scholarly journals A Salt-Signaling Network Involving Ethylene, Extracellular ATP, Hydrogen Peroxide, and Calcium Mediates K+/Na+ Homeostasis in Arabidopsis

2020 ◽  
Vol 21 (22) ◽  
pp. 8683
Author(s):  
Tao Lang ◽  
Chen Deng ◽  
Jun Yao ◽  
Huilong Zhang ◽  
Yin Wang ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Nacl Stress ◽  
Extracellular Atp ◽  
Interactive Effects ◽  
Short Term ◽  
Hypocotyl Length ◽  
Ionic Flux ◽  
Ethylene Precursor ◽  
State Ionic ◽  
Salt Signaling

This work aimed at investigating the interactive effects of salt-signaling molecules, i.e., ethylene, extracellular ATP (eATP), H2O2, and cytosolic Ca2+ ([Ca2+]cyt), on the regulation of K+/Na+ homeostasis in Arabidopsisthaliana. The presence of eATP shortened Col-0 hypocotyl length under no-salt conditions. Moreover, eATP decreased relative electrolyte leakage and lengthened root length significantly in salt-treated Col-0 plants but had no obvious effects on the ethylene-insensitive mutants etr1-1 and ein3-1eil1-1. Steady-state ionic flux kinetics showed that exogenous 1-aminocyclopropane-1-carboxylic acid (ACC, an ethylene precursor) and eATP-Na2 (an eATP donor) significantly increased Na+ extrusion and suppressed K+ loss during short-term NaCl treatment. Moreover, ACC remarkably raised the fluorescence intensity of salt-elicited H2O2 and cytosolic Ca2+. Our qPCR data revealed that during 12 h of NaCl stress, application of ACC increased the expression of AtSOS1 and AtAHA1, which encode the plasma membrane (PM) Na+/H+ antiporters (SOS1) and H+-ATPase (H+ pumps), respectively. In addition, eATP markedly increased the transcription of AtEIN3, AtEIL1, and AtETR1, and ACC treatment of Col-0 roots under NaCl stress conditions caused upregulation of AtRbohF and AtSOS2/3, which directly contribute to the H2O2 and Ca2+ signaling pathways, respectively. Briefly, ethylene was triggered by eATP, a novel upstream signaling component, which then activated and strengthened the H2O2 and Ca2+ signaling pathways to maintain K+/Na+ homeostasis under salinity.

scholarly journals Interactive effects of ambient ozone and climate measured on growth of mature loblolly pine trees

1996 ◽  
Vol 26 (4) ◽  
pp. 670-681 ◽  
Author(s):  
S.B. McLaughlin ◽  
D.J. Downing
Keyword(s):  
Soil Moisture ◽  
Loblolly Pine ◽  
Moisture Stress ◽  
Growth Patterns ◽  
Forest Growth ◽  
Interactive Effects ◽  
Forest Trees ◽  
Short Term ◽  
Data Set ◽  
Ambient Ozone

Seasonal growth patterns of mature loblolly pine (Pinustaeda L.) trees over the interval 1988–1993 have been analyzed to evaluate the effects of ambient ozone on growth of large forest trees. Patterns of stem expansion and contraction of 34 trees were examined using serial measurements with sensitive dendrometer band systems. Study sites, located in eastern Tennessee, varied significantly in soil moisture, soil fertility, and stand density. Levels of ozone, rainfall, and temperature varied widely over the 6-year study interval. Regression analysis identified statistically significant influences of ozone on stem growth patterns, with responses differing widely among trees and across years. Ozone interacted with both soil moisture stress and high temperatures, explaining 63% of the high frequency, climatic variance in stem expansion identified by stepwise regression of the 5-year data set. Observed responses to ozone were rapid, typically occurring within 1–3 days of exposure to ozone at ≥40 ppb and were significantly amplified by low soil moisture and high air temperatures. Both short-term responses, apparently tied to ozone-induced increases in whole-tree water stress, and longer term cumulative responses were identified. These data indicate that relatively low levels of ambient ozone can significantly reduce growth of mature forest trees and that interactions between ambient ozone and climate are likely to be important modifiers of future forest growth and function. Additional studies of mechanisms of short-term response and interspecies comparisons are clearly needed.

scholarly journals Does Deep-Underground Storage Stimulate the Germination of Canola (Brassica napus L.) Seed?

2020 ◽  
Vol 12 (6) ◽  
pp. 23
Author(s):  
Yuxin He ◽  
Chao Liu ◽  
Heping Xie ◽  
Jingchen Wang ◽  
Yang Wang ◽  
...  
Keyword(s):  
Seed Storage ◽  
Biomass Accumulation ◽  
Underground Storage ◽  
Total Biomass ◽  
Short Term ◽  
Hypocotyl Length ◽  
Brassica Napus L ◽  
The Earth ◽  
Deep Underground ◽  
Compensatory Effect

Agriculture is a crucial area to be considered when exploring and exploiting the use of deep-underground space. We investigated the feasibility of deep-underground seed storage by keeping canola seed in either envelopes or sealed packages at four depths below the Earth’s surface (0, 240, 690, and 1410 m) at a gold mine in northeastern China. We studied the effects of storage depth and duration by conducting germination tests with the stored seed. The results showed that the rate of germination was reduced in seed stored at deeper levels and was also lower at all depths after a more prolonged period of storage. Seeds from sealed packages exhibited better resistance to the deep-underground environment than seeds kept in envelopes. However, measurements of hypocotyl lengths and biomass accumulation revealed that the germination of seeds stored in deep-underground was initially inhibited but recovered well compared with the control as the storage depth increased. The total biomass of the hypocotyl increased as the depth of seed storage deepened, indicating the existence of a compensatory effect on seed germination. The findings suggest that short-term deep-underground storage of seeds in sealed packages would improve the germination performance of cultivated canola in terms of the hypocotyl length and biomass accumulation and might be considered as a pre-sowing strategy.

scholarly journals Increased Thermal Sensitivity of a Tropical Marine Gastropod Under Combined CO2 and Temperature Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Jay J. Minuti ◽  
Charlee A. Corra ◽  
Brian S. Helmuth ◽  
Bayden D. Russell
Keyword(s):  
Defense Mechanism ◽  
Thermal Sensitivity ◽  
Interactive Effects ◽  
Lethal Temperature ◽  
Weather Extremes ◽  
Short Term ◽  
Metabolic Plasticity ◽  
The Face ◽  
Metabolic Performance ◽  
Maximum Metabolic Rate

The ability of an organism to alter its physiology in response to environmental conditions offers a short-term defense mechanism in the face of weather extremes resulting from climate change. These often manifest as multiple, interacting drivers, especially pH and temperature. In particular, decreased pH can impose constraints on the biological mechanisms which define thermal limits by throwing off energetic equilibrium and diminishing physiological functions (e.g., in many marine ectotherms). For many species, however, we do not have a detailed understanding of these interactive effects, especially on short-term acclimation responses. Here, we investigated the metabolic plasticity of a tropical subtidal gastropod (Trochus maculatus) to increased levels of CO2 (700 ppm) and heating (+3°C), measuring metabolic performance (Q10 coefficient) and thermal sensitivity [temperature of maximum metabolic rate (TMMR), and upper lethal temperature (ULT)]. Individuals demonstrated metabolic acclimation in response to the stressors, with TMMR increasing by +4.1°C under higher temperatures, +2.7°C under elevated CO2, and +4.4°C under the combined stressors. In contrast, the ULT only increased marginally in response to heating (+0.3°C), but decreased by −2.3°C under CO2, and −8.7°C under combined stressors. Therefore, although phenotypic plasticity is evident with metabolic acclimation, acute lethal temperature limits seem to be less flexible during short-term acclimation.

scholarly journals The Dose-dependent Dual Effects of Corticosterone on Spatial Memory Ability After Traumatic Brain Injury Are Mediated by Two Corticosteroid Receptor Systems

2021 ◽  
Author(s):  
Bin Zhang ◽  
Mengshi Yang ◽  
Qiongyu Yan ◽  
Xiaojian Xu ◽  
Fei Niu ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Spatial Memory ◽  
Signaling Pathways ◽  
Hippocampal Neurons ◽  
High Dose ◽  
Short Term ◽  
Memory Ability ◽  
Neurotoxic Effects ◽  
Dose Dependent

Abstract Background: Our recent studies reported the opposite effects of mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) on neuron survival after traumatic brain injury (TBI). However, as a mixed agonist for MR and GR, whether short term use of high-dose endogenous glucocorticoids exerts neurotoxic effects by excessive activation of GR, what is the set-point, and the possible signaling pathways remain unclear. This study examined the dose-dependent dual effects of corticosterone (CORT) on the spatial memory, the survival of hippocampal neurons and the possible receptor-mediated downstream signaling pathways after TBI.Methods: Based on controlled cortical impact (CCI) and CORT treatments, Sprague-Dawley rats (n=168) were randomly divided into the sham, CCI, CCI + CORT1 (0.3 mg/kg), CCI + CORT2 (3 mg/kg), CCI + CORT3 (30 mg/kg), CCI + CORT1 + spirolactone (spirolactone: 50 mg/kg/d), and CCI + CORT3 + RU486 (RU486: 50 mg/kg/d) groups. Brain tissues were collected on postinjury day 3 and processed for histology and western blot analysis.Results: On postinjury day 3, we tested the learning and memory ability, neuronal apoptosis in the hippocampus, activation levels of MR and GR, Bcl-2 family proteins, and apoptosis-related intracellular signaling pathways. We found that different doses of CORT exhibited dual effects on the survival of hippocampal neurons and the spatial memory. Lower doses of CORT (0.3, 3 mg/kg) significantly increased the activation of MR, upregulated the phosphorylation of Akt/CREB/Bad and the Bcl-2 expression, reduced the number of apoptotic neurons, and subsequently improved the spatial memory. In contrast, higher dose of CORT (30 mg/kg) exerted opposite effect by over activating GR, upregulating the expressions of P53/Bax, and inhibiting the Erk/CREB activities. Conclusion: The results suggest that there is a threshold between the neuroprotective and neurotoxic effects of endogenous GC, higher dose of which, even for short-term use, should also be avoided after TBI.

The temperature response of leaf dark respiration in 15 provenances of Eucalyptus grandis grown in ambient and elevated CO2

2017 ◽  
Vol 44 (11) ◽  
pp. 1075 ◽  
Author(s):  
Michael J. Aspinwall ◽  
Vinod K. Jacob ◽  
Chris J. Blackman ◽  
Renee A. Smith ◽  
Mark G. Tjoelker ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Tree Species ◽  
Unit Area ◽  
Dark Respiration ◽  
Eucalyptus Grandis ◽  
Temperature Response ◽  
Respiratory Physiology ◽  
Interactive Effects ◽  
Short Term ◽  
Leaf Dark Respiration

The effects of elevated CO2 on the short-term temperature response of leaf dark respiration (R) remain uncertain for many forest tree species. Likewise, variation in leaf R among populations within tree species and potential interactive effects of elevated CO2 are poorly understood. We addressed these uncertainties by measuring the short-term temperature response of leaf R in 15 provenances of Eucalyptus grandis W. Hill ex Maiden from contrasting thermal environments grown under ambient [CO2] (aCO2; 400 µmol mol–1) and elevated [CO2] (640 µmol mol–1; eCO2). Leaf R per unit area (Rarea) measured across a range of temperatures was higher in trees grown in eCO2 and varied up to 104% among provenances. However, eCO2 increased leaf dry mass per unit area (LMA) by 21%, and when R was expressed on a mass basis (i.e. Rmass), it did not differ between CO2 treatments. Likewise, accounting for differences in LMA among provenances, Rmass did not differ among provenances. The temperature sensitivity of R (i.e. Q10) did not differ between CO2 treatments or among provenances. We conclude that eCO2 had no direct effect on the temperature response of R in E. grandis, and respiratory physiology was similar among provenances of E. grandis regardless of home-climate temperature conditions.

scholarly journals Short-Term Nitrogen Addition Does Not Significantly Alter the Effects of Seasonal Drought on Leaf Functional Traits in Machilus pauhoi Kanehira Seedlings

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 78 ◽  
Author(s):  
Hua Yu ◽  
Dongliang Cheng ◽  
Baoyin Li ◽  
Chaobin Xu ◽  
Zhongrui Zhang ◽  
...  
Keyword(s):  
Functional Traits ◽  
C:N Ratio ◽  
Leaf Traits ◽  
N Deposition ◽  
Interactive Effects ◽  
N Addition ◽  
Subtropical China ◽  
Short Term ◽  
Leaf Functional Traits ◽  
Seasonal Drought

Research Highlights: Short-term nitrogen (N) addition did not significantly alter the effects of seasonal drought on the leaf functional traits in Machilus pauhoi Kanehira seedlings in N-rich subtropical China. Background and Objectives: Seasonal drought and N deposition are major drivers of global environmental change that affect plant growth and ecosystem function in subtropical China. However, no consensus has been reached on the interactive effects of these two drivers. Materials and Methods: We conducted a full-factorial experiment to analyze the single and combined effects of seasonal drought and short-term N addition on chemical, morphological and physiological traits of M. pauhoi seedlings. Results: Seasonal drought (40% of soil field capacity) had significant negative effects on the leaf N concentrations (LNC), phosphorus (P) concentrations (LPC), leaf thickness (LT), net photosynthetic rate (A), transpiration rate (E), stomatal conductance (Gs), and predawn leaf water potential (ψPD), and significant positive effects on the carbon:N (C:N) ratio and specific leaf area (SLA). Short-term N addition (50 kg N·hm−2·year−1 and 100 kg N·hm−2·year−1) tended to decrease the C:N ratio and enhance leaf nutrient, growth, and photosynthetic performance because of increased LNC, LPC, LT, leaf area (LA), SLA, A, E, and ψPD; however, it only had significant effects on LT and Gs. No significant interactive effects on leaf traits were detected. Seasonal drought, short-term N addition, and their interactions had significant effects on soil properties. The soil total C (STC), nitrate N (NO3−-N) and soil total N (STN) concentrations were the main factors that affected the leaf traits. Conclusions: Seasonal drought had a stronger effect on M. pauhoi seedling leaf traits than short-term N deposition, indicating that the interaction between seasonal drought and short-term N deposition may have an additive effecton M. pauhoi seedling growth in N-rich subtropical China.

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