scholarly journals EPIP-Evoked Modifications of Redox, Lipid, and Pectin Homeostasis in the Abscission Zone of Lupine Flowers

2021 ◽  
Vol 22 (6) ◽  
pp. 3001
Author(s):  
Emilia Wilmowicz ◽  
Agata Kućko ◽  
Wojciech Pokora ◽  
Małgorzata Kapusta ◽  
Katarzyna Jasieniecka-Gazarkiewicz ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cell Wall ◽  
Redox Homeostasis ◽  
Abscission Zone ◽  
Wall Structure ◽  
Related Research ◽  
Flower Abortion ◽  
Mitogen Activated Protein ◽  
Acyl Lipids ◽  
Flower Abscission

Yellow lupine is a great model for abscission-related research given that excessive flower abortion reduces its yield. It has been previously shown that the EPIP peptide, a fragment of LlIDL (INFLORESCENCE DEFICIENT IN ABSCISSION) amino-acid sequence, is a sufficient molecule to induce flower abortion, however, the question remains: What are the exact changes evoked by this peptide locally in abscission zone (AZ) cells? Therefore, we used EPIP peptide to monitor specific modifications accompanied by early steps of flower abscission directly in the AZ. EPIP stimulates the downstream elements of the pathway—HAESA and MITOGEN-ACTIVATED PROTEIN KINASE6 and induces cellular symptoms indicating AZ activation. The EPIP treatment disrupts redox homeostasis, involving the accumulation of H2O2 and upregulation of the enzymatic antioxidant system including superoxide dismutase, catalase, and ascorbate peroxidase. A weakening of the cell wall structure in response to EPIP is reflected by pectin demethylation, while a changing pattern of fatty acids and acyl lipids composition suggests a modification of lipid metabolism. Notably, the formation of a signaling molecule—phosphatidic acid is induced locally in EPIP-treated AZ. Collectively, all these changes indicate the switching of several metabolic and signaling pathways directly in the AZ in response to EPIP, which inevitably leads to flower abscission.

scholarly journals Drought Disrupts Auxin Localization in Abscission Zone and Modifies Cell Wall Structure Leading to Flower Separation in Yellow Lupine

2020 ◽  
Vol 21 (18) ◽  
pp. 6848
Author(s):  
Aleksandra Bogumiła Florkiewicz ◽  
Agata Kućko ◽  
Małgorzata Kapusta ◽  
Sebastian Burchardt ◽  
Tomasz Przywieczerski ◽  
...  
Keyword(s):  
Cell Wall ◽  
Control Plant ◽  
Pectin Methylesterase ◽  
Economic Consequences ◽  
Abscission Zone ◽  
Cell Wall Structure ◽  
Plant Production ◽  
Wall Structure ◽  
Flower Abortion ◽  
Yellow Lupine

Drought causes the excessive abscission of flowers in yellow lupine, leading to yield loss and serious economic consequences in agriculture. The structure that determines the time of flower shedding is the abscission zone (AZ). Its functioning depends on the undisturbed auxin movement from the flower to the stem. However, little is known about the mechanism guiding cell–cell adhesion directly in an AZ under water deficit. Therefore, here, we seek a fuller understanding of drought-dependent reactions and check the hypothesis that water limitation in soil disturbs the natural auxin balance within the AZ and, in this way, modifies the cell wall structure, leading to flower separation. Our strategy combined microscopic, biochemical, and chromatography approaches. We show that drought affects indole-3-acetic acid (IAA) distribution and evokes cellular changes, indicating AZ activation and flower abortion. Drought action was manifested by the accumulation of proline in the AZ. Moreover, cell wall-related modifications in response to drought are associated with reorganization of methylated homogalacturonans (HG) in the AZ, and upregulation of pectin methylesterase (PME) and polygalacturonase (PG)—enzymes responsible for pectin remodeling. Another symptom of stress action is the accumulation of hemicelluloses. Our data provide new insights into cell wall remodeling events during drought-induced flower abscission, which is relevant to control plant production.

A comparative study of the fatty acids of some micrococci

1971 ◽  
Vol 17 (12) ◽  
pp. 1503-1508 ◽  
Author(s):  
A. E. Girard
Keyword(s):  
Fatty Acids ◽  
Cell Wall ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Comparative Study ◽  
Acid Composition ◽  
Wall Structure ◽  
Gram Positive ◽  
Gram Negative ◽  
Branched Chain

A comparative study was made of the fatty acids of several gram-positive, -variable, and -negative micrococci. The fatty acids detected in M. diversus, M. denitrificans, and M. cerificans (Acinetobacter cerificans) were similar to those previously reported in gram-negative cocci and bacilli. The major fatty acid was oleic acid and the next most abundant acids were palmitic and palmitoleic. Micrococcus agilis, a gram-positive bacterium, was shown to have a branched-chain methyltetradecanoic acid as the major component (72%). Branched-chain and odd-numbered carbon acids as well as copious amounts of palmitic and palmitoleic acids were found in M. roseus, a gram-variable organism. Correlations were made between fatty acid composition, cell wall structure, and gram reaction of M. agilis, M. roseus, and M. cerificans. Micrococcus agilis demonstrated a typical amorphous gram-positive wall, M. roseus was shown to have a layered wall, and M. cerificans had a cell wall characteristic of gram-negative bacteria. The relationship of fatty acid composition and ultrastructure to the taxonomic position of the "problematic" micrococci was discussed.

scholarly journals Ethylene-dependent effects on generative organ abscission of Lupinus luteus

2017 ◽  
Vol 86 (1) ◽  
Author(s):  
Kamil Frankowski ◽  
Agata Kućko ◽  
Agnieszka Zienkiewicz ◽  
Krzysztof Zienkiewicz ◽  
Juan de Dios Alché ◽  
...  
Keyword(s):  
Physiological Response ◽  
Considerable Increase ◽  
Separation Process ◽  
Abscission Zone ◽  
Lupinus Luteus ◽  
Flower Abortion ◽  
Dividing Cells ◽  
Generative Organ ◽  
Flower Abscission ◽  
Acc Content

The abscission of certain organs from the plant is part of the fulfilment of its developmental programs. The separation process occurs in a specialized abscission zone usually formed at the base of detached organ. The changing level of phytohormones, particularly ethylene, is the element responsible for coordinating anatomical and physiological transformation that accompanies organ abscission. The application of ethylene (ET) on <em>Lupinus luteus</em> stimulates flower abortion. However, the treatment with 1-aminocyclopropane-1-carboxylic acid (ACC) – direct ET precursor – does not cause such a strong physiological response. In turn, when applied on the pedicels both ET biosynthesis (2-aminoethoxyvinylglycine; AVG) and action (norbornadiene; NBD) inhibitors reversed the stimulatory effect of ET on generative organ separation. In order to determine ET role in the flower abscission process in <em>L. luteus</em>, we identified the sequences coding for synthase (<em>LlACS</em>) and oxidase (<em>LlACO</em>) of ACC and measured their expression levels. Abscission zone activation is accompanied by a considerable increase both in <em>LlACS</em> and <em>LlACO</em> cDNAs and also ACC content, which is specifically localized in the dividing cells at the base of the flower being detached. Obtained results suggest that ET is a strong stimulator of flower abortion in <em>L. luteus</em>.

Bacterial Peptidoglycan Stapling with Functionalized D-Amino Acids

2019 ◽  
Author(s):  
Sylvia L. Rivera ◽  
Akbar Espaillat ◽  
Arjun K. Aditham ◽  
Peyton Shieh ◽  
Chris Muriel-Mundo ◽  
...  
Keyword(s):  
Cell Wall ◽  
Clinical Success ◽  
Bacterial Species ◽  
Enzymatic Reaction ◽  
Amino Acid Derivative ◽  
Wall Structure ◽  
Live Bacteria ◽  
Cross Links ◽  
Osmotic Lysis ◽  
Bacterial Peptidoglycan

Transpeptidation reinforces the structure of cell wall peptidoglycan, an extracellular heteropolymer that protects bacteria from osmotic lysis. The clinical success of transpeptidase-inhibiting β-lactam antibiotics illustrates the essentiality of these cross-linkages for cell wall integrity, but the presence of multiple, seemingly redundant transpeptidases in many bacterial species makes it challenging to determine cross-link function precisely. Here we present a technique to covalently link peptide strands by chemical rather than enzymatic reaction. We employ bio-compatible click chemistry to induce triazole formation between azido- and alkynyl-D-alanine residues that are metabolically installed in the cell walls of Gram-positive and Gram-negative bacteria. Synthetic triazole cross-links can be visualized by substituting azido-D-alanine with azidocoumarin-D-alanine, an amino acid derivative that undergoes fluorescent enhancement upon reaction with terminal alkynes. Cell wall stapling protects the model bacterium Escherichia coli from β-lactam treatment. Chemical control of cell wall structure in live bacteria can provide functional insights that are orthogonal to those obtained by genetics.<br>

Recent Developments in the Downstream Processing of Phycobiliproteins from Algae: A Review

2021 ◽  
Vol 06 ◽  
Author(s):  
Ayekpam Chandralekha Devi ◽  
G. K. Hamsavi ◽  
Simran Sahota ◽  
Rochak Mittal ◽  
Hrishikesh A. Tavanandi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Large Scale ◽  
Downstream Processing ◽  
Review Article ◽  
Current Status ◽  
Wall Structure ◽  
Scale Production ◽  
Cell Wall Disruption ◽  
Recent Developments ◽  
Macro Algae

Abstract: Algae (both micro and macro) have gained huge attention in the recent past for their high commercial value products. They are the source of various biomolecules of commercial applications ranging from nutraceuticals to fuels. Phycobiliproteins are one such high value low volume compounds which are mainly obtained from micro and macro algae. In order to tap the bioresource, a significant amount of work has been carried out for large scale production of algal biomass. However, work on downstream processing aspects of phycobiliproteins (PBPs) from algae is scarce, especially in case of macroalgae. There are several difficulties in cell wall disruption of both micro and macro algae because of their cell wall structure and compositions. At the same time, there are several challenges in the purification of phycobiliproteins. The current review article focuses on the recent developments in downstream processing of phycobiliproteins (mainly phycocyanins and phycoerythrins) from micro and macroalgae. The current status, the recent advancements and potential technologies (that are under development) are summarised in this review article besides providing future directions for the present research area.

scholarly journals A Metzincin and TIMP-Like Protein Pair of a Phage Origin Sensitize Listeria monocytogenes to Phage Lysins and Other Cell Wall Targeting Agents

2021 ◽  
Vol 9 (6) ◽  
pp. 1323
Author(s):  
Etai Boichis ◽  
Nadejda Sigal ◽  
Ilya Borovok ◽  
Anat A. Herskovits
Keyword(s):  
Cell Wall ◽  
Listeria Monocytogenes ◽  
Mammalian Cells ◽  
Protein Pair ◽  
Growth Conditions ◽  
Wall Structure ◽  
Antibiotic Resistant ◽  
Extracellular Milieu ◽  
Virion Release ◽  
Genes Encoding

Infection of mammalian cells by Listeria monocytogenes (Lm) was shown to be facilitated by its phage elements. In a search for additional phage remnants that play a role in Lm’s lifecycle, we identified a conserved locus containing two XRE regulators and a pair of genes encoding a secreted metzincin protease and a lipoprotein structurally similar to a TIMP-family metzincin inhibitor. We found that the XRE regulators act as a classic CI/Cro regulatory switch that regulates the expression of the metzincin and TIMP-like genes under intracellular growth conditions. We established that when these genes are expressed, their products alter Lm morphology and increase its sensitivity to phage mediated lysis, thereby enhancing virion release. Expression of these proteins also sensitized the bacteria to cell wall targeting compounds, implying that they modulate the cell wall structure. Our data indicate that these effects are mediated by the cleavage of the TIMP-like protein by the metzincin, and its subsequent release to the extracellular milieu. While the importance of this locus to Lm pathogenicity remains unclear, the observation that this phage-associated protein pair act upon the bacterial cell wall may hold promise in the field of antibiotic potentiation to combat antibiotic resistant bacterial pathogens.

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