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Wrinkled 1 (WRI1) Homologs, AP2-Type Transcription Factors Involving Master Regulation of Seed Storage Oil Synthesis in Castor Bean (Ricinus communisL.)  [PDF]
Daichi Tajima, Ayami Kaneko, Masatsugu Sakamoto, Yumena Ito, Nong Thi Hue, Masayuki Miyazaki, Yushi Ishibashi, Takashi Yuasa, Mari Iwaya-Inoue
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.42044
Abstract: Among APETALA2 (AP2)-type plant specific transcription factor family, WRINKLED1 (WRI1), has appeared to be a master gene transcriptionally regulating a set of carbon metabolism- and fatty acid synthesis (FAS)-related genes responsible for seed specific triacylglycerols (TAGs) storage in oil plants. B3 type transcription factors, such as ABI3 and FUS3, are known to be involved in seed development, such as seed storage protein synthesis and maturation. Based on the recent whole genome sequence data of castor bean (Ricinus communis L.), putative WRI1 homologs (RcWRI1, RcWRI2) specifically expressed in castor bean seed have been identified by comparing organ specific expression profiles among seed development-related transcription factors, seed storage specific genes (Ricin, RcOleosin) and a set of FAS genes including genes for sucrose synthase (RcSUS2), biotin carboxyl carrier protein (a subunit of acetyl-CoA carboxylase, RcBCCP2) and ketoacyl-acyl carrier protein synthase (RcKAS1). Immunoreactive signals with WRI1, FUS3 and ABI5-related polypeptides were also detected in seed specifically, consistent with the expression profiles of seed development-related genes. The WRI1 binding consensus sites, [CnTnG](n)(7)[CG], designated as the AW-box, were found at the promoter region of RcBCCP2 and RcKAS1. Thus, RcWRI1 possibly play a pivotal role in seed specific TAGs storage during seed development by directly activating FAS -related genes.
WRINKLED1, A Ubiquitous Regulator in Oil Accumulating Tissues from Arabidopsis Embryos to Oil Palm Mesocarp  [PDF]
Wei Ma, Que Kong, Vincent Arondel, Aruna Kilaru, Philip D. Bates, Nicholas A. Thrower, Christoph Benning, John B. Ohlrogge
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068887
Abstract: WRINKLED1 (AtWRI1) is a key transcription factor in the regulation of plant oil synthesis in seed and non-seed tissues. The structural features of WRI1 important for its function are not well understood. Comparison of WRI1 orthologs across many diverse plant species revealed a conserved 9 bp exon encoding the amino acids “VYL”. Site-directed mutagenesis of amino acids within the ‘VYL’ exon of AtWRI1 failed to restore the full oil content of wri1-1 seeds, providing direct evidence for an essential role of this small exon in AtWRI1 function. Arabidopsis WRI1 is predicted to have three alternative splice forms. To understand expression of these splice forms we performed RNASeq of Arabidopsis developing seeds and queried other EST and RNASeq databases from several tissues and plant species. In all cases, only one splice form was detected and VYL was observed in transcripts of all WRI1 orthologs investigated. We also characterized a phylogenetically distant WRI1 ortholog (EgWRI1) as an example of a non-seed isoform that is highly expressed in the mesocarp tissue of oil palm. The C-terminal region of EgWRI1 is over 90 amino acids shorter than AtWRI1 and has surprisingly low sequence conservation. Nevertheless, the EgWRI1 protein can restore multiple phenotypes of the Arabidopsis wri1-1 loss-of-function mutant, including reduced seed oil, the “wrinkled” seed coat, reduced seed germination, and impaired seedling establishment. Taken together, this study provides an example of combining phylogenetic analysis with mutagenesis, deep-sequencing technology and computational analysis to examine key elements of the structure and function of the WRI1 plant transcription factor.
Wrinkled Embeddings  [PDF]
Yakov M. Eliashberg,Nikolai M. Mishachev
Mathematics , 2011,
Abstract: A {\it wrinkled embedding} $f:V^n\to W^m$ is a topological embedding which is a smooth embedding everywhere on $V$ except a set of $(n-1)$-dimensional spheres, where $f$ has cuspidal corners. In this paper we prove that any rotation of the tangent plane field $TV\subset TW$ of a {\it smoothly embedded} submanifold $V\subset W$ can be approximated by a homotopy of {\it wrinkled embeddings} $V\to W$.
甘蓝型油菜WRI1基因cDNA的克隆与序列分析  [PDF]
施春霖,刘聪,肖旦望,陈社员,官春云,熊兴华
湖南农业大学学报(自然科学版) , 2013,
Abstract: 通过RT–PCR方法克隆了甘蓝型油菜湘油15号5个WRI1基因cDNA。测序结果显示,BnWRI1–1大小为1 248 bp,BnWRI1–2和BnWRI1–3大小为1 254 bp,BnWRI1–4、BnWRI1–5大小为1 242 bp;聚类分析结果显示,所克隆WRI1基因cDNA在进化关系上属于AP2/ERF转录因子家族,同拟南芥AtWRI1(At3G54320)同处1个分支,并且所克隆基因cDNA来自甘蓝型油菜不同的基因组;通过核苷酸序列比对分析,得到所克隆WRI1基因cDNA单核苷酸变异位点40个;特异性酶切位点分析显示,来源于A基因组的BnWRI1–1、BnWRI1–2、BnWRI1–3第892位与来源于C基因组的BnWRI1–4和 BnWRI1–5第880位的核苷酸发生变异,导致Bcl I识别位点的变化;酶切试验结果表明,采用BclI酶可区分甘蓝型油菜的AtWRI1–like WRI1 基因的A或C 基因组来源。
The deformation of wrinkled graphene  [PDF]
Zheling Li,Ian A. Kinloch,Robert J. Young,Kostya S. Novoselov,George Anagnostopoulos,John Parthenios,Costas Galiotis,Konstantinos Papagelis,Ching-Yu Lu,Liam Britnell
Physics , 2015, DOI: 10.1021/nn507202c
Abstract: The deformation of monolayer graphene, produced by chemical vapor deposition (CVD), on a polyester film substrate has been investigated through the use of Raman spectroscopy. It has been found that the microstructure of the CVD graphene consists of a hexagonal array of islands of flat monolayer graphene separated by wrinkled material. During deformation, it was found that the rate of shift of the Raman 2D band wavenumber per unit strain was less than 25% of that of flat flakes of mechanically-exfoliated graphene, whereas the rate of band broadening per unit strain was about 75% of that of the exfoliated material. This unusual deformation behavior has been modeled in terms of mechanically-isolated graphene islands separated by the graphene wrinkles, with the strain distribution in each graphene island determined using shear lag analysis. The effect of the size and position of the Raman laser beam spot has also been incorporated in the model. The predictions fit well with the behavior observed experimentally for the Raman band shifts and broadening of the wrinkled CVD graphene. The effect of wrinkles upon the efficiency of graphene to reinforce nanocomposites is also discussed.
Ballistic electron transport in wrinkled superlattices  [PDF]
T. L. Mitran,G. A. Nemnes,L. Ion,Daniela Dragoman
Physics , 2015,
Abstract: Inspired by the problem of elastic wave scattering on wrinkled interfaces, we studied the scattering of ballistic electrons on a wrinkled potential energy region. The electron transmission coefficient depends on both wrinkle amplitude and periodicity, having different behaviors for positive and negative scattering potential energies. For scattering on potential barriers, minibands appear in electron transmission, as in superlattices, whereas for scattering on periodic potential wells the transmission coefficient has a more complex form. Besides suggesting that tuning of electron transmission is possible by modifying the scattering potential via voltages on wrinkled gate electrodes, our results emphasize the analogies between ballistic electrons and elastic waves even in scattering problems on non-typical configurations.
Differential growth of wrinkled biofilms  [PDF]
D. R. Espeso,A. Carpio,B. Einarsson
Physics , 2015, DOI: 10.1103/PhysRevE.91.022710
Abstract: Biofilms are antibiotic-resistant bacterial aggregates that grow on moist surfaces and can trigger hospital-acquired infections. They provide a classical example in biology where the dynamics of cellular communities may be observed and studied. Gene expression regulates cell division and differentiation, which affect the biofilm architecture. Mechanical and chemical processes shape the resulting structure. We gain insight into the interplay between cellular and mechanical processes during biofilm development on air-agar interfaces by means of a hybrid model. Cellular behavior is governed by stochastic rules informed by a cascade of concentration fields for nutrients, waste and autoinducers. Cellular differentiation and death alter the structure and the mechanical properties of the biofilm, which is deformed according to Foppl-Von Karman equations informed by cellular processes and the interaction with the substratum. Stiffness gradients due to growth and swelling produce wrinkle branching. We are able to reproduce wrinkled structures often formed by biofilms on air-agar interfaces, as well as spatial distributions of differentiated cells commonly observed with B. subtilis.
Mutations in an AP2 Transcription Factor-Like Gene Affect Internode Length and Leaf Shape in Maize  [PDF]
Fukun Jiang, Mei Guo, Fang Yang, Keith Duncan, David Jackson, Antoni Rafalski, Shoucai Wang, Bailin Li
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0037040
Abstract: Background Plant height is an important agronomic trait that affects yield and tolerance to certain abiotic stresses. Understanding the genetic control of plant height is important for elucidating the regulation of maize development and has practical implications for trait improvement in plant breeding. Methodology/Principal Findings In this study, two independent, semi-dwarf maize EMS mutants, referred to as dwarf & irregular leaf (dil1), were isolated and confirmed to be allelic. In comparison to wild type plants, the mutant plants have shorter internodes, shorter, wider and wrinkled leaves, as well as smaller leaf angles. Cytological analysis indicated that the leaf epidermal cells and internode parenchyma cells are irregular in shape and are arranged in a more random fashion, and the mutants have disrupted leaf epidermal patterning. In addition, parenchyma cells in the dil1 mutants are significantly smaller than those in wild-type plants. The dil1 mutation was mapped on the long arm of chromosome 6 and a candidate gene, annotated as an AP2 transcription factor-like, was identified through positional cloning. Point mutations near exon-intron junctions were identified in both dil1 alleles, resulting in mis-spliced variants. Conclusion An AP2 transcription factor-like gene involved in stalk and leaf development in maize has been identified. Mutations near exon-intron junctions of the AP2 gene give mis-spliced transcript variants, which result in shorter internodes and wrinkled leaves.
Critical Thickness Ratio for Buckled and Wrinkled Fruits and Vegetables  [PDF]
Hui-Hui Dai,Yang Liu
Physics , 2013, DOI: 10.1209/0295-5075/108/44003
Abstract: Fruits and vegetables are usually composed of exocarp and sarcocarp and they take a variety of shapes when they are ripe. Buckled and wrinkled fruits and vegetables are often observed. This work aims at establishing the geometrical constraint for buckled and wrinkled shapes based on a mechanical model. The mismatch of expansion rate between the exocarp and sarcocarp can produce a compressive stress on the exocarp. We model a fruit/vegetable with exocarp and sarcocarp as a hyperelastic layer-substrate structure subjected to uniaxial compression. The derived bifurcation condition contains both geometrical and material constants. However, a careful analysis on this condition leads to the finding of a critical thickness ratio which separates the buckling and wrinkling modes, and remarkably, which is independent of the material stiffnesses. More specifically, it is found that if the thickness ratio is smaller than this critical value a fruit/vegetable should be in a buckling mode (under a sufficient stress); if a fruit/vegetable in a wrinkled shape the thickness ratio is always larger than this critical value. To verify the theoretical prediction, we consider four types of buckled fruits/vegetables and four types of wrinkled fruits/vegetables with three samples in each type. The geometrical parameters for the 24 samples are measured and it is found that indeed all the data fall into the theoretically predicted buckling or wrinkling domains. Some practical applications based on this critical thickness ratio are briefly discussed.
Plant AP2/ERF transcription factors  [PDF]
Saleh Abdelaty,Pagés Montserrat
Genetika , 2003, DOI: 10.2298/gensr0301037s
Abstract: Transcription factors (TFs) play important roles in plant development and its response to the biotic and abiotic stresses. AP2/ERF transcription factors family is unique to plants and a conserved AP2/ERF domain of about 60 amino acids characterized these transcription factors. AP2/ERF genes have been shown to regulate developmental processes and the response of plants to various types of biotic and environmental stress. Here, we summarize the current knowledge of AP2/ERF plant transcription factor family.
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