Ultrastructural and cytochemical aspects of induced apogamy following abscisic acid pre-treatment of secondary moss protonema

Planta ◽  
1981 ◽  
Vol 151 (5) ◽  
pp. 427-433 ◽  
Author(s):  
M. K. Menon ◽  
P. R. Bell
Keyword(s):  
Abscisic Acid ◽  
Moss Protonema ◽  
Pre Treatment ◽  
Induced Apogamy

scholarly journals Melatonin Improves Drought Resistance in Maize Seedlings by Enhancing the Antioxidant System and Regulating Abscisic Acid Metabolism to Maintain Stomatal Opening Under PEG-Induced Drought

2021 ◽  
Author(s):  
Zhuo Li ◽  
Xiaoyu Su ◽  
Yulu Chen ◽  
Xiaocong Fan ◽  
Lingzhi He ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Antioxidant System ◽  
Related Gene ◽  
Maize Seedlings ◽  
Gas Exchange Parameters ◽  
Photosynthetic Gas Exchange ◽  
Pre Treatment ◽  
Endogenous Melatonin ◽  
Exchange Parameters

AbstractMaize (Zea mays L.) is highly sensitive to drought stress, resulting in large losses in yield; therefore, strategies aimed at enhancing drought tolerance are essential. Melatonin improves stress tolerance in plants; however, its mechanism in maize seedlings under drought stress remains unknown. Therefore, we investigated the effects of foliar-sprayed melatonin (100 umol L−1) on the antioxidant system, photosynthetic gas exchange parameters, stomatal behavior, endogenous melatonin and abscisic acid (ABA)-related gene expression in maize seedling leaves under 20% polyethylene glycol (PEG)-induced drought stress. PEG treatment resulted in oxidative stress and stomatal closure, resulting in chlorophyll degradation and inhibition of photosynthesis; thereby, reducing seedling biomass. Melatonin pretreatment significantly improved the relative water content, photosynthetic gas exchange parameters and stomatal behavior; thereby, maintaining chlorophyll contents and photosynthesis. Melatonin also stimulated the antioxidant system, enhancing the clearance of reactive-oxygen species, preventing severe damage under PEG-induced drought. Pre-treatment also increased endogenous melatonin and inhibited up-regulation of NCED1, an ABA synthesis-related gene, as well as selectively up-regulating ABA catabolic genes ABA8ox1 and ABA8ox3, reducing ABA accumulation and inducing stomatal reopening. Overall, these findings suggest that melatonin pre-treatment alleviated the inhibitory effects of drought stress on photosynthesis, enhancing tolerance in maize seedlings.

scholarly journals Effect of exogenously-applied abscisic acid, putrescine and hydrogen peroxide on drought tolerance of barley

Biologia ◽  
2020 ◽  
Vol 76 (2) ◽  
pp. 453-468
Author(s):  
Ernest Skowron ◽  
Magdalena Trojak
Keyword(s):  
Hydrogen Peroxide ◽  
Abscisic Acid ◽  
Energy Dissipation ◽  
Drought Tolerance ◽  
Foliar Application ◽  
Photochemical Efficiency ◽  
Rubisco Activase ◽  
Primary Acceptor ◽  
Pre Treatment ◽  
Effects Of Drought

Abstract The objective of this study was to identify the effect of abscisic acid (ABA), putrescine (Put) and hydrogen peroxide (H2O2) foliar pre-treatment on drought tolerance of barley. Despite water limitation, ABA-sprayed plants preserved increased water content, photosynthetic efficiency of PSII (ΦPSII) and CO2 assimilation rate (Pn) compared to untreated stressed plants. The ABA-treated plants presented also the lowest rate of lipid peroxidation (MDA), lowered the rate of PSII primary acceptor reduction (1 – qP) and increased the yield of regulated energy dissipation (NPQ) with higher accumulation of PGRL1 (PROTON GRADIENT REGULATION LIKE1) protein. These plants preserved a similar level of photochemical efficiency and the rate of electron transport of PSII (ETRII) to the well-watered samples. The significantly less pronounced response was observed in Put-sprayed samples under drought. Additionally, the combined effects of drought and H2O2 application increased the 1 – qP and quantum yield of non-regulated energy dissipation in PSII (ΦNO) and reduced the accumulation of Rubisco activase (RCA). In conclusion, ABA foliar application allowed to balance water retention and preserve antioxidant capacity resulting in efficient photosynthesis and the restricted risk of oxidative damage under drought. Neither hydrogen peroxide nor putrescine has been able to ameliorate drought stress as effectively as ABA.

Exogenous Glucose and Abscisic Acid Pre-treatment in Indica Rice (Oryza sativa L. spp. indica) Responses to Sodium Chloride Salt Stress

2007 ◽  
Vol 2 (2) ◽  
pp. 141-152 ◽  
Author(s):  
Suriyan Cha-um ◽  
Sittiruk Roytakul ◽  
Thamakron Sathung ◽  
Atikhun Maijandang ◽  
Suchada Tengsiriwa ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Abscisic Acid ◽  
Salt Stress ◽  
Sodium Chloride ◽  
Oryza Sativa L ◽  
Indica Rice ◽  
Chloride Salt ◽  
Exogenous Glucose ◽  
Pre Treatment

scholarly journals Foliar Pre-Treatment with Abscisic Acid Enhances Olive Tree Drought Adaptability

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 341
Author(s):  
Cátia Brito ◽  
Lia-Tânia Dinis ◽  
Helena Ferreira ◽  
José Moutinho-Pereira ◽  
Carlos M. Correia
Keyword(s):  
Abscisic Acid ◽  
Compatible Solutes ◽  
Biomass Accumulation ◽  
Net Photosynthesis ◽  
Olive Tree ◽  
Limiting Factor ◽  
Severe Drought ◽  
Early Recovery ◽  
Pre Treatment ◽  
Olive Trees

Water is the most widely limiting factor for plants distribution, survival and agricultural productivity, their responses to drought and recovery being critical for their success and productivity. Olea europaea L. is a well-adapted species to cyclic drought events, still at considerable expense of carbon reserves and CO2 supply. To study the role of abscisic acid (ABA) as a promoter of drought adaptability, young potted olive trees subjected to three drought-recovery cycles were pre-treated with ABA. The results demonstrated that ABA pre-treatment allowed the delay of the drought effects on stomatal conductance (gs) and net photosynthesis (An), and under severe drought, permitted the reduction of the non-stomatal limitations to An and the relative water content decline, the accumulation of compatible solutes and avoid the decline of photosynthetic pigments, soluble proteins and total thiols concentrations and the accumulation of ROS. Upon rewatering, ABA-sprayed plants showed an early recovery of An. The plant ionome was also changed by the addition of ABA, with special influence on root K, N and B concentrations. The improved physiological and biochemical functions of the ABA-treated plants attenuated the drought-induced decline in biomass accumulation and potentiated root growth and whole-plant water use efficiency after successive drought-rewatering cycles. These changes are likely to be of real adaptive significance, with important implications for olive tree growth and productivity.

scholarly journals Physiological characterization of Jasmine flower (Jasminum sambac) senescence during storage

2016 ◽  
Vol 8 (3) ◽  
pp. 1475-1478
Author(s):  
V. Lavanya ◽  
Udaykumar Nidoni ◽  
B. Kisan ◽  
H. Amarananjundeshwara ◽  
V. Ramya
Keyword(s):  
Abscisic Acid ◽  
Boric Acid ◽  
Phenolic Content ◽  
Total Phenolics ◽  
Physiological Characterization ◽  
Pre Treatment ◽  
Jasminum Sambac ◽  
Early Rise ◽  
Made In

The aim of this work was to identify metabolic differences and hormonal profiles in jasmine flower (Jasminum sambac) and to investigate the possibility that experimental promotion of retardation of the senescence of jasmine flower may mediated by abscisic acid (ABA) and phenolic content. Determinations of ABA and phenols were made in flower senescing under different conditions using two different packaging materials such as polyethylene (PE) and polypropylene (PP) of 200 gauge micron thickness with no ventilation. Pre-treatment of 4 % boric acid for jasmine flowers was selected. Abscisic acid levels in petals also increased during senescence 91.27 pmol g-1, but much less in boric acid-treated jasmine flower 34.16 pmol g-1. However, the lowest content of total phenolics was measured in buds and partially opened flowers 50.90 μg/g but highest in fully opened 61.80 μg/g on the fourth day of storage, respectively. It was concluded that boric acid prevented the early rise in ethylene production and considerably improved jasmine flower shelf-life.

EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

1995 ◽  
Vol 53 ◽  
pp. 538-539
Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher
Keyword(s):  
Steel Surface ◽  
Surface Preparation ◽  
Treatment Method ◽  
Chrome Plating ◽  
Transmission Electron ◽  
Alloy Steels ◽  
Pre Treatment ◽  
Hard Chrome ◽  
Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

Evaluating the effect of a group pre-treatment chemotherapy psycho-education session for chemotherapy-naive gynecologic cancer patients and their caregivers

2021 ◽  
Vol 160 (1) ◽  
pp. 234-243
Author(s):  
Diana Samoil ◽  
Nazek Abdelmutti ◽  
Lisa Ould Gallagher ◽  
Nazlin Jivraj ◽  
Naa Kwarley Quartey ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Gynecologic Cancer ◽  
Education Session ◽  
Pre Treatment
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