Uncovering the ultrastructure of ramiform pits in the parenchyma cells of bamboo [Phyllostachys edulis (Carr.) J. Houz.]

Holzforschung ◽  
2020 ◽  
Vol 74 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Caiping Lian ◽  
Shuqin Zhang ◽  
Xianmiao Liu ◽  
Junji Luo ◽  
Feng Yang ◽  
...  

AbstractPits are the main transverse channels of intercellular liquid transport in bamboo. Ramiform pits are a special type of simple pit with two or more branches. However, little is known about the morphology and physiological functions of ramiform pits. The anatomy of plants can provide important evidence for the role of cells. To better understand the ultrastructure and the structure-function relationship of ramiform pits, their characteristics need to be investigated. In this study, both qualitative and quantitative features of ramiform pits were studied using field-emission environmental scanning electron microscopy (FE-ESEM). The samples included the native structures and the replica structures obtained by resin castings. The results show that the ramiform pits have a diverse morphology that can be divided into main categories: type I (the primary branches) and type II (the secondary branches). The distribution of ramiform pits is different in ground parenchyma cells (GPCs) and vascular parenchyma cells (VPCs). The number, the pit aperture diameter and the pit canal length of ramiform pits in the VPCs were, respectively, greater (3-fold), larger (2–3-fold) and shorter (1.3-fold) than those in the GPCs.

Holzforschung ◽  
2019 ◽  
Vol 73 (7) ◽  
pp. 629-636 ◽  
Author(s):  
Caiping Lian ◽  
Rong Liu ◽  
Cheng Xiufang ◽  
Shuqing Zhang ◽  
Junji Luo ◽  
...  

Abstract The pits on parenchyma cell walls facilitate transfer of liquids between adjacent cells in the bamboo. To better understand the structure-function relationship of the pits, the structural characteristics of the pits in bamboo parenchyma cells need to be investigated. In this study, the pit structures were studied by field-emission environmental scanning electron microscopy (SEM). The samples included the native structure and the replica structure via resin castings. The results showed that the parenchyma cells possessed various shapes and the pits were diverse. Parenchyma cells exposed both simple and bordered pits. Pitting between vascular parenchyma cells (VPCs) was similar to that of the metaxylem vessel. In particular, a branched pit structure was found for the first time in the parenchyma cell.


Biochemistry ◽  
1982 ◽  
Vol 21 (11) ◽  
pp. 2592-2600 ◽  
Author(s):  
Yee Hsiung Chen ◽  
Jang Chyi Tai ◽  
Wan Jen Huang ◽  
Ming Zong Lai ◽  
Mien Chie Hung ◽  
...  

2007 ◽  
Vol 282 (49) ◽  
pp. 35530-35535 ◽  
Author(s):  
Christopher J. Millard ◽  
Ian R. Ellis ◽  
Andrew R. Pickford ◽  
Ana M. Schor ◽  
Seth L. Schor ◽  
...  

The motogenic activity of migration-stimulating factor, a truncated isoform of fibronectin (FN), has been attributed to the IGD motifs present in its FN type 1 modules. The structure-function relationship of various recombinant IGD-containing FN fragments is now investigated. Their structure is assessed by solution state NMR and their motogenic ability tested on fibroblasts. Even conservative mutations in the IGD motif are inactive or have severely reduced potency, while the structure remains essentially the same. A fragment with two IGD motifs is 100 times more active than a fragment with one and up to 106 times more than synthetic tetrapeptides. The wide range of potency in different contexts is discussed in terms of cryptic FN sites and cooperativity. These results give new insight into the stimulation of fibroblast migration by IGD motifs in FN.


2005 ◽  
Vol 143 (1) ◽  
pp. 43-55 ◽  
Author(s):  
L. W. ZENG ◽  
P. S. COCKS ◽  
S. G. KAILIS ◽  
J. KUO

Changes in the seed coat morphology of 12 annual legumes were studied using environmental scanning electron microscopy (ESEM). The seeds of Biserrula pelecinus L. cv. Casbah, Ornithopus sativus cv. Cadiz, Trifolium clypeatum L., T. spumosum L., T. subterraneum L. cv. Bacchus Marsh, Trigonella balansae Boiss. & Reuter., Trigonella monspeliaca L. and Vicia sativa subsp. amphicarpa Dorthes (morthes.) were examined by ESEM after exposure to field conditions for 6 months, while those of Medicago polymorpha L. cv. Circle Valley, Trifolium clypeatum L., T. glanduliferum Boiss., T. lappaceum L., T. spumosum L., and T. subterraneum L. cv. Dalkeith, were examined after 2 years' exposure. The entry of water into seeds was followed by covering various parts of the seed coat with petroleum jelly and soaking the treated seeds in dyes.As the seeds softened over time, more and larger fractures appeared on the seed coat. Water entered the seed either through fractures, over the seed coat as a whole or through the lens. It is hypothesized that the formation of fractures occurs after physicochemical changes in the seed coat, probably associated with changes in the amount and nature of seed coat lipids.The newly matured whole seeds of M. polymorpha cv. Circle Valley, T. clypeatum, T. glanduliferum, T. lappaceum, T. spumosum, and T. subterraneum cv. Dalkeith were analysed for lipid content in 1997. The seed coats of T. subterraneum cv. Dalkeith and T. spumosum were separated from the cotyledons and examined in detail for lipid content.The lipid content of whole seeds ranged from 48 (T. lappaceum) to 167 mg/g (T. subterraneum cv. Dalkeith). Total lipid of the whole seeds of T. subterraneum cv. Dalkeith and T. glanduliferum declined by about 9 mg/g over 2 years, while in T. spumosum it declined by about 17 mg/g.In contrast, the major fatty acids in the seed coat declined by 0·67 mg/g over the 2 years. Change in seed coat lipids showed a marked similarity to changes in hardseededness for both T. subterraneum cv. Dalkeith and T. spumosum. The results strongly suggest that seed softening is associated with loss of lipids in the seed coat, because lipids have physical characteristics that are altered at temperatures experienced in the field.


2014 ◽  
Vol 997 ◽  
pp. 496-499 ◽  
Author(s):  
Peng Zhao ◽  
De Qing Xie ◽  
Guang Yan Li ◽  
Yun Sheng Zhang

Portland cement has low chemical and physical affinity for traditional building materials. This hinders the restoration of historical buildings and modern rustic architecture where blue bricks are used. Pig blood–lime mortar is one of the most important technological inventions in the Chinese architectural history. Mortar in this work was fabricated according to formulas of the literature, and some analyses were conducted for further understanding their microstructure. Environmental scanning electron microscopy was utilized to analyze mechanism of interaction between key components of ancient mortar bonding materials. Results show that pig blood accelerates the formation of microstructure at early stage. Pig blood plays the role of biological templates which regulates the growth of calcium carbonate crystal.


2021 ◽  
Vol 22 (19) ◽  
pp. 10310
Author(s):  
Cristina Romero-López ◽  
Alfredo Berzal-Herranz ◽  
José Luis Martínez-Guitarte ◽  
Mercedes de la Fuente

The telomeric transcriptome of Chironomus riparius has been involved in thermal stress response. One of the telomeric transcripts, the so-called CriTER-A variant, is highly overexpressed upon heat shock. On the other hand, its homologous variant CriTER-B, which is the most frequently encoded noncoding RNA in the telomeres of C. riparius, is only slightly affected by thermal stress. Interestingly, both transcripts show high sequence homology, but less is known about their folding and how this could influence their differential behaviour. Our study suggests that CriTER-A folds as two different conformers, whose relative proportion is influenced by temperature conditions. Meanwhile, the CriTER-B variant shows only one dominant conformer. Thus, a temperature-dependent conformational equilibrium can be established for CriTER-A, suggesting a putative functional role of the telomeric transcriptome in relation to thermal stress that could rely on the structure–function relationship of the CriTER-A transcripts.


2018 ◽  
Author(s):  
Angèle Abboud ◽  
Pierre Bédoucha ◽  
Jan Byška ◽  
Thomas Arnesen ◽  
Nathalie Reuter

N-terminal acetyltransferases (NATs) are enzymes catalysing the transfer of the acetyl from Ac-CoA to the N-terminus of proteins, one of the most common protein modifications. Unlike NATs, lysine acetyltransferases (KATs) transfer an acetyl onto the amine group of internal lysines. To date, not much is known on the exclusive substrate specificity of NATs towards protein N-termini. All the NATs and some KATs share a common fold called GNAT. The main difference between NATs and KATs is an extra hairpin loop found only in NATs called β6β7 loop. It covers the active site as a lid. The hypothesized role of the loop is that of a barrier restricting the access to the catalytic site and preventing acetylation of internal lysines. We investigated the dynamics-function relationships of all available structures of NATs covering the three domains of life. Using elastic network models and normal mode analysis, we found a common dynamics pattern conserved through the GNAT fold; a rigid V-shaped groove, formed by the β4 and β5 strands and three relatively more dynamic loops α1α2, β3β4 and β6β7. We identified two independent dynamical domains in the GNAT fold, which is split at the β5 strand. We characterized the β6β7 hairpin loop slow dynamics and show that its movements are able to significantly widen the mouth of the ligand binding site thereby influencing its size and shape. Taken together our results show that NATs may have access to a broader ligand specificity range than anticipated.


1990 ◽  
Vol 68 (2) ◽  
pp. 354-363 ◽  
Author(s):  
David G. Fisher

Four distinct anatomical types of minor veins occur in Cananga odorata leaves. In order of decreasing size, they are (i) type I, with tracheary elements, fibers, vascular parenchyma cells, companion cells, and mostly nacreous-walled sieve-tube members; (ii) type II, with the same cell types except that the sieve-tube members have walls that usually lack nacreous thickenings; (iii) type III, with only vascular parenchyma cells and tracheids; and (iv) type IV (vein endings), with tracheary elements only. The proportions of the total minor vein length occupied by each are type I, 15.1%; type II, 27.2%; type III, 24.4%; and type IV, 33.3%. Thus about 60% of the minor vein network lacks sieve tubes. The average interveinal distance for all minor veins is 121 μm, but the average for veins containing sieve-tubes is 329 μm. Other salient features include vascular parenchyma cells up to 130 μm long, bundle-sheath cells whose lateral protuberances into the mesophyll increase extensively with decreasing vein size, and five layers of horizontally oriented spongy parenchyma cells. These features may facilitate transport of assimilate to the relatively small proportion of the minor vein network that contains sieve tubes.


2020 ◽  
Vol 48 (3) ◽  
pp. 1255-1268
Author(s):  
Alejandro J. Cagnoni ◽  
María F. Troncoso ◽  
Gabriel A. Rabinovich ◽  
Karina V. Mariño ◽  
María T. Elola

Galectin-8 (Gal-8) is a tandem-repeat type galectin with affinity for β-galactosides, bearing two carbohydrate recognition domains (CRD) connected by a linker peptide. The N- and C-terminal domains (Gal-8N and Gal-8C) share 35% homology, and their glycan ligand specificity is notably dissimilar: while Gal-8N shows strong affinity for α(2-3)-sialylated oligosaccharides, Gal-8C has higher affinity for non-sialylated oligosaccharides, including poly-N-acetyllactosamine and/ or A and B blood group structures. Particularly relevant for understanding the biological role of this lectin, full-length Gal-8 can bind cell surface glycoconjugates with broader affinity than the isolated Gal-8N and Gal-8C domains, a trait also described for other tandem-repeat galectins. Herein, we aim to discuss the potential use of separate CRDs in modelling tandem-repeat galectin-8 and its biological functions. For this purpose, we will cover several aspects of the structure–function relationship of this protein including crystallographic structures, glycan specificity, cell function and biological roles, with the ultimate goal of understanding the potential role of each CRD in predicting full-length Gal-8 involvement in relevant biological processes.


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