Electrical impedance analysis in plant tissues: The effect of freeze-thaw injury on the electrical properties of potato tuber and carrot root tissues

1992 ◽  
Vol 72 (2) ◽  
pp. 545-553 ◽  
Author(s):  
M. I. N. Zhang ◽  
J. H. M. Willison
Keyword(s):  
Plasma Membrane ◽  
Potato Tuber ◽  
Electrical Impedance ◽  
Membrane Capacitance ◽  
Potato Tubers ◽  
Carrot Root ◽  
Freeze Thaw ◽  
Intracellular Resistance ◽  
Root Tissues ◽  
Extracellular Resistance

Electrical impedances in the range 100 Hz to 800 KHz were measured in potato tubers and carrot root cortex both before and after freeze-thaw cycles. These impedance data were analyzed using equivalent circuit modelling based on complex nonlinear least squares (CNLS) (Zhang and Willison 1991a). After freezing to and thawing from −3, −6, −9 and −12 °C, carrot root tissues were best characterized by a double shell model composed of extracellular resistance, cytoplasmic resistance, plasma membrance capacitance, vacuole interior resistance, and tonoplast capacitance. Although freeze–thaw cycles to −3 or −6 °C did not kill the carrot tissues, extracellular resistance and vacuole interior resistance were halved relative to control tissues, and cytoplasmic resistance decreased to a third of the control value. Plasma membrane capacitance and tonoplast capacitance were not affected by the −3 and −6 °C noninjurious stresses. After carrot root or potato tuber tissues had been killed by freezing (−3 °C for potato tuber and −18 °C for carrot), the tissues were best represented by a single-shell model composed of extravesicular resistance, intravesicular resistance, and vesicle membrane. Compared with unfrozen controls, freeze-killed potato tubers were characterized by a 30-fold decrease in extracellular resistance, a 7-fold decrease in intracellular resistance, and a 10-fold decrease in plasma membrane capacitance. Freeze-killed carrot roots were characterized by a 30-fold decrease in extracellular resistance, 3-fold decrease in intracellular resistance, and 3.5-fold decrease in plasma membrane capacitance. These results are compatible with massive rupturing of protoplasts during lethal freeze–thaw injury.Key words: Solanum tuberosum L., Daucus carota L., freeze–thaw injury, electrical impedance

scholarly journals Responses of Parameters for Electrical Impedance Spectroscopy and Pressure–Volume Curves to Drought Stress in Pinus bungeana Seedlings

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 359
Author(s):  
Ai-Fang Wang ◽  
Bao Di ◽  
Tapani Repo ◽  
Marja Roitto ◽  
Gang Zhang
Keyword(s):  
Drought Stress ◽  
Impedance Spectroscopy ◽  
Drought Tolerance ◽  
Osmotic Potential ◽  
Electrical Impedance ◽  
Electrical Impedance Spectroscopy ◽  
Tree Seedlings ◽  
Intracellular Resistance ◽  
Pinus Bungeana ◽  
Extracellular Resistance

Background and Objectives: Drought occurs more frequently in Northern China with the advent of climate change, which might increase the mortality of tree seedlings after afforestation due to hydraulic failure. Therefore, investigating water relations helps us understand the drought tolerance of tree seedlings. Electrical impedance spectroscopy (EIS) is widely used to assess the responses of plant tissues to stress factors and may potentially reveal the water relations of cells. The aim of this study is to reveal the relationships between EIS and water related parameters, produced by pressure–volume (PV) curves in lacebark pine (Pinus bungeana Zucc.) seedlings reacting to drought stress. Materials and Methods: Four-year-old pot seedlings were divided into three parts (0, 5, and 10 days of drought) before planting, the treated seedlings were then replanted, and finally exposed to post-planting drought treatments with the following soil relative water contents: (i) adequate irrigation (75%–80%), (ii) light drought (55%–60%), (iii) moderate drought (35%–40%), and (iv), severe drought (15%–20%). During the post-planting growth phase, the EIS parameters of needles and shoots, and the parameters of PV curves, were measured coincidently; thus, the correlations between them could be obtained. Results: The extracellular resistance (re) of needles and shoots were substantially reduced after four weeks of severe post-planting drought stress. Meanwhile, the osmotic potential at the turgor-loss point (ψtlp) and the saturation water osmotic potential (ψsat) of shoots decreased after drought stress, indicating an osmotic adjustment in acclimating to drought. The highest correlations were found between the intracellular resistance (ri) of the shoots and ψtlp and ψsat. Conclusions: EIS parameters can be used as a measure of drought tolerance. The change in intracellular resistance is related to the osmotic potential of the cell and cell wall elasticity. Extracellular resistance is a parameter that shows cell membrane damage in response to drought stress in lacebark pine seedlings.

Measurement of heat injury in plant tissue by using electrical impedance analysis

1993 ◽  
Vol 71 (12) ◽  
pp. 1605-1611 ◽  
Author(s):  
M. I. N. Zhang ◽  
J. H. M. Willison ◽  
M. A. Cox ◽  
S. A. Hall
Keyword(s):  
Heat Stress ◽  
Solanum Tuberosum ◽  
Electrical Impedance ◽  
Solanum Tuberosum L ◽  
Impedance Analysis ◽  
Membrane Capacitance ◽  
Temperature Changes ◽  
Heat Injury ◽  
Membrane Thermostability ◽  
Extracellular Resistance

Electrical impedance spectra (100 Hz to 800 kHz) were measured in pieces of potato (Solanum tuberosum L.) tuber tissue that had been heat stressed. Analysis of the impedance data based on equivalent circuits showed that tissue injury was revealed as decreases in membrane capacitance and extracellular resistance. By using a single piece of tissue, membrane thermostability (in relation to heat stress temperature or time of heat stress) was measured. Nonstressful temperature changes produced changes in tissue parameters that were fully reversible when the direction of temperature change was reversed. Stressful temperature changes produced irreversible changes in parameters. During heat injury, decrease in extracellular resistance always preceded a decrease in tonoplast capacitance. It is suggested that two stages may be involved in heat injury to membranes: functional injury leading to electrolyte leakage to extracellular space, and structural damage leading to membrane disintegration. It is concluded that electrical impedance analysis is useful in plant heat stress physiology. Key words: potato (Solanum tuberosum L.) tuber, electrical impedance, membrane capacitance, heat injury, membrane thermostability.

scholarly journals Expression Levels of the γ-Glutamyl Hydrolase I Gene Predict Vitamin B9 Content in Potato Tubers

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 734 ◽  
Author(s):  
Bruce R. Robinson ◽  
Carolina Garcia Salinas ◽  
Perla Ramos Parra ◽  
John Bamberg ◽  
Rocio I. Diaz de la Garza ◽  
...  
Keyword(s):  
Potato Tuber ◽  
Tomato Fruit ◽  
Genetically Engineered ◽  
Food Crops ◽  
Great Success ◽  
Rice Grain ◽  
Rna Seq ◽  
Potato Tubers ◽  
Vitamin B9 ◽  
Folate Biosynthesis

Biofortification of folates in staple crops is an important strategy to help eradicate human folate deficiencies. Folate biofortification using genetic engineering has shown great success in rice grain, tomato fruit, lettuce, and potato tuber. However, consumers’ skepticism, juridical hurdles, and lack of economic model have prevented the widespread adoption of nutritionally-enhanced genetically-engineered (GE) food crops. Meanwhile, little effort has been made to biofortify food crops with folate by breeding. Previously we reported >10-fold variation in folate content in potato genotypes. To facilitate breeding for enhanced folate content, we attempted to identify genes that control folate content in potato tuber. For this, we analyzed the expression of folate biosynthesis and salvage genes in low- and high-folate potato genotypes. First, RNA-Seq analysis showed that, amongst all folate biosynthesis and salvage genes analyzed, only one gene, which encodes γ-glutamyl hydrolase 1 (GGH1), was consistently expressed at higher levels in high- compared to low-folate segregants of a Solanum boliviense Dunal accession. Second, quantitative PCR showed that GGH1 transcript levels were higher in high- compared to low-folate segregants for seven out of eight pairs of folate segregants analyzed. These results suggest that GGH1 gene expression is an indicator of folate content in potato tubers.

THE FLUORESCENCE OF FROZEN POTATO TUBER AND APPLE FRUIT TISSUE UNDER ULTRA-VIOLET LIGHT

1945 ◽  
Vol 23c (2) ◽  
pp. 76-78 ◽  
Author(s):  
W. Newton ◽  
W. Jones
Keyword(s):  
Potato Tuber ◽  
Ultra Violet ◽  
Apple Fruit ◽  
Potato Tubers ◽  
Tuber Tissue ◽  
Fruit Tissue ◽  
Potato Tuber Tissue ◽  
Violet Light ◽  
Apple Tissue ◽  
Acetone Extracts

Freshly cut sections of frozen potato tuber and apple fruit tissue exhibit a brilliant fluorescence when examined in a dark room under an ultra-violet (Stroblite) lamp. The fluorescence disappears from the apple tissue upon thawing but is retained in potato tuber tissue. Thus the ultra-violet lamp serves as a useful diagnostic means of detecting frost or low temperature injury in potato tubers. Many other plant tissues were frozen and examined, but proved to be non-fluorescent. Acetone extracts of both normal and frozen potato tuber tissue were fluorescent, but similar extracts of both frozen and normal apple fruit were not. Although normal potato tissue is non-fluorescent and frozen tissue is brightly fluorescent, no differences were found in the brightness of the acetone extracts.

scholarly journals First Report of “Candidatus Liberibacter solanacearum” Associated with Psyllid-Affected Carrots in Norway

Plant Disease ◽  
2012 ◽  
Vol 96 (3) ◽  
pp. 454-454 ◽  
Author(s):  
J. E. Munyaneza ◽  
V. G. Sengoda ◽  
L. Sundheim ◽  
R. Meadow
Keyword(s):  
Ribosomal Protein ◽  
16S Rdna ◽  
Bacterial Species ◽  
Consensus Sequence ◽  
Economic Damage ◽  
Carrot Root ◽  
Candidatus Liberibacter Solanacearum ◽  
First Report ◽  
Candidatus Liberibacter ◽  
Root Tissues

Carrot (Daucus carota) plants with symptoms resembling those associated with the carrot psyllid Trioza apicalis and the bacterium “Candidatus Liberibacter solanacearum” (1–4) were observed in 70 to 80% of commercial fields and experimental plots in southeastern Norway from late July to mid-September of 2011; all cultivars grown were affected with approximately 10 to 100% symptomatic plants per field. T. apicalis, a pest of carrot in northern and central Europe, including Norway, can cause as much as 100% crop loss and is associated with “Ca. L. solanacearum” (1–4). Symptoms on affected plants include leaf curling, yellow and purple discoloration of leaves, stunted growth of shoots and roots, and proliferation of secondary roots. Carrot plant samples were collected from five T. apicalis-infested fields in Ostfold, Vestfold, Oppland, and Hedmark counties. Total DNA was extracted from petiole and root tissues of 54 plants, including 27 symptomatic plants and 27 asymptomatic plants from four cultivars (Namdal, Panther, Romance, and Yukon) with the cetyltrimethylammonium bromide (CTAB) buffer extraction method (2,3). DNA samples were tested by PCR assay using primer pairs OA2/OI2c and CL514F/R to amplify a portion of 16S rDNA and rplJ/rplL ribosomal protein genes, respectively, of “Ca. L. solanacearum” (2,3). A 1,168-bp 16S rDNA fragment was detected in the DNA from 22 (81.5%) symptomatic plants and a 668-bp rplJ/rplL fragment was amplified from the DNA of 26 (96.3%) symptomatic and 5 (18.5%) asymptomatic plants, indicating the presence of liberibacter. No liberibacter was detected in the asymptomatic carrot plants with the primer pair OA2/OI2c. Amplicons from the DNA of four carrot root samples with each primer pair were cloned (pCR2.1-TOPO; Invitrogen, Carlsbad, CA) and three clones of each of the eight amplicons were sequenced (MCLAB, San Francisco, CA). BLAST analysis of the 16S rDNA consensus sequence from the carrot root tissues (GenBank Accession No. JN863097) showed 100% identity to those of “Ca. L. solanacearum” previously amplified from carrot (GU373048 and GU373049) and T. apicalis (GU477254 and GU477255) in Finland (2,3). The rplJ/rplL consensus sequence from the carrots (GenBank Accession No. JN863098) was 99% identical to the sequences of rplJ/rplL “Ca. L. solanacearum” ribosomal protein gene from carrots in Finland (GU373050 and GU373051). To our knowledge, this is the first report of “Ca. L. solanacearum” associated with carrot in Norway. This bacterial species has caused millions of dollars in losses to potato and several other solanaceous crops in North and Central America and New Zealand (1). This plant pathogen has also been reported from carrots and T. apicalis in Finland, where it has caused significant economic damage to carrot crops (2–4). References: (1) J. E. Munyaneza. Southwest. Entomol. 35:471, 2010. (2) J. E. Munyaneza et al. Plant Dis. 94:639, 2010. (3) J. E. Munyaneza et al. J. Econ. Entomol. 103:1060, 2010. (4) A. Nissinen et al. Entomol. Exp. Appl. 125:277, 2007.

scholarly journals A triggered mechanism retrieves membrane in seconds after Ca(2+)-stimulated exocytosis in single pituitary cells

1994 ◽  
Vol 124 (5) ◽  
pp. 667-675 ◽  
Author(s):  
P Thomas ◽  
AK Lee ◽  
JG Wong ◽  
W Almers
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Time Constant ◽  
Flash Photolysis ◽  
Membrane Capacitance ◽  
Coated Vesicles ◽  
Neuroendocrine Cells ◽  
Pituitary Cells ◽  
Excitable Cells ◽  
Late Step

In neuroendocrine cells, cytosolic Ca2+ triggers exocytosis in tens of milliseconds, yet known pathways of endocytic membrane retrieval take minutes. To test for faster retrieval mechanisms, we have triggered short bursts of exocytosis by flash photolysis of caged Ca2+, and have tracked subsequent retrieval by measuring the plasma membrane capacitance. We find that a limited amount of membrane can be retrieved with a time constant of 4 s at 21-26 degrees C, and that this occurs partially via structures larger than coated vesicles. This novel mechanism may be arrested at a late step. Incomplete retrieval structures then remain on the cell surface for minutes until the consequences of a renewed increase in cytosolic [Ca2+] disconnect them from the cell surface in < 1 s. Our results provide evidence for a rapid, triggered membrane retrieval pathway in excitable cells.

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