Responses of tobacco pollen to high humidity and heat stress: viability and germinability in vitro and in vivo

1991 ◽  
Vol 4 (2) ◽  
Author(s):  
K.R. Shivanna ◽  
H.F. Linskens ◽  
M. Cresti
Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1856
Author(s):  
Nikoletta Murvai ◽  
Lajos Kalmar ◽  
Bianka Szalaine Agoston ◽  
Beata Szabo ◽  
Agnes Tantos ◽  
...  

Details of the functional mechanisms of intrinsically disordered proteins (IDPs) in living cells is an area not frequently investigated. Here, we dissect the molecular mechanism of action of an IDP in cells by detailed structural analyses based on an in-cell nuclear magnetic resonance experiment. We show that the ID stress protein (IDSP) A. thaliana Early Response to Dehydration (ERD14) is capable of protecting E. coli cells under heat stress. The overexpression of ERD14 increases the viability of E. coli cells from 38.9% to 73.9% following heat stress (50 °C × 15 min). We also provide evidence that the protection is mainly achieved by protecting the proteome of the cells. In-cell NMR experiments performed in E. coli cells show that the protective activity is associated with a largely disordered structural state with conserved, short sequence motifs (K- and H-segments), which transiently sample helical conformations in vitro and engage in partner binding in vivo. Other regions of the protein, such as its S segment and its regions linking and flanking the binding motifs, remain unbound and disordered in the cell. Our data suggest that the cellular function of ERD14 is compatible with its residual structural disorder in vivo.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Joydip Mukherjee ◽  
Sujata Pandita ◽  
Ruokuobeinuo Huozha ◽  
Manju Ashutosh

Twelve healthy lactating Murrah buffaloes of similar parity (3rd) between 90 and 120 days of lactation, selected from the herd of National Dairy Research Institute (Karnal, India) and maintained at managemental practices as followed at the Institute they were included in this experiment. The animals were divided into two groups based on their production level in previous lactation. The average milk production level of group 1 and II was 9.3 and 6 lit/day, respectively. Blood was collected from these buffaloes on three occasions 10 days apart. The lymphocytes were separated and cultured in RPMI 1640 medium with PHA-P for 24 h at 37°C in a humidified CO2incubator (95% air and 5%  CO2). The lymphocyte responsiveness was also evaluated in response to thein vivoheat stress andin vitrocortisol. Mitogen-induced stimulation index was not affected by production level (). Stimulation index was significantly reduced () in both the groups when cortisol was added at 2.0 ng level in the culture. However, in heat-stressed buffaloes stimulation index did not vary despite increasing levels of cortisol, thus indicating that lymphocyte may become cortisol resistant during periods of acute heat stress. The results showed that lymphocyte proliferation response can be effectively used to study buffalo cell-mediated immunityin vitro.


2014 ◽  
Vol 11 (3) ◽  
pp. 2276-2284 ◽  
Author(s):  
HONGBO CHEN ◽  
ABDELNASIR ADAM ◽  
YANFEN CHENG ◽  
SHU TANG ◽  
JÖRG HARTUNG ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Jamal Hussen

The dromedary camel (Camelus dromedarius) is well-adapted to the desert environment with the ability to tolerate increased internal body temperatures rising daily to 41–42°C during extreme hot. This study was undertaken to assess whether in vitro incubation of camel blood at 41°C, simulating conditions of heat stress, differently alters cell vitality, phenotype, and function of leukocytes, compared to incubation at 37°C (normothermia). Using flow cytometry, the cell vitality (necrosis and apoptosis), the expression of several cell markers and adhesion molecules, and the antimicrobial functions of camel leukocytes were analyzed in vitro. The fraction of apoptotic cells within the granulocytes, lymphocytes, and monocytes increased significantly after incubation of camel whole blood at 41°C for 4 h. The higher increase in apoptotic granulocytes and monocytes compared to lymphocytes suggests higher resistance of camel lymphocytes to heat stress. Functionally, incubation of camel blood at 41°C for 4 h enhanced the phagocytosis and ROS production activities of camel neutrophils and monocytes toward S. aureus. Monocytes from camel blood incubated at 41°C for 4 h significantly decreased their expression level of MHC class II molecules with no change in the abundance of CD163, resulting in a CD163high MHC-IIlow M2-like macrophage phenotype. In addition, heat stress treatment showed an inhibitory effect on the LPS-induced changes in camel monocytes phenotype. Furthermore, in vitro incubation of camel blood at 41°C reduced the expression of the cell adhesion molecules CD18 and CD11a on neutrophils and monocytes. Collectively, the present study identified some heat-stress-induced phenotypic and functional alterations in camel blood leukocytes, providing a paradigm for comparative immunology in the large animals. The clinical relevance of the observed changes in camel leukocytes for the adaptation of the camel immune response to heat stress conditions needs further in vitro and in vivo studies.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bin Yin ◽  
Ruirui Lian ◽  
Zhen Li ◽  
Yueyue Liu ◽  
Shifa Yang ◽  
...  

Keap1-Nrf2-ARE and heat shock proteins (Hsps) are important endogenous protection mechanisms initiated by heat stress to play a double protective role for cell adaptation and survival. H9C2 cells and 80 300-day-old specific pathogen-free chickens were randomly divided into the control and tea polyphenol groups and used to establish a heat stress model in vitro and in vivo. This task was conducted to explore the protection and mechanism of tea polyphenols in relieving thermal injury. A supplement with 10 μg/mL tea polyphenols could effectively relieve the heat damage of H9C2 cells at 42°C. Accordingly, weaker granular degeneration, vacuolar degeneration, and nucleus deep staining were shown. A strong antioxidant capacity was manifested in the upregulation of the total antioxidant capacity (T-AOC) (at 5 h, P < 0.05 ), Hemeoxygenase-1 mRNA (at 2 h, P < 0.01 ), superoxide dismutase (SOD) (at 2, 3, and 5 h, P < 0.05 ), and Nrf2 (at 0 and 5 h, P < 0.01 ). A high expression of Hsps was reflected in CRYAB at 3 h; Hsp27 at 0, 2, and 3 h ( P < 0.01 ); and Hsp70 at 3 and 5 h ( P < 0.01 ). The supplement with 0.2 g/L tea polyphenols in the drinking water also had a good effect in alleviating the heat stress damage of the myocardial cells of hens at 38°C. Accordingly, light pathological lesions and downregulation of the myocardial injury-related indicators (LDH, CK, CK-MB, and TNF-α) were shown. The mechanism was related to the upregulation of T-AOC (at 0 h, P < 0.05 ), GSH-PX (at 0.5 d, P < 0.01 ), SOD (at 0.5 d), and Nrf2 (at 0 d with P < 0.01 and 2 d with P < 0.05 ) and the induced expression of CRYAB (at 0.5 and 2 d), Hsp27 (at 0, 0.5, and 5 d), and Hsp70 (at 0 and 0.5 d). In conclusion, the tea polyphenols enhanced the antioxidant capacity and induced Hsps to relieve heat stress injury.


2014 ◽  
Vol 13 (4) ◽  
pp. 9371-9381 ◽  
Author(s):  
Y.F. Cheng ◽  
J.R. Sun ◽  
H.B. Chen ◽  
A. Abdelnasir ◽  
S. Tang ◽  
...  

Author(s):  
Hao Yang ◽  
Yulong Zhao ◽  
Ning Chen ◽  
Yanpei Liu ◽  
Shaoyu Yang ◽  
...  

Abstract In plants, 3´,5´-cyclic adenosine monophosphate (cAMP) is an important second messenger with varied functions; however, only a few adenylyl cyclases (ACs) that synthesize cAMP have been identified. Moreover, the biological roles of ACs/cAMP in response to stress remain largely unclear. In this study, we used quantitative proteomics techniques to identify a maize heat-induced putative disease-resistance RPP13-like protein 3 (ZmRPP13-LK3), which has three conserved catalytic AC centres. The AC activity of ZmRPP13-LK3 was confirmed by in vitro enzyme activity analysis, in vivo RNAi experiments, and functional complementation in the E. coli cyaA mutant. ZmRPP13-LK3 is located in the mitochondria. The results of in vitro and in vivo experiments indicated that ZmRPP13-LK3 interacts with ZmABC2, a possible cAMP exporter. Under heat stress, the concentrations of ZmRPP13-LK3 and cAMP in the ABA-deficient mutant vp5 were significantly less than those in the wild-type, and treatment with ABA and an ABA inhibitor affected ZmRPP13-LK3 expression in the wild-type. Application of 8-Br-cAMP, a cAMP analogue, increased heat-induced expression of heat-shock proteins in wild-type plants and alleviated heat-activated oxidative stress. Taken together, our results indicate that ZmRPP13-LK3, a new AC, can catalyse ATP for the production of cAMP and may be involved in ABA-regulated heat resistance.


2011 ◽  
Vol 23 (1) ◽  
pp. 204 ◽  
Author(s):  
W. Huanca ◽  
R. L. Condori ◽  
M. A. Chileno ◽  
J. Cainzos ◽  
J. J. Becerra ◽  
...  

The objectives of the study were to evaluate the ovarian follicular response, cumulus–oocyte complex (COC) collection rate, fertilization, and culture of COC collected from alpacas after treatment with 2 different gonadotropins. Female alpacas were assigned to Group 1 (n = 8), 200 mg of FSH (Folltropin, Bioniche, Belleville, Ontario, Canada) divided b.i.d. for 3 days, plus a single IM dose of 1000 IU of hCG (Chorulon, Intervet, Salamanca, Spain) 24 h after the last FSH treatment; or Group 2 (n = 10), 750 IU of eCG (Folligon, Intervet) as a single dose, plus a single IM dose of 1000 IU of hCG on Day 3 after eCG treatment (Day 0 = start of the superstimulatory treatment). At 20 to 22 h post-hCG treatment, the ovaries were surgically exposed and COC were aspirated from follicles ≥6 mm and evaluated. The COC with a homogeneous cytoplasm and 2 or more layers of cumulus cells were transferred to plates with a 40-μL drop of TCM-199 maturation medium supplemented with 10% FCS (vol/vol) plus 0.5 μg mL–1 of FSH, 10 μg mL–1 of hCG, 0.2 mM sodium pyruvate, 50 μg mL–1 of gentamicin, and 1 μg mL–1 of oestradiol under mineral oil with 10 to 12 oocytes/drop and maturated 24 h at 39°C in an atmosphere of 5% CO2 and high humidity. After maturation, COC were removed and fertilized in vitro using epididymal sperm. Testes were collected from mature males from a slaughterhouse and transported to the laboratory. The caudal epididymide was isolated. A prick was made on the convoluted tubules with a sterile hypodermic needle and the fluid, rich in spermatozoa, was aspirated in syringes containing 2 mL of Tris-fructose egg yolk extender. Motile spermatozoa were obtained by centrifugation at 600 × g on a Percoll discontinuous gradient (45.0:22.5%) for 10 min. The supernatant was then removed by aspiration and the pellet was resuspended in TL-HEPES and centrifuged again at 300 × g for 5 min. The pellet was resuspended in TL-stock. Gametes were co-incubated for 18 h at 39°C with 5% CO2 and high humidity. Presumptive zygotes were cultured in KSOM medium supplemented with 1 mM glutamine, 0.3 mM sodium pyruvate, 50 μg mL–1 of gentamicin, EDTA, essential and nonessential amino acids, and BSA for 3 days and cultured in SOF medium for 7 days. Embryo development was evaluated at 72 h and 7 days. Data were subjected to ANOVA. The number of follicles ≥6 mm did not differ at the time of COC collection (19.3 ± 5.7 and 21.5 ± 7.3), and the number of COC collected was 16.7 ± 5.3 and 17.3 ± 6.6 for the FSH group and the eCG group, respectively. The cleavage rate was 45.2 and 42.1% for the FSH group and the eCG group, respectively, at 72 h of culture, and the blastocyst stage at Day 7 (22.2 v. 19.3) did not differ between treatments. In conclusion, the FSH and eCG treatments did not differ in the ovarian follicular response, COC collection rate, fertilization, and culture of COC. Both gonadotropins can be used in the IVF protocol for alpacas. Grant 064 FINCyT-PIBAP 2008 and Grant 032-2009 PROCYT–CONCYTEC.


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