell line, as well as in primary T cells. This was due to the blockade of recruitment of retinoid-related orphan receptor γt to the IL-17A promoter. In contrast, IL-17A expression was significantly enhanced in Gfi1-deficient T cells under Th17-promoting differentiation conditions as compared with wild-type T cells. In contrast, the impacts of Gfi1 in iTregs were not as strong as in Th17 cells. Taken together, these data strongly suggest that Gfi1 is a negative regulator of Th17 differentiation, which represents a novel mechanism for the regulation of Th17 development by cytokines.
We propose a novel method for synthesizing a visible-light image from a near-infrared one taken from the same viewpoint. Generating a multi-channel color image from a single-channel one is generally ...an ill-posed problem. As texture and color cues, the method refers to visible-light color images of the same scene but taken from a different point. The proposed method focuses on the estimation of the luminance component rather than the chrominance one because chrominance is not sensitive for human vision, and relatively easier to be estimated than luminance. Our cost function to optimize the luminance component is designed with the assumption that the synthesized image should be globally similar to the input infrared image structure and locally similar to the reference image patterns. Our experimental results show that the proposed method produces an artificial visible-light image, whose color appearance is more natural than color conversion methods, and geometrically more accurate than texture transfer-based methods.
Abstract Considering the prevalence of ever‐changing conditions in the natural world, investigation of photosynthetic responses in C 4 plants under fluctuating light is needed. Here, we studied the ...effect of dynamic illumination on photosynthesis in totally 10 C 3 , C 3 –C 4 intermediate, C 4 ‐like and C 4 dicots and monocots at CO 2 concentrations of 400 and 800 μmol mol −1 . C 4 and C 4 ‐like plants had faster photosynthetic induction and light‐induced stomatal dynamics than C 3 plants at 400 μmol mol −1 , but not at 800 μmol mol −1 CO 2 , at which the CO 2 supply rarely limits photosynthesis. C 4 and C 4 ‐like plants had a higher water use efficiency than C 3 plants at both CO 2 concentrations. There were positive correlations between photosynthetic induction and light‐induced stomatal response, together with CO 2 compensation point, which was a parameter of the CO 2 ‐concentrating mechanism of C 4 photosynthesis. These results clearly show that C 4 photosynthesis in both monocots and dicots adapts to fluctuating light conditions more efficiently than C 3 photosynthesis. The rapid photosynthetic induction response in C 4 plants can be attributed to the rapid stomatal dynamics, the CO 2 ‐concentrating mechanism or both.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Considering the prevalence of ever-changing conditions in the natural world, investigation of photosynthetic responses in C4 plants under fluctuating light is needed. Here, we studied the effect of ...dynamic illumination on photosynthesis in totally 10 C3, C3-C4 intermediate, C4-like and C4 dicots and monocots at CO2 concentrations of 400 and 800 μmol mol-1. C4 and C4-like plants had faster photosynthetic induction and light-induced stomatal dynamics than C3 plants at 400 μmol mol-1, but not at 800 μmol mol-1 CO2, at which the CO2 supply rarely limits photosynthesis. C4 and C4-like plants had a higher water use efficiency than C3 plants at both CO2 concentrations. There were positive correlations between photosynthetic induction and light-induced stomatal response, together with CO2 compensation point, which was a parameter of the CO2-concentrating mechanism of C4 photosynthesis. These results clearly show that C4 photosynthesis in both monocots and dicots adapts to fluctuating light conditions more efficiently than C3 photosynthesis. The rapid photosynthetic induction response in C4 plants can be attributed to the rapid stomatal dynamics, the CO2-concentrating mechanism or both.Considering the prevalence of ever-changing conditions in the natural world, investigation of photosynthetic responses in C4 plants under fluctuating light is needed. Here, we studied the effect of dynamic illumination on photosynthesis in totally 10 C3, C3-C4 intermediate, C4-like and C4 dicots and monocots at CO2 concentrations of 400 and 800 μmol mol-1. C4 and C4-like plants had faster photosynthetic induction and light-induced stomatal dynamics than C3 plants at 400 μmol mol-1, but not at 800 μmol mol-1 CO2, at which the CO2 supply rarely limits photosynthesis. C4 and C4-like plants had a higher water use efficiency than C3 plants at both CO2 concentrations. There were positive correlations between photosynthetic induction and light-induced stomatal response, together with CO2 compensation point, which was a parameter of the CO2-concentrating mechanism of C4 photosynthesis. These results clearly show that C4 photosynthesis in both monocots and dicots adapts to fluctuating light conditions more efficiently than C3 photosynthesis. The rapid photosynthetic induction response in C4 plants can be attributed to the rapid stomatal dynamics, the CO2-concentrating mechanism or both.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The cytokine, transforming growth factor-β1 (TGF-β1), converts naive T cells into regulatory T cells that prevent autoimmunity. However, in the presence of interleukin (IL)-6, TGF-β1 has also been ...found to promote differentiation into IL-17-producing helper T (Th17) cells that are deeply involved in autoimmunity and inflammation. However, it has not been clarified how TGF-β1 and IL-6 determine such a distinct fate. Here we found that a master regulator for Th17, retinoic acid-related orphan receptor γt (RORγt), was rapidly induced by TGF-β1 regardless of the presence of IL-6. IL-6 reduced Foxp3 expression, and overexpression of Foxp3 in a T cell line resulted in a strong reduction of IL-17A expression. We have characterized the IL-17A promoter and found that RORγt binding is sufficient for activation of the minimum promoter in the HEK 293T cells. RORγt-mediated IL-17A promoter activation was suppressed by forced expression of Foxp3. Foxp3 directly interacted with RORγt through exon 2 region of Foxp3. The exon 2 region and forkhead (FKH) domain of Foxp3 were necessary for the suppression of RORγt-mediated IL-17A promoter activation. We propose that induction of Foxp3 is the mechanism for the suppression of Th17 and polarization into inducible Treg.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Plants grown under field conditions experience fluctuating light. Understanding the natural genetic variations for a similarly dynamic photosynthetic response among untapped germplasm resources, as ...well as the underlying mechanisms, may offer breeding strategies to improve production using molecular approaches. Here, we measured gas exchange under fluctuating light, along with stomatal density and size, in eight wild tomato species and two tomato cultivars. The photosynthetic induction response showed significant diversity, with some wild species having faster induction rates than the two cultivars. Species with faster photosynthetic induction rates had higher daily integrated photosynthesis, but lower average water use efficiency because of high stomatal conductance under natural fluctuating light. The variation in photosynthetic induction was closely associated with the speed of stomatal responses, highlighting its critical role in maximizing photosynthesis under fluctuating light conditions. Moreover, stomatal size was negatively correlated with stomatal density within a species, and plants with smaller stomata at a higher density had a quicker photosynthetic response than those with larger stomata at lower density. Our findings show that the response of stomatal conductance plays a pivotal role in photosynthetic induction, with smaller stomata at higher density proving advantageous for photosynthesis under fluctuating light in tomato species. The interspecific variation in the rate of stomatal responses could offer an untapped resource for optimizing dynamic photosynthetic responses under field conditions.
Poor grain filling, characterized by incidence of partially filled grain, is one of the major problems to be improved for maximizing the yield potential in rice (Oryza sativa L.) cultivars with ...numerous spikelets in a panicle (extra‐heavy panicle type EHPT). This study evaluated the grain‐filling‐related alleles at APS2 and APL2, the loci for the small and large subunits of ADP‐glucose pyrophosphorylase (AGPase), respectively, and at SUT1, sucrose transporter, for their effects and interactions on grain filling and associated traits of EHPT cultivars. Two sets of derived lines were developed. Each of these lines was one of the eight possible homozygotes of alleles derived from rice cultivars Akenohoshi and Milyang 23 at the three loci in nearly common genetic backgrounds. They were examined for grain‐filling traits in two different years. Results showed that APL2‐2, and SUT1‐2 in part, derived from Milyang 23 showing relatively good grain filling, significantly improved grain filling compared with APL2‐1 and SUT1‐1 from Akenohoshi showing poor filling. This improvement in grain filling may result from increased AGPase activity and expression of APL2 and SUT1 proteins, by means of APL2‐2 and SUT1‐2. However, the variations in AGPase activity, protein expression, and the degree of grain filling were not associated with the gene expression of the three loci, implying post‐transcriptional regulation. These results strongly suggested that APL2‐2 and SUT1‐2 are associated with good grain filling.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Although it has been well established that TGF-beta plays a pivotal role in immune regulation, the roles of its downstream transcription factors, Smad2 and Smad3, have not been fully clarified. ...Specifically, the function of Smad2 in the immune system has not been investigated because of the embryonic lethality of Smad2-deficient mice. In this study, we generated T cell-specific Smad2 conditional knockout (KO) mice and unexpectedly found that Smad2 and Smad3 were redundantly essential for TGF-beta-mediated induction of Foxp3-expressing regulatory T cells and suppression of IFN-gamma production in CD4(+) T cells. Consistent with these observations, Smad2/Smad3-double KO mice, but not single KO mice, developed fatal inflammatory diseases with higher IFN-gamma production and reduced Foxp3 expression in CD4(+) T cells at the periphery. Although it has been suggested that Foxp3 induction might underlie TGF-beta-mediated immunosuppression, TGF-beta still can suppress Th1 cell development in Foxp3-deficient T cells, suggesting that the Smad2/3 pathway inhibits Th1 cell development with Foxp3-independent mechanisms. We also found that Th17 cell development was reduced in Smad-deficient CD4(+) T cells because of higher production of Th17-inhibitory cytokines from these T cells. However, TGF-beta-mediated induction of RORgamma t, a master regulator of Th17 cell, was independent of both Smad2 and Smad3, suggesting that TGF-beta regulates Th17 development through Smad2/3-dependent and -independent mechanisms.
The strain dependency of the spectrum and latency of tumors has been reported in p53-deficient (KO) mice, suggesting the presence of modifiers for the outcome of the p53 deficiency. The modifiers ...provide clues to the oncogenic pathway in cells lacking p53, the most frequently mutated gene in a wide variety of human cancers. To search the modifiers, we induced 160 lymphomas and 69 skin tumors by gamma-irradiation of p53(KO/+) backcross mice between BALB/c and MSM strains and performed genome scan. BALB/c-derived alleles at three loci on chromosome 19, Mp53D1 (modifier of p53-deficiency) at D19Mit5, Mp53D2 at D19Mit90 and Mp53D3 at D19Mit123, extended the latency of thymic lymphoma development (P values in Mantel-Cox test were 0.0007, 0.0007 and 0.0003, respectively). Mp53D3 also increased the latency of skin tumors (P value, 0.0008). The linkage of Mp53D2 was confirmed by the experiment using 94 p53-KO mice consomic for chromosome 19, providing a significant linkage. However, the linkage was not confirmed for Mp53D1 or Mp53D3, suggesting epistasis of genes involved in the tumorigenesis.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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![[Paper] Visible-Light Image...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2186-7364/small "[Paper] Visible-Light Image Synthesis from Infrared Images Using Texture Transfer")
