Phenovariation induced in Streptocarpus prolixus (Gesneriaceae) by β-glucosyl Yariv reagent

2003 ◽  
Vol 81 (4) ◽  
pp. 338-344 ◽  
Author(s):  
Richard A Rauh ◽  
Dominick V Basile

Streptocarpus prolixus C.B. Clarke is a species in the family Gesneriaceae characterized by an acaulescent vegetative body. Instead of a stem bearing leaves developing from a shoot apical meristem, its vegetative body derives from the continued, intercalary growth of one of its cotyledons. β-glucosyl Yariv phenyglycoside (β-D-Glc)3 selectively binds a class of cell surface associated proteoglycans and glycoproteins known as arabinogalactan-proteins (AGPs). Treating seeds and seedlings of S. prolixus with (β-D-Glc)3 induced phenovariants considered phyogenetically significant because they copied morphological features (phenocopied) characteristic of other, presumably more primitive species of Streptocarpus as well as species in other genera in the family to which it belongs. These results paralleled those obtained in earlier experiments with S. prolixus using antimetabolites of hydroxyproline-containing proteins (Hyp-proteins). Treatment with α-galactosyl phenylglycoside, a Yariv reagent that does not bind AGPs, did not induce phenovariants. The finding that (β-D-Glc)3 produced the same "phyletic phenocopies" as Hyp-protein antagonists strongly suggests that the morphoregulatory Hyp-proteins that were antagonized in the earlier experiments were AGPs and that AGPs play a pivotal role in pattern formation and pattern change during plant morphogenesis.Key words: Yariv phenyglycoside, arabinogalactan-protein, AGPs, Streptocarpus, phenovariation, morphogenesis.

2021 ◽  
Vol 8 ◽  
Author(s):  
Tereza Přerovská ◽  
Anna Pavlů ◽  
Dzianis Hancharyk ◽  
Anna Rodionova ◽  
Anna Vavříková ◽  
...  

Arabinogalactan proteins are very abundant, heavily glycosylated plant cell wall proteins. They are intensively studied because of their crucial role in plant development as well as their function in plant defence. Research of these biomacromolecules is complicated by the lack of tools for their analysis and characterisation due to their extreme heterogeneity. One of the few available tools for detection, isolation, characterisation, and functional studies of arabinogalactan proteins is Yariv reagents. Yariv reagent is a synthetic aromatic glycoconjugate originally prepared as an antigen for immunization. Later, it was found that this compound can precipitate arabinogalactan proteins, namely, their ß-D-(1→3)-galactan structures. Even though this compound has been intensively used for decades, the structural basis of arabinogalactan protein precipitation by Yariv is not known. Multiple biophysical studies have been published, but none of them attempted to elucidate the three-dimensional structure of the Yariv-galactan complex. Here we use a series of molecular dynamics simulations of systems containing one or multiple molecules of ß-D-galactosyl Yariv reagent with or without oligo ß-D-(1→3)-galactan to predict the structure of the complex. According to our model of Yariv-galactan complexes, Yariv reagent forms stacked oligomers stabilized by π-π and CH/π interactions. These oligomers may contain irregularities. Galactan structures crosslink these Yariv oligomers. The results were compared with studies in literature.


2020 ◽  
Author(s):  
Ian Sims ◽  
Richard Furneaux

A gum that exudes from the wounded trunk of the New Zealand native tree Meryta sinclairii has been isolated. The gum was completely precipitated by the β-glucosyl Yariv reagent and was thus determined to be an arabinogalactan-protein (AGP). It contained >95% w/w carbohydrate and only 2% w/w protein with a high level of hydroxyproline. SEC-MALLS showed that the gum had a weight-average molecular weight of 4.45×106Da compared with 6.02×105Da for gum arabic. Constituent sugar and linkage analyses were consistent with polymers comprised of a highly branched backbone of 1,3-linked galactopyranosyl (Galp) residues, with side-chains made up of arabinofuranose- (Araf) containing oligosaccharides, terminated variously by rhamnopyranosyl (Rhap), arabinopyranosyl (Arap), Galp and glucuronopyranosyl (GlcpA) residues. Analysis by one-dimensional and two-dimensional 1H and 13C NMR experiments confirmed the linkage analyses. The structure of the gum is discussed in comparison with the structure of gum arabic and other AGPs. © 2003 Elsevier Science Ltd. All rights reserved.


Zootaxa ◽  
2021 ◽  
Vol 4950 (2) ◽  
pp. 398-400
Author(s):  
OKAN KÜLKÖYLÜOĞLU

Most recently, Coimbra et al. (2020) published an article in this journal (Zootaxa, 4729 (2): 177–194) questioning the taxonomic position of the genus Copytus Skogsberg, 1939 (Crustacea, Ostracoda) along with proposing it as the type genus of their new family (Copytidae Coimbra et al., 2020), and erecting two new species that were listed by previous authors as Copytus sp. 1 and Copytus sp. 2. The main diagnostic characteristics of their new proposed family (and the genus Copytus) are the hinge type and muscle scars on the carapace and/or valves (see lines 6–8 from the bottom, p. 179 in Coimbra et al. 2020). They also underlined that (p. 179) “...this study is based exclusively on the morphology of the animals’ hard parts”. While the authors considered another genus (Neocopytus) proposed by Külköylüoğlu, Colin & Kılıç (2007) of the family Neocytherididae as invalid, they interestingly transferred some species of Neocopytus to Copytus as species of their new family (Coimbra et al. 2020). Herein, my point with the comments listed below is to clarify that, when possible, both soft and hard parts should be considered in taxonomy, and such an integrated approach clearly indicates that Neocopytus is a valid and taxonomically useful genus. 


2021 ◽  
Vol 5 (1) ◽  
pp. 14-16
Author(s):  
Raden Muhamad Imaduddin Yumni ◽  
Mohd Fauzihan Karim ◽  
Mohd Razik Midin

The family of Cucurbitaceae consists of species with economical and nutritional value. Morphologically, there are only few differences between Cucumis species. The interspecific and intraspecific variation in the genome size of the Cucumis species are not discovered yet. Due to this, this study aims to determine the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis using flow cytometry (FCM) method. Nuclei suspension of selected Cucumis species were extracted using LBO1 lysis buffer by manual chopping technique and stained by propidium iodide priot to FCM analysis. Genome size of C. sativus, C. melo inodorus (Honeydew) and C. melo cantalupensis (Rockmelon) were determined by using Glycine max (Soybean) as an external reference standard (2C = 2.5 pg). This study found that the genome size of C. sativus, C. melo inodorus and C. melo cantalupensis estimated to be 2.83 pg, 3.00 pg and 3.47 pg respectively. The genome size data obtained from this study can be used in future genome studies as well as species characterization.


1990 ◽  
Vol 68 (9) ◽  
pp. 760-767 ◽  
Author(s):  
J. A. Tuszynski ◽  
M. Otwinowski

In this paper we investigate the family of nonlinear partial differential equations used to describe the kinetics of critical phenomena within the Landau–Ginzburg model. An analysis of the recently obtained symmetry-reduction results for a number of such equations is provided from the point of view of pattern formation at criticality. Various possibilities occur depending on the choice of control parameters. An illustration is provided using several physical examples such as metamagnets and liquid crystals.


1997 ◽  
Vol 75 (9) ◽  
pp. 1509-1517 ◽  
Author(s):  
K. Enkerli ◽  
C. W. Mims ◽  
M. G. Hahn

Immunolabeling and transmission electron microscopic techniques were used to investigate the chemical nature of wall appositions in roots of susceptible and resistant soybean plants inoculated with Phytophthora sojae race 2. The extrahaustorial matrix associated with the haustorium of Phytophthora sojae also was examined. Antibodies against (1 → 3)-β-glucan, a terminal α-fucosyl-containing epitope present in xyloglucan and rhamnogalacturonan I, and an arabinosylated (1 → 6)-β-galactan epitope present in arabinogalactan proteins were used. (1 → 3)-β-Glucan (callose), xyloglucan, and arabinogalactan proteins were found to be localized in all wall appositions regardless of how long after inoculation the appositions developed or whether plants were susceptible or resistant to Phytophthora sojae. (1 → 3)-β-Glucan also was found in fungal walls and at host cell plasmodesmata. None of the four antibodies labeled the extrahaustorial matrix. The antibody against arabinogalactan protein recognized the host plasma membrane, but not the invaginated host plasma membrane associated with the extrahaustorial matrix. This result indicates that the properties or the composition of the host plasma membrane may change locally once it becomes an extrahaustorial membrane. Key words: Phytophthora sojae, Glycine max, callose, immunolabeling, wall appositions, papillae.


Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 3045-3055 ◽  
Author(s):  
L. Zheng ◽  
J. Zhang ◽  
R.W. Carthew

Coordinated morphogenesis of ommatidia during Drosophila eye development establishes a mirror-image symmetric pattern across the entire eye bisected by an anteroposterior equator. We have investigated the mechanisms by which this pattern formation occurs and our results suggest that morphogenesis is coordinated by a graded signal transmitted bidirectionally from the presumptive equator to the dorsal and ventral poles. This signal is mediated by frizzled, which encodes a cell surface transmembrane protein. Mosaic analysis indicates that frizzled acts non-autonomously in an equatorial to polar direction. It also indicates that relative levels of frizzled in photoreceptor cells R3 and R4 of each ommatidium affect their positional fate choices such that the cell with greater frizzled activity becomes an R3 cell and the cell with less frizzled activity becomes an R4 cell. Moreover, this bias affects the choice an ommatidium makes as to which direction to rotate. Equator-outwards progression of elav expression and expression of the nemo gene in the morphogenetic furrow are regulated by frizzled, which itself is dynamically expressed about the morphogenetic furrow. We propose that frizzled mediates a bidirectional signal emanating from the equator.


Phytotaxa ◽  
2021 ◽  
Vol 496 (1) ◽  
pp. 101-103
Author(s):  
ANAND KUMAR ◽  
GOPAL KRISHNA ◽  
TAPAS CHAKRABARTY

The Asian genus Glyptopetalum Thwaites (1856: 267) comprises 35 species (Savinov 2014) of which 5 species are occurring in India (Ramamurthy 2000). Glyptopetalum griffithii Prain (1891: 209) was described on the basis of a single gathering obtained by Griffith from the Mishmi hills, Arunachal Pradesh, India. Later, Kanjilal et al. (1936: 266) recognized and treated this species based on a collection by Kanjilal from Pashighat in Arunachal Pradesh. Eventually Ramamurthy (2000: 112) also accepted the species in his treatment of the family Celastraceae for the Flora of India. Chakrabarty & Gangopadhyay (1990: 129) as well as Savinov (2014: 187) erroneously considered G. griffithii a name based on Euonymus griffithii Kurz (1870: 73). However, the latter was proposed as a new name for Hippocratea angulata Griffith (1854: 473), due to the existence of Euonymus angulata Wight (1846: t. 1053), whereas G. griffithii was originally described as species new to science.  


Zootaxa ◽  
2019 ◽  
Vol 4622 (1) ◽  
pp. 1-99 ◽  
Author(s):  
S. RAVICHANDRAN ◽  
P. VIGNESHWARAN ◽  
G. RAMESHKUMAR

The parasitic isopod family Cymothoidae Leach, 1818 of the India exclusive economic zone is reviewed. A total of 56 nominal species corresponding to 48 valid species belonging to sixteen genera are reviewed from 73 host species belonging to 35 families. Mothocya plagulophora (Haller, 1880), Nerocila depressa Milne Edwards, 1840, Nerocila loveni Bovallius, 1887, Nerocila trichiura (Miers, 1877), Norileca triangulata (Richardson, 1910) and Ryukyua globosa Williams & Bunkley-Williams, 1994 are redescribed. Indusa pustulosa Pillai, 1954 is synonymised with Agarna malayi Tiwari, 1952; Cymothoa krishnai Jayadev Babu & Sanjeeva Raj, 1984 is synonymised with Cymothoa eremita (Brünnich, 1783) and Nerocila priacanthusi Kumari, Rao & Shyamasundari, 1987 is synonymised with Nerocila arres Bowman & Tareen, 1983. Ourozeuktes bopyroides (Lesueur, 1814) is revised and excluded from the Indian fauna. The Indian cymothoid species Agarna bengalensis Kumari, Rao & Shaymasundari, 1990, Cymothoa asymmetrica Pillai, 1954 and Nerocila hemirhamphusi Shyamasundari, Rao & Kumari, 1990 are regarded here as species inquirenda. A key to the Indian genera of the family Cymothoidae and keys to the Indian species of the genera Cymothoa, Joryma, Mothocya, and Nerocila are presented. A checklist of the valid Cymothoidae species until now reported from Indian marine fishes are compiled. Host preferences, morphological variability and distribution are discussed. 


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