scholarly journals Brief exposure to a diverse range of environmental stress enhances stress tolerance in the polyextremophilic Antarctic midge, Belgica antarctica

2020 ◽  
Author(s):  
J. D. Gantz ◽  
B. N. Philip ◽  
N. M. Teets ◽  
Y. Kawarasaki ◽  
L. J. Potts ◽  
...  
Keyword(s):  
Environmental Stress ◽  
Stress Tolerance ◽  
Cold Tolerance ◽  
Abiotic Stresses ◽  
Environmental Cues ◽  
Ambient Conditions ◽  
Diverse Range ◽  
Rapid Cold Hardening ◽  
Belgica Antarctica ◽  
The Antarctic

AbstractInsects use rapid acclimation to enhance their tolerance of abiotic stresses within minutes to hours. These responses are critical adaptations for insects and other small ectotherms to tolerate drastic changes in temperature, hydration, or other factors that can fluctuate precipitously with ambient conditions or as a result of behavior. Rapid cold-hardening, where insects use brief exposure to modest chilling as a cue to enhance their cold tolerance, is the most thoroughly-studied of these responses and relatively little is known about rapid acclimation that is either triggered by or enhances tolerance of other abiotic stresses. Here, we used larvae of the Antarctic midge, Belgica antarctica, a polar extremophile that routinely experiences numerous stresses in nature, to investigate how 2 h exposure to modest environmental stresses affect stress tolerance in insects. Brief pretreatment by various stresses, including hyperosmotic challenge, hypoosmotic challenge, acidity, basicity, and UV irradiation enhanced stress tolerance in B. antarctica larvae relative to untreated controls. These results indicate that numerous environmental cues can trigger rapid acclimation in insects and that these responses can enhance tolerance of multiple stresses.

scholarly journals Onset of seasonal metabolic depression in the Antarctic midge Belgica antarctica appears to be independent of environmental cues

2019 ◽  
Vol 45 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Drew E. Spacht ◽  
J. D. Gantz ◽  
Richard E. Lee ◽  
David L. Denlinger
Keyword(s):  
Environmental Cues ◽  
Metabolic Depression ◽  
Belgica Antarctica ◽  
The Antarctic

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.

Characterization of drought-induced rapid cold-hardening in the Antarctic midge, Belgica antarctica

Polar Biology ◽  
2019 ◽  
Vol 42 (6) ◽  
pp. 1147-1156 ◽  
Author(s):  
Yuta Kawarasaki ◽  
Nicholas M. Teets ◽  
Benjamin N. Philip ◽  
Leslie J. Potts ◽  
J. D. Gantz ◽  
...  
Keyword(s):  
Cold Hardening ◽  
Rapid Cold Hardening ◽  
Belgica Antarctica ◽  
The Antarctic

Stress tolerance in a polyextremophile: the southernmost insect

2015 ◽  
Vol 93 (9) ◽  
pp. 679-686 ◽  
Author(s):  
R.E. Lee ◽  
D.L. Denlinger
Keyword(s):  
Biotic Interactions ◽  
Cross Tolerance ◽  
Atp Production ◽  
Genome Wide ◽  
Rapid Cold Hardening ◽  
Belgica Antarctica ◽  
Genes Encoding ◽  
Shock Proteins ◽  
The Antarctic ◽  
Autophagy Inhibition

Since biotic interactions within the simple terrestrial communities on the Antarctic Peninsula are limited compared with tropical and temperate regions, survival is largely dictated by the numerous abiotic challenges. Our research focuses on adaptations to environmental stresses experienced by the Antarctic midge (Belgica antarctica Jacobs, 1900), the southernmost free-living insect. Midge larvae can survive freezing and anoxia year-round. Not only can frozen larvae undergo rapid cold-hardening (RCH) at temperatures as low as –12 °C, but RCH develops more rapidly in frozen compared with supercooled larvae. Whether larvae overwinter in a frozen state or cryoprotectively dehydrated may depend on hydration levels within their hibernacula. Larvae constitutively up-regulate genes encoding heat shock proteins, as well as the antioxidant enzymes superoxide dismutase and catalase. Larvae accumulate osmoprotectants in response to freezing, desiccation, and exposure to seawater; exposure to one of these osmotic stressors confers cross-tolerance to the others. Molecular responses to dehydration stress include extensive genome-wide changes that include differential expression of aquaporins among tissues, upregulation of pathways associated with autophagy, inhibition of apoptosis, and downregulation of metabolism and ATP production.

scholarly journals Down-Regulation of SlGRAS10 in Tomato Confers Abiotic Stress Tolerance

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 623
Author(s):  
Sidra Habib ◽  
Yee Yee Lwin ◽  
Ning Li
Keyword(s):  
Salt Stress ◽  
Abiotic Stress ◽  
Plant Growth ◽  
Stress Tolerance ◽  
Abiotic Stresses ◽  
Abiotic Stress Tolerance ◽  
Functional Characterization ◽  
Flavonoid Biosynthesis ◽  
Ros Scavenging ◽  
Down Regulation

Adverse environmental factors like salt stress, drought, and extreme temperatures, cause damage to plant growth, development, and crop yield. GRAS transcription factors (TFs) have numerous functions in biological processes. Some studies have reported that the GRAS protein family plays significant functions in plant growth and development under abiotic stresses. In this study, we demonstrated the functional characterization of a tomato SlGRAS10 gene under abiotic stresses such as salt stress and drought. Down-regulation of SlGRAS10 by RNA interference (RNAi) produced dwarf plants with smaller leaves, internode lengths, and enhanced flavonoid accumulation. We studied the effects of abiotic stresses on RNAi and wild-type (WT) plants. Moreover, SlGRAS10-RNAi plants were more tolerant to abiotic stresses (salt, drought, and Abscisic acid) than the WT plants. Down-regulation of SlGRAS10 significantly enhanced the expressions of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) to reduce the effects of reactive oxygen species (ROS) such as O2− and H2O2. Malondialdehyde (MDA) and proline contents were remarkably high in SlGRAS10-RNAi plants. Furthermore, the expression levels of chlorophyll biosynthesis, flavonoid biosynthesis, and stress-related genes were also enhanced under abiotic stress conditions. Collectively, our conclusions emphasized the significant function of SlGRAS10 as a stress tolerate transcription factor in a certain variety of abiotic stress tolerance by enhancing osmotic potential, flavonoid biosynthesis, and ROS scavenging system in the tomato plant.

Life history traits of adults and embryos of the Antarctic midge Belgica antarctica

Polar Biology ◽  
2014 ◽  
Vol 37 (8) ◽  
pp. 1213-1217 ◽  
Author(s):  
Eri Harada ◽  
Richard E. Lee ◽  
David L. Denlinger ◽  
Shin G. Goto
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Belgica Antarctica ◽  
The Antarctic
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