Biochemistry and function of cutin and suberin

1984 ◽  
Vol 62 (12) ◽  
pp. 2918-2933 ◽  
Author(s):  
P. E. Kolattukudy

Cutin, the structural component of plant cuticle, is a biopolyester composed of hydroxy- and hydroxyepoxy-fatty acids. The major monomers are a 16-hydroxy C16 acid, a 10,16-dihydroxy C16 acid together with its positional isomers, 18-hydroxy C18 acids, 18-hydroxy-9,10-epoxy C18 acids, and 9,10,18-trihydroxy C18 acids. The hydroxylation, epoxidation, and epoxide hydration reactions postulated to be involved in the biosynthesis of these monomers have been demonstrated in tissue slices and in cell-free preparations. The synthesis of the polymer occurs by the enzymatic transfer of the hydroxyacyl groups from CoA to the free hydroxyl groups in cutin primer. Natural and wound periderms and a variety of internal barrier layers contain a somewhat analogous polymer called suberin. This polymer is probably composed of aromatic domains somewhat similar to those found in lignin and aliphatic polyester domains somewhat similar to cutin. The chemical composition and biosynthesis of this polymer is discussed. Pathogenic fungi use a hydrolytic enzyme, cutinase, to gain entry into the plant through the cuticle. The fungal cutinase has been isolated from a variety of pathogenic fungi and characterized. This enzyme is a "serine hydrolase" containing the characteristic catalytic triad. The primary structure of this enzyme has been determined using both amino acid and nucleotide sequencing of the cloned copy DNA. Inhibition of cutinase was shown to prevent fungal infection of plants. This novel approach to fungal control is described.

2001 ◽  
Vol 711 ◽  
Author(s):  
Alexander Zelikin ◽  
Venkatram Shastri ◽  
David Lynn ◽  
Jian Farhadi ◽  
Ivan Martin ◽  
...  

ABSTRACTConductive polymers such as polypyrrole (Ppy) are potentially useful as an active interface for altering cellular processes and function. Their utilization in medically related applications however have been substantially held back by their non-degradable nature. Herein we report a novel approach to creation of bioerodible polypyrroles via modification of pyrrole beta-carbon with an ionizable moiety. It has been shown that the erosion rate of acid-bearing derivative of polypyrrole increases with pH, which is consistent with the pH dependent ionization of carboxylic acid group. The novel paradigm proposed for the creation of bioerodible polypyrroles allows for simple and efficient control over the erosion rate of the substrate independent of the polymer chain length, via the choice of the terminal ionizable group and its concentration along the polymer backbone.


2021 ◽  
Vol 5 (1) ◽  
pp. 86
Author(s):  
Grace Purnamasari Christian ◽  
Wahyu Irawati

<p>The post-harvest fungi is one of the greatest cause of various diseases. Particularly, in fungus that infects seeds, the toxic substance called aflatoxin is found. This has caused us to wonder: Has fungi been pathogenic fungi since the beginning of creation? The purpose of this research is to study: 1) The Place of Fungi in God’s Original Creation and the Origin of Pathogenic Fungi, 2) Characterization of post-harvest fungus on corn seeds, 3) Aspergillus sp.’s Structure as Proof of God’s Wonderful Original Creation and Providence, and 4) The factors that contribute to the growth of fungi in post-harvest corn seeds and our responsibility. We conclude that in the beginning, fungi were a part of God’s originally good and perfect creation. These fungi were created by God with the structure and function to support its operation in fulfilling God’s creative purpose. The complex structure of Aspergillus niger and Aspergillus flavus that infected the corn seeds showed God’s providence after the Fall. Pathogenic fungi were the result of the Fall of man into sin. Their growth is caused by the failure to give proper care to the crops. But this should not discourage us since the Bible tells us that God is continually working to restore His creation. Therefore, we are called to be stewards of His creation, to develop and preserve whatever is entrusted in our hands, including the crops for God’s glory and under His authority until He has fully renewed and restored everything.</p><p><strong>BAHASA INDONESIA ABSTRACT:</strong> Jamur pasca panen merupakan salah satu penyebab terbesar timbulnya berbagai penyakit, khususnya disebabkan oleh jamur yang menginfeksi biji-bijian dan menghasilkan substansi beracun disebut dengan aflatoksin. Keadaan ini menimbulkan pertanyaan apakah jamur patogenik ada sejak awal penciptaan? Penelitian ini bertujuan untuk mempelajari: 1) Posisi jamur patogenik di awal penciptaan dan asal mula jamur patogenik, 2) karakteristik jamur pasca panen pada biji jagung, 3) struktur <em>Aspergillus</em> sp sebagai bukti dari providensi Allah akan ciptaanNya yang sangat luar biasa, 4) faktor-faktor yang berkontribusi terhadap pertumbuhan jamur pasca panen biji jagung dan Tanggung jawab kita. Dari hasil penelitian ini disimpulkan bahwa pada mulanya, jamur merupakan bagian ciptaan Allah yang sungguh amat baik dan sempurna. Struktur yang kompleks dari <em>Aspergillus niger</em> dan <em>Aspergillus flavus </em>yang menginfeksi biji jagung menunjukkan providensi Allah setelah kejatuhan dosa. Pertumbuhan jamur patogenik merupakan gambaran kejatuhan manusia ke dalam dosa yaitu kegagalan manusia untuk memberikan pemeliharaan yang memadahi pada biji-bijian pasca panen. Namun demikian, keadaan ini tidak mematahkan semangat kita karena Alkitab mengatakan bahwa Allah masih terus bekerja untuk memulihkan ciptaanNya. Oleh karena itu, diharapkan kita semua menjadi pelayan atas ciptaanNya untuk mengembangkan dan menjaga apa yang dipercayakan kepada kita di bawah otoritasNya termasuk biji-bijian untuk memuliakan Allah hingga Dia secara penuh memperbaharui dan memulihkan segala sesuatu</p>


2018 ◽  
Author(s):  
Caroline Fecher ◽  
Laura Trovò ◽  
Stephan A. Müller ◽  
Nicolas Snaidero ◽  
Jennifer Wettmarshausen ◽  
...  

AbstractMitochondria vary in morphology and function in different tissues, however little is known about their molecular diversity among cell types. To investigate mitochondrial diversity in vivo, we developed an efficient protocol to isolate cell type-specific mitochondria based on a new MitoTag mouse. We profiled the mitochondrial proteome of three major neural cell types in cerebellum and identified a substantial number of differential mitochondrial markers for these cell types in mice and humans. Based on predictions from these proteomes, we demonstrate that astrocytic mitochondria metabolize long-chain fatty acids more efficiently than neurons. Moreover, we identified Rmdn3 as a major determinant of ER-mitochondria proximity in Purkinje cells. Our novel approach enables exploring mitochondrial diversity on the functional and molecular level in many in vivo contexts.


Open Biology ◽  
2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Mingyang Zou ◽  
Yu Liu ◽  
Shu Xie ◽  
Luxi Wang ◽  
Dexin Li ◽  
...  

Autism spectrum disorder (ASD) is a group of developmental disabilities, the aetiology of which remains elusive. The endocannabinoid (eCB) system modulates neurotransmission and neuronal plasticity. Evidence points to the involvement of this neuromodulatory system in the pathophysiology of ASD. We investigated whether there is a disruption to the eCB system in ASD and whether pharmacological modulation of the eCB system might offer therapeutic potential. We examined three major components of the eCB system—endogenous cannabinoids, their receptors and associated enzymes—in ASD children as well as in the valproic acid (VPA) induced animal model in autism. Furthermore, we specifically increased 2-arachidonoylglycerol (2-AG) levels by administering JZL184, a selective inhibitor of monoacylglycerol lipase which is the hydrolytic enzyme for 2-AG, to examine ASD-like behaviours in VPA-induced rats. Results showed that autistic children and VPA-induced rats exhibited reduced eCB content, increased degradation of enzymes and upregulation of CBRs. We found that repetitive and stereotypical behaviours, hyperactivity, sociability, social preference and cognitive functioning improved after acute and chronic JZL184 treatment. The major efficacy of JZL184 was observed after administration of a dosage regimen of 3 mg kg −1 , which affected both the eCB system and ASD-like behaviours. In conclusion, a reduced eCB signalling was observed in autistic children and in the ASD animal model, and boosting 2-AG could ameliorate ASD-like phenotypes in animals. Collectively, the results suggested a novel approach to ASD treatment.


1998 ◽  
Vol 42 (7) ◽  
pp. 1563-1567 ◽  
Author(s):  
Dena Lyras ◽  
Christine Storie ◽  
Andrea S. Huggins ◽  
Paul K. Crellin ◽  
Trudi L. Bannam ◽  
...  

ABSTRACT The chloramphenicol resistance gene catD fromClostridium difficile was shown to be encoded on the transposons Tn4453a and Tn4453b, which were structurally and functionally related to Tn4451 fromClostridium perfringens. Tn4453a and Tn4453b excised precisely from recombinant plasmids, generating a circular form, as is the case for Tn4451. Evidence that this process is mediated by Tn4453-encodedtnpX genes was obtained from experiments which showed that in trans these genes complemented a Tn4451tnpXΔ1 mutation for excision. Nucleotide sequencing showed that the joint of the circular form generated by the excision of Tn4453a and Tn4453b was similar to that from Tn4451. These results suggest that the Tn4453-encoded TnpX proteins bind to similar DNA target sequences and function in a manner comparable to that of TnpX from Tn4451. Furthermore, it has been shown that Tn4453a and Tn4453b can be transferred to suitable recipient cells by RP4 and therefore are mobilizable transposons. It is concluded that, like Tn4451, they must encode a functional tnpZ gene and a targetoriT or RSA site. The finding that related transposable elements are present in C. difficile andC. perfringens has implications for the evolution and dissemination of antibiotic resistance genes and the mobile elements on which they are found within the clostridia.


2018 ◽  
Vol 285 (1876) ◽  
pp. 20172833 ◽  
Author(s):  
Rannveig M. Jacobsen ◽  
Anne Sverdrup-Thygeson ◽  
Håvard Kauserud ◽  
Tone Birkemoe

Ecological networks are composed of interacting communities that influence ecosystem structure and function. Fungi are the driving force for ecosystem processes such as decomposition and carbon sequestration in terrestrial habitats, and are strongly influenced by interactions with invertebrates. Yet, interactions in detritivore communities have rarely been considered from a network perspective. In the present study, we analyse the interaction networks between three functional guilds of fungi and insects sampled from dead wood. Using DNA metabarcoding to identify fungi, we reveal a diversity of interactions differing in specificity in the detritivore networks, involving three guilds of fungi. Plant pathogenic fungi were relatively unspecialized in their interactions with insects inhabiting dead wood, while interactions between the insects and wood-decay fungi exhibited the highest degree of specialization, which was similar to estimates for animal-mediated seed dispersal networks in previous studies. The low degree of specialization for insect symbiont fungi was unexpected. In general, the pooled insect–fungus networks were significantly more specialized, more modular and less nested than randomized networks. Thus, the detritivore networks had an unusual anti-nested structure. Future studies might corroborate whether this is a common aspect of networks based on interactions with fungi, possibly owing to their often intense competition for substrate.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2083
Author(s):  
Kaige Zhang ◽  
Yifan Jiang ◽  
Hongwei Zhao ◽  
Tobias G. Köllner ◽  
Sumei Chen ◽  
...  

Roots provide anchorage and enable the absorption of water and micronutrients from the soil for plants. Besides these essential functions, roots are increasingly being recognized as an important organ for the production of diverse secondary metabolites. The goal of this study was to investigate the chemical composition and function of terpenoid secondary metabolites in roots of different cultivars of the popular ornamental plant Chrysanthemum morifolium Ramat. Although C. morifolium is known for rich production of secondary metabolites in its flower heads and leaves, the diversity of secondary metabolites in roots remains poorly characterized. In this study, 12 cultivars of C. morifolium were selected for comparative analysis. From their roots, a total of 20 terpenoids were detected, including four monoterpenes, 15 sesquiterpenes, and one diterpene. The cultivar ‘She Yang Hong Xin Ju’ exhibited the highest concentration of total terpenoids at approximately 730 µg·g−1 fresh weight. Most cultivars contained sesquiterpenes as the predominant terpenoids. Of them, (E)-β-farnesene was detected in all cultivars. Based on their terpenoid composition, the 12 cultivars were planed into four groups. To gain insights into the function of root secondary metabolites, we performed bioassays to assess their effects on growth of three species of pathogenic fungi: Fusarium oxysporum, Magnaporthe oryzae, and Verticillium dahliae. Significant variability in antifungal activity of the root extracts among different cultivars were observed. The cultivar ‘Xiao Huang Ju’ was the only cultivar that had significant inhibitory effects on all three species of fungi. Our study reveals the diversity of terpenoids in roots of C. morifolium and their function as a chemical defense against fungi.


2020 ◽  
Vol 21 (5) ◽  
pp. 491-497 ◽  
Author(s):  
Mihai Strachinaru ◽  
Daniel J Bowen ◽  
Alina Constatinescu ◽  
Olivier C Manintveld ◽  
Jasper J Brugts ◽  
...  

Abstract Aims A significant proportion of left ventricle assist device (LVAD) patients have very difficult transthoracic echocardiographic images. The aim of this study was to find an echocardiographic window which would provide better visualization of the heart in LVAD patients with limited acoustic windows. Methods and results Based on the anatomic relationships in LVAD patients, a right intercostal transhepatic approach was proposed. By using a computer simulator, we searched for the appropriate probe orientation. Further, 15 ambulatory LVAD patients (age 56 ± 15 years, 73% males) underwent two echocardiographic studies: one normal transthoracic echocardiography following the institutional protocol (Echo 1) and a second study which included the transhepatic approach (Echo 2). The two exams were performed by two different sonographers and the results validated by a third observer for agreement. The transhepatic intercostal window was feasible in all patients, with an image quality allowing good visualization of structures in 93%. Precise quantification of the left ventricular (LV) and right ventricular (RV) function was achieved more often in the Echo 2 (10 vs. 3 patients for LV, P = 0.03 and 14 vs. 8 patients for RV, P = 0.04). A significant difference existed also in the quantification of the LVAD inflow cannula flow by pulsed Doppler (11 patients in Echo 2 vs. 3 patients in Echo 1, P = 0.009). Conclusion This is the first study describing a new echocardiographic window in LVAD patients. The transhepatic window may provide better quantification of left and RV dimensions and function and improvement in Doppler interrogation of the inflow cannula.


2016 ◽  
Vol 42 (2) ◽  
Author(s):  
Hasnain Hussain ◽  
Nikson Fatt Ming Chong

AbstractObjective:Restoration of catalytic activity of Isa2 fromMethods:The six conserved amino acid residues absent in the Stisa2 gene were restored by mutation using the overlap extension PCR and the asymmetrical overlap extension PCR methods. Next, mutant Stisa2 with restored catalytic residues was expressed inResults:Both qualitative and quantitative analysis showed that the restoration of the conserved residues in the catalytic site did not restore starch debranching activity. Molecular modeling showed greater than expected distances between the catalytic triad in mutant Stisa2. These additional distances are likely to prevent hydrogen bonding which stabilizes the reaction intermediate, and are critical for catalytic activity.Conclusions:These results suggest that during evolution, mutations in other highly conserved regions have caused significant changes to the structure and function of the catalytic network. Catalytically inactive Isa2, which is conserved in starch-producing plants, has evolved important non-catalytic roles such as in substrate binding and in regulating isoamylase activity.


2017 ◽  
Vol 30 (12) ◽  
pp. 771-780 ◽  
Author(s):  
M Hinrichsen ◽  
M Lenz ◽  
J M Edwards ◽  
O K Miller ◽  
S G J Mochrie ◽  
...  

AbstractWe present a novel method to fluorescently label proteins, post-translationally, within live Saccharomycescerevisiae. The premise underlying this work is that fluorescent protein (FP) tags are less disruptive to normal processing and function when they are attached post-translationally, because target proteins are allowed to fold properly and reach their final subcellular location before being labeled. We accomplish this post-translational labeling by expressing the target protein fused to a short peptide tag (SpyTag), which is then covalently labeled in situ by controlled expression of an open isopeptide domain (SpyoIPD, a more stable derivative of the SpyCatcher protein) fused to an FP. The formation of a covalent bond between SpyTag and SpyoIPD attaches the FP to the target protein. We demonstrate the general applicability of this strategy by labeling several yeast proteins. Importantly, we show that labeling the membrane protein Pma1 in this manner avoids the mislocalization and growth impairment that occur when Pma1 is genetically fused to an FP. We also demonstrate that this strategy enables a novel approach to spatiotemporal tracking in single cells and we develop a Bayesian analysis to determine the protein’s turnover time from such data.


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