Seasonal changes in cambium activity from active to dormant stage affect the formation of secondary xylem in Pinus tabulaeformis Carr

2021 ◽  
Author(s):  
Yayu Guo ◽  
Huimin Xu ◽  
Hongyang Wu ◽  
Weiwei Shen ◽  
Jinxing Lin ◽  
...  
Keyword(s):  
Cell Walls ◽  
Secondary Xylem ◽  
Periodic Acid ◽  
Wood Formation ◽  
Vascular Cambium ◽  
Pinus Tabulaeformis ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Dormant Stage ◽  
Cambium Activity

Abstract Understanding the changing patterns of vascular cambium during seasonal cycles is crucial to reveal the mechanisms that control cambium activity and wood formation, but this area has been underexplored, especially in conifers. Here, we quantified the changing cellular morphology patterns of cambial zones during the active, transition and dormant stages. With the help of toluidine blue and periodic acid Schiff staining to visualize cell walls and identify their constituents, we observed decreasing cambial cell layers, thickening of newly formed xylem cell walls and increased polysaccharide granules in phloem from June to the following March over the course of our collecting period. Pectin immunofluorescence showed that dormant stage cambium can produce highly abundant de-esterified homogalacturonan and (1–4)-β-D-galactan epitopes, while active cambium can strong accumulate high methylesterified homogalacturonan. Calcofluor white staining and confocal Raman spectroscopy analysis revealed regular changes in the chemical composition of cell walls, such as relative lower cellulose deposition in transition stage in vascular cambium, and higher lignin accumulation was found in dormant stage in secondary xylem. Moreover, RT-qPCR analysis suggested that various IAA (Aux/IAA protein), CesA, CslA and HDZ genes, as well as NAC, PME3 and PME4, may be involved in cambium activities and secondary xylem formation. Taken together, these findings provide new information about cambium activity and cell differentiation in the formation, structure, and chemistry in conifers during the active–dormant transition.

scholarly journals A novel pathway controlling cambium initiation and - activity via cytokinin biosynthesis in Arabidopsis

2020 ◽  
Author(s):  
Arezoo Rahimi ◽  
Omid Karami ◽  
Angga Dwituti Lestari ◽  
Dongbo Shi ◽  
Thomas Greb ◽  
...  
Keyword(s):  
Secondary Xylem ◽  
Secondary Growth ◽  
Wood Formation ◽  
Vascular Cambium ◽  
Loss Of Function ◽  
Specific Expression ◽  
Cytokinin Biosynthesis ◽  
Inflorescence Stems ◽  
Xylem Formation ◽  
Cambium Activity

AbstractPlant secondary growth, also referred to as wood formation, includes the production of secondary xylem, which is derived from meristematic cambium cells embedded in vascular tissues. Despite the importance of secondary xylem in plant growth and wood formation, the molecular mechanism of secondary growth is not yet well understood. Here we identified an important role for the Arabidopsis thaliana (Arabidopsis) AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED 15 (AHL15) gene, encoding for a putative transcriptional regulator, in controlling vascular cambium activity and secondary xylem formation. Secondary xylem development was significantly reduced in inflorescence stems of the Arabidopsis ahl15 loss-of-function mutant, whereas AHL15 overexpression led to extensive secondary xylem formation. AHL15 expression under a vascular meristem-specific promoter also enhanced the amount of interfascicular secondary xylem. Moreover, AHL15 appeared to be required for the enhanced secondary xylem formation in the Arabidopsis double loss-of-function mutant of the SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) and FRUITFULL (FUL) genes. A well-known central regulator of cambial activity is the plant hormone cytokinin. We showed that the expression of two cytokinin biosynthesis genes (ISOPENTENYL TRANSERASE (IPT) 3 and 7) is decreased in ahl15 loss-of-function mutant stems, whereas the secondary xylem deficiency in these mutant stems can be resorted by cambium-specific expression of the Agrobacterium tumefaciens IPT gene, indicating that AHL15 acts through the cytokinin pathway. These findings support a model whereby AHL15 acts as a central factor inducing vascular cambium activity downstream of SOC1 and FUL and upstream of IPT3, IPT7 and LOG4, LOG5 governing the rate of secondary xylem formation in Arabidopsis inflorescence stems.

Lectins as Cytochemical Probes of the Developing Wheat Grain. V. Demonstration of Separate Polysaccharides Containing N-Acetyl-D-Glucosamine and D-Galactose in Nuclear Epidermal Cell Walls

1984 ◽  
Vol 11 (3) ◽  
pp. 179 ◽  
Author(s):  
BA Baldo ◽  
D Barnett ◽  
JW Lee
Keyword(s):  
Epidermal Cell ◽  
Cell Walls ◽  
Wheat Germ ◽  
Periodic Acid ◽  
Fluorescein Isothiocyanate ◽  
Wheat Grain ◽  
Periodic Acid Schiff ◽  
Thin Sections ◽  
Lectin Staining ◽  
Wheat Germ Lectin

Fluorescein isothiocyanate-labelled lectin from wheat-gem, which binds N-acetyl-D-glucosamine, and Griffonia simplicifolia, Arachis hypogaea and Glycine max lectins, each of which binds D-galactose, react with nucellar epidermal cell walls in thin sections of plastic-embedded developing wheat grain. Reactivity of these cell walls with periodic acid-Schiff reagent, the absence of staining with protein stains and the failure of a number of proteases and the endoglycosidases D and H to prevent the binding suggested that the lectin-reactive wall components are neither proteins nor N-glycosidically linked glycoproteins. Morphological differences in lectin staining patterns and treatment of sections with chitinase and α-galactosidase, prior to the reaction with the lectins, indicated that two separate polysaccharides are probably involved in the binding. Chitinase removed the reactivity of the nucellar epidermal cell walls for wheat-germ lectin but the binding of D-galactose-specific lectins was unimpaired. Conversely, α-galactosidase did not affect the binding of wheat-germ lectin but reactivity with the galactose-specific lectins was abolished. From the available evidence we conclude that one polysaccharide in the nucellar epidermal cell wall reacts with wheat-germ lectin and contains N-acetyl-D-glucosamine in a chitin-like structure. The other polysaccharide reacts with D-galactose- specific lectins by virtue of terminal α-D-galactose residues. Hydrolysis and subsequent chromatographic analysis of nucellar epidermal cell walls peeled from immature grains revealed the presence of D-glucosamine, D-glucose, D-galactose, D-xylose, L-arabinose and a trace of D-mannose.

Seasonal cambial activity and wood formation in trees and lianas of Leguminosae growing in the Atlantic Forest: a comparative study

Botany ◽  
2015 ◽  
Vol 93 (4) ◽  
pp. 211-220 ◽  
Author(s):  
Arno Fritz das Neves Brandes ◽  
Claudio Sergio Lisi ◽  
Leonardo Davi S.A.B. da Silva ◽  
Kishore S. Rajput ◽  
Cláudia Franca Barros
Keyword(s):  
Tree Species ◽  
Secondary Xylem ◽  
Cambial Activity ◽  
Wood Formation ◽  
Montane Forest ◽  
Vascular Cambium ◽  
Growth Rings ◽  
Indirect Methods ◽  
Annual Growth Rings ◽  
Direct And Indirect Methods

Cambial activity and the formation of secondary xylem were investigated in the main stem of three arboreal leguminous species and one liana. To compare the seasonal vascular cambium behavior of these species, two methods were concurrently applied: induction of injury in the vascular cambium and anatomical analysis of the vascular cambium and adjacent zones (differentiation zone). One tree species, Pseudopiptadenia contorta (DC.) G.P.Lewis & M.P.Lima, was sampled in three forest formations: alluvial, submontane, and montane. Two more tree species, Apuleia leiocarpa (Vogel) J.F.Macbr. and Pseudopiptadenia leptostachya (Benth.) Rauschert, were sampled in submontane and montane forest, respectively. Dalbergia frutescens (Vell.) Britton var. frutescens, a liana, was sampled in montane forest. All species investigated showed distinctive formation of annual growth rings. Reactivation of the vascular cambium was observed at the end of spring, and it remained active during the summer. Thereafter, cambial activity either ceased or declined dramatically at the end of autumn. Similar to the tree species studied, cambial activity in D. frutescens var. frutescens showed similar seasonal cambial activity throughout the year. Based on both direct and indirect methods, our results showed that cambial activity and wood formation only occurred during the rainy season, suggesting the potential of these species for use in dendrochronological studies.

A Retrospective Review of Diagnostic Testing for Onychomycosis of the Foot

2015 ◽  
Vol 105 (6) ◽  
pp. 503-508 ◽  
Author(s):  
Nell Blake ◽  
Junjia Zhu ◽  
Giselle Hernandez ◽  
Paul Joseph Juliano
Keyword(s):  
Periodic Acid ◽  
Diagnostic Testing ◽  
Insurance Companies ◽  
Fungal Culture ◽  
Test Results ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Clinically Significant ◽  
Patient’S History ◽  
The Cost

Background Onychomycosis is a fungal infection of the nail that can be caused by dermatophytes, yeasts, or nondermatophyte molds. To diagnose onychomycosis, a clinician must use the patient's history, physical findings, and diagnostic testing, which can include calcofluor white/potassium hydroxide (KOH) mount, fungal culture (FC), and periodic acid–Schiff (PAS) stain. Some insurance companies require authorization for antifungal medication and request laboratory results to confirm infection. We sought to compare the reliability of KOH, PAS, and FC diagnostic results for confirmation of fungal disease, to determine the sensitivity and specificity of each test, and to investigate the cost of each test. In addition, we statistically observed the relationship between the test results and demographic variables. Methods Toenail clippings were obtained from 108 patients clinically diagnosed as having onychomycosis. Diagnostic tests were then performed on each sample; the results were obtained from medical records. Results For PAS, KOH, and FC, 60.2%, 43.5%, and 39.8% of results, respectively, were positive. Agreement for each pair of tests was slightly higher for FC and KOH. Sensitivities for KOH and PAS were 0.64 and 0.79, respectively. Specificity was 0.79 for KOH and 0.54 for PAS. Both PAS and KOH had a higher percentage of positive test results for men than for women. Conclusions Of the three tests evaluated, PAS gives the most consistent positive results and has the highest sensitivity. Therefore, PAS should be considered as the best test to verify clinically significant onychomycosis.

scholarly journals Histochemical study of Encephalitozoon cuniculi spores in the kidneys of naturally infected New Zealand rabbits

2017 ◽  
Vol 29 (3) ◽  
pp. 269-277 ◽  
Author(s):  
Luis E. Rodríguez-Tovar ◽  
Alejandra Villarreal-Marroquín ◽  
Alicia M. Nevárez-Garza ◽  
Uziel Castillo-Velázquez ◽  
Heidi G. Rodríguez-Ramírez ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Background Noise ◽  
Histochemical Study ◽  
Periodic Acid ◽  
Encephalitozoon Cuniculi ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Hematoxylin And Eosin ◽  
Schiff Reaction ◽  
Host Tissues

Encephalitozoon cuniculi is an important microsporidian pathogen that is considered an emergent, zoonotic, and opportunistic. It infects both domestic and laboratory rabbits, generating severe chronic interstitial and granulomatous nephritis with fibrosis and granulomatous encephalitis. Encephalitozoonosis is diagnosed in paraffin-embedded sections by examining the spores in the host tissues. The spores are difficult to observe when the samples are stained with hematoxylin and eosin (H&E), particularly when there is an inflammatory reaction and tissue damage. The spores are easily mistaken for other microorganisms, such as fungi (yeasts), protozoa, and bacteria. In our study, we used kidney samples from E. cuniculi–positive rabbits and employed 14 recommended histologic stains for detecting microsporidia spores: alcian blue, calcofluor white, Giemsa, Gram, Grocott, H&E, Luna, Luxol fast blue, Masson trichrome, modified trichrome stain (MTS), periodic acid–Schiff reaction (PAS), Van Gieson, Warthin–Starry (WS), and Ziehl–Neelsen (ZN).We concluded that MTS and Gram stain, detected by light microscopy, and calcofluor white stain, detected by ultraviolet light microscopy, are the best stains for detecting spores of E. cuniculi in paraffin-embedded tissues from infected rabbits. These stains were superior to WS, ZN, Giemsa, and PAS for identifying spores without background “noise” or monochromatic interference. Also, they allow individual spores to be discerned in paraffin-embedded tissues. MTS allows observation of the polar tube, polaroplast, and posterior vacuole, the most distinctive parts of the spore.

Onychomycosis and Tinea Pedis in the Feet of Patients With Diabetes

2021 ◽  
pp. 153473462110094
Author(s):  
Javier Aragón-Sánchez ◽  
María E. López-Valverde ◽  
Gerardo Víquez-Molina ◽  
Ana Milagro-Beamonte ◽  
Luis Torres-Sopena
Keyword(s):  
Potassium Hydroxide ◽  
Tinea Pedis ◽  
Periodic Acid ◽  
Univariate Analysis ◽  
Significant Variable ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Patients With Diabetes ◽  
History Of ◽  
Direct Fluorescence

This study aimed to determine the prevalence of onychomycosis and interdigital tinea pedis in a cohort of Spanish patients with diabetes in whom onychomycosis was clinically suspected (n = 101). Samples from a first toenail scraping and the fourth toe clefts were subjected to potassium hydroxide direct vision and incubated in Sabouraud and dermatophyte test medium. Fifty-eight samples were also analyzed by a pathologist using periodic acid-Schiff staining and Calcofluor white direct fluorescence microscopy. Onychomycosis was only confirmed in 41 patients (40.6%). The most frequent aetiological agent was Trichophyton rubrum, isolated in 10 patients (36%), followed by Candida parapsilosis in 7 patients (25%). Tests on the fourth toe cleft samples were only positive in 11 patients (10.9%), and in all cases, onychomycosis was also diagnosed. Neuroischemic foot was the only significant variable associated with onychomycosis in the univariate analysis ( P < .01). A positive result for mycosis in the fourth toe cleft was found in 11 cases (10.9%) and was associated with a history of myocardial infarction ( P< .01; odds ratio [OR]: 84.2, confidence interval [CI]: 6.8-1036.4) and neuroischemic foot ( P< .01; OR: 13.7, CI: 12.6-71.6) in the multivariate model. In conclusion, the prevalence of onychomycosis and tinea pedis in patients with diabetes in whom onychomycosis was clinically suspected was 40.6% and 10.9%, respectively. In addition, onychomycosis was not always associated with tinea pedis. These results show that clinical diagnosis has low accuracy in people with diabetes mellitus, and that diagnosis should not be based on clinical toenail characteristics alone.

scholarly journals Vascular Cambium: The Source of Wood Formation

2021 ◽  
Vol 12 ◽  
Author(s):  
Dian Wang ◽  
Yan Chen ◽  
Wei Li ◽  
Quanzi Li ◽  
Mengzhu Lu ◽  
...  
Keyword(s):  
Secondary Xylem ◽  
Wood Formation ◽  
Vascular Cambium ◽  
Future Research ◽  
Developmental Processes ◽  
Stem Cell Regulation ◽  
Paper Making ◽  
Proliferation And Differentiation ◽  
Vascular Stem Cells ◽  
Complex Regulatory Network

Wood is the most abundant biomass produced by land plants and is mainly used for timber, pulping, and paper making. Wood (secondary xylem) is derived from vascular cambium, and its formation encompasses a series of developmental processes. Extensive studies in Arabidopsis and trees demonstrate that the initiation of vascular stem cells and the proliferation and differentiation of the cambial derivative cells require a coordination of multiple signals, including hormones and peptides. In this mini review, we described the recent discoveries on the regulation of the three developmental processes by several signals, such as auxin, cytokinins, brassinosteroids, gibberellins, ethylene, TDIF peptide, and their cross talk in Arabidopsis and Populus. There exists a similar but more complex regulatory network orchestrating vascular cambium development in Populus than that in Arabidopsis. We end up with a look at the future research prospects of vascular cambium in perennial woody plants, including interfascicular cambium development and vascular stem cell regulation.

scholarly journals Loss of Wood Formation Genes in Monocot Genomes

2019 ◽  
Vol 11 (7) ◽  
pp. 1986-1996 ◽  
Author(s):  
Danielle Roodt ◽  
Zhen Li ◽  
Yves Van de Peer ◽  
Eshchar Mizrachi
Keyword(s):  
Zostera Marina ◽  
Gene Network ◽  
Secondary Cell Wall ◽  
Secondary Xylem ◽  
Wood Formation ◽  
Vascular Cambium ◽  
Cambial Cell ◽  
Regulatory Model ◽  
Differentiation Gene ◽  
Additional Losses

Abstract Woodiness (secondary xylem derived from vascular cambium) has been gained and lost multiple times in the angiosperms, but has been lost ancestrally in all monocots. Here, we investigate the conservation of genes involved in xylogenesis in fully sequenced angiosperm genomes, hypothesizing that monocots have lost some essential orthologs involved in this process. We analyzed the conservation of genes preferentially expressed in the developing secondary xylem of two eudicot trees in the sequenced genomes of 26 eudicot and seven monocot species, and the early diverging angiosperm Amborella trichopoda. We also reconstructed a regulatory model of early vascular cambial cell identity and differentiation and investigated the conservation of orthologs across the angiosperms. Additionally, we analyzed the genome of the aquatic seagrass Zostera marina for additional losses of genes otherwise essential to, especially, secondary cell wall formation. Despite almost complete conservation of orthology within the early cambial differentiation gene network, we show a clear pattern of loss of genes preferentially expressed in secondary xylem in the monocots that are highly conserved across eudicot species. Our study provides candidate genes that may have led to the loss of vascular cambium in the monocots, and, by comparing terrestrial angiosperms to an aquatic monocot, highlights genes essential to vasculature on land.

Development of Vascular Cambium and Compression Wood Formation in the Shoot of Young Spruce (Picea Jezoensis Var. Hondoensis)

IAWA Journal ◽  
1986 ◽  
Vol 7 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Nobuo Yoshizawa ◽  
Yujiro Tanaka ◽  
Toshinaga Idei
Keyword(s):  
Cross Sections ◽  
Compression Wood ◽  
Secondary Xylem ◽  
Wood Formation ◽  
Vascular Cambium ◽  
Tracheary Elements ◽  
Picea Jezoensis ◽  
Appreciable Difference

In the course of the righting movement in young spruce trees (Picea jezoensis Carr. var. hondoensis Rehd.) inclined at 45°, the occurrence of compression wood associated with the development of vascular cambium in the shoot was observed. In shoots, the recovery first took place at the mid point, a few days after inclination. The observations of serial cross sections taken from the apex downward revealed no appreciable difference in the development of the procambium-cambium continuum between the upper- and underside of the shoot. The formation and structure of primary tracheary elements were similar, irrespective of the site of the procambium in the shoot. No compression wood cells occurred before the vascular cambium cylinder was complete. The stimulus of compression wood formation is received only by the differentiating secondary xylem tissues derived from the cambium cylinder.

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