Electrochemical reduction has previously been reported for uranium oxide and mixed oxide nuclear fuel (uranium oxide, plutonium oxide). The laboratory scale electrochemical reduction of plutonium oxide powder is demonstrated in CaCl2- 1wt%CaO. The plutonium oxide contained within a permeable steel basket cathode is sacrificed during the process. A graphite anode is also employed during the reduction, leading to a significant contamination of the product.
석유화학원료의 공급 불안정 및 기후환경변화 대처가 절실한 상황으로 최근 신재생에너지 분야에 관한 관심이 증대 되고 있다. 더불어 2012년부터 발효된 RPS(Renewable Portfolio Standard) 규제에 따라 국내 발전사들의 신재생에너지원으로 부터의 전기 생산 의무가 본격화되고 있다. 특히 폐자원 및 폐바이오매스를 이용한 에너지 생산 분야는 원료의 안정적인 공급 가능성과 기존 처리 방법의 제한적 이용으로 열화학적 전환 기술을 이용한 에너지 생산기술이 각광받고 있다. 대표적인 열화학적 전환 기술들 중 열분해 기술은 폐바이오매스에 적용을 통하여 기존 석탄 에너지 전환 시설의 대체 자원으로의 이용이 가능하며, 원료의 수급성 측면 및 다양한 원료 특성에 대응하기 위해 반탄화(Torrefaction) 기술이 제시되고 있다. 반탄화 기술은 폐바이오매스를 에너지원으로 적극 활용하기 위한 전처리 공정으로, 무산소 조건에서 낮은 온도영역인 200~300℃에서 가열하여 원료 내 함유된 휘발분 및 수분 제거를 통해 연료로 전환된다. 생성된 반탄화물은 소수성 및 낮은 함수율에 따라 운송성이 확대되며, 고정탄소 성분의 증가로 인한 높은 에너지밀도로, 석탄과 유사한 특성을 지니게 된다. 따라서 본 연구에서는 국내에서 발생되는 폐바이오매스의 에너지원으로의 적용성 평가를 위해 농산물에서 주로 발생되는 왕겨 및 볏짚을 이용한 반탄화 반응 특성을 분석하였다. 반탄화물은 특정 반응시간에서의 반응 온도에 따라 생성하였으며, 에너지수율 및 질량 수율을 고려한 최적의 반탄화 조건을 모색하였다. 본 실험 결과 왕겨 및 볏짚을 이용한 최적의 탄화물 생산조건은 반응 온도 250~300℃ 및 반응 시간 20~30분 경우로 나타났으나, 각각의 탄화물 수율 및 발열량의 차이가 확연하게 나타났다. 왕겨의 경우 약 73.5%의 탄화물 수율 및 약 4,320.0 kcal/kg의 탄화물 발열량이 분석되었으나, 볏짚의 경우의 탄화물의 수율 및 발열량은 각각 68.2% 및 약 4,547.7 kcal/kg으로 나타났다. 이러한 탄화물 생산 특성의 차이는 바이오매스 원료의 Lignocellulose 특성과 주로 관련된 것으로 예상되고 있으며, 이러한 연구 결과를 통해 폐바이오매스의 석탄발전 설비에서의 혼합 연소 방식으로 적용될 것으로 기대 된다.
폐바이오매스를 이용하여 Bio-SRF로 활용을 위해 제시되고 있는 반탄화(Torrefaction) 기술은 대표적인 신재생에너지 활용 방안으로, 원료의 공급 안정성 및 제한적 처리 방법으로 인해 각광받고 있다. 일찍부터 해외에서는 반탄화 기술을 통해 생성된 탄화물의 높은 적용성을 인지하여 상용규모의 기술 개발이 활성화 되어 있으며, 주로 활용 가능한 폐바이오매스가 많이 발생되는 유럽 및 북미 지역에서 활발하게 수행되고 있다. 반면 국내에서는 기존 폐바이오매스는 매립 위주로 처리되어오고 있으며, 최근에서야 폐바이오매스의 자원 인식 전환을 통해 적극적으로 기술개발사업에 노력을 기울이고 있는 추세이다. 이러한 생산된 반탄화물은 소수성 및 낮은 함수율로 인해 운송 용이성 확대와 더불어 고정탄소 성분의 증가에 따른 높은 에너지 밀도로 석탄발전 설비에서의 혼합 연소를 통한 활용이 기대되고 있다. 반탄화물은 무산소 조건 상에서 200~300℃의 반응 온도 영역에서 열분해 과정 중 폐바이오매스 내 함유된 수분 및 휘발분 제거를 통해 얻을 수 있다. 반면에 국내에서 시행되고 있는 Bio-SRF 기준은 탄화물을 에너지원으로 활용하는 측면에서 엄격하게 다뤄져 적용 가능한 폐바이오매스 종류가 한정적이다. 이러한 배경은 원료로 사용되고 있는 폐바이오매스 종류별 함유하고 있는 염소, 황분 및 회분 함량이 다양하며, 이러한 성분들은 향후 반탄화물이 적용 될 소각 및 가스화 시스템 내부 부식 등에 따른 연속운전 저해 요소로 작용이 가능하기 때문이다. 따라서 본 연구에서는 적용범위가 제한적인 폐바이오매스를 활용하여 Bio-SRF 규격을 충족시키는 반탄화물을 생산하기 위해 다수의 폐바이오매스의 혼합비율에 따른 반탄화물 특성을 검토하였다. 대상 원료로, 폐목재와 고품질 하수슬러지 및 저품질 하수슬러지별 반응 온도 및 반응 시간에 따라 생산된 반탄화물 특성 실험결과를 이용하여 Bio-SRF 기준을 충족시키는 원료의 최적 혼합비율을 도출하였다. 저품질 하수슬러지와 폐목재를 활용할 경우 습윤 기준 하수슬러지 60% 및 폐목재 40% 의 혼합비율이, 고품질 하수슬러지의 경우 습윤기준 하수슬러지 80% 및 폐목재 20%가 최적조건으로 도출되었다. 본 연구를 통해 처리 방법이 제한적인 폐바이오매스를 이용한 반탄화물 생산이 가능할 것으로 기대되며, 향후 폐바이오매스의 대상 범위를 확대를 통해 혼합 폐바이오매스를 이용한 반탄화물 기술 개발에 중요한 가이드라인으로 제시될 것으로 사료된다.
Autophagy is a self-degradative process which accompanies the formation of double-membraned vesicles inside the cell. In the mouse uterus, autophagy is enhanced during steroid hormone deprivation and associated with acute inflammation. There are 17 major Autophagy related genes (Atg). Herein we investigated the role for Atg7 by using uterine cell-specific deletion model of this gene. We crossed Atg7flox/flox (Atg7f/f) mouse and Anti-Mullerian hormone type 2 receptor (Amhr2)-Cre mice (Amhr2-Cre; Atg7f/f). Amhr2 is mainly expressed in stroma and myometrium in the uterus, ovary, and oviduct, during 30 to 60 days. To confirm the region of Cre expression and to monitor whether conditional deletion of Atg7 was by Cre recombinase, we isolated uterine epithelial and stromal cells from 8 and 16 weeks mice by enzymatic digestion and performed RT-PCR. We confirmed that Amhr2-Cre is expressed in stoma and myomotrium, but not in epithelium. Then we examined the uterine histology and embryonic development of day 3 pregnant Amhr2-Cre; Atg7f/f mice. However, there was no specific difference between Atg7f/f (control) and Amhr2-Cre; Atg7f/f mice. To examine the effect of hormone deprivation, we performed western blotting and immunofluorescence staining of p62 (SQSTM1), an indicator of autophagic flux, and LC3B, a marker of autophagic activation, in Amhr2-Cre; Atg7f/f mice ovariectomized (OVX) for 2 weeks. p62 increased dramatically in OVX Amhr2-Cre; Atg7f/f uteri but not in control mice, suggesting that autophagic activation did not occur in the absence of Atg7 in the uterine stroma and that this led to massive accumulation of p62 in this cell type. p62 marks to-be-degraded proteins and target them for autophagic-lysosomal degradation. Thus it is predictable that Atg7-driven uterine autophagy is responsible for degradation of macromolecules during hormone deprivation.
DGCR8 is a RNA-binding protein working with DROSHA to produce pre-microRNA in the nucleus, while DICER does not only mature microRNA but also endogenous siRNAs in the cytoplasm. Here, we have produced Dgcr8 conditional knock-out mice using progesterone receptor (PR)-Cre (Dgcr8flox/flox; PRcre/+ mice, Dgcr8d/d) and demonstrated that canonical microRNAs dependent of DROSHA-DGCR8 complex are required for uterine development as well as female fertility in mice. Adult Dgcr8d/d females did not undergo regular reproductive cycle and produce any pups when housed with fertile males, whereas administration of exogenous gonadotropins induced normal ovulation with corpus luteal formation in these mice. Ovulated oocytes from Dgcr8d/d mice had comparable fertilization potentials and were normally developed to the blastocyst after fertilization as compared to those in control Dgcr8f/f mice. Interestingly, PR-Cre-dependent Dgcr8 deletion showed aberrant infiltration of acute inflammatory immune cells to female reproductive organs only when Dgcr8d/d mice were mated with male mice. With respect to uterine development, gross morphology, histology, and weight of Dgcr8d/d uterus were similar to those of control at 3-week-old age. However, multiple uterine abnormalities were noticeable at 4-week-old age when PR expression is significantly increased, and these deformities became severe onwards. Gland formation and myometrial layers were significantly reduced, and stromal cell compartment did not expand and became atrophic during uterine development in these mice. These results were consistent with aberrantly reduced cell proliferation in stromal cell compartments of Dgcr8d/d mice. Collectively, our results suggest that DGCR8 dependent-canonical microRNAs are essential for development and physiology of the uterus with respect to morphogenesis, proper immune modulation, reproductive cycle, and steroid hormone responsiveness in mice.
Autophagy means “self-eating” and it is a major catabolic pathway within cells. A basal level of autophagy is required for survival of cells or organisms, but prolonged activation of autophagy may have an adverse effect. In mammalian systems, autophagy is stimulated by nutrient starvation or deprivation of growth factors. Ovariectomy on day 4 of pregnancy in mice to deprive blastocysts of estrogen induces “dormancy” in blastocysts and delay the process of implantation until estrogen is given. Dormant blastocysts maintain a state of low metabolism in utero and survive for many days without initiating implantation under the unfavorable condition of estrogen deficiency. We tested the hypothesis if an autophagic response is operative in dormant blastocysts for prolonged survival in utero during the delayed implantation. We observed that autophagy is highly activated in dormant blastocysts. Interestingly, autophagic activation is more prominent in trophectoderm than in inner cell mass. Activation of blastocysts by estrogen supplementation induces formation of multivesicular bodies and exosomes in the trophectoderm. Dormant blastocysts with longer period of autophagic activation show compromised development after implantation. Thus, autophagy may be a critical cellular mechanism to provide energy source during extended survival of dormant blastocysts. However, prolonged activation of autophagy may compromise developmental outcome of blastocysts with irreparable cellular damage.
Purpose – This paper aims to identify and rank factors that influence impulse buying behavior among shoppers in Dubai.
Research design, data, and methodology – Questionnaires were collected from 168 Dubai shoppers using non-probability quota sampling. Factor Analysis was completed to identify factors triggering impulse buying traits.
Results – Six antecedent factors were identified: hedonism, in-store influences, product related influences, socialization, promotional activities, and convenience. Surprisingly, product related influences were the most significant in stimulating impulse buying behavior.
Conclusions – This research suggests that a multitude of factors affect shopper propensity for impulse buying, with non-economic factors like product and in-store related influences having a significant impact. Hence, retail managers should concentrate on these in merchandising and promotional efforts. Against the backdrop of Dubai, one of the biggest retail destinations, this study contributes to present knowledge on impulse buying behavior. In terms of shopper inclinations and likeliness to purchase products, it highlights how shoppers respond to special in-store displays and discount offerings. For marketers, the findings regarding relative significance of various factors may help in strategies to attract consumers.
Enhancing yield has been a major challenge of agriculture. In rice, tiller number is one of the important biomass and yield components. A maize mutant grassy tillers1 (gt1) increases lateral branches in maize. The GT1 gene encodes a class I homeodomain leucine zipper (HD-Zip) protein. In maize, the gt1 expression is induced by shading and is dependent on the activity of teosinte branched1 (tb1), a major domestication locus controlling tillering and lateral branching. To estimate the biological role and agricultural utility of gt1 in rice, rice homologue (OsGT1) has been isolated and its overexpressors and RNAi lines were generated. Field data showed that OsGT1 overexpressors reduced tillers and panicles while RNAi lines increased them, compared to wild type. Shade signal is an important factor in determining lateral branching. To understand the relationship between OsGT1 and shade avoidance, plants have been grown under 50% shading in the field. Also, double genetic combinations with phytochrome mutants (phyA, B, and C) are being examining for tillering phenotype. These ongoing researches will provide insights in determining the action of OsGT1 on branching and shade avoidance in rice.
The wild relatives of soybean [Glycine soja Sieb. and Zucc.] have curly/wavy nature whereas cultivated varieties are upright. Such morphological characteristics have agronomic importance too. To investigate the molecular mechanism of development contributing to coiled morphology, screening was carried out to look for Arabidopsis mutants in activation tagging lines obtained by activation T-DNA treatment that have curly/wavy morphology. A mutant named Coiled Branch 1 (cbr1), is found to have a wavy and curly morphology with coiling branches. Plasmid rescue and genomic southern blot analysis revealed the site of T-DNA insertion in the genome. RT-PCR was performed to monitor expression levels of the genes adjacent to the T-DNA integration sites, and showed the activation of an E3 ubiquitin ligase gene. Database search showed that the gene with the RING domain belongs to a family of E3 ubiquitin ligases. Complementation test by overexpression and RNA interference of the gene was also carried out. The complementation test results showed that the novel gene activation tagging affected the cbr1 mutant phenotypes. Ubiquitylation has been linked virtually to every cellular process including plant development. E3 ubiquitin ligase has been reported to recognize target proteins that are to be ubiquinated for further degradation by the proteasome complex. Further, more detailed studies are needed to identify the specific substrate(s) of the novel E3 ubiquitin ligase gene.
Nitrogen in rice paddy soils and utilized as the major source for N-assimilation in rice crops. In roots, transcriptional activities of ammonium uptake and assimilation genes are highly sensitive to the availability of exogenous ammonium. However, little is known about the transcription factor genes that regulated by ammonium supply and its role to roots and plant developments. To study the transcription factor genes that involved in Ammonium response, two weeks old rice seedlings treated using Ammonium from 0 to 3 hours. Total RNA collected from each sample and samples were prepared for Agilent 8x60K microarray system. Based on the microarray data, we select transcription factor genes that highly affected by ammonium and selected knock out mutant candidates that used for phenotype screening.
고추의 적색소는 고추의 상품성을 가늠하는 중요한 척도이면서 식재료 뿐 아니라 상업적으로도 다양하게 활용되고 있다. 본 연구는 적색소 성분의 함량과 관계하는 QTL 마커를 개발하기 위하여 적색소 성분 분석을 위한 mapping 집단을 육성하였고, 적색소 성분에 대한 QTL mapping을 수행하였다. 적색소 분석을 위한 mapping 집단인 ‘만다린’과 ‘블랙클러스터’를 양친으로 하는 F7 RIL 집단에서의 색도(ASTA value) 분포는 1.64에서 117.26의 범주에 있으며 그 분포 양상은 정규분포를 보여 QTL분석에 적합한 것으로 확인되었다.Mapping 집단의 양친들에 대해서 454 GS-FLX pyrosequencing을 이용한 NGS를 수행하였고, 그 결과 ‘만다린’과 ‘블랙클러스터’각각 120.44Mb와 142.54Mb의 염기서열 데이터를 확보할 수 있었으며, ‘만다린’에서 1,025개, ‘블랙클러스터’에서 1,059개의 SNP들을 확보하게 되었다. 이 SNP들을 HRM 분석에 용이하도록 프라이머를 제작하여 유전자 지도 작성을 수행한 결과 총 246개의 SNP 마커를 이용하여 약 512cM을 설명할 수 있는 21개 연관군의 유전자 지도가 작성되었다. 분석 집단 93계통들에서 측정된 ASTA 값을 이용하여 수행한 QTL 분석 결과 총 6개의 QTL 을 확인하였다. 이들 QTL과 근접한 마커들은 향후 고추의 적색소 함량 연구에 매우 유용한 정보로 활용될 것이며, 아직까지 개발된 바 없는 적색소 함량 연관 마커 개발에 가능성을 열어줄 것으로 기대한다.
Soybean [Glycine max (L.) Merr.] seeds are abundant in high-quality proteins and fats. In addition, soybean seeds are also rich in secondary metabolites, such as isoflavones, lecithin, and saponins. Triterpene saponins are major components of these physiologically active metabolites in soybean seeds. Soybean saponins are classified as group A and DDMP saponins. Among them group A saponins are undesirable component of food products due to bitterness and astringency and also cause foaming in tofu production. Whereas, DDMP saponins and their derivatives are less bitter and astringent and beneficial to human health when consumed as regular diet. Therefore, reducing the group A saponins or increasing the DDMP saponins are required to improve the food quality. The present study focused to identify and characterize the gene which is encoding a protein responsible for biosynthesis of DDMP saponins. EMS mutant lines (sg-7-1 & sg-7-2) which lack DDMP saponins were developed. The breeding cross has been made with these two mutants with two cultivars, Pungsannamul and Wooram to study the segregation and genetic linkage analysis, respectively. The segregation analysis showed that the mutant phenotype is controlled by single recessive gene. TLC analysis for phenotyping F2 population of Wooram X sg-7-1 showed mutant, wild and heterozygous types. To surprise two more patterns were detected and they were named as strange type1 (ST1) and strange type2 (ST2). Further, SSR marker analysis will be carried out to locate the gene which encoding a protein responsible for biosynthesis of DDMP saponins.
Soybean germplasm have diverse accessions with great variation in their ability to survive and reproduce under salt stress conditions. In general, cultivated soybeans are more sensitive to salt stress than their wild relatives, however exceptions are found in both the groups. These variations in response to salt stress makes soybean germplasm an interesting collection of genetic resources to be explored for the identification of salt-tolerance genes, and their mechanism of action. Here, in this report we presented a data showing differential response of selected accessions of both cultivated and wild soybeans to salt stress. Two modes of salt treatment; gradual salt stress (GS) as well as salt shock (SS) were used in this study. The GS was found more effective in finding the difference in response of soybean accessions to salt stress. Various genetic marker based methods are in use to identify and isolate the potential genes contributing to the salt tolerance in soybean. Even then there is a paucity of knowledge on the key genes contributing to the salt tolerance in soybean. We expect that a recently developed functional screen based method, like yeast based functional screen, using cDNA library generated from different salt tolerant accessions of soybean could lead to identification of novel genes responsible for salt tolerance in soybean. Also, we propose for the use of RNA isolated from different stages of GS and SS for making cDNA library to be used for functional screening.
Soybean [Glycine max (L.) Merr.] have a variety of flower colors which are controlled by six different genes (W1,W2,W3,W4,Wm, and Wp). Among these genes, mutation in W3 gene causes near white flowers in the background of w4 genotype whereas the genotype W3w4 does purple throat flowers. Earlier studies showed that dihydroflavonol 4-reductase1 (DFR1) gene was closely linked to the flower color variants for W3 locus. In order to find out the W3 gene responsible for w3 phenotype, we first, studied the candidate gene Glyma14g07940 (DFR1) which is having 100% similarity with DFR probe sequence. Sequence analysis of DFR1 between W3 and w3 soybeans showed one base substitution in exon 6 of w3 mutant soybean resulting in one amino acid change in the amino acid sequence. However, comparison of amino acid sequences of DFR proteins from various crop plants showed that there is no functional change in the protein. Besides, the promoter analysis showed that, 311 bp of indel was traced in 5’-upstream promoter region of DFR1 gene in the w3 mutant. Here, we show that the near white or purple throat phenotypes in G. max is associated with existence or nonexistence of indel at 5’- upstream promoter region and low or high expression of DFR1, respectively. These results suggest that w3 phenotype may be caused by certain regulator of DFR1 gene located near or distant from DFR1 in G. max. In further study, we need to check the correlation between promoter indel with W3 expression level through GUS analysis.
Grain color distinguishes between the pigmentation of the outer layer of the kernel. It is known that environmental factors affects the production of anthocyanins and abiotic stresses like high light intensity, low temperature, high salinity and/or drought stress, and others increase their amounts. After 7 days the germination rate between yellow and dark-purple seeds were almost the same with and without stress (100% yellow seeds under stress and without stress germinated, 93.3% under stress and 96.6% without stress of purple seeds germinated), even though at the final stage the germination was almost the same, we can conclude base on our observations that the germination takes place at a different rate. We think that this might be related to the seed color, since the germination of purple seeds under salt stress started earlier than the yellow ones, until both reached the same point. The antioxidant activity was higher in seedlings from dark-purple seeds than the yellow ones, and they were higher under salt stress than without it, supporting our hypothesis that the purple color in wheat seeds works as a protection under salt stress. Furthermore, the qRT-pCR showed that some genes related to the flavonoid pathway were expressed or had more expression in the seedlings from dark-purple seeds than yellow ones.
Capsinoids, low-pungent compounds, have the same biological effects as capsaicinoids such as anticancer and anti-obesity. A precursor of capsinoids, vanillyl alcohol, is known to be produced by mutations in the putative-aminotransferase (pAMT) gene. In the previous study, ‘SNU11-001’ (Capsicum chinense) containing high levels of capsinoids was identified in germplasm collections of Capsicum. This collection has a unique mutation in the pAMT gene that can cause dysfunction of this gene. In order to develop pepper varieties containing high capsinoids contents, marker-assisted foreground and background selections were performed during backcross breeding. Compared to the conventional backcrossing, marker-assisted backcrossing (MABC) is extremely useful for recovery of a recurrent parent’s genetic background. For foreground selection, plants carrying the pAMT/pamt genotype were selected from a BC1F1 and BC2F1 populations using SCAR markers derived from the unique pAMT mutation of ‘SNU11-001’. To obtain background selection markers, a total of 412 single nucleotide polymorphism (SNP) markers was screened on ‘Shinghong’ parental lines and ‘SNU11-001’ to obtain polymorphic SNP markers. Of the 412 SNP markers, 144 and 204 polymorphic SNP markers evenly distributed in pepper genome were finally selected. BC1F1 and BC2F1 plants carrying the pAMT/pamt genotype were subjected to background selection using the selected marker sets. Multiple genotype analysis was done using a high-throughput genotyping system (EP1TM, Fluidigm®, USA). As a result, one BC1F1 plant 84% similar to the recurrent parent and several BC2F1 plants more than 96% recovery rate of the recurrent parent were selected. Genetic backgrounds of the selected BC2F1 plants were evaluated by the genotype-by-sequencing (GBS) method in order to confirm the background selection results using the SNP marker set. GBS results showed that recovery rate and positions of introgressed segments were well matched between two methods demonstrating MABC can be successfully done with a couple hundred SNP markers.
Establisment of rice library is an essential approach for rice functional genomics study. Utilizaing maize transposable element Ac/Ds is a promising method to construct insertional mutagenesis library of rice. Ac/Ds tagging system has received extensive application in rice during the past several years. The maize Ds element is one of the main tagging vehicles used in rice. Narrow leaf mutant have short height, narrow leaf width and large angle. To compare with wild type and narrow leaf mutant in detail, we observed the leaves under microscope. In specific portion(large and small vein), no significantly reduce cell size and number of cell. Knock-out of the OsNLR(narrow leaf ribokinase) gene inhibits internodes, panicles, angle(between leaf and stem), leaf, seed. OsNLR was shown to specifically expressed on leaf. In real time PCR analysis with mature leaf of wild type and mutant, there might be a functional association between OsAGO7, NRL1, NAL1 and NAL7 in regulating leaf development. We tested on the experimental field using wild type and mutant plants. In agricutural traits that contain leaf and seed related traits(except angle) significantly reduce in mutant plants. These results demonstrate that OsNLR gene may be associated with leaf development.
We used an efficient system to create rice mutant by Ac/Ds transposon insertion mutagenesis, such as selected homozygous mutant in dwarf phenotypes. We reported here the identification of function of dwarf OsGASD gene(Oryza sativa Gibberellin Acid Sensitive Dwarf). OsGASD gene encodes a 344 amino acid polypeptide and no homology proteins in Gene Bank. The osgasd mutnat was sensitive to exogenous gibberellic acid(GA) level. We performed experiment to controlled expression the OsGASD gene, its role in plant development, a quantitative analysis of endogenous GA content and sensitivity to GA. The osgasd mutant includes smaller amount of active GAs than wild-type. osgasd mutant plant of GA biosynthesis pathway causes GA deficiency and dwarf plants, and endogenous GA suppliance can restore the wild type phenotype in this mutant. There result indicated that OsGASD gene regulated the elongation of shoot, stem and plant height. The increased expression of OsGASD gene dramatically induces expression of the factors associated with GA biosynthesis, whereas osgasd mutant suppression of the factors associated with GA biosynthesis, loading to dwarf phenotypes. That applied GA3 at the plant development stage to survey the response of OsGASD gene to GA3. We suggest that OsGASD gene is related to factors of GA biosynthesis pathway regulating rice internodes development.
R2R3 MYB transcription factors play regulatory roles in plant responses to various environmental stresses and nutrient deficiency. In this study, we isolated MYB-like gene respond to phosphorus deprivation in rice and designated OsMYB4P, an R2R3 MYB transcription factor, from rice under low-phosphate conditions. OsMYB4P is 993bp long and encodes a 330 amino acid polypeptide. OsMYB4P was localized in the nucleus and acted as a transcriptional activator. Transcriptional levels of OsMYB4P in cell suspension, shoots, and roots of rice increased under low phosphate conditions. Shoots and roots of OsMYB4P overexpressing plants grew well in high and low phosphate conditions. In addition, root system architecture was altered considerably as a result of OsMYB4P overexpression. Under both phosphate sufficient and deficient conditions, more Pi accumulated in shoots and roots of OsMYB4P overexpressing plants than in the wild type. Overexpression of OsMYB4P led to greater expression of Pi transporter-family proteins OsPT1, OsPT2, OsPT4, OsPT7, and OsPT8 in shoots, and to decreased or unchanged expression of these proteins in roots, with the exception of OsPT8. These results demonstrate that OsMYB4P may be associated with efficient utilization of Pi in rice.
The ubiquitin-26S proteasome system is important in the quality control of intracellular proteins. The ubiquitin-26S proteasome system includes the E1 (ubiquitin activating), E2 (ubiquitin conjugating) and E3 (ubiquitin ligase) enzymes. U-box proteins are a derived version of RING-finger domains, which have E3 enzyme activity. Here, we present the isolation of a novel U-box protein, OsUPS, from rice (Oryza sativa).The cDNA encoding the O.sativa U-box protein(OsUPS) comprises 1338bp, with an open reading frame of 445 amino acids. The open reading frame of the OsUPS protein is comprised of notable domains: a single ~70-amino acid domain and a GKL domain that contains conserved glycine, lysine/ arginine residues and leucine-rich feature. We found that full-length expression of OsUPS was up-regulated in both rice plants and cell culture in the absence of inorganic phosphate (Pi). A self-ubiquitination assay indicated that the bacterially expressed OsUPS protein had E3 ligase activity, and subcellular localization results showed that OsUPS was located in the chloroplast. Suppression of OsUPS resulted in servre signs of toxicity caused by the over-accumulation of Pi. These results support the notion that OsUPS plays an important role in the Pi signaling pathway through the ubiquitin-26S proteasome system.