Osmotic stress effects on the freezing tolerance of the antarctic nematodePanagrolaimus davidi

1996 ◽  
Vol 166 (5) ◽  
pp. 344-349 ◽  
Author(s):  
D. A. Wharton ◽  
N. B. To
Keyword(s):  
Osmotic Stress ◽  
Freezing Tolerance ◽  
Stress Effects ◽  
The Antarctic

scholarly journals INFLUENCE OF ABIOTIC STRESS FACTORS ON THE HYDRATION OF PLANT TISSUES OF SEDUM HYBRIDUM L. (AIZOPSIS HYBRIDA (L.) GRULICH)

2021 ◽  
Author(s):  
N.V. Terletskaya ◽  
T.N. Kobylina ◽  
Zh.A. Kenzhebayeva
Keyword(s):  
Abiotic Stress ◽  
Osmotic Stress ◽  
Plant Material ◽  
Stress Factors ◽  
Moisture Loss ◽  
Control Group ◽  
Plant Tissues ◽  
Stress Effects ◽  
Abiotic Stress Factors ◽  
Adaptive Effect

Genus Sedum (family Crassulaceae) - succulents adapted to lack of moisture. Morphophysiological reactions of immature Sedum hybridum L. (Aizopsis hybrida (L.) Grulich) plants to stressful conditions of water scarcity, salinization and low positive temperatures are described. The high resistance of plants to the studied stress effects is shown. The tendency of the dynamics of the highest moisture loss by plants of the control group and the lowest by plants cultivated at PEG–6000 at a concentration of 200 mmol/l was noted, which indicates the adaptive effect of this level of osmotic stress on Sedum hybridum plants. To obtain a completely dry Sedum hybridum mass for various physiological experiments, it is necessary to maintain the plant material at a temperature of 105⸰ C, with at least 40 hours.

scholarly journals Development of the pollen in the antarctic flowering plant Colobanthus quitensis (Kunth) Bartl.

2012 ◽  
Vol 60 (2) ◽  
pp. 3-8 ◽  
Author(s):  
Irena Giełwanowska ◽  
Anna Bochenek ◽  
Ewa Szczuka
Keyword(s):  
Osmotic Stress ◽  
Flowering Plant ◽  
Natural Conditions ◽  
Callose Wall ◽  
Colobanthus Quitensis ◽  
Mother Cells ◽  
The Antarctic

<i>Colobanthus quitensis</i> (Kunth) Bartl. produced two types very small bisexual fl owers. In the Antarctic natural conditions chasmogamic and cleistogamic fl owers most often form fi ve stamina with short fi laments. Two microsporangia with a three-layer wall form in the anther. Microspore mother cells, which develop into microspores after meiosis, form inside the microsporangium. Microsporocytes of <i>Colobanthus quitensis</i> are surrounded with a thick callose layer, the special wall. After meiosis, the callose wall is dissolved and microspores are released from the tetrad. The production of proorbicules, orbicules and peritapetal membrane, and the construction of a complex sporoderm with numerous apertural sites were observed. When microspore and pollen protoplasts underwent necrosis, probably as a result of temperature and osmotic stress, sporoderm layers formed around microspores, and the cell tapetum did not disintegrate. However, woody wall layers did not accumulate in endothecium cells.

Osmotic Stress: Effects of Its Application to a Portion of Wheat Root Systems

Science ◽  
1964 ◽  
Vol 144 (3625) ◽  
pp. 1463-1464
Author(s):  
Raymond E. Meyer ◽  
Joe R. Gingrich
Keyword(s):  
Osmotic Stress ◽  
Root Systems ◽  
Wheat Root ◽  
Stress Effects

Rapid cold-hardening in larvae of the Antarctic midge Belgica antarctica: cellular cold-sensing and a role for calcium

2008 ◽  
Vol 294 (6) ◽  
pp. R1938-R1946 ◽  
Author(s):  
Nicholas M. Teets ◽  
Michael A. Elnitsky ◽  
Joshua B. Benoit ◽  
Giancarlo Lopez-Martinez ◽  
David L. Denlinger ◽  
...  
Keyword(s):  
Cell Survival ◽  
Freezing Tolerance ◽  
Fat Body ◽  
Malpighian Tubules ◽  
Cold Hardening ◽  
Rapid Cold Hardening ◽  
Belgica Antarctica ◽  
The Antarctic ◽  
Cold Sensing

In many insects, the rapid cold-hardening (RCH) response significantly enhances cold tolerance in minutes to hours. Larvae of the Antarctic midge, Belgica antarctica, exhibit a novel form of RCH, by which they increase their freezing tolerance. In this study, we examined whether cold-sensing and RCH in B. antarctica occur in vitro and whether calcium is required to generate RCH. As demonstrated previously, 1 h at −5°C significantly increased organismal freezing tolerance at both −15°C and −20°C. Likewise, RCH enhanced cell survival of fat body, Malpighian tubules, and midgut tissue of larvae frozen at −20°C. Furthermore, isolated tissues retained the capacity for RCH in vitro, as demonstrated with both a dye exclusion assay and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based viability assay, thus indicating that cold-sensing and RCH in B. antarctica occur at the cellular level. Interestingly, there was no difference in survival between tissues that were supercooled at −5°C and those frozen at −5°C, suggesting that temperature mediates the RCH response independent of the freezing of body fluids. Finally, we demonstrated that calcium is required for RCH to occur. Removing calcium from the incubating solution slightly decreased cell survival after RCH treatments, while blocking calcium with the intracellular chelator BAPTA-AM significantly reduced survival in the RCH treatments. The calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7) also significantly reduced cell survival in the RCH treatments, thus supporting a role for calcium in RCH. This is the first report implicating calcium as an important second messenger in the RCH response.

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