scholarly journals Acacia (wattle) and Cananga (ylang-ylang): from spiral to whorled and irregular (chaotic) phyllotactic patterns – a pictorial report

2016 ◽  
Vol 85 (4) ◽  
Author(s):  
Rolf Rutishauser
Keyword(s):  
Vascular Plants ◽  
Explanatory Models ◽  
Geometrical Parameters ◽  
Wild Type ◽  
Flower Buds ◽  
Developmental Models ◽  
Stamen Primordia ◽  
Biophysical Processes ◽  
Geometrical Constraints ◽  
Cananga Odorata

Phyllotaxis, i.e., the arrangement of leaves around the stem and leaf-like organs inside flowers is regular in most vascular plants. Thus, developmental models usually explain regular phyllotactic patterns such as Fibonacci spirals and decussate/whorled patterns that obey Hofmeister’s rule: primordia form as far away as possible from previously initiated primordia. However, flowering plants showing at first Fibonacci spirals or whorled phyllotaxes may switch to other patterns that lack an obvious order and thus may be called irregular or even chaotic. Vegetative shoot tips of various Australian wattles (<em>Acacia</em> spp., Leguminosae in eudicots) and flower buds of ylang-ylang (<em>Cananga odorata</em>) and other Annonaceae (basal angiosperms) provide examples of irregular patterning. This pictorial report provides food for thought for scientists interested in phyllotaxis patterns beyond the usual spiral and whorled patterns. Emphasis is given on irregular phyllotaxes that occur in wild-type plants, mainly correlated with geometrical parameters such as leaf and stamen primordia that are very small as compared to the size of their apical meristems. They call for additional explanatory models, combining auxin-driven development with geometrical constraints and biophysical processes.

scholarly journals Comparative Proteomic Analysis of Wild-Type Physcomitrella patens and an OPDA-Deficient Physcomitrella patens Mutant with Disrupted PpAOS1 and PpAOS2 Genes after Wounding

2020 ◽  
Author(s):  
Weifeng Luo ◽  
Setsuko Komatsu ◽  
Tatsuya Abe ◽  
Hideyuki Matsuura ◽  
Kosaku Talahashi
Keyword(s):  
Protein Synthesis ◽  
Proteomic Analysis ◽  
Vascular Plants ◽  
Acid Metabolism ◽  
Physcomitrella Patens ◽  
Energy Utilization ◽  
Wild Type Plant ◽  
Wild Type ◽  
In The Wild ◽  
Energy Synthesis

Wounding is a serious environmental stress in plants. Oxylipins such as jasmonic acid play an important role in defense against wounding. Mechanisms to adapt to wounding have been investigated in vascular plants; however, those mechanisms in nonvascular plants remain elusive. To examine the response to wounding in Physcomitrella patens, a model moss, a proteomic analysis of wounded P. patens was conducted. Proteomic analysis showed that wounding increased the abundance of proteins related to protein synthesis, amino acid metabolism, protein folding, photosystem, glycolysis, and energy synthesis. 12-Oxo-phytodienoic acid (OPDA) was induced by wounding and inhibited growth. Therefore, OPDA is considered a signaling molecule in this plant. Proteomic analysis of a P. patens mutant in which the PpAOS1 and PpAOS2 genes, which are involved in OPDA biosynthesis, are disrupted showed accumulation of proteins involved in protein synthesis in response to wounding in a similar way to the wild-type plant. In contrast, the fold-changes of the proteins in the wild-type plant were significantly different from those in the aos mutant. This study suggests that PpAOS gene expression enhances photosynthesis and effective energy utilization in response to wounding in P. patens.

scholarly journals A Comparison of sun, ovate, fs8.1 and Auxin Application on Tomato Fruit Shape and Gene Expression

2019 ◽  
Vol 60 (5) ◽  
pp. 1067-1081 ◽  
Author(s):  
Yanping Wang ◽  
Josh P Clevenger ◽  
Eudald Illa-Berenguer ◽  
Tea Meulia ◽  
Esther van der Knaap ◽  
...  
Keyword(s):  
Tomato Fruit ◽  
Cell Number ◽  
Fruit Shape ◽  
Biological Processes ◽  
Near Isogenic Lines ◽  
Wild Type ◽  
Flower Buds ◽  
Cytoskeleton Organization ◽  
Actin Cytoskeleton Organization ◽  
Shape Changes

Abstract Elongated tomato fruit shape is the result of the action of the fruit shape genes possibly in coordination with the phytohormone auxin. To investigate the possible link between auxin and the fruit shape genes, a series of auxin (2,4-D) treatments were performed on the wild-type and the fruit shape near-isogenic lines (NILs) in Solanum pimpinellifolium accession LA1589 background. Morphological and histological analyses indicated that auxin application approximately 3 weeks before anthesis led to elongated pear-shaped ovaries and fruits, which was mainly attributed to the increase of ovary/fruit proximal end caused by the increase of both cell number and cell size. Fruit shape changes caused by SUN, OVATE and fs8.1 were primarily due to the alterations of cell number along different growth axes. Particularly, SUN caused elongation by extending cell number along the entire proximal-distal axis, whereas OVATE caused fruit elongation in the proximal area, which was most similar to the effect of auxin on ovary shape. Expression analysis of flower buds at different stages in fruit shape NILs indicated that SUN had a stronger impact on the transcriptome than OVATE and fs8.1. The sun NIL differentially expressed genes were enriched in several biological processes, such as lipid metabolism, ion transmembrane and actin cytoskeleton organization. Additionally, SUN also shifted the expression of the auxin-related genes, including those involved in auxin biosynthesis, homeostasis, signal transduction and polar transport, indicating that SUN may regulate ovary/fruit shape through modifying the expression of auxin-related genes very early during the formation of the ovary in the developing flower.

scholarly journals Coronavirus Spike Glycoprotein, Extended at the Carboxy Terminus with Green Fluorescent Protein, Is Assembly Competent

2004 ◽  
Vol 78 (14) ◽  
pp. 7369-7378 ◽  
Author(s):  
Berend Jan Bosch ◽  
Cornelis A. M. de Haan ◽  
Peter J. M. Rottier
Keyword(s):  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Chimeric Protein ◽  
Viral Envelope ◽  
Wild Type ◽  
Virus Propagation ◽  
S Protein ◽  
Protein Functions ◽  
Geometrical Constraints ◽  
Green Fluorescent

ABSTRACT Due to the limited ultrastructural information about the coronavirion, little is known about the interactions acting at the interface between nucleocapsid and viral envelope. Knowing that subtle mutations in the carboxy-terminal endodomain of the M protein are already lethal, we have now probed the equivalent domain of the spike (S) protein by extending it terminally with a foreign sequence of 27 kDa: the green fluorescent protein (GFP). When expressed individually in murine cells, the S-GFP chimeric protein induced the formation of fluorescent syncytia, indicating that it was synthesized and folded properly, trimerized, and transported to the plasma membrane, where it exhibited the two key S protein functions, i.e., interaction with virus receptor molecules and membrane fusion. Incorporation into virus-like particles demonstrated the assembly competence of the chimeric spike protein. The wild-type S gene of mouse hepatitis coronavirus (MHV) was subsequently replaced by the chimeric construct through targeted recombination. A viable MHV-SGFP was obtained, infection by which could be visualized by the fluorescence induced. The efficiency of incorporation of the chimeric protein into particles was, however, reduced relative to that in wild-type particles which may explain, at least in part, the reduced infectivity produced by MHV-SGFP infection. We conclude that the incorporation of spikes carrying the large GFP moiety is apparently impaired by geometrical constraints and selected against during the assembly of virions. Probably due to this disadvantage, deletion mutants, having lost the foreign sequences, rapidly evolved and outcompeted the chimeric viruses during virus propagation. The fluorescent MHV-SGFP will now be a convenient tool to study coronaviral cell entry.

Vein density is independent of epidermal cell size in Arabidopsis mutants

2017 ◽  
Vol 44 (4) ◽  
pp. 410 ◽  
Author(s):  
Madeline R. Carins Murphy ◽  
Graham J. Dow ◽  
Gregory J. Jordan ◽  
Timothy J. Brodribb
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Size ◽  
Epidermal Cell ◽  
Cell Expansion ◽  
Vascular Plants ◽  
Cost Ratio ◽  
Wild Type ◽  
Vein Density ◽  
Leaf Tissues ◽  
Epidermal Cell Size

Densities of leaf minor veins and stomata are co-ordinated within and across vascular plants. This maximises the benefit-to-cost ratio of leaf construction by ensuring stomata receive the minimum amount of water required to maintain optimal aperture. A ‘passive dilution’ mechanism in which densities of veins and stomata are co-regulated by epidermal cell size is thought to facilitate this co-ordination. However, unlike stomata, veins are spatially isolated from the epidermis and thus may not be directly regulated by epidermal cell expansion. Here, we use mutant genotypes of Arabidopsis thaliana (L.) Heynh. with altered stomatal and epidermal cell development to test this mechanism. To do this we compared observed relationships between vein density and epidermal cell size with modelled relationships that assume veins and stomata are passively diluted by epidermal cell expansion. Data from wild-type plants were consistent with the ‘passive dilution’ mechanism, but in mutant genotypes vein density was independent of epidermal cell size. Hence, vein density is not causally linked to epidermal cell expansion. This suggests that adaptation favours synchronised changes to the cell size of different leaf tissues to coordinate veins and stomata, and thus balance water supply with transpirational demand.

scholarly journals Ascorbate deficiency does not limit non-photochemical quenching in Chlamydomonas reinhardtii

2019 ◽  
Author(s):  
André Vidal-Meireles ◽  
Dávid Tóth ◽  
László Kovács ◽  
Juliane Neupert ◽  
Szilvia Z. Tóth
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Vascular Plants ◽  
Regulation Of Gene Expression ◽  
Growth Conditions ◽  
Photochemical Quenching ◽  
Wild Type ◽  
Knockout Mutant ◽  
Dependent Component ◽  
Non Photochemical Quenching ◽  
Energy Dependent

SummaryAscorbate (vitamin C) plays essential roles in development, signaling, hormone biosynthesis, regulation of gene expression, stress resistance and photoprotection. In vascular plants, violaxanthin de-epoxidase (VDE) requires ascorbate (Asc) as reductant, thereby it is required for the energy-dependent component of non-photochemical quenching (NPQ). In order to assess the role of Asc in NPQ in green algae, which are known to contain low amounts of Asc, we searched for an insertional Chlamydomonas reinhardtii mutant affected in the VTC2 gene, essential for Asc biosynthesis. The Crvtc2-1 knockout mutant was viable and, depending on the growth conditions, it contained 10 to 20% Asc relative to its wild type. When Chlamydomonas was grown photomixotrophically at moderate light, the zeaxanthin-dependent component of NPQ emerged upon strong red illumination both in the Crvtc2-1 mutant and in its wild type. Deepoxidation was unaffected by Asc deficiency, demonstrating that the Chlorophycean VDE found in Chlamydomonas does not require Asc as a reductant. The rapidly induced, energy-dependent NPQ component, characteristic of photoautotrophic Chlamydomonas cultures grown at high light, was not limited by Asc deficiency either. On the other hand, a reactive oxygen species-induced photoinhibitory NPQ component was greatly enhanced upon Asc deficiency, both under photomixotrophic and photoautotrophic conditions. These results demonstrate that Asc has distinct roles in NPQ formation in Chlamydomonas than in vascular plants.One-sentence summaryIn Chlamydomonas -in contrast to seed plants-, ascorbate is not required for violaxanthin deepoxidation and energy-dependent non-photochemical quenching but it mitigates photoinhibitory quenching.

Application of a CFD-Based Program for the Optimization of a Centrifugal Impeller

2003 ◽  
Author(s):  
Simone Pazzi ◽  
Francesco Martelli ◽  
Marco Giachi ◽  
Michela Testa
Keyword(s):  
New Technologies ◽  
Leading Edge ◽  
Computational Effort ◽  
Flow Coefficient ◽  
Low Flow ◽  
Centrifugal Impeller ◽  
Geometrical Parameters ◽  
Design Point ◽  
Blade Thickness ◽  
Geometrical Constraints

A typical centrifugal impeller characterized by a low flow coefficient and cylindrical blades is redesigned by means of an intelligent automatic search program. The procedure consists of a Feasible Sequential Quadratic Programming (FSQP) algorithm [6] coupled to a Lazy Learning (LL) interpolator [1] to speed-up the process. The program is able to handle geometrical constraints to reduce the computational effort devoted to the analysis of non-physical configurations. The objective function evaluator is an in-house developed structured CFD code. The LL approximator is called each time the stored database can provide a sufficiently accurate performance estimate for a given geometry, thus reducing the effective CFD computations. The impeller is represented by 25 geometrical parameters describing the vane in the meridional and s-θ planes, the blade thickness and the leading edge shape. The optimisation is carried out on the impeller design point maximizing the polytropic efficiency with more or less constant flow coefficient and polytropic head. The optimization is accomplished keeping unaltered those geometrical parameters which have to be kept fixed in order to make the impeller fit the original stage. The optimisation, carried out on a cluster of sixteen PCs, is self-learning and leads to a geometry presenting an increased design point efficiency. The program is completely general and can be applied to any component which can be described by a finite number of geometrical parameters and computed by any numerical instrument to provide performance indices. The work presented in this paper has been developed inside the METHOD EC funded project for the implementation of new technologies for optimisation of centrifugal compressors.

Unknown geometrical constraints estimation and trajectory planning for robotic door-opening task with visual teleoperation assists

2019 ◽  
Vol 39 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Hongjun Xing ◽  
Kerui Xia ◽  
Liang Ding ◽  
Haibo Gao ◽  
Guangjun Liu ◽  
...  
Keyword(s):  
Trajectory Planning ◽  
Coordinate Transformation ◽  
Geometrical Parameters ◽  
Mobile Manipulators ◽  
Rescue Operation ◽  
End Effector ◽  
Content Type ◽  
Physical Constraints ◽  
Door Opening ◽  
Geometrical Constraints

Purpose The purpose of this paper is to enable autonomous door-opening with unknown geometrical constraints. Door-opening is a common action needed for mobile manipulators to perform rescue operation. However, it remains difficult for them to handle it in real rescue environments. The major difficulties of rescue manipulation involve contradiction between unknown geometrical constraints and limited sensors because of extreme physical constraints. Design/methodology/approach A method for estimating the unknown door geometrical parameters using coordinate transformation of the end-effector with visual teleoperation assists is proposed. A trajectory planning algorithm is developed using geometrical parameters from the proposed method. Findings The relevant experiments are also conducted using a manipulator suited to extreme physical constraints to open a real door with a locked latch and unknown geometrical parameters, which demonstrates the validity and efficiency of the proposed approach. Originality/value This is a novel method for estimating the unknown door geometrical parameters with coordinate transformation of the end-effector through visual teleoperation assists.

Wuschel and W40 Expression Analysis Undergoing Different Lc Locus Background in Tomato

2013 ◽  
Vol 864-867 ◽  
pp. 571-574
Author(s):  
Ying Liu ◽  
Hui Li ◽  
Qing Bo Zhang ◽  
Yan Ling Wang ◽  
Tian Li Li
Keyword(s):  
Candidate Gene ◽  
Fruit Size ◽  
Development Stage ◽  
Wild Type ◽  
Flower Buds ◽  
Flower Bud ◽  
Mutant Type ◽  
Tomato Fruits ◽  
Stem Apex ◽  
Locule Number

In tomato fruits, the number of locules varies from two to up to 10 or more. lc is relative to fruit size and locule number. As a candidate gene underlying lc, wuschel was mapped to the same region as lc. MLK1 with locule numbers up to 10 and FL1 with locule numbers 2-4, are selected to identify the type of lc loci, the expression of wuschel. MLK1 lc belongs to lc-mutant type and FL1 is lc-wild type. Wuschel is completely same in MLK1 and FL1, but expresses differentially. With the development of flower buds, wuschel expression decreased in both materials stem apex, meanwhile it was higher in MLK1 than FL1 at the corresponding development stage of flower bud. Therefore, these results suggest that wuschel is more possible for candidate gene underlying lc to regulate locule numbers. These results will provide important information for lc regulating locule number in tomato.

scholarly journals Rosa platyacantha Schrenk from Kazakhstan—Natural Source of Bioactive Compounds with Cosmetic Significance

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2578
Author(s):  
Askhat Sabitov ◽  
Katarzyna Gaweł-Bęben ◽  
Zuriyadda Sakipova ◽  
Marcelina Strzępek-Gomółka ◽  
Uliana Hoian ◽  
...  
Keyword(s):  
Type Species ◽  
Biological Activities ◽  
Human Melanoma ◽  
Bioactive Molecules ◽  
Wild Type ◽  
Flower Buds ◽  
Mountainous Regions ◽  
Phytochemical Composition ◽  
Skin Keratinocytes ◽  
Inhibitory Potential

Plants belonging to the Rosa genus are known for their high content of bioactive molecules and broad spectrum of healing and cosmetic activities. Rosa platyacantha Schrenk is a wild-type species abundant in the mountainous regions of Kazakhstan. The phytochemical composition as well as the bioactivity of R. platyacantha extracts have not been fully investigated to date. In this study, various parts of R. platyacantha plant, collected in Almaty region, Kazakhstan, were used to prepare five hydroalcoholic extracts (R1–R5). The extracts were compared for the content of phytochemicals and selected biological activities, which are important for the potential cosmetic application of R. platyacantha. Extract R3, prepared from flower buds, showed the most significant antioxidant and tyrosinase inhibitory potential, decreasing the monophenolase and diphenolase activities of tyrosinase. Extract R3 showed also collagenase inhibitory activity and cytotoxicity against human melanoma cells A375, being less cytotoxic for noncancerous skin keratinocytes HaCaT. Analysis of fractions E and F, obtained from R3 extracts, revealed that quercetin, kaempferol, rutin, and their derivatives are more likely responsible for the tyrosinase inhibitory properties of R. platyacantha extracts.

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