scholarly journals Antioxidant Adjustments of Olive Trees (Olea Europaea) under Field Stress Conditions

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 684
Author(s):  
Márcia Araújo ◽  
João Prada ◽  
Nuno Mariz-Ponte ◽  
Conceição Santos ◽  
José Alberto Pereira ◽  
...  
Keyword(s):  
Water Status ◽  
Harmful Effect ◽  
Metabolite Profile ◽  
Protective Role ◽  
Stress Conditions ◽  
Guaiacol Peroxidase ◽  
Enzymatic System ◽  
Important Species ◽  
Field Stress ◽  
Olive Trees

Extreme climate events are increasingly frequent, and the 2017 summer was particularly critical in the Mediterranean region. Olive is one of the most important species of this region, and these climatic events represent a threat to this culture. However, it remains unclear how olive trees adjust the antioxidant enzymatic system and modulate the metabolite profile under field stress conditions. Leaves from two distinct adjacent areas of an olive orchard, one dry and the other hydrated, were harvested. Tree water status, oxidative stress, antioxidant enzymes, and phenolic and lipophilic metabolite profiles were analyzed. The environmental conditions of the 2017 summer caused a water deficit in olive trees of the dry area, and this low leaf water availability was correlated with the reduction of long-chain alkanes and fatty acids. Hydrogen peroxide (H2O2) and superoxide radical (O2•–) levels increased in the trees collected from the dry area, but lipid peroxidation did not augment. The antioxidant response was predominantly marked by guaiacol peroxidase (GPOX) activity that regulates the H2O2 harmful effect and by the action of flavonoids (luteolin-7-O-glucuronide) that may act as reactive oxygen species scavengers. Secoiridoids adjustments may also contribute to stress regulation. This work highlights for the first time the protective role of some metabolite in olive trees under field drought conditions.

scholarly journals Morphological and Physio-Biochemical Responses of Watermelon Grafted onto Rootstocks of Wild Watermelon [Citrullus colocynthis (L.) Schrad] and Commercial Interspecific Cucurbita Hybrid to Drought Stress

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 359
Author(s):  
Mahdi Bikdeloo ◽  
Giuseppe Colla ◽  
Youssef Rouphael ◽  
Mohammad Reza Hassandokht ◽  
Forouzandeh Soltani ◽  
...  
Keyword(s):  
Water Stress ◽  
Growth Traits ◽  
Citrullus Lanatus ◽  
Water Status ◽  
Stress Conditions ◽  
Guaiacol Peroxidase ◽  
Citrullus Colocynthis ◽  
Apple Rootstock ◽  
Internodal Length ◽  
Biochemical Responses

This study aimed to assess the morphological and physio-biochemical responses of a commercial watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai) cv. ‘Crimson Sweet’ grafted onto a drought-tolerant rootstock of wild watermelon (bitter apple, Citrullus colocynthis (L.) Schrad, ‘Esfahan’) in comparison with an ungrafted ‘Crimson Sweet’ watermelon or one grafted onto a commercial interspecific Cucurbita hybrid (Cucurbita maxima Duch. × Cucurbita moschata Duch.) rootstock (‘Shintoza’) under water stress. The experiment was conducted in pots under a controlled environment in a greenhouse, and water stress was imposed by maintaining moisture level in pots at 100% (well water (WW)) or 50% (water deficit (WD)) of container capacity (CC). WD significantly decreased most of the morphological traits in ungrafted and grafted plants, while the decrease in growth traits was lower in grafted plants than ungrafted plants. The response of grafted plants onto wild watermelon rootstock (‘Esfahan’) for most of the affected parameters (shoot fresh and dry weight, vine length and internodal length) was, however, comparable to those grafted onto commercial Cucurbita hybrid rootstock (‘Shintoza’). Plants grafted onto bitter apple (wild watermelon) exhibited a relatively lower decrease in growth and biomass, besides showing higher antioxidant activity (e.g., guaiacol peroxidase) concomitant with the lower accumulation of malondialdehyde and electrolyte leakage in the leaf tissues in comparison with ungrafted plants. The overall growth performance, as well as those under water stress conditions in commercial rootstock-grafted watermelon, was related to its better plant water status (e.g., high relative water content) which was likely ascertained by its greater root efficiency. This suggests that watermelons grafted onto bitter apple rootstock and Cucurbita hybrid rootstock were constitutively more resistant to drought, with higher efficiency in mitigating oxidative stress than ungrafted treatment. The above findings demonstrated that bitter apple, a well-adapted desert species, can be used as an alternative rootstock to commercial rootstocks (e.g., ‘Shintoza’) for watermelon grafting under water stress conditions. In addition, bitter apple rootstock can be involved in rootstock breeding programs to improve drought tolerance in watermelon.

Picloram Uptake, Translocation, and Efficacy in Relation to Water Status of Russian Knapweed (Acroptilon repens)

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Robert G. Morrison ◽  
Norman K. Lownds ◽  
Tracy M. Sterling
Keyword(s):  
Water Stress ◽  
Water Status ◽  
Stress Conditions ◽  
Russian Knapweed ◽  
Leaf Surfaces ◽  
Treated Leaf ◽  
Acroptilon Repens

Picloram uptake, translocation, and efficacy were studied using greenhouse-grown Russian knapweed plants. Uptake of14C-picloram, applied as discrete droplets to adaxial leaf surfaces of well-watered plants, averaged less than 10% of that applied. Most uptake occurred within 30 min of application. Uptake increased linearly with external picloram concentrations from 6.2 to 74.5 mM and was proportional to picloram concentration. Only about 10% of absorbed picloram was translocated out of the treated leaf of well-watered plants within 96 h, with approximately equal acropetal and basipetal translocation. Water stress before, at the time of, and after picloram application did not affect picloram uptake, but reduced total translocation and increased the relative amount translocated basipetally. Water stress also reduced picloram efficacy. Although Silwett L-77 increased picloram uptake into Russian knapweed leaves, it did not increase efficacy under water stress conditions.

scholarly journals Physiological parameters to select upland rice genotypes for tolerance to water deficit

2015 ◽  
Vol 50 (7) ◽  
pp. 534-540 ◽  
Author(s):  
Cleber Morais Guimarães ◽  
Luís Fernando Stone ◽  
Adriano Pereira de Castro ◽  
Odilon Peixoto de Morais Júnior
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Upland Rice ◽  
Water Status ◽  
Leaf Temperature ◽  
Physiological Parameters ◽  
Stress Conditions ◽  
Diffusive Resistance ◽  
Susceptible Control ◽  
Rice Genotypes

Abstract: The objective of this work was to evaluate the feasibility of using physiological parameters for water deficit tolerance, as an auxiliary method for selection of upland rice genotypes. Two experiments - with or without water deficit - were carried out in Porangatu, in the state of Goiás, Brazil; the water deficit experiment received about half of irrigation that was applied to the well-watered experiment. Four genotypes with different tolerance levels to water stress were evaluated. The UPLRI 7, B6144F-MR-6-0-0, and IR80312-6-B-3-2-B genotypes, under water stress conditions, during the day, showed lower stomatal diffusive resistance, higher leaf water potential, and lower leaf temperature than the control. These genotypes showed the highest grain yields under water stress conditions, which were 534, 601, and 636 kg ha-1, respectively, and did not differ significantly among them. They also showed lower drought susceptibility index than the other genotypes. 'BRS Soberana' (susceptible control) was totally unproductive under drought conditions. Leaf temperature is a easy-read parameter correlated to plant-water status, viable for selecting rice genotypes for water deficit tolerance.

Shoot hydraulic characteristics, plant water status and stomatal response in olive trees under different soil water conditions

2013 ◽  
Vol 373 (1-2) ◽  
pp. 77-87 ◽  
Author(s):  
J. M. Torres-Ruiz ◽  
A. Diaz-Espejo ◽  
A. Morales-Sillero ◽  
M. J. Martín-Palomo ◽  
S. Mayr ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Status ◽  
Plant Water Status ◽  
Plant Water ◽  
Stomatal Response ◽  
Hydraulic Characteristics ◽  
Water Conditions ◽  
Olive Trees ◽  
Soil Water Conditions

scholarly journals Interleukin-22 reverses human islet dysfunction and apoptosis triggered by hyperglycemia and LIGHT

2018 ◽  
Vol 60 (3) ◽  
pp. 171-183
Author(s):  
Shadab Abadpour ◽  
Bente Halvorsen ◽  
Afaf Sahraoui ◽  
Olle Korsgren ◽  
Pål Aukrust ◽  
...  
Keyword(s):  
Islet Cells ◽  
Harmful Effect ◽  
Human Islets ◽  
Protective Role ◽  
Human Islet ◽  
Islet Function ◽  
Post Transplantation ◽  
Interleukin 22 ◽  
Glucose Stimulated Insulin Secretion

Interleukin (IL)-22 has recently been suggested as an anti-inflammatory cytokine that could protect the islet cells from inflammation- and glucose-induced toxicity. We have previously shown that the tumor necrosis factor family member, LIGHT, can impair human islet function at least partly via pro-apoptotic effects. Herein, we aimed to investigate the protective role of IL-22 on human islets exposed to the combination of hyperglycemia and LIGHT. First, we found upregulation of LIGHT receptors (LTβR and HVEM) in engrafted human islets exposed to hyperglycemia (>11 mM) for 17 days post transplantation by using a double islet transplantation mouse model as well as in human islets cultured with high glucose (HG) (20 mM glucose) + LIGHT in vitro, and this latter effect was attenuated by IL-22. The effect of HG + LIGHT impairing glucose-stimulated insulin secretion was reversed by IL-22. The harmful effect of HG + LIGHT on human islet function seemed to involve enhanced endoplasmic reticulum stress evidenced by upregulation of p-IRE1α and BiP, elevated secretion of pro-inflammatory cytokines (IL-6, IL-8, IP-10 and MCP-1) and the pro-coagulant mediator tissue factor (TF) release and apoptosis in human islets, whereas all these effects were at least partly reversed by IL-22. Our findings suggest that IL-22 could counteract the harmful effects of LIGHT/hyperglycemia on human islet cells and potentially support the strong protective effect of IL-22 on impaired islet function and survival.

WATER STATUS OF OLIVE TREES UNDER DRY-FARMING AND DRIP-IRRIGATION

1993 ◽  
pp. 157-164 ◽  
Author(s):  
J.E. Fernández ◽  
F. Moreno ◽  
J. Martín-Aranda
Keyword(s):  
Drip Irrigation ◽  
Water Status ◽  
Olive Trees ◽  
Dry Farming

Antioxidant defences in olive trees during drought stress: changes in activity of some antioxidant enzymes

2005 ◽  
Vol 32 (1) ◽  
pp. 45 ◽  
Author(s):  
Adriano Sofo ◽  
Bartolomeo Dichio ◽  
Cristos Xiloyannis ◽  
Andrea Masia
Keyword(s):  
Drought Stress ◽  
Water Deficit ◽  
Active Oxygen Species ◽  
Net Photosynthesis ◽  
Cellular Damage ◽  
Guaiacol Peroxidase ◽  
Severe Drought ◽  
Antioxidant Defences ◽  
Stress Changes ◽  
Olive Trees

The effects of drought on the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD), indoleacetate oxidase (IAAox) and polyphenol oxidase (PPO) were studied in 2-year old Olea europaea L. (cv. ‘Coratina’) plants grown under high temperatures and irradiance levels and gradually subjected to a controlled water deficit. After 20 d without irrigation, mean predawn leaf water potential fell from –0.37 to –5.37 MPa, and decreases in net photosynthesis and transpiration occurred. The activities of SOD, APX, CAT and POD increased in relation to the severity of drought stress in both leaves and roots. In particular, a marked increase in APX activity was found in leaves of plants at severe drought stress. CAT activity increased during severe water deficit conditions in leaves and fine roots. The patterns of POD and IAA oxidase activity ran in parallel and showed increases in relation to the degree of drought. In contrast, PPO activity decreased during the progression of stress in all the tissues studied. The results show that the ability of olive trees to up-regulate the enzymatic antioxidant system might be an important attribute linked to drought tolerance. This could limit cellular damage caused by active oxygen species during water deficit.

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