Showing 6 results for Abscisic Acid
Nasim Talaei, Azar Shahpiri,
Volume 3, Issue 10 (3-2015)
Abstract
Aleurone layer which is a thin layer in cereal seeds plays a key role in seed germination. The barley (Hordeum vulgare) aleurone layer can be separated from the other seed tissues and maintained in culture medium, allowing the researchers to study different plant signals at molecular level. In the present study the expression of genes encoding ascorbate peroxidase (Apx), Apx1 and Apx2, was analyzed in aleurone layer treated with GA, ABA and salicylic acid incubated in different time points 6, 12, 18, 24, 48 and 72 hours. In addition the soluble protein was extracted from aleurone layers treated with these hormones and the activity of Apx was studied. The results show that the expression of genes Apx1 and Apx2 were not affected by hormones. However the Apx activity in aleurone layer treated with GA between 24-72 hours were decreased which was completely diffenet with aleurone layer incubated with other hormoned or medium without hormone.
Roozbeh Farhoudi, Ali Soheli Far, Adel Modhej,
Volume 5, Issue 17 (9-2016)
Abstract
In order to evaluate the allelopatic potential of artichoke (Cynara cardunculus) on germination, growth, lipid peroxidation and some hormones content of Cyperus rotundus rhizome were assessed in Islamic Azad University, Shoushtar Branch (Iran). The experiments were carried out under completely randomized design with 6 treatments (0, 20%, 40%, 60%, 80% and 100% C. cardunculus aqueous extract as irrigation water) in 5 replications. Remarkable decreases were observed in seedling fresh weight, shoot height, α-amylase activity, Indole acetic acidand Gibberellins content of C. rotundus rhizome in line with the increase in C. cardunculus extract percentage. Lowest α-amylase activity (1.25 nmol gr rhizome min-1), Indole acetic acid (50 µg gr-1 ) and Gibberellins (95 µg gr-1) in C. rotundus rhizome obtained from 100% C. cardunculus aqueous extract. Malondialdehyde and Abscisic Acid content reached its top concentration in C. rotundus rhizome (0.92µmo-1 gr FW and 172 µg gr-1) treated with 100% C. cardunculus aqueous extract as irrigation water. This study supported the assumption argued that C. cardunculus extract inhibited the C. rotundus rhizome growth through increasing lipid peroxidation and decreased Indole acetic acid and Gibberellins content.
Dr. Parviz Moradi,
Volume 6, Issue 19 (3-2018)
Abstract
Thyme is one of the best known genera within Labiatae family, because of its more than 250 species and its antimicrobial and antispasmodic uses. At the present time, demand for thyme products are increasing and hence research demand is increasing. Environmental factors such as drought can affect plant growth and production. Phytohormones take a crucial role in this stress. Indicated T. serpyllum as the most tolerant and T. vulgaris as the most susceptible genotypes to water deficit stress been used. At the end of stress period, shoot dry weight , water content, water potential and soil moisture were measured. Based upon these traits, tolerant plants known as water saver plants, while, sensitive plants behaved as water spender plants. This experiment was conducted at the University of Birmingham, School of Biosciences in 2013. During the stress, leaf samples were harvested and analyzed through mass spectrometry based metabolomics approach. The results of tolerant plants indicated significant increase in drought-stressed plant rather than control plants as follows: 173% increase in salysilic acid, 133% increase in neoxantin (abscisic acid substrate), 166% of auxin and 180% of gibberellic acid. Nevertheless, sensitive plants showed significant increase in jasmonic acid 132%, salysilic acid 242% and decrease in neoxanthin 62% and gibberellic acid 36%. Auxin had non-significant difference between stressed and control plants of sensitive populations. Increasing of neoxanthin in tolerant plants occurred with water content maintenance and decreased shoot dry weight. This experiment confirmed the key role of abscisic acid and salysilic acid in drought stress tolerance mechanism. Even though, it seems overall response of plant to drought stress is the result of all the phytohormones interaction. Increasing ABA precursor caused growth inhibition in drought tolerant plants, which eventually provided less water usage. Since, sensitive plants didn’t exhibit neoxantin elevation, which seems it is due to being lower than water potential threshold.
Dr Mohammad Reza Sarafraz Ardakani,
Volume 8, Issue 29 (5-2019)
Abstract
The interaction of hormones plays an important role in plant equilibrium, especially, when plants encountered to environmental stresses, during both vegetative and generative stages. For this purposes, the experiment was designed based on the interaction effect of exogenous treatments of individual kinetin (Kin) and 24-epibrassinolide (24-EBL) and their dual application with two level of field capacity of 100% (control) and 50% (drought stress) from the origin of post-anthesis stage in three wheat cultivars including drought-tolerant (Pishtaz), drought-semi-tolerant (Sabalan) and drought-susceptible (Gaspard) as factorial experiment based on split plot in a randomized complete design with four replications in greenhouse condition. Then, flag leaves fresh and dry weight (FW and DW, respectively) and relative water content (RWC), abscisic acid (ABA), peroxide hydrogen (H2O2) and malondialdehyde ( MDA ) levels and enzyme activity of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalas ( CAT ) were assayed and compared at post-anthesis stage. During drought stress, FW, DW and RWC, especially in the Gaspard cultivar, decreased significantly. The ABA level increased under drought stress, especially in drought-tolerant cultivar. The 24-EBL was the most effective treatment in related to increasing of FW and DW, recovery of RWC and increment of ABA level during drought stress, especially in drought-tolerant cultivar. Drought stress significantly increased the activity of SOD, APX and CAT in Pishtaz cultivar more than Sabalan and Gaspard cultivars. In contrast, less accumulation of H2O2 and MDA was observed in drought-tolerant cultivar than both drought-semi-tolerant and drought- susceptible cultivars. Despite the fact that, EBL was the most effective treatment in related to increment of antioxidant enzymes activity, Kin and EBL combination caused the most reduction of oxidative stress traits. In conclusion, Pishtaz cultivar compared to Sabalan and Gaspard cultivars benefited from hormonal treatment for increasing of antioxidant efficiency under drought stress.
Zohreh Haghighikafash, Shahrzad Khoramnejadian, Aliakbar Ghotbiravandi, Somayeh Farhangdehghan,
Volume 10, Issue 42 (5-2021)
Abstract
Traffic noise pollution is one of the most important environmental problems in today's societies, especially in populated cities around the world. The aim of this study was to investigate the effect of traffic noise on physiological traits of Salvia splendens. Plants were divided into two equal groups (control and treatment) and each group was grown in two separate growth rooms for two months under the same controlled conditions. Traffic noise was recorded during peak traffic hours in the city. Frequency analysis was performed on the samples during the recording process. Plants in the exposed group were exposed to traffic noise for 15 days and 16 hours a day, while the plants in the control group were placed in complete silence. Exposure to traffic noise led to an increase in calcium content, hydrogen peroxide content, followed by the activity of antioxidant enzymes such as catalase, peroxidase and ascorbate peroxidase compared to the control group. On the other hand, traffic noise significantly decreased indole-3-acetic acid (IAA) content and increased the content of Absisic acid (ABA). According to the results of this study, traffic noise by creating oxidative damage and interfere with hormonal balance can have a negative impact on the growth and physiology of Salvia splendens.
Shahin Shahgholi, Saeed Sayfzadeh, Esmaeil Hadidi Masouleh, Naser Shahsavari, Hamidreza Zakerin,
Volume 12, Issue 56 (11-2023)
Abstract
In order to investigate the effect of foliar application of micro-elements on some biochemical traits and wheat yield under water stress conditions, an experiment was carried out in the form of split plots based on a randomized complete block design in three replications in Varamin during the two crop years 2016–2017 and 2017–2018. The main factors of irrigation regimes at three levels (I1: normal irrigation, I2: cut-off irrigation at the beginning of stem growth, and I3: cut-off irrigation at the beginning of stem growth and seed filling) and sub-factors including foliar spraying of micro-elements at eight levels (M1: control (without foliar spraying), M2: boron foliar application, M3: zinc, M4: iron, M5: zinc+boron, M6: iron+boron, M7: zinc+iron and M8: zinc+boron+iron) were considered. The irrigation was done twice in the autumn and four times in the spring under normal irrigation conditions. The foliar spraying of each of the micronutrients from the sources of iron sulfate, boron sulfate and zinc sulfate with a concentration of 5/1000 was carried out in two stages: stemming and spike emergence. The results showed the effect of irrigation regimes, foliar application of micro-elements and their interaction on the content of chlorophyll a, b and total chlorophyll, the concentration of chlorophyllase enzyme, malondialdehyde and abscisic acid. Also, the simple effect of irrigation and foliar spraying was significant on total sugar concentration and grain yield. The results showed that the interruption of irrigation led to a decrease in total chlorophyll. Foliar spraying of zinc + boron + iron (M8) in all three levels of irrigation regimes led to a significant increase in total chlorophyll. The highest amount of total chlorophyll was obtained under normal irrigation conditions, along with zinc+boron+iron (I1M8) foliar spraying at a rate of 6.03 mg.g-1 of fresh leaves. Also, foliar spraying of zinc+boron+iron in irrigation treatments (I2) and (I3) (respectively, with averages of 5.2 and 4.55 mg.g-1 of fresh leaves) led to an increase in total chlorophyll compared to control. In general, the use of foliar applications of iron, zinc, and boron can improve the physiological characteristics of wheat under stressful conditions while increasing grain yield.
