scholarly journals Relative humidity regimes modify epicuticular wax metabolism and fruit properties during Navelate orange conservation in an ABA-dependent manner

2022 ◽  
Vol 369 ◽  
pp. 130946
Author(s):  
Paco Romero ◽  
María Teresa Lafuente
1991 ◽  
Vol 70 (1) ◽  
pp. 466-471 ◽  
Author(s):  
A. J. Ryan ◽  
C. V. Gisolfi ◽  
P. L. Moseley

To determine whether reinduction of 70,000-Da (70K) stress protein synthesis could be used as an assay for thermal history and/or cellular levels of 70K stress protein in hyperthermic humans, leukocytes were obtained before and after 2 h of exercise and then incubated at 37 or 41 degrees C. Five healthy males completed 2 h of treadmill exercise consisting of running at 4–6 km/h for 30–45 min followed by 75–90 min of walking up a 2–10% grade. This exercise bout was performed by two subjects in hot (46 degrees C, 15% relative humidity) and by five subjects in cooler (30 degrees C, 40% relative humidity) environmental conditions. Exercise resulting in rectal temperature (Tre) less than 40 degrees C did not alter the amount of 70K stress protein synthesized by leukocytes incubated at 41 degrees C. In contrast, exercise resulting in Tre greater than 40 degrees C reduced the amount of 70K stress protein synthesized by leukocytes incubated at 41 degrees C. A protein immunoblot, probed with an antibody specific for the inducible 72K stress protein, showed that the reduction of 35S-labeled 70K stress protein in these postexercise leukocyte samples occurred without marked elevations of this protein. In vitro incubation of human leukocytes at 40 degrees C for 15–120 min reduced, in a time-dependent manner, the amount of 70K stress protein synthesized during a subsequent 41 degrees C heat stress. This reduction of 70K stress protein synthesis in 41 degrees C-treated leukocytes was abolished when cycloheximide was present during the 40 degrees C preincubation.(ABSTRACT TRUNCATED AT 250 WORDS)


1982 ◽  
Vol 60 (12) ◽  
pp. 2896-2902 ◽  
Author(s):  
E. Sutter ◽  
R. W. Langhans

Observation by scanning electron microscopy (SEM) revealed that cabbage plants in vitro had no structured epicuticular wax whereas plants grown in a growth chamber or in the greenhouse had considerable amounts of structured epicuticular wax. Plants grown in vitro developed increasing amounts of structured epicuticular wax after transfer to the greenhouse. Water loss per unit leaf area was greater in plants recently removed from in vitro conditions than in either plants grown in the growth chamber or in cultured plants that had been hardened off. Epicuticular wax was formed in plants grown in vitro at 35% relative humidity indicating that relative humidity is an important factor in the in vitro development of wax. The contribution of light to the formation of epicuticular wax and the relationship of the wax to survival of the plants when they are removed from in vitro culture are discussed.


2012 ◽  
Vol 102 (8) ◽  
pp. 794-803 ◽  
Author(s):  
Heather M. Young ◽  
Sheeja George ◽  
Dario F. Narváez ◽  
Pratibha Srivastava ◽  
Andrew C. Schuerger ◽  
...  

Soybean rust (SBR), caused by Phakopsora pachyrhizi, is a damaging fungal disease of soybean (Glycine max). Although solar radiation can reduce SBR urediniospore survival, limited information is available on how solar radiation affects SBR progress within soybean canopies. Such information can aid in developing accurate SBR prediction models. To manipulate light penetration into soybean canopies, structures of shade cloth attenuating 30, 40, and 60% sunlight were constructed over soybean plots. In each plot, weekly evaluations of severity in lower, middle, and upper canopies, and daily temperature and relative humidity were recorded. Final plant height and leaf area index were also recorded for each plot. The correlation between amount of epicuticular wax and susceptibility of leaves in the lower, middle, and upper canopies was assessed with a detached leaf assay. Final disease severity was 46 to 150% greater in the lower canopy of all plots and in the middle canopy of 40 and 60% shaded plots. While daytime temperature within the canopy of nonshaded soybean was greater than shaded soybean by 2 to 3°C, temperatures recorded throughout typical evenings and mornings of the growing season in all treatments were within the range (10 to 28.5°C) for SBR development as was relative humidity. This indicates temperature and relative humidity were not limiting factors in this experiment. Epicuticular wax and disease severity in detached leaf assays from the upper canopy had significant negative correlation (P = 0.009, R = –0.84) regardless of shade treatment. In laboratory experiments, increasing simulated total solar radiation (UVA, UVB, and PAR) from 0.15 to 11.66 MJ m–2 increased mortality of urediniospores from 2 to 91%. Variability in disease development across canopy heights in early planted soybean may be attributed to the effects of solar radiation not only on urediniospore viability, but also on plant height, leaf area index, and epicuticular wax, which influence disease development of SBR. These results provide an understanding of the effect solar radiation has on the progression of SBR within the soybean canopy.


Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Chester G. Mcwhorter

Studies were conducted to investigate the uniformity of epicuticular wax deposition on leaf blades of johnsongrass. Johnsongrass leaves grown under drought stress had greatly increased epicuticular wax weights compared to leaves from plants with adequate moisture, but relative humidity (95% vs. 40 ± 5%) had little effect on wax deposition. Wax weights decreased as leaves matured. Sections of lower leaf surfaces of young johnsongrass leaves tended to have more wax than sections of upper leaf surfaces, but weights were nearly equal on upper vs. lower leaf surfaces of older leaves. The narrow side of asymmetrical johnsongrass leaf blades often had more wax per unit area than the wide side. The area over the midvein contained more wax per unit area than either the narrow or wide side of the leaf blade. Greatest wax concentrations on individual leaves were over the midvein area near the leaf apex. Leaf blades of johnsongrass had more wax per unit area than leaves of corn or grain sorghum.


Author(s):  
Gemma A.J. Kuijpers ◽  
Harvey B. Pollard

Exocytotic fusion of granules in the adrenal medulla chromaffin cell is triggered by a rise in the concentration of cytosolic Ca2+ upon cell activation. The protein synexin, annexin VII, was originally found in the adrenal medulla and has been shown to cause aggregation and to support fusion of chromaffin granules in a Ca2+-dependent manner. We have previously suggested that synexin may there fore play a role in the exocytotic fusion process. In order to obtain more structural information on synexin, we performed immuno-electron microscopy on frozen ultrathin sections of both isolated chromaffin granules and chromaffin cells.Chromaffin granules were isolated from bovine adrenal medulla, and synexin was isolated from bovine lung. Granules were incubated in the presence or absence of synexin (24 μg per mg granule protein) and Ca2+ (1 mM), which induces maximal granule aggregation, in 0.3M sucrose-40m MMES buffer(pH 6.0). Granules were pelleted, washed twice in buffer without synexin and fixed with 2% glutaraldehyde- 2% para formaldehyde in 0.1 M phosphate buffer (GA/PFA) for 30 min. Chromaffin cells were isolated and cultured for 3-5 days, and washed and incubated in Krebs solution with or without 20 uM nicotine. Cells were fixed 90 sec after on set of stimulation with GA/PFA for 30 min. Fixed granule or cell pellets were washed, infiltrated with 2.3 M sucrose in PBS, mounted and frozen in liquid N2.


2020 ◽  
Vol 64 (2) ◽  
pp. 383-396
Author(s):  
Lara K. Krüger ◽  
Phong T. Tran

Abstract The mitotic spindle robustly scales with cell size in a plethora of different organisms. During development and throughout evolution, the spindle adjusts to cell size in metazoans and yeast in order to ensure faithful chromosome separation. Spindle adjustment to cell size occurs by the scaling of spindle length, spindle shape and the velocity of spindle assembly and elongation. Different mechanisms, depending on spindle structure and organism, account for these scaling relationships. The limited availability of critical spindle components, protein gradients, sequestration of spindle components, or post-translational modification and differential expression levels have been implicated in the regulation of spindle length and the spindle assembly/elongation velocity in a cell size-dependent manner. In this review, we will discuss the phenomenon and mechanisms of spindle length, spindle shape and spindle elongation velocity scaling with cell size.


2014 ◽  
Vol 84 (1-2) ◽  
pp. 79-91 ◽  
Author(s):  
Amin F. Majdalawieh ◽  
Hyo-Sung Ro

Background: Foam cell formation resulting from disrupted macrophage cholesterol efflux, which is triggered by PPARγ1 and LXRα, is a hallmark of atherosclerosis. Sesamin and sesame oil exert anti-atherogenic effects in vivo. However, the exact molecular mechanisms underlying such effects are not fully understood. Aim: This study examines the potential effects of sesamin (0, 25, 50, 75, 100 μM) on PPARγ1 and LXRα expression and transcriptional activity as well as macrophage cholesterol efflux. Methods: PPARγ1 and LXRα expression and transcriptional activity are assessed by luciferase reporter assays. Macrophage cholesterol efflux is evaluated by ApoAI-specific cholesterol efflux assays. Results: The 50 μM, 75 μM, and 100 μM concentrations of sesamin up-regulated the expression of PPARγ1 (p< 0.001, p < 0.001, p < 0.001, respectively) and LXRα (p = 0.002, p < 0.001, p < 0.001, respectively) in a concentration-dependent manner. Moreover, 75 μM and 100 μM concentrations of sesamin led to 5.2-fold (p < 0.001) and 6.0-fold (p<0.001) increases in PPAR transcriptional activity and 3.9-fold (p< 0.001) and 4.2-fold (p < 0.001) increases in LXR transcriptional activity, respectively, in a concentration- and time-dependent manner via MAPK signaling. Consistently, 50 μM, 75 μM, and 100 μM concentrations of sesamin improved macrophage cholesterol efflux by 2.7-fold (p < 0.001), 4.2-fold (p < 0.001), and 4.2-fold (p < 0.001), respectively, via MAPK signaling. Conclusion: Our findings shed light on the molecular mechanism(s) underlying sesamin’s anti-atherogenic effects, which seem to be due, at least in part, to its ability to up-regulate PPARγ1 and LXRα expression and transcriptional activity, improving macrophage cholesterol efflux. We anticipate that sesamin may be used as a therapeutic agent for treating atherosclerosis.


2014 ◽  
Vol 84 (1-2) ◽  
pp. 27-34 ◽  
Author(s):  
Nasser M. Al-Daghri ◽  
Khalid M. Alkharfy ◽  
Nasiruddin Khan ◽  
Hanan A. Alfawaz ◽  
Abdulrahman S. Al-Ajlan ◽  
...  

The aim of our study was to evaluate the effects of vitamin D supplementation on circulating levels of magnesium and selenium in patients with type 2 diabetes mellitus (T2DM). A total of 126 adult Saudi patients (55 men and 71 women, mean age 53.6 ± 10.7 years) with controlled T2DM were randomly recruited for the study. All subjects were given vitamin D3 tablets (2000 IU/day) for six months. Follow-up mean concentrations of serum 25-hydroxyvitamin D [25-(OH) vitamin D] significantly increased in both men (34.1 ± 12.4 to 57.8 ± 17.0 nmol/L) and women (35.7 ± 13.5 to 60.1 ± 18.5 nmol/L, p < 0.001), while levels of parathyroid hormone (PTH) decreased significantly in both men (1.6 ± 0.17 to 0.96 ± 0.10 pmol/L, p = 0.003) and women (1.6 ± 0.17 to 1.0 ± 0.14 pmol/L, p = 0.02). In addition, there was a significant increase in serum levels of selenium and magnesium in men and women (p-values < 0.001 and 0.04, respectively) after follow-up. In women, a significant correlation was observed between delta change (variables at six months-variable at baseline) of serum magnesium versus high-density lipoprotein (HDL)-cholesterol (r = 0.36, p = 0.006) and fasting glucose (r = - 0.33, p = 0.01). In men, there was a significant correlation between serum selenium and triglycerides (r = 0.32, p = 0.04). Vitamin D supplementation improves serum concentrations of magnesium and selenium in a gender-dependent manner, which in turn could affect several cardiometabolic parameters such as glucose and lipids.


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