This study was performed in order to determine the effects of gradually increasing temperatures on maize, which belongs to the C4 plant group. 20 day old seedlings were exposed to increasing heat ...stress (25/20, 30/25, 35/30, 40/35, 45/40°C at 16/8 photoperiods) for 5 days. The first temperature treatment (25/20°C) was used as control. Stress injury was measured in terms of malondialdehyde (MDA), hydrogen peroxide (H2O2), chlorophyll (a and b), carotenoid and anthocyanin contents and maximum quantum efficiency of photosystem II (Fv/Fm). MDA and H2O2 levels were found to significantly increase at high temperatures (35, 40, 45°C). Chlorophyll content was observed to be highest at 35°C and a decrease was determined at 40 and 45°C. Fv/Fm was found to decrease at 40 and 45°C. Carotenoid and anthocyanin contents dramatically increased under high temperature stress. In addition, significant increases were determined in the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) under high temperature (45°C), while peroxidase (POX) and glutathione S-transferase (GST) activities showed no change. Treatments above 35°C triggered high temperature stress in maize seedlings. The results of this study showed that temperatures above 35°C lead to stress effects on photosynthesis and induced enzymatic and non-enzymatic antioxidant activity in maize seedlings.
This study was performed in order to determine the effects of gradually increasing temperatures on maize, which belongs to the C4 plant group. 20 day old seedlings were exposed to increasing heat ...stress (25/20, 30/25, 35/30, 40/35, 45/40°C at 16/8 photoperiods) for 5 days. The first temperature treatment (25/20°C) was used as control. Stress injury was measured in terms of malondialdehyde (MDA), hydrogen peroxide (H2O2), chlorophyll (a and b), carotenoid and anthocyanin contents and maximum quantum efficiency of photosystem II (Fv/Fm). MDA and H2O2 levels were found to significantly increase at high temperatures (35, 40, 45°C). Chlorophyll content was observed to be highest at 35°C and a decrease was determined at 40 and 45°C. Fv/Fm was found to decrease at 40 and 45°C. Carotenoid and anthocyanin contents dramatically increased under high temperature stress. In addition, significant increases were determined in the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) under high temperature (45°C), while peroxidase (POX) and glutathione S-transferase (GST) activities showed no change. Treatments above 35°C triggered high temperature stress in maize seedlings. The results of this study showed that temperatures above 35°C lead to stress effects on photosynthesis and induced enzymatic and non-enzymatic antioxidant activity in maize seedlings.
This study was performed in order to determine the effects of gradually increasing temperatures on maize, which belongs to the C4 plant group. 20 day old seedlings were exposed to increasing heat ...stress (25/20, 30/25, 35/30, 40/35, 45/40°C at 16/8 photoperiods) for 5 days. The first temperature treatment (25/20°C) was used as control. Stress injury was measured in terms of malondialdehyde (MDA), hydrogen peroxide (H2O2), chlorophyll (a and b), carotenoid and anthocyanin contents and maximum quantum efficiency of photosystem II (Fv/Fm). MDA and H2O2 levels were found to significantly increase at high temperatures (35, 40, 45°C). Chlorophyll content was observed to be highest at 35°C and a decrease was determined at 40 and 45°C. Fv/Fm was found to decrease at 40 and 45°C. Carotenoid and anthocyanin contents dramatically increased under high temperature stress. In addition, significant increases were determined in the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) under high temperature (45°C), while peroxidase (POX) and glutathione S-transferase (GST) activities showed no change. Treatments above 35°C triggered high temperature stress in maize seedlings. The results of this study showed that temperatures above 35°C lead to stress effects on photosynthesis and induced enzymatic and non-enzymatic antioxidant activity in maize seedlings.
Bu çalışmada, topraksız tarım koşullarında farklı tuz stresi ve kalsiyum dozlarının domateste verim ve kalite üzerine etkisi araştırılmıştır. Çalışmada üç farklı tuz dozu (2, 4 ve 6 dS/m) ve dört ...farklı kalsiyum dozu (0, 50, 100 ve 200 ppm) modifiye edilmiş Hoagland besin solüsyonu ile birlikte bitkilere uygulanmıştır. Standart Hoagland çözeltisi 2 dS/m olarak hazırlanmış ve yüksek tuz konsantrasyonları için (4 ve 6 dS/m) NaCl kullanılmıştır. Yüksek tuzluluk (4 ve 6) pazarlanabilir verimde düşüşe neden olurken, yüksek kalsiyum dozları (100 ve 200 ppm) tuzluluğun verim üzerindeki etkisini önemli ölçüde azaltmıştır. En yüksek tuz konsantrasyonunda (6 dS/m) kalsiyumun 100 ppm'den 200 ppm'e yükselmesi pazarlanabilir verimi 122,51 ton/ha'dan 199,74 ton/ha'a çıkarmıştır. Yaprak klorofil içeriği (SPAD) tuz konsantrasyonundan etkilenmezken, artan kalsiyum dozları klorofil içeriğinde artışa neden olmuştur. Özellikle yüksek tuz stresi altında (6 dS/m) kalsiyumun klorofil artışına etkisi daha belirgin olmuştur. Meyvede elektriksel iletkenlik, suda çözünebilir kuru madde miktarı (Brix) ve titre edilebilir asit miktarı tuzluluk arttıkça artarken, pH azalmıştır. Yüksek tuzlulukta kalsiyum arttıkça Brix ve titre edilebilir asit miktarı azalmıştır. Sonuç olarak, besin solüsyonunun tuz konsantrasyonunun yüksek olması pazarlanabilir ve toplam verimde önemli düzeyde düşüşe neden olurken, tuz stresi altında yüksek kalsiyum uygulaması verim kaybını azaltmıştır. Tuz stresi x kalsiyum interaksiyonu meyve kalite parametrelerini önemli düzeyde etkilemiştir.
Abstract
Objectives
The high salinization stress to seedling is the substantial ecological problem in the ongoing era. It negatively influences the growth that retard mitotic division by enhancing ...aberrations in nuclear chromatin. In the light of these views, the current work was designed to investigate the response of Vigna seedlings root tip cells to the presence of NaCl ions.
Materials and methods
NM-92 and NM19-19 seeds were imbibed separately in distilled water for 24 h and allowed to grow into 0, 50, 150, 250, and 350 mM NaCl solution for 24 h. Excised root tips were stained, and slides were scored at 100× objective for the mitotic index (MI) and chromosomal aberrations.
Results
Our data demonstrated that as NaCl molarity increased, the MI was declined along with various chromatin abnormalities. The 150 mM of NaCl showed more lagging (69%) of chromosomes during anaphase in NM19-19. The highest stickiness at metaphase stage (68%) was found in 250 mM NaCl in variety NM19-19. However, both varieties were differed non-significantly for c-mitosis that was recorded 99% at 350 mM NaCl concentration.
Conclusions
The NaCl ions toxicity induced various cytological anomalies in seedling roots that adversely affect the growth of Vigna seedlings.
The mechanism(s) by which Zn alleviates NaCl stress was investigated in Pistacia vera L. 'Badami'. Pistachio
seedlings were treated with 0, 800, 1600, 2400, and 3200 mg of NaCl kg-1 of soil, along ...with Zn (0, 5, 10, and 20 mg kg-1
of soil). NaCl stress induced high oxidative stress, increasing lipid peroxidation, electrolyte leakage, and lipoxygenase
(LOX, E.C. 1.13.11.12) activity to high levels. Zn supplement efficiently reduced all these adverse effects of salt stress.
However, there were no significant differences among the above parameters in plants treated with Zn only. NaCl stress
significantly increased the activity of antioxidant enzymes. The activity of antioxidant enzymes (superoxide dismutase
SOD, E.C. 1.15.1.1, catalase CAT, E.C. 1.11.1.6. and ascorbate peroxidase APX, E.C. 1.11.1.11) increased significantly
in NaCl + Zn-treated plants, as compared with those treated with either NaCl or Zn alone. These results support the
positive effects of Zn on antioxidant enzyme activity scavenging the reactive oxygen species produced in response to salt
stress. Zinc treatment caused a significant increase in the amount of phenolics and in ascorbic acid content, as compared
with salt treatment alone. Zinc treatment alone did not result in very high antioxidant enzyme activity in non-stressed
plants.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Bu araştırma din görevlilerin iş stresi, iş doyumu, tükenmişlik ve işten ayrılma niyetlerine
ilişkin durumun belirlenmesi amacıyla yapılmıştır. Ayrıca araştırma kapsamında, ilgili kavramların,
din ...görevlilerinin sahip olduğu demografik değişkenlerle olan etkileşimi ve kavramların
kendi içindeki ilişki düzeyleri de incelenmiştir. Araştırma Türkiye’nin 7 coğrafi bölgesinden belirlenen
büyükşehir merkezlerinde (İstanbul, Ankara, İzmir, Mersin, Gaziantep, Samsun ve Erzurum)
çalışan 1125 din görevlisi üzerinde yürütülmüştür. Verileri toplamak amacıyla dört ayrı ölçek
formu kullanılmış ve analizler istatistiki analiz programı aracılığıyla yorumlanmıştır. Araştırma
sonucuna göre din görevlileri, orta düzeyde tükenmişlik yaşarken, düşük düzeyde iş doyumuna
sahiptirler. Bunun yanında din görevlileri çok yüksek düzeyde iş stresine ve orta düzeyde
işten ayrılma niyetlerine sahiptirler. Literatürde din görevlilerinin tükenmişlik ve iş doyumlarını
belirlemeye çalışan farklı araştırmalar olsa da bu araştırma iş doyumu ve tükenmişliğin kaynağı
olarak bilinen iş stresini ve stresin en önemli sonucu olan işten ayrılma niyetini ölçmeyi amaçlayan
öncü çalışma olması sebebiyle önem arz etmektedir.
Specific understanding of root anatomy plasticity under salt stress is lacking and requires creation of efficient screening techniques for stress condition s. To fill this gap, this study aimed to ...determine the anatomical plasticity in root chracteristics of 31 different rice cultivars (from ‘Best’ to ‘Low’ yielding) grown under real field conditions (saline and non-saline) from planting to harvesting and to reveal detailed root anatomical parameters that can be used to select and breed salt-tolerant rice. Anatomical and histochemical features of all cultivars and thin structures of the apoplastic barriers were investigated. The amount of silica (Si), 35 different anatomical characteristics, anatomical plasticity characteristics, plasticity rates, plasticity trends and changes and strategies of each group under saline and non-saline conditions were compared. The results showed that protective anatomical characters improved/remained equal to, and worsened/remained equal to those of the controls, in the ‘Best’ and other groups, respectively, from non-saline to saline conditions. Anatomical plasticity is essentially directly related to apoplastic barrier features. High genotypic variation was observed in root anatomy in all cultivars, but foremost traits were as follows: (1) cell size, (2) Si presence, (3) Si accumulation shape, (4) Si distribution towards root stele, (5) xylem arch features, (6) lignification-suberization properties in apoplastic barriers and their degrees, (7) presence/absence of idioblast cells filled with gummic and phenolic substances and (8) moderate anatomical plasticity. Cultivars with the most stabile anatomy under saline and non-saline conditions should be used to select and breed salt-resistant rice.
Specific understanding of root anatomy plasticity under salt stress is lacking and requires creation of efficient screening techniques for stress condition s. To fill this gap, this study aimed to ...determine the anatomical plasticity in root chracteristics of 31 different rice cultivars (from ‘Best’ to ‘Low’ yielding) grown under real field conditions (saline and non-saline) from planting to harvesting and to reveal detailed root anatomical parameters that can be used to select and breed salt-tolerant rice. Anatomical and histochemical features of all cultivars and thin structures of the apoplastic barriers were investigated. The amount of silica (Si), 35 different anatomical characteristics, anatomical plasticity characteristics, plasticity rates, plasticity trends and changes and strategies of each group under saline and non-saline conditions were compared. The results showed that protective anatomical characters improved/remained equal to, and worsened/remained equal to those of the controls, in the ‘Best’ and other groups, respectively, from non-saline to saline conditions. Anatomical plasticity is essentially directly related to apoplastic barrier features. High genotypic variation was observed in root anatomy in all cultivars, but foremost traits were as follows: (1) cell size, (2) Si presence, (3) Si accumulation shape, (4) Si distribution towards root stele, (5) xylem arch features, (6) lignification-suberization properties in apoplastic barriers and their degrees, (7) presence/absence of idioblast cells filled with gummic and phenolic substances and (8) moderate anatomical plasticity. Cultivars with the most stabile anatomy under saline and non-saline conditions should be used to select and breed salt-resistant rice.
Specific understanding of root anatomy plasticity under salt stress is lacking and requires creation of efficient screening techniques for stress condition s. To fill this gap, this study aimed to ...determine the anatomical plasticity in root chracteristics of 31 different rice cultivars (from ‘Best’ to ‘Low’ yielding) grown under real field conditions (saline and non-saline) from planting to harvesting and to reveal detailed root anatomical parameters that can be used to select and breed salt-tolerant rice. Anatomical and histochemical features of all cultivars and thin structures of the apoplastic barriers were investigated. The amount of silica (Si), 35 different anatomical characteristics, anatomical plasticity characteristics, plasticity rates, plasticity trends and changes and strategies of each group under saline and non-saline conditions were compared. The results showed that protective anatomical characters improved/remained equal to, and worsened/remained equal to those of the controls, in the ‘Best’ and other groups, respectively, from non-saline to saline conditions. Anatomical plasticity is essentially directly related to apoplastic barrier features. High genotypic variation was observed in root anatomy in all cultivars, but foremost traits were as follows: (1) cell size, (2) Si presence, (3) Si accumulation shape, (4) Si distribution towards root stele, (5) xylem arch features, (6) lignification-suberization properties in apoplastic barriers and their degrees, (7) presence/absence of idioblast cells filled with gummic and phenolic substances and (8) moderate anatomical plasticity. Cultivars with the most stabile anatomy under saline and non-saline conditions should be used to select and breed salt-resistant rice.
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