فهرست مطالب

Plant Physiology - Volume:8 Issue: 2, Winter 2018

Iranian Journal of Plant Physiology
Volume:8 Issue: 2, Winter 2018

  • تاریخ انتشار: 1396/12/28
  • تعداد عناوین: 8
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  • Roya Razavizadeh, Mozhdeh Karami Pages 2321-2331
    Drought stress is one of the main non-biological factors limiting the growth and yield of plants in dry and semi-dry regions of the world. Plants are the source of much chemicals derived from secondary metabolism. Carum copticum is a plant from the Apiaceae family with the seeds containing 2-4% the essential oil which are rich in monoterpenes such as thymol and are widely used as an antibacterial agent. This experiment was conducted in order to evaluate the effects of drought stress on physiological parameters and essential oil properties of seedlings and callus of C. copticum. For this purpose, seeds ofC. copticum were cultured in Murashige and Skoog medium containing 0, 2, 4, 6, and 8% PEG. Also,calluses cultured were in MS medium containing 0.25 mg.L-1 2, 4-Dichlorophenoxyacetic acid, and 1 mg.L-1 benzyl amino purine and different levels of PEG. After PEG treatment for 4 weeks, results showed that drought stress decreased chlorophylls and carotenoids contents while it increased anthocyanin, phenolic compounds, protein contents, and CAT and APX activities. Unlike CAT and APX, water deficit induced a significant reduction in superoxide dismutase activity. The content of reducing sugars and proline increased progressively when drought stress increased. Furthermore, PEG changed the essential-oil composition in shoots and calluses. Drought stress increased thymol and p-cymene concentration, though it decreased γ-terpinene. In general, these results showed the high tolerance of C. copticum to drought stress and also revealed positive effects of drought on the antioxidant activities and essential oil composition.
    Keywords: Carum copticum, polyethylene glycol, callus, tissue culture, Essential oil
  • Saleh Shahabivand *, Akbar Padash, Ahmad Aghaee, Yousef Nasiri, Parisa Fathi Rezaei Pages 2333-2344
    Plant biostimulants such as arbuscular mycorrhizal (AM) fungi and humic substances (HS) can be used as an appropriate alternative to chemical fertilizers, as regards to environmental problems of chemicals. The effects of Funneliformis mosseae as an AM fungus, HS (foliar spray and topdressing application), and chemical fertilizer (NK), separately or interacting, on biochemical responses in Mentha piperita L. plants were investigated under field conditions. Results revealed that the mentioned three factors appear as valid practicable method for improving growth and metabolites of peppermints cultivated in the field even when root colonization of AM fungus does not achieve high rates. The triple interaction between mycorrhizal inoculation, HS application (especially foliar spray), and NK fertilizer treatment induced the maximum accumulation of photosynthetic pigments, starch, soluble sugars, total proteins, proline, total phenolics, and the antioxidants in leaves. However, positive effects of F. mosseae and HS were more than those of the chemical fertilizer. We propose that F. mosseae and foliar spray of HS, particularly in combination can be used as suitable plant biostimulants in peppermint plants under field conditions, which in turn will improve soil health and reduce environmental problems.
    Keywords: Chemical fertilizer, humic substances, mycorrhizal fungi, peppermint, plant biostimulants
  • Sahar Gholi-Tolouie, Mahdi Davari, Nemat Sokhandan-Bashir, Mohammad Sedghi * Pages 2345-2351
    Changes in the activity of antioxidant enzymes, proline, and total soluble carbohydrates (TSC) were evaluated in tomato (Solanum lycopercicum cv. Superchief) plants in response to salicylic acid (SA) and jasmonic acid (JA) and inoculation with CMV (Cucumber mosaic virus) on days 0, 1, 2, 4, 6, 8, and 15 after virus inoculation (dpi). Results showed that proline content increased in all treatments except for control while TSC content decreased in all treatments except the control. TSC content decreased by 50% in CMV treated plants, but the reduction was very slow in hormone treatments. SA decreased the catalase (CAT) activity until 6 dpi and then increased CAT activity to 15 dpi while other treatments except the control increased CAT activity over time. The highest activity of peroxidase (POD) was observed in SA treatment and the highest activity of superoxide dismutase (SOD) and phenylalanine ammonia lyase (PAL) was related to SA␏舱 treatment. These results show that combination of SA with JA can control the CMV in tomato plants cv. Superchief through the inhibition of TSC reduction which is an indicator of normal photosynthesis capacity.
    Keywords: Cucumber mosaic virus (CMV), tomato, proline, oxidative stress
  • Leila Zeinali Yedegari, Nayer Mohammadkhani * Pages 2353-2359
    Drought causes an increase in some gene expression in plant tissues such as plasma membrane intrinsic proteins type 1 (PIP1), 9-cis-epoxycarotenoid dioxygenase (NCED) SlAREB1. The effects of exogenous abscisic acid (ABA) and two sulfonamide compounds, namely, sulfacetamide (Sa) and sulfasalazine (SS) were studied on gene expression of tomato (Lycopersicon esculentum Mill. Cv. Super chief) under drought stress. We extracted these three genes from Lycopersicon esculantum Mill. Cv. Super chief leaves treated with ABA, sulfacetamide (Sa) and sulfasalazine (SS) after 24 h and 144 h of drought conditions. All treatments caused an increase in LePIP1, LeNCED1, and SlAREB1 genes expression under drought stress, leading to maintenance of the life potential of tomato plants under water deficit. It seems that these genes help the tomato plants to live under drought conditions.
    Keywords: Abscisic acid, sulfacetamide, sulfasalazine, LeNCED, LePIP1
  • Mahdieh Ebrahimi * Pages 2361-2370
    The study was conducted to investigate the effects of ethylenediaminetetraacetic acid (EDTA) on seedling emergence, morphological characteristics, and photosynthetic pigments of Chenopodium album (L.) in lead (Pb) contaminated soil. The Pb contaminated soils were taken from Hirmand River. The soil samples mixed with 0.71 g Li-1 Pb (PbNO3)2 to increase the Pb concentration. EDTA was added to the soil in concentrations of 1.5, 3 and, 9 mg kg-1 after sowing the seeds. Results showed that EDTA significantly decreased seedling emergence. The highest reduction in germination was related to 9 mg kg-1 EDTA. With increasing EDTA dosage, mean seedling emergence time increased. The highest seedling vigor index (17.29) was related to the control treatment while the lowest seedling vigor index (2.15) was measured in 9 mg kg-1 EDTA. With increasing EDTA concentration, plant biomass decreased. The highest reduction was observed in 9 mg kg-1 EDTA. The maximum and minimum pedicel length, radical length, and tolerance index were measured in 1.5 and 9 mg kg-1 EDTA treatments, respectively. The highest amounts of chlorophyll a, b, total chlorophyll, and carotenoid were observed in 1.5 mg kg-1 EDTA. Increased EDTA from 1.5 to 9 mg kg-1 led to a decrease in photosynthetic pigments.In general, results showed that EDTA at high concentrations had deterrent impacts on the plant growth. Therefore, high concentrations of this compound are not suggested to increase remediation efficiency of Pb contaminated soil.
    Keywords: Aminopolycarboxylic acids, tolerance index, seedling vigor index, Lead, Chenopodium album (L.)
  • Behzad Babazadeh Darjazi * Pages 2371-2379
    Studies have demonstrated that phenolic compounds andcarotenoids are essential for prevention of diseases. On the other hand, endogenous ethylene enhances the ripening of fruits and stimulatesthe biosynthesis of carotenoids as well as chlorophylls destruction. The aim of this study was to evaluate the effect of rootstocks on phenolic compounds andcarotenoids. The contents of individual phenolic compounds in peel were evaluated by HPLC. Total flavonoids content was determined using colorimetric assay. Free radical activity was evaluated with DPPH reagent, and total carotenoid and chlorophylls contents were measured using a spectrophotometer. The content of ethylene in fruits was determined by Gas chromatography. HPLC analysis identified seven phenolic compounds in the peel of Younesi tangerine. Hesperidin was the major compound for all rootstocks. Among the six rootstocks studied, flying dragon demonstrated thehighest level of phenolic compounds, carotenoids, and ethylene. Findings suggest that the rootstocks can affect the amount of phenolic compounds, carotenoids, and ethylene of the fruit.
    Keywords: carotenoids, citrus rootstocks, ethylene, Phenolic compounds, Younesi tangerine
  • Nour Ali Sajedi *, Hamid Madani Pages 2381-2389
    This study investigated the effect of two forms of Se at three rates (0, 18, and 36 g/ha) on wheat and barley under rain fed conditions. Results showed that spraying application of 18 g/ha Se increased Chl a and Chl a contents while the selenium rate 36 g/ha decreased plant pigments. Evaluations of Chl a, Chl b, chlorophyll total a, carotenoids, chlorophyll total content, relative water content, and grain yield were higher in barley than in wheat. Foliar applications of selenate and selenite increased relative water content and decreased electrolyte leakage and MDA content in both plants but applying only Se increased catalase activity. The effect of sodium selenate on catalase activity was more than that of sodium selenite in both barley and wheat. Treatments had no significant effect on the glutathione content. In the plants treated with foliar application of 18 g/ha Se, grain yield increased by 6.3% compared with the control. It was concluded that foliar application of 18 g/ha sodium selenate or sodium selenite presents a good antioxidant chemical for improved physiological and biochemical characteristics for both wheat and barley grain yield under semi-arid or arid conditions.
    Keywords: biochemical traits, plant pigments, rain fed, Selenium, spraying application
  • Mozhgan Farzami Sepehr *, Farhad Nourozi Pages 2391-2401
    In a greenhouse study, decontamination capacity of the species Polypogon monspoliensis was investigatedfor detoxification of petroleum-polluted soils caused by sewage and waste materials of Tehran Petroleum Refinery. For this purpose, the amount of total oil and grease before and 45 days after transplanting one-month-old seedlings in the soils of five different treatments were measured. Pollution-free agricultural soil and contaminated soil were mixed together with the weight ratios of 1 to 9 (%10), 2 to 8 (%20), 3 to 7 (%30), 4 to 6 (%40), and 5 to 5 (%50). These were then compared with the amounts obtained from control treatment without vegetation, but with the same concentration of pollution. Findings demonstrated that the maximum reduction in the petroleum rate (84.85%) was related to the treatment of 10% contamination containing the plant. Increase in the shoot height in treatments 10% and 20% as well as the root dry and fresh weight in treatments 10% , 20% , and 30% shows that probably activity of more rhizosphere microorganisms of the plant in these treatments has led to the improvement in the growth of plant organs comparing to the treatments without pollution.
    Keywords: phytoremediation, total oil, grease, rhizosphere, microorganisms, petroleum, contaminated soil