Membrane-related hallmarks of kinetin-induced PCD of root cortex cells

2016 ◽  
Vol 36 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Andrzej Kaźmierczak ◽  
Magdalena Doniak ◽  
Przemysław Bernat
1987 ◽  
Vol 83 (1) ◽  
pp. 159-162 ◽  
Author(s):  
Xiao-Jun Zhao ◽  
Edward Sucoff ◽  
Eduard J. Stadelmann

2018 ◽  
Vol 70 (3) ◽  
pp. 413-423 ◽  
Author(s):  
Mohamed Farissi ◽  
Mohammed Mouradi ◽  
Omar Farssi ◽  
Abdelaziz Bouizgaren ◽  
Cherki Ghoulam

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.


1970 ◽  
Vol 25 (12) ◽  
pp. 1477-1479 ◽  
Author(s):  
Charlotte Hecht-Buchholz ◽  
Horst Marschner

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


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrzej Kaźmierczak ◽  
Anita Kunikowska ◽  
Magdalena Doniak ◽  
Andrzej Kornaś

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.


1974 ◽  
Vol 52 (4) ◽  
pp. 783-789 ◽  
Author(s):  
Susan J. Alexander ◽  
Robert Hall

The morphology and distribution of Verticillium dahliae Kleb. within the ornamental chrysanthemum (Chrysanthemum morifolium Ramat) was determined at intervals after placement of rooted cuttings into infested potting mix. Most infection sites on the root system occurred on roots that developed after potting. Estimates of the number of infection courts per 100 cm of root ranged from 5.6 to 15.8. Root-cortex cells responded to invasion by producing lignitubers and a dark pigment. Microsclerotia had formed within root-cortex cells 8 days after potting. Hyphae, conidia, and conidiophores were observed throughout the vascular system. Hyphal widths ranged from 1.3 to 3.6 μm; conidial dimensions ranged from 1.8 × 3.6 to 2.6 × 5.8 μm. Colonization of vessels of stem and leaves was initially discontinuous and was therefore presumably initiated by conidia. Hyphae in root and stem vessels were generally narrow and there was rarely more than one strand per vessel. Occlusion of the lumen or pore plate of vessel elements in root and stem by hyphae, conidia, gums, gels, or tyloses was not observed. Conidia accumulated in petioles and basal portions of the midrib and lateral veins of leaves, often blocking pore plates. Initially, hyphae in leaf vessel elements were narrow but as wilt symptoms appeared, wide sinuous hyphae predominated, often coursing freely among adjacent vessel elements through pit-pairs and pore plates. Mycelium and conidia appeared to occur sufficiently abundantly in leaf vessels to significantly restrict water flow.


PROTOPLASMA ◽  
2012 ◽  
Vol 250 (4) ◽  
pp. 851-861 ◽  
Author(s):  
Anita Kunikowska ◽  
Anna Byczkowska ◽  
Andrzej Kaźmierczak

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