Freeze-thaw injury is enhanced by post-thaw leaching in water

1994 ◽  
Vol 74 (2) ◽  
pp. 357-358 ◽  
Author(s):  
J. H. M. Willison ◽  
C. H. Cheung ◽  
M. I. N. Zhang ◽  
X. Xiao
Keyword(s):  
Brassica Rapa ◽  
Phosphate Buffer ◽  
Vital Staining ◽  
Deionized Water ◽  
Root Tissue ◽  
Plant Tissues ◽  
Triphenyltetrazolium Chloride ◽  
Freeze Thaw ◽  
Injured Tissue ◽  
Key Words:Brassica

Turnip (Brassica rapa L.) root tissue was exposed to freeze-thaw stresses of −7, −9, -−11 and −19 °C. The post-thawed tissues were either subjected to leaching in deionized water for 2 h or left at 100% humidity. Tissue survival was then assayed by vital staining using modified 2,3,5-triphenyltetrazolium chloride (TTC) staining in 0.2 M phosphate buffer. Tissue survival was significantly lower for leached samples than for non-leached samples. It is concluded that freeze-thaw injury in plant tissues is enhanced by post-thaw leaching in water. The 0.05 M phosphate buffer commonly used for TTC staining also damaged freeze-thaw injured tissue. Key words:Brassica rapa L., 2,3,5-triphenyltetrazolium chloride (TTC), freeze-thaw injury, leaching

Resolution of Channels in the Exine by Translocation of Colloidal Iron

1971 ◽  
Vol 29 ◽  
pp. 352-353
Author(s):  
John R. Rowley
Keyword(s):  
Phosphate Buffer ◽  
Pollen Development ◽  
Osmium Tetroxide ◽  
Pollen Grains ◽  
Deionized Water ◽  
Colloidal Iron ◽  
Fixed Material ◽  
Epilobium Angustifolium ◽  
Untreated Material ◽  
Microspore Mitosis

The morphology of the exine of many pollen grains, at the time of flowering, is such that one can suppose that transport of substances through the exine occurred during pollen development. Holes or channels, microscopic to submicroscopic, are described for a large number of grains. An inner part of the exine of Epilobium angustifolium L. and E. montanum L., which may be referred to as the endexine, has irregularly shaped channels early in pollen development although by microspore mitosis there is no indication of such channeling in chemically fixed material. The nucleus in microspores used in the experiment reported here was in prophase of microspore mitosis and the endexine, while lamellated in untreated grains, did not contain irregularly shaped channels. Untreated material from the same part of the inflorescence as iron treated stamens was examined following fixation with 0.1M glutaraldehyde in cacodylate-HCl buffer at pH 6.9 (315 milliosmoles) for 24 hrs, 4% formaldehyde in phosphate buffer at pH 7.2 (1,300 milliosmoles) for 12 hrs, 1% glutaraldehyde mixed with 0.1% osmium tetroxide for 20 min, osmium tetroxide in deionized water for 2 hrs and 1% glutaraldehyde mixed with 4% formaldehyde in 0.1M cacodylate-HCl buffer at pH 6.9 for two hrs.

scholarly journals An HPLC-automated Derivatization for Glutathione and Related Thiols Analysis in Brassica rapa L.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1157
Author(s):  
Francesco Nacca ◽  
Concetta Cozzolino ◽  
Petronia Carillo ◽  
Pasqualina Woodrow ◽  
Amodio Fuggi ◽  
...  
Keyword(s):  
Brassica Rapa ◽  
High Performance ◽  
Internal Standard ◽  
Plant Tissues ◽  
Cellular Functions ◽  
Sulphur Compounds ◽  
Stress Protection ◽  
Automated Method ◽  
Reduced Forms

The high content of glucosinolates and glutathione makes the Brassicaceae an important healthy food. Thiols and especially glutathione and γ-Glu-Cys-Gly tripeptide are involved in many fundamental cellular functions such as oxidative stress protection. Although several methods for sulphur compounds analysis in biological samples are actually used, the determination of glutathione and other sulphur derivatives in plant tissues is rather problematic due to their extreme susceptibility to oxidation, which can lead to their overestimation. The aim of this work was the improvement and validation of an automated method for determination of reduced and oxidised glutathione, cysteine and γ-glutamylcysteine in plant tissues. The method consists of a fully automated pre-column derivatization of thiols based on monobromobimane reagent, a high-performance liquid chromatography derivatives separation, and a fluorimetric detection and quantification. The method was successfully applied for determination of the oxidized and reduced forms of Cys, γ-GC and GSH content in leaves, petioles, inflorescences and roots of Brassica rapa L. subsp. Sylvestris. At harvest, in freshly cut plants, the average contents of GSH/2GSSG were 840/45, 345/70 and 150/70 nmol g−1 FW for the florets, leaf blades and stems, respectively; those of Cys/2Cys were 80/12, 29/12 and 24/6 nmol g-1 FW; while those of γ-GC/γ-GCCG-γ were 8.0/4.0, and 6.0/3.0, 3.0/2.0 nmol g−1 FW, respectively. Such amounts were lower in low-sulphur-grown plants at harvest. The very low coefficient of variation between repeated tests (maximum 1.6%), the high recovery of internal standard (>96%) and the linear correlation coefficient of the calibration (R2 > 0.99) support the efficiency of this method that allowed analysing about 50 samples/die in a totally automated manner with no operator intervention. Our results show that the reported method integrations can significantly improve thiols detection via HPLC.

The possible role of embryo sac degeneration in yield reduction of summer turnip rape cultivar Candle

1995 ◽  
Vol 75 (3) ◽  
pp. 595-598
Author(s):  
Xiuying Tian ◽  
L. Van Caeseele ◽  
M. J. Sumner
Keyword(s):  
Brassica Rapa ◽  
Seed Set ◽  
Embryo Sac ◽  
Pollen Tubes ◽  
Yield Reduction ◽  
Turnip Rape ◽  
Key Words:Brassica

When pollination occurred within 24 h after anthesis, 69.2% of the pods of Brassica rapa cultivar Candle contained at least 50% fertilized ovules. If pollination occurred later than 4 d after anthesis, an occasional ovule near the base of the pistil was fertilized; however, no significant seed set was observed. Pollen tubes were observed entering the locules of the ovary from pollinations carried out as late as 5 d after anthesis. At 3 d after anthesis, in unpollinated flowers, a general deterioration of the embryo-sac contents began and gradually increased to include integumentary cells by 6 d after anthesis. Some ovules swelled as though they were fertilized, but no embryos were present. The results suggest that yield reductions in this species may occur because of the reduction of fertilization potential through rapid degeneration of embryo sacs following anthesis. Key words:Brassica rapa, embryo sac, yield

scholarly journals Asymbiotic in vitro germination and seed quality assessment of Australian terrestrial orchids

2012 ◽  
Vol 60 (7) ◽  
pp. 592 ◽  
Author(s):  
Nicole Dowling ◽  
Manfred Jusaitis
Keyword(s):  
Seed Quality ◽  
Culture Media ◽  
Vital Staining ◽  
Terrestrial Orchid ◽  
Triphenyltetrazolium Chloride ◽  
Asymbiotic Seed Germination ◽  
Orchid Species ◽  
Terrestrial Orchids ◽  
Asymbiotic Germination

Determining the seed quality and germination requirements for threatened orchid species in storage is vital for future conservation efforts. Seeds of many Australian terrestrial orchid species are held in conservation collections around the country, but few have been germinated in vitro, fuelling concerns over their long-term viability. This study tested three methods of assessing orchid seed quality; asymbiotic germination was compared with vital staining using triphenyltetrazolium chloride or fluorescein diacetate. Six culture media were examined for efficacy in promoting asymbiotic seed germination of four Australian terrestrial orchid species (Pterostylis nutans, Microtis arenaria, Thelymitra pauciflora and Prasophyllum pruinosum). Germination occurred on all media but germination rates were consistently highest on BM1 and development was most advanced on BM1, P723 and Malmgren media. Subsequent trials tested the efficacy of BM1 for asymbiotic germination of additional genera (Caladenia, Calochilus and Diuris), several congeneric species, and two species collected from several different provenances within each of their ranges. The results indicate that asymbiotic germination on BM1 medium is an effective technique for testing the performance of Australian terrestrial orchid seeds. The efficacy of vital stains to determine seed viability, however, remains uncertain, as significant disagreement between degree of staining and germinability was observed for some species.

Accumulation of copper and nickel in plant tissues and an insect gall of lowbush blueberry, Vaccinium angustifolium, near an ore smelter at Sudbury, Ontario, Canada

1991 ◽  
Vol 69 (7) ◽  
pp. 1483-1490 ◽  
Author(s):  
G. Bagatto ◽  
J. D. Shorthouse
Keyword(s):  
Key Words ◽  
Host Plant ◽  
Leaf Tissue ◽  
Primary Site ◽  
Root Tissue ◽  
Plant Tissues ◽  
Vaccinium Angustifolium ◽  
Copper Nickel ◽  
Lowbush Blueberry ◽  
Insect Gall

The accumulation of copper and nickel in plant tissues and galls of Hemadas nubilipennis on lowbush blueberry near an ore smelter at Sudbury, Ontario, was investigated. Concentrations of these metals in the root, stem, and leaf tissue decline logarithmically with increasing distance from the Sudbury smelter. The pattern of accumulation for copper and nickel in the various tissues was root > stem > leaf > berry; however, metal differences in these tissues were not as great in plants farther from the smelter. The root tissue is the primary site of accumulation of these metals when environmental levels of copper and nickel are high. The highest concentrations of copper and nickel were found in the galls, indicating that gall tissues act as a strong physiological sink for micronutrients and redirect nutrients from the host plant. Key words: Vaccinium angustifolium, copper, nickel, gall, Sudbury.

OBSERVATIONS ON THE USE OF TETRAZOLIUM SALTS IN THE VITAL STAINING OF BACTERIA

1959 ◽  
Vol 5 (3) ◽  
pp. 245-250 ◽  
Author(s):  
L. Eidus ◽  
B. B. Diena ◽  
L. Greenberg
Keyword(s):  
Bacterial Growth ◽  
Vital Staining ◽  
Nitro Blue Tetrazolium ◽  
Complete Inhibition ◽  
Triphenyltetrazolium Chloride ◽  
Tetrazolium Salts ◽  
Blue Tetrazolium

Studies on the vital staining of bacteria were carried out to determine the concentrations of tetrazolium salts required for optimal staining, and the amounts which could cause complete inhibition of bacterial growth. Four salts were studied: neotetrazolium chloride (NTC), triphenyltetrazolium chloride (TTC), blue tetrazolium (BT), and nitro-blue tetrazolium (NBT). Evidence has been presented to show that only living, actively metabolizing cells can reduce neotetrazolium to formazan.

scholarly journals Zeta potential of bacterial cells: Effect of wash buffers

2017 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting
Keyword(s):  
Ionic Strength ◽  
Zeta Potential ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Phosphate Buffer ◽  
Defined Medium ◽  
Deionized Water ◽  
Nonspecific Adsorption ◽  
E Coli ◽  
Ph Range

Zeta potential, defined as the electric charge at the shear plane, is widely used as a proxy parameter for bacterial cell surface charge. Nonspecific adsorption of ions or polyelectrolytes onto the cell surface, however, alters the value and polarity of the measured zeta potential, leading to erroneous results. Multiple wash and centrifugation steps are commonly used in preparing cells for zeta potential analysis, where various wash buffers (such as 9 g/L NaCl, 0.001M KCl, and 0.1M NaNO3) are routinely used for removing (by charge screening) ions and charged molecules that bind nonspecifically to the cell surface. Using Escherichia coli DH5α grown in LB Lennox (with 2 g/L glucose), experiment data showed that the zeta potential-pH profile was not significantly different over the pH range from 2 to 12 for deionized water, 9 g/L NaCl, and phosphate buffer saline (PBS) wash buffers. As LB Lennox is a low salt medium without a phosphate buffer, it was likely that the extent of nonspecific adsorption of ions on the cell surface was not severe, and the different wash buffers would correspondingly not exert much effect on measured zeta potential. Zeta potential-pH profiles for E. coli grown in a semi-defined medium (with a high capacity phosphate buffer system), on the other hand, was significantly different over the pH range from 1 to 12 for deionized water, 9 g/L NaCl, 0.1M NaNO3, 0.1M sodium acetate, and 0.1M sodium citrate wash buffers with the deviation positively correlated with wash buffer’s ionic strength. Furthermore, the point of zero charge (pHzpc) for E. coli grown in the semi-defined medium varies between 1.5 and 3, in an ionic strength dependent manner, for the various wash buffers tested. Collectively, this preliminary study highlights the importance of wash buffer ionic strength in affecting removal efficiency of non-specifically absorbed ions on bacterial cell surface, where a threshold exists (0.15M) for charge screening to be effective. At the upper bound, 0.6M ionic strength might remove cations intrinsic to the cell envelope, leading to possible cell surface damage and erroneous measurements.

scholarly journals 424 A Comparison of Techniques Used for Determining Freezing Injury on Two Apple (Malus × domestica Borkh.) Cultivars: Liberty and RedMax

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 466C-466
Author(s):  
M.E. Garcia ◽  
Linda A. Boccuzzo
Keyword(s):  
Block Design ◽  
Vital Staining ◽  
Fruit Trees ◽  
Early Spring ◽  
Freezing Injury ◽  
Testing Time ◽  
Triphenyltetrazolium Chloride ◽  
Deciduous Fruit ◽  
Comparison Of Techniques ◽  
Artificial Freezing

Hardiness testing of the wood of deciduous fruit trees has been conducted using a variety of techniques. In our studies, the objective was to determine an efficient method of determining freezing injury for apple (Malus × domestica Borkh.) wood. We tested 1-year old wood of two cultivars: Liberty and RedMax. The wood was tested over the course of 2 years (1998 and 1999). Collection began in the late fall and continued throughout the winter (until it was determined full hardiness had been achieved) and then again in the early spring. The wood was cut into 1-cm sections and frozen. The artificial freezing was conducted in an ethanol bath, with the temperature lowered at 5 °C/h. Samples were removed in 3-min intervals. After freezing, the wood was acclimated to 4 °C for 12 h. Three tests were conducted to determine the hardiness/injury to the tissues. The tests used were: discoloration, callus growth and vital staining (with 2,3,5-triphenyltetrazolium chloride). This was a split block design with samples collected randomly from each tree. Four replicates (12 trees) of each cultivar were tested. Results showed that the callus test predicted the same LT50 as the other two tests, discoloration and vital staining. Discoloration was not easy to differentiate and was the most time-consuming. The callus grown by the apple wood was easily formed and distinguished. The callus test does not require the tetrazolium stain; therefore, one less step was needed in comparison to the vital staining test. This reduced testing time by over 6 h.

scholarly journals Zeta potential of bacteria cells: Effect of wash buffers

2016 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting
Keyword(s):  
Ionic Strength ◽  
Zeta Potential ◽  
Cell Surface ◽  
Phosphate Buffer ◽  
Defined Medium ◽  
Deionized Water ◽  
Ph Profile ◽  
Nonspecific Adsorption ◽  
E Coli ◽  
Ph Range

Zeta potential, defined as the electric charge at the shear plane, is widely used as a proxy for bacteria cell surface charge. Nonspecific adsorption of ions or polyelectrolytes onto the cell surface, however, alters the value and polarity of the measured zeta potential, leading to erroneous results. Multiple wash and centrifugation steps are commonly used in preparing cells for zeta potential analysis, where various wash buffers (such as 9 g/L NaCl, 0.001M KCl, and 0.1M NaNO3) are routinely used for removing (by charge screening) ions and charged molecules that bind nonspecifically to the cell surface. Preliminary data showed that, for Escherichia coli DH5α (ATCC 53868) grown in LB Lennox (with 2 g/L glucose, or LBG), the zeta potential-pH profile was not significantly different over the pH range from 2 to 12 for deionized water, 9 g/L NaCl, and phosphate buffer saline (PBS) wash buffers. As LBG is a low salt medium without a phosphate buffer, it was likely that the extent of nonspecific adsorption of ions on the cell surface was not substantial, and the different wash buffers would correspondingly not affect measured zeta potential much. For E. coli grown in a semi-defined medium (with a high capacity phosphate buffer system), the zeta potential-pH profile was significantly different over the pH range from 1 to 12 for deionized water, 9 g/L NaCl, 0.1M NaNO3, 0.1M sodium acetate, and 0.1M sodium citrate wash buffers with the extent of difference positively correlated with wash buffer’s ionic strength. Furthermore, the point of zero charge (pHzpc) for E. coli grown in the semi-defined medium varies between 1.5 and 3, in an ionic strength-dependent manner, for the various wash buffers tested. Collectively, this preliminary study suggests that wash buffers' ionic strength strongly affect removal efficiency of nonspecifically absorbed ions on bacteria surfaces, where a threshold exists (0.15M) for charge screening to be effective. At the upper bound, 0.6M ionic strength might result in removal of cations that stabilizes the cell envelope; thus, leading to possible cell surface damage and erroneous measurements.

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