Due to the increased production and release of silver nanoparticles (AgNPs) in the environment, the concerns about the possibility of toxicity and oxidative damage to plant ecosystems should be considered. In the present study, the...
moreDue to the increased production and release of silver nanoparticles (AgNPs) in the environment, the concerns about the possibility of toxicity and oxidative damage to plant ecosystems should be considered. In the present study, the effects of different concentrations of AgNPs (0, 0.5, 1, 2, 3 and 4 g/L) synthesized using the extract of camelina ( Camelina sativa ) leaves on the growth and the biochemical traits of camelina seedlings were investigated. The results showed that AgNPs significantly increased Ag accumulation in the roots and shoots which decreased the growth and photosynthetic pigments of camelina seedlings. The highest decrease in the height and total dry weight was observed by 53.1 and 61.8% under 4 g/L AgNPs, respectively over control plants. AgNPs application over 2 g/L enhanced the accumulation of proline, malondialdehyde, hydrogen peroxide and methylglyoxal, and up-regulated the activity of antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) and glyoxalase (glyoxalase I and II) system which indicates oxidative stress induction in camelina seedlings. Moreover, AgNPs reduced ASA and GSH contents and increased DHA and GSSG contents, hence disrupting the redox balance. These results showed that AgNPs at 4 g/L had the most toxic effects on the camelina growth. Therefore, increasing oxidative stress markers and the activity of antioxidant enzymes and enzymes involved in glyoxalase system indicated the oxidative stress induced by AgNPs treatments over 2 g/L as well as the induction of antioxidant defense systems to combat AgNPs-induced oxidative stress.
Drought stress is one of the most important limiting factors in crop yield through impact on the cellular and physiological functions of the plant. Therefore, the study of physiological responses of plants can help to better understanding...
moreDrought stress is one of the most important limiting factors in crop yield through impact on the cellular and physiological functions of the plant. Therefore, the study of physiological responses of plants can help to better understanding the drought tolerance mechanisms. In this experiment, 125 wild diploid wheat genotypes of Aegilops tauschii were evaluated for the physiological responses under rainfed and supplemental irrigation conditions. The physiological characteristics such as leaf relative water content (RWC), excised leaf water retention (ELWR), relative water loss (RWL), chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, ion leakage, membrane stability index (MSI) and proline content were measured. The results showed that the higher proline content, lower chlorophyll degradation rate and low amount of the membrane stability index (MSI) may inhibit the grain yield reduction under rainfed conditions. It was also found that the lower ion leakage due to the low cel...
In present study, growth, arsenic accumulation, and antioxidant responses in root of Isatis cappadocica were investigated in response to application of arsenate and phosphate. Reduction in root dry weights was significant with 1200 μM...
moreIn present study, growth, arsenic accumulation, and antioxidant responses in root of Isatis cappadocica were investigated in response to application of arsenate and phosphate. Reduction in root dry weights was significant with 1200 μM arsenate and 5 μM phosphate treatments. Phosphate had a steady effect on root dry weight improvement, especially in high arsenate treatments ≥ 200 μM. As concentrations in roots increased with increasing arsenate supply levels, growth decreased markedly with increasing phosphate in each arsenate treatment. Applied arsenate induced oxidative stress, which caused increasing the concentrations of hydrogen peroxide (H2O2) and malondialdehyde (MDA). The activities of antioxidant enzyme such as catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in Isatis cappadocica roots increased significantly from 200-800 μM arsenate and 5 μM phosphate treatments while their activities were decreased at 1200 μM arsenate and 5 μM phosphate, compared with the c...
Arsenic is considered as one of the most important environmental contaminant compound. Some plant species can grow in arsenic contaminated soil and they are able to reduce arsenic toxicity. Nowadays, phytoremediation as a new and friendly...
moreArsenic is considered as one of the most important environmental contaminant compound. Some plant species can grow in arsenic contaminated soil and they are able to reduce arsenic toxicity. Nowadays, phytoremediation as a new and friendly environmental technique employs the use of plants to remediate contaminated soil. Previous studies showed that Isatis cappadocica is an arsenic hyperaccumulator plant. Accordingly, we conducted this experiment to compare the interaction of arsenic and phosphorus on osmolytes content of I. cappadocica for better understanding the mechanisms applied by this species. Therefore, the plants were grown for 6 weeks in a medium, embedded with combinations of 50, 200, 800 & 1200 μmol l−1 arsenic and 5, 50, 200, 800 & 1600 μmol l−1 phosphorus, respectively. The osmolytes content and the arsenic concentration of harvestable parts were determined. The highest concentration of arsenic was obtained in plants treated with 1200 μmol l−1 As and 5 μmol l−1 phosphoru...
Salicylic acid (SA) and jasmonic acid (JA) as plant growth regulators (PGRs) have the potential to ameliorate plant development and tolerance to deleterious effects of toxic metals like nickel (Ni). Therefore, the current study was...
moreSalicylic acid (SA) and jasmonic acid (JA) as plant growth regulators (PGRs) have the potential to ameliorate plant development and tolerance to deleterious effects of toxic metals like nickel (Ni). Therefore, the current study was carried out to evaluate SA and JA's interactive effect on the root antioxidative response of two Alyssum inflatum Nyár. populations against Ni-toxicity. Two A. inflatum species under Ni-stress conditions (0, 100, 200, and 400 µM) were exposed to alone or combined levels of SA (0, 50, and 200 µM) and JA (0, 5, and 10 µM) treatments. Results showed that high Ni doses reduced the roots fresh weight (FW) in two populations than control; however, the use of external PGRs had ameliorated roots biomass by mitigated Ni-toxicity. Under Ni toxicity, SA and JA, especially their combination, induced high Ni accumulation in plants' roots. Moreover, the application of SA and JA alone, as well as combined SA + JA, was found to be effective in the scavenging of h...
Elevated soil saline levels resulting from natural geological, hydrological and pedological process, and from using salty water for irrigation may inhibit seed germination and seedling establishment of safflower, the prospective oil-seed...
moreElevated soil saline levels resulting from natural geological, hydrological and pedological process, and from using salty water for irrigation may inhibit seed germination and seedling establishment of safflower, the prospective oil-seed crops. A germination study on safflower seeds and a short-term toxicity experiment with different concentrations of NaCl (control, 50, 100 and 200 mM) on safflower seedlings were conducted. Percent germination over control decreased significantly with increasing concentrations of NaCl. There were genotypic differences among the test genotypes in response to salt stress exposure. The performance of the G5 (Gilla) was the best among the genotypes. Germination of G5 was not inhibited at all up to 100 mM NaCl treatment. Root tolerance index (RTI) and relative shoot height (RSH) for safflower seedlings decreased with increasing concentrations of NaCl. In general, G5 (Gilla) has more tolerance to NaCl than the other studied genotypes.
Worldwide agricultural productivity is subjected to increase in environmental constraints, particularly drought and salinity. The aim of this study was to evaluate the physiological responses of safflower (Carthamus tinctorius L.) calli...
moreWorldwide agricultural productivity is subjected to increase in environmental constraints, particularly drought and salinity. The aim of this study was to evaluate the physiological responses of safflower (Carthamus tinctorius L.) calli exposed to water stress and salinity in order to elucidate some acclimatory mechanisms. Therefore, different calli of safflower genotypes, G1 (LRV-51-51), G2 (Lesaf), G3 (Gila), G4 (Kino-76) and G5 (Isfahan), were exposed to different concentrations of mannitol and NaCl for one month. The ongoing research was conducted in order to evaluate relative growth rate, relative water content, tolerances index, ion (Na+ and K+) and proline content and cell viability of genotypes. The results indicated that a significant decrease in callus growth, water content and cell viability occurred under both stresses with the highest reduction under mannitol-induced osmotic stress. Although the leached and retained Na+ ion contents increased, the retained K+ content de...
Abstract Abiotic stresses prompt a wide range of signals in plant cells, which are coordinated and united into various growth and development–related processes. Plants are able to respond to stress trough phytohormones (plant growth...
moreAbstract Abiotic stresses prompt a wide range of signals in plant cells, which are coordinated and united into various growth and development–related processes. Plants are able to respond to stress trough phytohormones (plant growth regulators), which are signal molecules and respond to environmental stimuli. Adaptive responses of plants to abiotic stresses are fine-tuned by a network of phytohormones’ signaling and their cross talk, which play a vital role in the molecular mechanisms that optimize the response of plants under such stresses. In recent years, recognizing mechanisms of phytohormonal signaling by plants to cope with hostile growth conditions and to ensure sustainable crop production under stress conditions is an important area of plant research. The significant contribution of abscisic acid as “stress hormone” and other classical phytohormones including auxins, brassinosteroids, ethylene, gibberellins, cytokinins during the wide range of abiotic stresses is well characterized. Recently, the role of other phytohormones, such as jasmonic acid, salicylic acid, and nitric oxide (NO), during responses to abiotic stress(es) has also been demonstrated, and the role of other new class of phytohormones, such as strigolactones and karrikins, has also been investigated, which has been covered in this chapter. These phytohormones provide adaptation to abiotic stresses, and simultaneously regulate various physiological processes, such as stomatal closing, thereby leading to reducing water loss, and thus enhancing osmotic stress tolerance. Generally, during abiotic stress the phosphorylation cascades as cross talk points in phytohormonal signaling prompt changes in gene expression, which can affect the biosynthesis, signaling, and action of other phytohormones.
Cultivated cardoon is a multipurpose crop with adaptability to limiting environments. Two genotypes (“Bianco Avorio” and “Spagnolo”) were comparatively characterized in response to short and prolonged 100 mM NaCl stress in hydroponics....
moreCultivated cardoon is a multipurpose crop with adaptability to limiting environments. Two genotypes (“Bianco Avorio” and “Spagnolo”) were comparatively characterized in response to short and prolonged 100 mM NaCl stress in hydroponics. Salt induced no growth variations between genotypes or symptoms of NaCl toxicity, but boosted ABA accumulation in roots and leaves. Both genotypes had high constitutive phenol content, whose major components were depleted upon 2 days of stress only in “Bianco Avorio”. Prolonged stress stimulated accumulation of proline, phenylpropanoids, and related transcripts, and non-enzymatic antioxidant activity. Decreased antioxidant enzymes activities upon short stress did not occur for APX in “Spagnolo”, indicating a stronger impairment of enzymatic defenses in “Bianco Avorio”. Nonetheless, H2O2 and lipid peroxidation did not increase under short and prolonged stress in both genotypes. Overall, the two genotypes appear to share similar defense mechanisms but, ...
To assess the potential for arsenic (As) hyperaccumulation of native plant species, plant and soil samples were collected from the Zarshuran area (north-western Iran), which has a history of As pollution from mining. Total and...
moreTo assess the potential for arsenic (As) hyperaccumulation of native plant species, plant and soil samples were collected from the Zarshuran area (north-western Iran), which has a history of As pollution from mining. Total and water-soluble As in the soil ranged from 11.2 to 6525 and from 0.004 to 13.08 mg kg(-1), respectively. Among 89 plant species, the highest foliar As concentrations were found in Isatis capadocica (up to 3000 mg kg(-1)) and Hesperis persica (up to 1500 mg kg(-1)). Over a broad range of soil As concentrations, these species maintained more than 10-fold increased foliar As concentrations and soil to leaf As transfer coefficients in comparison with all the other species sampled at the same sites. Based on these characteristics, in combination with their ability to accumulate As to concentrations exceeding 1000 mg kg(-1) on a dry weight basis in their foliage, both species should be classified as As hyperaccumulators. I. capadocica and H. persica, both Brassicacaeae, are the first terrestrial angiosperms shown to possess the As hyperaccumulation trait. Both species are fairly robust with relatively high biomass productivity and, therefore, potentially useful in on site phytoremediation, particularly I. capadocica, because of its higher robustness and As accumulation capacity.
Members of Fusarium solani species complex (FSSC) are common pathogens of potato, causing dry rot in the west of Iran which involved Hamedan, Kermanshah, Eilam and Kurdistan provinces. Therefore, the objectives in this study were to...
moreMembers of Fusarium solani species complex (FSSC) are common pathogens of potato, causing dry rot in the west of Iran which involved Hamedan, Kermanshah, Eilam and Kurdistan provinces. Therefore, the objectives in this study were to isolate and identify disease-causing FSSC from infected potato tubers based on the morphological and molecular characteristics. Forty-five isolates of Fusarium were obtained from potato tubers collected from the wet market in different regions of the west of Iran and identified as FSSC through morphological characters. All of the isolates were evaluated for their pathogenicity on healthy potato tubers in the planthouse. The tubers rot symptoms were observed on the 21st day after inoculation of Fusarium isolates on the tubers tested. In the tubers inoculation tests, lesion sizes were quite variable; therefore, the measurement was done to compare the depth and width of lesion expansion among the isolates. Based on the sequence data from translation elongation factor (EF-lα) gene and internal transcript spacer (ITS) regions analysis, all of the selected FSSC isolates were divided into two major groups. This is the first report on molecular identification of FSSC strains isolated from potato tubers in Iran and Fusarium falciforme was reported for the first time in Iran.
ABSTRACT Effects of different arsenic (As) concentration (030mg L1) on seed germination, root tolerance index, relative shoot height, root and shoot biomass, photosynthetic pigments and arsenic accumulation in two wheat varieties were...
moreABSTRACT Effects of different arsenic (As) concentration (030mg L1) on seed germination, root tolerance index, relative shoot height, root and shoot biomass, photosynthetic pigments and arsenic accumulation in two wheat varieties were investigated. Low concentrations of arsenic (02.5mg L1) stimulated germination percentage, shoot and root elongation, plant biomass as well as chlorophyll content as compared with control, however, these factors all decreased gradually at high concentrations of arsenic (530mg L1). Zarin' variety had a significantly higher tolerance to arsenic than Sardari.' Arsenic accumulation by plants root and shoot increased with the increasing arsenic concentrations in medium, which Zarin' had a higher ability to absorb and translocate arsenic to the shoots. Root accumulated more arsenic than shoot. The similar trend of chlorophyll content and wheat growth under different arsenic concentration suggesting that arsenic toxicity affects the photosynthesis which ultimately results in the reduction of wheat growth and yield.
Isatis capadocica, a brassica collected from Iranian arsenic-contaminated mine spoils and control populations, was examined to determine arsenate tolerance, metabolism and accumulation. I. cappadocica exhibited arsenate hypertolerance in...
moreIsatis capadocica, a brassica collected from Iranian arsenic-contaminated mine spoils and control populations, was examined to determine arsenate tolerance, metabolism and accumulation. I. cappadocica exhibited arsenate hypertolerance in both mine and nonmine populations, actively growing at concentrations of > 1 mm arsenate in hydroponic solution. I. cappadocica had an ability to accumulate high concentrations of arsenic in its shoots, in excess of 100 mg kg(-1) DW, with a shoot : root transfer ratio of > 1. The ability to accumulate arsenic was exhibited in both hydroponics and contaminated soils. Tolerance in this species was not achieved through suppression of high-affinity phosphate/arsenate root transport, in contrast to other monocotyledons and dicotyledons. A high percentage (> 50%) of arsenic in the tissues was phytochelatin complexed; however, it is argued that this is a constitutive, rather than an adaptive, mechanism of tolerance.