Effect of Chilling on DNA Endoreplication in Root Cortex Cells and Root Hairs of Soybean Seedlings

2003 ◽  
Vol 46 (3) ◽  
pp. 333-339 ◽  
Author(s):  
D. Stepinski
Keyword(s):  
Root Hairs ◽  
Root Cortex ◽  
Soybean Seedlings ◽  
Root Cortex Cells ◽  
Dna Endoreplication

scholarly journals Al3+ and Ca2+ Alteration of Membrane Permeability of Quercus rubra Root Cortex Cells

1987 ◽  
Vol 83 (1) ◽  
pp. 159-162 ◽  
Author(s):  
Xiao-Jun Zhao ◽  
Edward Sucoff ◽  
Eduard J. Stadelmann
Keyword(s):  
Membrane Permeability ◽  
Quercus Rubra ◽  
Root Cortex ◽  
Root Cortex Cells

scholarly journals Variations in leaf gas exchange, chlorophyll fluorescence and membrane potential of Medicago sativa root cortex cells exposed to increased salinity: The role of the antioxidant potential in salt tolerance

2018 ◽  
Vol 70 (3) ◽  
pp. 413-423 ◽  
Author(s):  
Mohamed Farissi ◽  
Mohammed Mouradi ◽  
Omar Farssi ◽  
Abdelaziz Bouizgaren ◽  
Cherki Ghoulam
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Membrane Potential ◽  
Salt Tolerance ◽  
Gas Exchange ◽  
Medicago Sativa ◽  
Leaf Gas Exchange ◽  
Root Cortex ◽  
Root Cortex Cells

Salinity is one of the most serious agricultural problems that adversely affects growth and productivity of pasture crops such as alfalfa. In this study, the effects of salinity on some ecophysiological and biochemical criteria associated with salt tolerance were assessed in two Moroccan alfalfa (Medicago sativa L.) populations, Taf 1 and Tata. The experiment was conducted in a hydro-aeroponic system containing nutrient solutions, with the addition of NaCl at concentrations of 100 and 200 mM. The salt stress was applied for a month. Several traits in relation to salt tolerance, such as plant dry biomass, relative water content, leaf gas exchange, chlorophyll fluorescence, nutrient uptake, lipid peroxidation and antioxidant enzymes, were analyzed at the end of the experiment. The membrane potential was measured in root cortex cells of plants grown with or without NaCl treatment during a week. The results indicated that under salt stress, plant growth and all of the studied physiological and biochemical traits were significantly decreased, except for malondialdehyde and H2O2 contents, which were found to be increased under salt stress. Depolarization of membrane root cortex cells with the increase in external NaCl concentration was noted, irrespective of the growth conditions. The Tata population was more tolerant to high salinity (200 mM NaCl) and its tolerance was associated with the ability of plants to maintain adequate levels of the studied parameters and their ability to overcome oxidative stress by the induction of antioxidant enzymes, such as guaiacol peroxidase, catalase and superoxide dismutase.

Einfluß von Tetraphenylborat auf die Feinstruktur von Zellen der Maiswurzelspitze / Influence of Tetraphenylboron on Fine Structure of Cells of Corn Root Tips

1970 ◽  
Vol 25 (12) ◽  
pp. 1477-1479 ◽  
Author(s):  
Charlotte Hecht-Buchholz ◽  
Horst Marschner
Keyword(s):  
Fine Structure ◽  
Membrane Structure ◽  
Endoplasmatic Reticulum ◽  
Root Tips ◽  
Root Cortex ◽  
Double Membrane ◽  
Corn Root ◽  
Ca 50 ◽  
Root Cortex Cells

Treatment (1-3h) of corn root tips with 5 × 10-5ᴍ tetraphenylboron (TPB) caused characteristic changes of the membrane structure in the outer layers of the root cortex cells. The mitochondria had lost their inner structure. At the double membrane of the mitochondria and at the membrane plasmalemma, tonoplast, and endoplasmatic reticulum there appeared numerous osmiophilic globuli (ca. 50 nm). The permeability of the membranes seemed to be increased extremely. It is suggested that the lipoproteine complex of the membranes was destroyed by interaction of TPB with ammonium groups of the membrane constituents

scholarly journals The Role of Primary and Secondary Infection in Host Response to Plasmodiophora brassicae

2014 ◽  
Vol 104 (10) ◽  
pp. 1078-1087 ◽  
Author(s):  
Mary Ruth McDonald ◽  
Kalpana Sharma ◽  
Bruce D. Gossen ◽  
Abhinandan Deora ◽  
Jie Feng ◽  
...  
Keyword(s):  
Plasmodiophora Brassicae ◽  
Secondary Infection ◽  
Root Hairs ◽  
Secondary Phase ◽  
Primary Phase ◽  
Root Cortex ◽  
Resting Spores ◽  
Cortical Infection ◽  
Root Hair Infection

The disease cycle of Plasmodiophora brassicae consists of a primary phase in root hairs followed by a secondary phase in the root cortex and adjacent tissues. However, the role of root hair infection in subsequent cortical infection and development of P. brassicae is not well understood. To examine the role of the primary and secondary stages separately, inoculation studies with resting spores (source of primary zoospores) and secondary zoospores of a virulent and avirulent pathotype were conducted on canola (Brassica napus). The size of secondary zoospores and number of nuclei were also examined. The zoospores were larger (≈9.6 to 14.4 μm) than in previous reports and all were uninucleate. Inoculation with secondary zoospores alone produced both primary and secondary infection, even with the avirulent pathotype. No symptoms developed from inoculation with avirulent primary zoospores but tiny, bead-shaped clubs developed from inoculation with avirulent secondary zoospores. Inoculation with virulent secondary zoospores alone resulted in lower disease severity than inoculation with virulent resting spores alone. The results indicate that recognition of infection by the host and initiation of a response (induction or suppression of resistance) occurs during primary infection, although recognition can also occur during cortical infection and development.

scholarly journals Nodulation of Aeschynomene afraspera and A. indica by Photosynthetic Bradyrhizobium Sp. Strain ORS285: The Nod-Dependent Versus the Nod-Independent Symbiotic Interaction

2011 ◽  
Vol 24 (11) ◽  
pp. 1359-1371 ◽  
Author(s):  
Katia Bonaldi ◽  
Daniel Gargani ◽  
Yves Prin ◽  
Joel Fardoux ◽  
Djamel Gully ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Lateral Roots ◽  
Root Hairs ◽  
Infection Process ◽  
Cortical Cells ◽  
Symbiotic Interaction ◽  
Root Cortex ◽  
Bradyrhizobium Sp ◽  
Infected Cells ◽  
Green Fluorescent

Here, we present a comparative analysis of the nodulation processes of Aeschynomene afraspera and A. indica that differ in their requirement for Nod factors (NF) to initiate symbiosis with photosynthetic bradyrhizobia. The infection process and nodule organogenesis was examined using the green fluorescent protein–labeled Bradyrhizobium sp. strain ORS285 able to nodulate both species. In A. indica, when the NF-independent strategy is used, bacteria penetrated the root intercellularly between axillary root hairs and invaded the subepidermal cortical cells by invagination of the host cell wall. Whereas the first infected cortical cells collapsed, the infected ones immediately beneath kept their integrity and divided repeatedly to form the nodule. In A. afraspera, when the NF-dependent strategy is used, bacteria entered the plant through epidermal fissures generated by the emergence of lateral roots and spread deeper intercellularly in the root cortex, infecting some cortical cells during their progression. Whereas the infected cells of the lower cortical layers divided rapidly to form the nodule, the infected cells of the upper layers gave rise to an outgrowth in which the bacteria remained enclosed in large tubular structures. Together, two distinct modes of infection and nodule organogenesis coexist in Aeschynomene legumes, each displaying original features.

scholarly journals Analysis of Promoter Activity of the Early Nodulin Enod40 in Lotus japonicus

2005 ◽  
Vol 18 (5) ◽  
pp. 414-427 ◽  
Author(s):  
Mette Grønlund ◽  
Andreas Roussis ◽  
Emmanouil Flemetakis ◽  
Nicolette E. M. Quaedvlieg ◽  
Helmi R. M. Schlaman ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Lotus Japonicus ◽  
Root Hairs ◽  
Early Time ◽  
Cellular Level ◽  
Nod Factors ◽  
Root Cortex ◽  
Model Legume ◽  
Early Nodulin ◽  
Nodulin Genes

Our comparative studies on the promoter (pr) activity of Enod40 in the model legume Lotus japonicus in stably transformed GusA reporter lines and in hairy roots of L. japonicus demonstrate a stringent regulation of the Enod40 promoter in the root cortex and root hairs in response to Nod factors. Interestingly, the L. japonicus Enod40-2 promoter fragment also shows symbiotic activity in the reverse orientation. Deletion analyses of the Glycine max (Gm) Enod40 promoter revealed the presence of a minimal region -185 bp upstream of the transcription start. Stable transgenic L. japonicus reporter lines were used in bioassays to test the effect of different compounds on early symbiotic signaling. The responses of prGmEnod40 reporter lines were compared with the responses of L. japonicus (Lj) reporter lines based on the LjNin promoter. Both reporter lines show very early activity postinoculation in root hairs of the responsive zone of the root and later in the dividing cells of nodule primordia. The LjNin promoter was found to be more responsive than the GmEnod40 promoter to Nod factors and related compounds. The use of prGmEnod40 reporter lines to analyze the effect of nodulin genes on the GmEnod40 promoter activity indicates that LJNIN has a positive effect on the regulation of the Enod40 promoter, whereas the latter is not influenced by ectopic overexpression of its own gene product. In addition to pointing to a difference in the regulation of the two nodulin genes Enod40 and Nin during early time points of symbiosis, the bioassays revealed a difference in the response to the synthetic cytokinin 6-benzylaminopurine (BAP) between alfalfa and clover and L. japonicus. In alfalfa and clover, Enod40 expression was induced upon BAP treatment, whereas this seems not to be the case in L. japonicus; these results correlate with effects at the cellular level because BAP can induce pseudonodules in alfalfa and clover but not in L. japonicus. In conclusion, we demonstrate the applicability of the described L. japonicus reporter lines in analyses of the specificity of compounds related to nodulation as well as for the dissection of the interplay between different nodulin genes.

scholarly journals Mechanism of kinetin-induced death of Vicia faba ssp. minor root cortex cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrzej Kaźmierczak ◽  
Anita Kunikowska ◽  
Magdalena Doniak ◽  
Andrzej Kornaś
Keyword(s):  
Cell Death ◽  
Vicia Faba ◽  
Permeability Transition ◽  
Ruthenium Red ◽  
Root Cortex ◽  
Raf Kinase ◽  
Cytokinin Receptors ◽  
Root Cortex Cells ◽  
Exogenous Factors

AbstractCell death (CD) may be induced by endogenous or exogenous factors and contributes to all the steps of plant development. This paper presents results related to the mechanism of CD regulation induced by kinetin (Kin) in the root cortex of Vicia faba ssp. minor. To explain the process, 6-(2-hydroxy-3-methylbenzylamino)purine (PI-55), adenine (Ad), 5′-amine-5′-deoxyadenosine (Ado) and N-(2-chloro-4-piridylo)-N′-phenylurea (CPPU) were applied to (i) block cytokinin receptors (CKs) and inhibit the activities of enzymes of CK metabolism, i.e., (ii) phosphoribosyltransferase, (iii) kinases, and (iv) oxidases, respectively. Moreover, ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA), lanthanum chloride (LaCl3), ruthenium red (RRed) and cyclosporine A (CS-A) were applied to (i) chelate extracellular calcium ions (Ca2+) as well as blocks of (ii) plasma-, (iii) endoplasmic reticulum- (ER) membrane Ca2+ ion channels and (iv) mitochondria- (MIT) Ca2+ ions release by permeability transition por (PTP), respectively. The measured physiological effectiveness of these factors was the number of living and dying cortex cells estimated with orange acridine (OA) and ethidium bromide (EB), the amounts of cytosolic Ca2+ ions with chlortetracycline (CTC) staining and the intensity of chromatin and Ca2+-CTC complex fluorescence, respectively. Moreover, the role of sorafenib, an inhibitor of RAF kinase, on the vitality of cortex cells and ethylene levels as well as the activities of RAF-like kinase and MEK2 with Syntide-2 and Mek2 as substrates were studied. The results clarified the previously presented suggestion that Kin is converted to appropriate ribotides (5′-monophosphate ribonucleotides), which cooperate with the ethylene and Ca2+ ion signalling pathways to transduce the signal of kinetin-programmed cell death (Kin-PCD). Based on the present and previously published results related to Kin-PCD, the crosstalk between ethylene and MAP kinase signalling, as well as inhibitors of CK receptors and enzymes of their metabolism, is proposed.

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