Temporal and spatial distribution of BN28 during low temperature acclimation of Brassica napus cv. Cascade seedlings

1997 ◽  
Vol 75 (1) ◽  
pp. 28-35
Author(s):  
Mitchel D. de Beus ◽  
Anne M. Johnson-Flanagan ◽  
Joseph G. Boothe
Keyword(s):  
Brassica Napus ◽  
Low Temperature ◽  
Leaf Age ◽  
Temporal Distribution ◽  
Leaf Tissue ◽  
Temperature Acclimation ◽  
Ground Tissue ◽  
Temporal And Spatial Distribution ◽  
Apical Meristems ◽  
Mature Leaves

The objective of this study was to determine the spatial and temporal distribution of the peptide BN28 in Brassica napus cv. Cascade seedlings during low temperature acclimation. Immunoblots revealed that BN28 was present in leaves and shoot apical meristems of plants grown under low temperature but was absent from older tissues in the stem. Immunocytochemistry was used to determine the distribution throughout leaf and apical meristem tissues. BN28 was found throughout the apical meristems, was localized in the ground tissue and epidermis of young leaves, and was restricted to the ground tissue and guard cells in mature leaves. Differences in total accumulation were also noted, with the youngest leaves having the highest accumulation of BN28 and the quantity decreasing with leaf age. Despite these differences, plant developmental stage did not affect the accumulation of BN28 in individual leaves. Post-transcriptional controls are expected to regulate accumulation of the protein, as bn28 mRNA accumulates during acclimation in both young and mature leaves. Immunolocalization studies of BN28 in acclimated leaf tissue confirmed that BN28 is cytoplasmically localized and has no apparent weak association with organelles or other cellular membrane systems. Key words: acclimation, Brassica, development, immunocytochemistry, low temperature, protein synthesis.

Determination of growth and maintenance coefficients by calorespirometry

2004 ◽  
Vol 31 (9) ◽  
pp. 929 ◽  
Author(s):  
Sannali Matheson ◽  
Derek J. Ellingson ◽  
V. Wallace McCarlie ◽  
Bruce N. Smith ◽  
Richard S. Criddle ◽  
...  
Keyword(s):  
Growth Rates ◽  
Leaf Age ◽  
Leaf Tissue ◽  
Heat Rate ◽  
Regulation Of Respiration ◽  
Convolvulus Arvensis ◽  
Verbascum Thapsus ◽  
Mature Leaves ◽  
Substrate Variation ◽  
Maintenance Coefficients

This study describes a calorespirometric method for determining the coefficients of the correlation of specific respiration and growth rates. To validate the calorespirometric method, coefficients obtained from calorespirometric data are compared with coefficients obtained from mass and elongation growth rates measured at three temperatures on oat (Avena sativa L.) shoots. Calorespirometric measurements were also made on leaf tissue of varying age from Verbascum thapsus L., Convolvulus arvensis L., and Helianthus tuberosus Nutt. Measurements on A. sativa, C. arvensis and H. tuberosus at several temperatures show maintenance coefficients generally increase with temperature, but, in disagreement with accepted theory, growth coefficients for C. arvensis and A. sativa vary with temperature. A comparison of rates expressed as intensive and extensive quantities showed that the decline in specific respiration and growth rates with age is caused by dilution-by-growth, not down-regulation of respiration rate by reduced demand. The ratio of heat rate to CO2 rate increases with leaf age, and, for fully mature leaves, exceeds the maximum possible value for carbohydrates. This shows that the catabolic substrate may vary with leaf age in immature leaves and cannot be assumed to consist only of carbohydrates in mature leaves. Dilution-by-growth, substrate variation, and inseparability of the variables in the growth-maintenance model all complicate physiological interpretation of the slope and intercept of plots of specific respiration rates v. specific growth rates.

Effect of Moisture Stress and Leaf Age on Bentazon Absorption in Common Cocklebur (Xanthium strumarium) and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Brian C. Levene ◽  
Micheal D. K. Owen
Keyword(s):  
Ammonium Nitrate ◽  
Plant Species ◽  
Leaf Age ◽  
Leaf Tissue ◽  
Moisture Stress ◽  
Abutilon Theophrasti ◽  
Xanthium Strumarium ◽  
Herbicide Application ◽  
Mature Leaves ◽  
Urea Ammonium Nitrate

More than 70% of all14C-bentazon absorption occurred within 4 h after herbicide application regardless of adjuvant Moisture stress reduced14C-bentazon absorption by common cocklebur and velvetleaf. Mature (second true leaf) and moisture-stressed leaves of velvetleaf had 50 and 17 μg cm−1more epicuticular wax (ECW) than did juvenile and unstressed leaves, respectively. Common cocklebur had less14C in the ECW and lower total14C in treated mature leaves compared to juvenile leaves. The use of 28% urea ammonium nitrate (UAN) or crop oil concentrate (COC) increased14C in ECW samples of both plant species, regardless of leaf age or moisture stress. More14C in the ECW did not always correlate with more14C in the leaf tissue. Adjuvants increased14C-bentazon absorption into leaves of plants that had been stressed.

scholarly journals The role of JrPPOs in the browning of walnut explants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shugang Zhao ◽  
Hongxia Wang ◽  
Kai Liu ◽  
Linqing Li ◽  
Jinbing Yang ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Production Efficiency ◽  
Phenolic Content ◽  
Leaf Tissue ◽  
Limiting Factor ◽  
Mature Leaves ◽  
Survival Percentage ◽  
Highly Active ◽  
Young Leaves

Abstract Background Tissue culture is an effective method for the rapid breeding of seedlings and improving production efficiency, but explant browning is a key limiting factor of walnut tissue culture. Specifically, the polymerization of PPO-derived quinones that cause explant browning of walnut is not well understood. This study investigated explants of ‘Zanmei’ walnut shoot apices cultured in agar (A) or vermiculite (V) media, and the survival percentage, changes in phenolic content, POD and PPO activity, and JrPPO expression in explants were studied to determine the role of PPO in the browning of walnut explants. Results The results showed that the V media greatly reduced the death rate of explants, and 89.9 and 38.7% of the explants cultured in V media and A media survived, respectively. Compared with that of explants at 0 h, the PPO of explants cultured in A was highly active throughout the culture, but activity in those cultured in V remained low. The phenolic level of explants cultured in A increased significantly at 72 h but subsequently declined, and the content in the explants cultured in V increased to a high level only at 144 h. The POD in explants cultured in V showed high activity that did not cause browning. Gene expression assays showed that the expression of JrPPO1 was downregulated in explants cultured in both A and V. However, the expression of JrPPO2 was upregulated in explants cultured in A throughout the culture and upregulated in V at 144 h. JrPPO expression analyses in different tissues showed that JrPPO1 was highly expressed in stems, young leaves, mature leaves, catkins, pistils, and hulls, and JrPPO2 was highly expressed in mature leaves and pistils. Moreover, browning assays showed that both explants in A and leaf tissue exhibited high JrPPO2 activity. Conclusion The rapid increase in phenolic content caused the browning and death of explants. V media delayed the rapid accumulation of phenolic compounds in walnut explants in the short term, which significantly decreased explants mortality. The results suggest that JrPPO2 plays a key role in the oxidation of phenols in explants after branch injury.

scholarly journals Regulation of BN115, a Low-Temperature-Responsive Gene from Winter Brassica napus

1994 ◽  
Vol 106 (3) ◽  
pp. 917-928 ◽  
Author(s):  
T. C. White ◽  
D. Simmonds ◽  
P. Donaldson ◽  
J. Singh
Keyword(s):  
Brassica Napus ◽  
Low Temperature ◽  
Temperature Responsive ◽  
Responsive Gene

scholarly journals Low temperature acclimation with electrical stimulation enhance the biocathode functioning stability for antibiotics detoxification

2016 ◽  
Vol 100 ◽  
pp. 157-168 ◽  
Author(s):  
Bin Liang ◽  
Deyong Kong ◽  
Jincai Ma ◽  
Chongqing Wen ◽  
Tong Yuan ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Low Temperature ◽  
Temperature Acclimation

scholarly journals The Effect of Low Temperature on Phosphate Esterification and Cell Membrane Permeability in Tomato Fruit and Cabbage Leaf Tissue

1964 ◽  
Vol 17 (1) ◽  
pp. 147 ◽  
Author(s):  
TL Lewis ◽  
M Workman
Keyword(s):  
Low Temperature ◽  
Tomato Fruit ◽  
Chilling Injury ◽  
Leaf Tissue ◽  
Cell Membrane Permeability ◽  
Energy Deficit ◽  
Chilling Temperature ◽  
Tomato Fruits ◽  
Threefold Increase ◽  
Increased Susceptibility

Exposure to O�C for 4 weeks caused a threefold increase in cell membrnno permeability of mature-green tomato fruits (susceptible to chilling injury) hut had no effect on that of cabbage leaves (not susceptible). While tomato fruits chilled for 12 days lost two-thirds of their capacity to esterify phosphate at 20�0, a steady rise in this capacity occurred during chilling of cabbage leaves for 5 weeks. In tomato fruits the rate of phosphate esterification at the chilling temperature fell in 12 days to about one-half of the rate at the commencement of chilling .. It is suggested that the characteristic symptoms of chilling injury in mature-green tomato fruits, viz. increased susceptibility to fungal attack and loss of the capacity to ripen normally. may result from an energy deficit caused by a chilling. induced reduction in the phosphorylative capacity of the tissue.

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