JOURNAL OF PLANT PROCESS AND FUNCTION
Year:2020 | Volume:9 | Issue:35|Papers Count:28

In order to evaluate the effect of deficit irrigation and different types of potassium fertilizers on improving the photosynthetic pigments content and chlorophyll florescence parameters in rice (cv. Tarom Hashemi), two field experiments were conducted in the Rice Research Institute (Amol) and model farm located in Savadkouh in a split plot based randomized complete block design with three replicates. Treatments were different irrigation methods at two levels (flooding, flooding after falling water depth under 10 cm of soil surface) and nine levels of potassium fertilizers application (including potassium sulphate, potassium chloride and biofertilizer). Chlorophyll a, b and a+b contents, maximum fluorescence, variable fluorescence, electron transport rate of photosystem II (ETR) and grain yield significantly decreased under deficit irrigation in both two stations as compared to flooding irrigation treatment. Current research demonstrated a positive effect of potassium fertilizer application through significant increment in chlorophyll content and non-photochemical quenching (NPQ) index in limited irrigation condition. The highest amounts of grain yield (4945 and 4770 kg ha-1 in the Amol and Savadkouh stations, respectively) were recorded when 50% of potassium sulfate and 50% of potassium chloride were applied as a basal and top dressing, respectively. According to the significant and positive correlation between grain yield and chlorophyll a and a+b content, maximum potential quantum efficiency of photosystem II (Fv/Fm) and ETR, it can be conclude that the application of 50% of potassium sulfate as a basal and 50% of potassium chloride as a top dressing was the most effective treatment in term of the studied traits, especially in the limited irrigation condition.

DREB transcription factors are one of the largest families of transcription factors in plants that are believed to play important regulatory functions in tolerance to environmental stress, but there is no complete information on their role in controlling the morphological and antioxidant properties of grown plants under normal conditions. In this study, some phenotypic characteristics of the dreb2a and dreb1a mutant arabidopsis were compared to the wild plant under normal growth conditions. Most properties of dreb2a were similiar to those of dreb1a mutant, but significantly different from the wild type. Both mutant lines showed accelerated emergence of radicle and cotyledons, but delayed appearance of bolting. Lateral branches formed on the flowering bolt in the mutant lines were 25% less, while the flowering axes were 20% more than that in the wild type plants. Both mutant lines displayed higher total number of siliques per plant (about 10%), total number of seeds per plant (about 40%) and total seed weight per plant (about 13%), while, they had lower seed soluble protein content and the cruciferin/napin ratio, as compared to the wild type. It is noteworthy that in 14-day seedlings and leaves of the plant at the stage of reproduction in two mutant lines compared to the wild line, the activity of antioxidant superoxide dismutase and peroxidase activity was on average 35% and hydrogen peroxide was on average 70% higher. These data indicated that the change in the expression of the studied genes played a key role in controlling the morphological and antioxidant status of the plants grown under normal conditions, and studying the cascade stages of the signal transduction managed by DREB family transcription factors can lead to a deeper understanding of the response mechanism of these plants to various environmental stresses.

In order to evaluate the effect of deficit irrigation treatment and foliar application of ascorbic and jasmonic acids on morphophysiological traits of safflower genotypes (Carthamus tinctorius L. ), an experiment was set out in a split plot factorial in a randomized complete block design with three replications at Shahrekord University Agricultural Research Station during the two years, i. e. 2016-2017. The main factor consisted of three levels of irrigation of 100%, 75% and 50% of the plant's water requirement of safflower and sub-factor including safflower genotypes including Sinai, Isfahan local, Faraman and foliar application with three levels including (0 concentration, foliar application of jasmonic acid with 0. 5 mM concentration and foliar application of ascorbic acid with 20 mM concentration(. The results showed that the highest cholliorophyll a, cholliorophyll b, relative water content, leaf area index, crop growth rate, oil percentage, grain yield and oil yield related to Sina genotype and 100% of the plant's water requirement and the least of these traits were related to the Isfahan local genotype and 50% of the plant's water requirement. Also, the results of this study showed that the interaction effects of genotype× deficit irrigtion and genotype× foliar application were significant only on cholliorophyll a and oil yield. Also, foliar application of Jasmic and ascorbic acids increased all traits compared to the non foliar application treatment. The results of this study showed that the differences between the genotypes and also effect of foliar application of jasmonic and ascorbic acids to increase of these traits were important components that could be used to select genotypes and suitable compounds to reduce undesirable effects of water stress in order to achieve increased economic performance.

In order to evaluate the physiology and biochemistry of sixth generation of rice mutant tolerant lines under salinity stress, an experiment was carried out as split plot arranged in a Completely Randomized Design with four replications. Main factor of experiment included three levels of salt stress (0, 45, 75 mmol/l) and sub factor included 5 local rice mutant lines contain Tarom Hashemi 1, Tarom Hashemi 2, Tarom Hashemi 3, Tarom Chaloosi and promising Nemat. The results of analysis of variance of interaction salt stress and rice mutant lines showed that affect of interaction on the studied traits was significant. In comparision with other lines, the results of experiment showed that Nemat under all levels of salt stress had the highest content of Proline that was accompanied with decrease of protein activity in this line. Catalase and Gayacol peroxidase activity under stress condition increased and and there was fewer amount of Malondialdehyde and ionic leakage. Considering the positive and significant correlation between dry weight of rice lines with Proline content (r = 0. 36 * ** ), Catalase (r = 0. 49 ), and Guaiacol peroxidase (r = 0. 51 ** ) and negative correlation with Protein content (r =-0. 29 * ) and Malondialdehyde (r =-0. 36 * ) it seemed to suggest that the Nemat mutant could be as the most tolerant line, since the resistance mechanism of this line involves osmotic regulation and increasing the amount of proline amino acids through protein degradation and catalase enzymatic system, so these traits can be considered as basic mechanisms for tolerance to salinity.

In order to the investigate Zn nano-chelate foliar application effects on photosynthetic parameters, glutamine synthetase, protein, grain yield and yield components of soybean under water deficit, a split-plot experiment was conducted as a randomized complete block design with three replications at Research Farm, Faculty of Agriculture, University of Lorestan, in 2016. The treatments consisted of different irrigation regimes (100, 80, 60 and 40% of plant water requirement) in the main plots and zinc nano-chelate foliar application (Control or distilled water and zinc as zinc nano-chelate containing 20% zinc absorbable ion) in the subplots. The results showed that by decreasing water requirement, some traits such as photosynthesis, transpiration, stomatal conductance, glutamine synthetase, the number of pods per plant, the number of grain per pod, 100-grain weight, grain yield, protein percentage of grain and protein yield decreased as well. In contrast, internal CO2 concentration (Ci) and SPAD value increased in stress condition. In normal condition, zinc nano-chelate treatment no effects on SPAD value, the number of seed per pod, 100-seed weight, seed and protein yield. In water deficit conditions, zinc nano-chelate foliar application increased the mentioned traits by 4. 2, 13. 8, 17. 3, 45. 7 and 39. 3 percent, respectively. In addition, in water deficient, zinc nano-chelate decreased Ci and stomatal conductance of leaves. In general, zinc nano-chelate application mitigated effects of water deficit and it was positive for improving soybean yield. Therefore, its application may improve tolerance of soybean.

With respect to the rise rate of the production and release of nanoparticles in nature, it is important to note the possibility of toxicity and oxidative damage to the plant ecosystem. Hence, this research was aimed to compare the biochemical and anti-oxidative indices of Onion treated with different concentrations of two types of silver nanoparticles (green synthesis and chemical synthesis) and investigating the probability of oxidative stress induction. In this study, the color of the leaf extract turning from pale yellow to dark brown, due to surface plasmon resonance of silver nanoparticles, indicated the successful synthesis of silver nanoparticles. The absorption spectrum of the synthesized silver nanoparticles showed a peak with λ max of 410 nm. TEM images revealed a uniform size of the synthesized particles, with almost spherical shape and the size range between 3 to10 nm, with an average of 5. 8 nm. XRD analysis revealed that the green synthesized silver nanoparticles were crystalline in nature. According to the results, both antioxidant enzymes represented linear increases in exposure to the chemical nanoparticles. Both nanoparticles caused increasing in lipid peroxidation, but the green synthesized nanoparticles had no significant difference compared with the control. The most phenol content belonged to chemical nano-silver (15. 16 mg Gallic g-1 FW at the concentration of 0. 05 gr l-1 ) and the least value to the control (4. 1 mg Gallic g-1 FW). The antioxidant activity of chemical nanoparticles was 8 times more than the green nanoparticles. According to the results of this research, green nanoparticles didn’ t have an oxidative effect on onion. However, some stimulus effects were revealed. It is worth noting that, the chemical nanoparticles, provoked plant defense reactions, by inducing oxidative stress, besides the inhibitory effect was dose-dependent.

Understanding various variations in tree leaf related to altitude and climate change define the plant adaptation. These variations will predict their respond to the future changes. According to the vast distribution of Persian oak (Quercus brantii) trees in Zagros forests, the study of structural changes and the recognition of the Persian oak ecological needs is crucial for their conservation and management. The aim of present study was to study the changes in the physiological traits of Persian oak leaves due to low changes in altitude as well as growing seasons (spring and autumn) in Gachan region, Ilam province. For this purpose, leaf physiological traits were investigated in three oak populations at altitudes of 1640 m, 1821 m, and 1900 m a. s. l along an altitudinal slope. In each population, five seed-grown trees with almost similar diameter and characteristics were selected. The sampled leaves were collected from outer and middle part of tree crown. The leaves were mixed together and then about 20 leaves were randomly sampled for physiological study. According to the results, highest values of EC, Chlorophyll a, and total chlorophyll were 31. 81%, 15. 57(Mg/g FW), and 20. 72 (Mg/g FW) in autumn and at low altitude. Highest amount of RWC and Proxidase were determined in spring and low altitude as 30. 15% and 0. 17 (μ mol-1-1-1-1 min g FW ), while highest amount of pH, carbohydrate and Catalase were respectively: 5. 12, 0. 09 (μ g/g FW), and 0. 70 (μ mol-1-1-1-1 min g FW ) in autumn and high altitude. Additionally, highest amount of proline was determined in spring and middle altitude as 0. 34 (μ g/g FW). In general, the results of this study indicate that the physiological traits of Persian oak leaves show least changes with respect to altitude as well as different growing seasons.

Salinity is one of the most important environmental stresses which affects the growth of plants. Most of the plants are sensitive to salt stress at the seedling stage, thus growth in salt-water accompanies with problems. Various agronomic and physiological practices (treatments) are applied to minimize the adverse effects of salinity on plant growth, and using plant growth regulator is one of them. This study was conducted to investigate the effect of melatonin on the resistance of Tagetes erecta seedlings to salinity. In order to evaluate the effect of different levels of salinity on early growth of Tagetes erecta seedlings, a factorial experiment was conducted in a completely randomized design with three replications. Experimental treatments consisted of two levels of 0. 25 and 0. 5 μ M of melatonin, and four different levels of saline solution containing pure sodium chloride at concentrations of 0, 50, 100 and 150 mM. In this research, the effect of pretreatment with two concentrations of Melatonin was investigated on the growth biochemical and antioxidant parameters of Tagetes erecta under salt stress. In some measured parameters, such as chlorophyll and protein content, pretreatment with 0. 25 µ M Melatonin 50, 100 and 150 mM NaCl was effective. Pretreatment with melatonin at both concentrations 0. 25 and 0. 5 µ M in seedlings which were under salinity stress, reduced MDA and other aldehydes. Salinity stress increased activity of catalase in leaves, while had no effect on the ascorbate and guaiacol peroxidaes activity. Pretreatment of seedlings with melatonin at concentrations 0. 25 µ M increased the catalase activity under salinity condition. However, pretreatment with melatonin only at concentrations 0. 25 µ M increased ascorbate and guaiacol peroxidaes activity in salinity condition. The results indicated that Tagetes erecta pretreatment by melatonin increased seedlings tolerance under salt stress.

In order to investigate the effects of foliar spraying of iron nanoparticles on improvement of some physiological and morphological traits of purslane (Portulaca oleracea) under cadmium stress, a factorial experiment was conducted in a completely randomized design with three replications. The experiment was conduted under greenhouse conditions at Sari Agricultural Sciences and Natural Resources University during 2017. The experimental factors included cadmium chloride in six levels (0, 25, 50, 75, 100 and 125 mg/kg soil) and foliar spring of iron nanoparticles in five levels (0, 0. 25, 0. 5, 0. 75 and 1 g/l). The results showed that the interction effects of iron nanoparticles and cadmium were significant on leaf area, root dry weight and proline content at 5% as well as leaf dry weight and chlorophyl contents at 1% probablity level. The leaf area responded a linear decrease trend with increasing cadmium levels at levels of 0, 0. 5, 0. 75 and 1 g/l of foliar spraying of iron nanoparticles. By contrast, as a segmented model at concentration of 0. 25 g/l. Foliar spraying of iron nanoparticles at all four levels increased root dry weight to 25 mg/kg of cadmium, but at levels above 25, the root dry weight decreased at higher level of Cd. Meanwhile, the concentration of 0. 5 g/l of foliar spraying of iron nanoparticles had the most effect on root dry weight by 34. 80% increase as compared to the control. SPAD value increased in both levels of 0. 5 and 0. 75 to 25 mg/kg of soil cadmium, 11. 19 and 28. 99% respectively, as compared to the control. In general, our results, indicated that foliar application of iron nanoparticles was effective to improve cadmium tolerance in purslane plant in low cadmium concentrations. However, more research is needed to investigate the mechanism of iron nanoparticles.

Considering the high water requirement of turfgrass during growth stages and the limitation of irrigation sources, it is important to find a suitable way to reduce the water requirement of the lawns as ground cover plants used in the Landscape. The purpose of this study was to investigate the effect of 2, 4, 5-T on the induction of callus from the hypocotyl explant in Kentucky bluegrass, in vitro osmotic stress using polyethylene glycol and evaluation of the tolerance to stress using folic acid in vitro conditions. Therefore, the research was conducted in four experiments. In the first experiment, the effect of 2, 4, 5-T (0. 5, 1 and 2 mg l-1 ) in combination with two concentrations of 0 and 0. 1 mg l-1 BA on callus induction in a hypocotyl explant was investigated. In the second experiment, 0,-0. 005,-0. 007,-0. 010, 0. 16 and-0. 02 (bar) concentrations of PEG were used for induction of osmotic stress in calli. In the third and fourth experiments, folic acid was used to suppress osmotic stress induced by PEG in two stages of callus and regeneratin plants. The results of the first experiment showed that highest percentage of callus induction at a concentration of 0. 5 mg l-1 of 2, 4, 5-T alone was observed. Based on the results of the second experiment, it was found that increasing the concentration of PEG decreased the growth indices in callus, so that in the concentration of-0. 016 and-0. 022 bar PEG, the least amount of measured traits of callus was observed. Also, the results of the third experiment showed that the use of folic acid in MS medium at 0. 5 and 1 mg l-1 concentration reduced callus growth traits and increased soluble sugar content. In the fourth experiment, the results showed a decrease in the measured traits of regenerated plants in-0. 022 bar PEG. The highest amount of soluble sugars in regenerated plants was observed in treatment 1 mg l-1 folic acid in combination with 0 bar PEG. In the third and fourth test, folic acid did not affect osmotic stress control.

In order to evaluate the effect of foliar application of iron and magnesium nano-chelate fertilizers on morphophysiological characteristics of Vigna sinensis L., an experiment was conducted in Shahroud University of Technology in 2010-2011. The experiment was carried out in a factorial arrangement with randomized complete block design with three replications. Treatments included five levels of iron (0, 0. 25, 0. 5 g/l of nanoparticles and the same concentration of normal iron) as the first factor and foliar application of magnesium with three levels (zero, 1% concentration of nanoparticles and the same concentration of normal magnesium) as a second factor. The traits including stem height, number of branches, distance from the first pod from soil surface, pod length, leaf area index, yield and yield components, Greenness Index, iron and magnesium elements and seed protein were measured. The results showed that the effect of different levels of iron and magnesium on all traits except grain protein was significant. The highest stem height, distance between the first pods from the soil surface and leaf area index were observed in the nano-iron treatment 0. 25 g/l and 1% nano magnesium. The iron composition of 0. 25 g/l and nano magnesium had the highest number of lateral branches (5. 46 branches per plant) and sheath length (16. 56 cm). While the Greenness Index traits and the amount of iron and magnesium in leaves, had the highest efficiency in 0. 5 grams per liter iron in both nano and normal forms, with normal magnesium treatment. However, the highest grain protein (22. 35%) was produced by using nano-iron at 0. 25 g/l alone. Also, the highest yield resulted from the application of Fe (0. 5 g/l) × nano-magnesium with mean of 2377. 73 kg/h and the lowest values were for the nano magnesium (792/55 kg/h). One of the reasons for the observed increase in yield in Fe (0. 5 g / L) × nano magnesium was the increase in the number of pods per plant and the weight of 1000 seeds. Amongst the yield components, number of seeds per pod were the highest when Fe × magnesium applied. It seemed that in all of the morphological and physiological traits, the leaf area index was the best with Fe (0. 25 g/l) (both nano and normal forms) ×nano magnesium treatment. However, in the traits of yield and other physiological traits iron treatments of 0. 5 grams per liter (both nano and normal forms) were superior to normal magnesium.

Smoke tree or venetian sumach (Cotinus coggygria Scop. ) is an attractive ornamental tree in landscape and rich in medicinal properties. In this study, the effects cow manure and vermicompost on decreasing salt stress in the common smoke tree were investigated. The experiment was factorial based on a completely randomized design including three levels of organic treatment (agricultural soils, 80% v/v soil + 20% v/v vermicompost, 80% v/v soil + 20% v/v cow manure) and three levels of saline water for irrigation (1, 4 and 7 dS. m-1 ) with three replications in the greenhouse. The results showed that the highest fresh and dry weight of leaves were obtained in cow manure and in 1 dS. m-1 salinity. The highest fresh and dry weight of root were obtained in vermicompost and in 4 dS. m-1 salinity. The highest fresh and dry weight of shoots were obtained in vermicompost and in 7 dS. m-1 salinity. The maximum amount of sodium, potassium and Na/K uptake were observed in 7 dS. m-1 salinity and vermicompost treatment. Application of cow manure and vermicompost in different salinity levels significantly increased catalase and peroxidase activity. Generally, the use of cow manure and vermicompost could improve the growth characteristics and nutrient absorption of plant under salt stress condition as compared with the control.

Humic acid can vary the toxicity of biotoxins at different environments when it is bond to them. Therefore, the interaction between nanoparticles and humic acid is specially considered in the view of environmental point. The objectives of this study were the investigation of ZnO nanoparticle toxicity on rapeseed at germination stage, and the reduction of the nanoparticle toxicity by humic acid in laboratory condition. The experiment was conducted with nine concentrations of 0, 250, 500, 750, 1000, 1250, 1500, 1750, 2000 mg / L zinc oxide nanoparticle and two concentrations of 0, 100 mg / L humic acid, as factorial in a completely randomized design with three replications. The results showed that increasing of the ZnO nanoparticle concentration caused increasing the activity of superoxide dismutase, ascorbate peroxidase, catalase and peroxidase enzymes, while the protein content showed a reduction trend. Humic acid application decreased the toxicity effects of ZnO nanoparticle. Increasing the concentration of ZnO nanoparticle caused reduction in germination indices (such as final germination percentage, germination energy, germination rate and seed vigor index). However, application of humic acid resulted in improving the germination indices, antioxidants activity in the plant and a reduction of toxicity by protecting the plant against the ZnO nanoparticle.

Sugar beet is a strategic and industrial crop and important in sugar production. Drought is a limited factor in sugar beet yield. Base on this, an experiment carried out using a split-plot format in the randomized complete block design with 4 replications in 1394-5 at Chenaran area (Bahman Jan village). The main plot included three drop irrigation regimes: 7, 14 and 21 days interval as normal, mild and intensive stress, subplot included four cultivars: Iranian cultivars, Paya and Shukufa and foreign cultivars Sementa and Pirola from German company KWS. The results showed, drought treatments decreased total yield. Also, drought stress increased chlorophyll (a and b) and TBARM as cellular oxidative index. It seems increased in chlorophyll is a mechanism for increasing drought tolerant. The maximum amount of catalase (119 unit) and superoxide (1481 unit) enzymes were obtained in mild and intensive drought treatment respectively. The expression of all three genes (CPX1, CPX2 and NDP) were increased by drought treatment, indicating the important role of these genes in drought tolerant.

A pot experiment was conducted during spring and summer of 2017 at the collage of agriculture of Isfahan University of Technology, Isfahan, Iran, in order to evaluate the effects of different concentrations of foliar ascorbic acid application on the response of sorghum (Speedfeed cultivar) to salinity. Treatments included two salinity levels (0 and 100 mM NaCl) and five concentrations of ascorbic acid (0, 50, 100, 150 and 200 mg/l). Treatments were arranged as factorial based on a completely randomized design with four replications. Salinity decreased potassium concentration, potassium/ sodium ratio, chlorophyll and carotenoid contents as well as shoot and root dry weights, while salt enhanced the concentrations of sodium and proline and the activities of antioxidant enzymes catalase, superoxide dismutase and ascorbate peroxidase. The decreases due to salinity at 0, 50, 100, 150 and 200 mg/l concentrations of ascorbic acid were 30, 27, 24, 27 and 20 percent, respectively. Foliar application of ascorbic acid improved plant growth parameters, the concentrations of proline and the activities of antioxidant enzymes but decreased sodium concentrations in sorghum plants. The highest increase in plant dry matter due to the application of ascorbic acid in both non-saline (30%) and saline (41%) conditions were obtained at 100 mg/l ascorbic acid. The increases due to ascorbic acid application in the antioxidant enzyme activity were greater for superoxide dismutase and ascorbate peroxidase as compared to the catalase. Based on the results of this experiment, ascorbic acid application not only improved the growth of sorghum plants, but also alleviated the negative effects of salinity in this plant.

In order to investigate the effect of salicylic acid on photosynthetic pigments, enzyme activity and yield of durum wheat cultivars under drought stress, a greenhouse experiment was conducted at College of Agriculture and Natural Resource of Darab, Shiraz University, as factorial based on complete randomized design with 3 replicates. Treatments included of drought stress in two levels of normal irrigation and drought stress at the beginning of the milking stage, and salicylic acid at 0, 1, 2, and 3 mM and three different durum wheat cultivars consisted of Shabrang, Behrang and Yavaros. The results showed that the late season drought stress, cultivar and salicylic acid had significant effect on chlorophyll a and b contents, as well as peroxidase and catalase enzymes, grain protein, plant height, and spike length, grain number per spike, biological yield and grain yield. The interaction of drought stress and salicylic acid had a significant effect on chlorophyll a and b contents, so that chlorophyll a and b contents with application of 3 mM salicylic acid in drought stress conditions were 32 and 35%, compared to the control (no application of salicylic acid), respectively. Under drought stress conditions, the highest carotenoid content (14. 83 mg /g Fw) was obtained in foliar application of 3mM salicylic acid, in Yavaros cultivar. Also, drought stress and salicylic acid had a significant effect on peroxidase and catalase enzymes and application of 3 mM salicylic acid caused 14 and 15% increase compared to the no application of salicylic acid, respectively. Finally, foliar application of 3 mM salicylic acid increased chlorophyll a and b contents as well as peroxidase and catalase enzymes activity compared to the no application of salicylic acid and increased 13% grain yield of Yavaros cultivar.

The aim of this study was to investigate the effects of different light intensities and ascorbic acid on some physiological and biochemical characteristics of Zinnia elegans L. The experiment was designed as a completely randomized design in a form of split-plot with three replications. The treatments consisted of three light intensity levels (600, 1200 and 1800 μ mol m-2-1 s ) as the main factor using shade net and weekly spraying three ascorbic acid concentrations (0, 1, 2 mM) as sub-plots. Analysis of variance showed that light intensity had a significant effect on all the studied traits, except for the guard cell width. As light intensity increased, proline content, catalase, and ascorbate peroxidase activity increased. The lower light intensity increased chlorophyll a and b, carotenoids, total chlorophyll, and peroxidase enzyme activity. Furthemore, with increasing light intensity, stomatal density and index, and epidermal cells density increased, so that stomatal density of plants grown under 1800 μ mol m-2-1 s light intensity was twice of that under 600 -2-1 μ mol m s light intensity. Moreover, application of ascorbic acid increased ascorbate peroxidase enzyme activity, stomatal density, guard cell length, while, it reduced proline content, catalase and peroxidase enzyme activities. Overall, the results showed that increasing light intensity induced stress in Zinnia and weekly application of ascorbic acid alleviated the stress effects.

Aquaporins are the main integral membrane proteins in the plasma membrane, that facilitate transport of water, carbon dioxide, and other small soluble material across the membrane. The aim of this study was to investigate the role of root aquaporins on the physiological, biochemical and biochemical changes and water relations under drought stress. For this purpose, a study was conducted in a completely randomized design on sweet pepper (Ps 301) under drought stress in a hydroponic medium. Sweet pepper plants were grown in hydroponically controlled condition and exposed to drought stress by applying polyethylene glycol (6000) and stopping the activity of aquaporin, using 50 mM of HgNO3. The results showed that in the presence of aquaporins, fresh and dry weight of root and shoot, relative humidity (22%), protein (47%), sodium content (29%), potassium (13%), and abscisic acid (19 %) increased. Also, in the absence of aquaporins under drought stress conditions, the negative potential of root water (57 %), the increase in the amount of proline (1. 2 times), the content of abscisic acid (12%) and the phenolic content (89. 7%) as a protective factor in the cell against free radicals were observed. Based on the results obtained from drought stress and stopping the activity of aquaporins, the role of water channels in osmotic regulation can be explained by the transfer of water and decreasing the deleterious effect of stress.

This study, investigates oil percentage and fatty acid composition of Silybum marianum seeds in habitats located in the west of Mazandaran province at different elevations and soil physiochemical properties. After identifying Silybum marianum shrubs in elevation classes of the study area, seeds were sampled using systematic random method and along a 100 m transect at 30 m intervals from three points. After the establishment of transects, in order to study soil physiochemical properties and their relationships with the quantity and quality of fatty acids and oil, three plots were placed in each site and as the number of plant samples, 18 soil samples were taken from the depth of 30 cm and around the roots of the plant. Hexane solvent and Soxhlet were used to determine oil content. Identifying fatty acid compositions and Silymarin extraction were done using gas chromatography spectrometer (GC/MS) and methanol solvent in ultrasonic bath, respectively. Based on the results, the highest amount of oil and Silymarin were obtained from plains and mountainous regions, respectively. According to the results, unlike Silymarin, habitats did not have a significant effect on oil content, also, the highest amount of oil and Silymarin were obtained from plains and mountainous regions, respectively. Considering the significant effect of habitat on the quality of oil, Oleic acid showed significant negative response to habitats. Soil organic matter and calcium carbonate also had inverse relationships with elevation. Sand, potassium, phosphorus and nitrogen indicated negative relationship with oil percentage. Elevation had positive relationship with Margaric acid and Linoleic acid, but negative relationship with Oleic acid. There was positive relationship between Palmitic acid and sand, phosphorus and nitrogen. Because the Oleic acid was predominant followed by the Linoleic acid, it can be concluded that Silybum marianum oil is in the Oleic-Linoleic oil group with high nutritional quality, thus cultivation of this oily seed could be an alternative to produce edible oil and reduce the dependence on other countries.

In an orchard experiment in 2016, the effects of foliar application of kaolin, potassium, phosphorus and their different combinations were examined on photosynthesis parameters of 8-year-old pistachio trees cv. “ Kalle-ghouchi” based on a randomized complete block design as factorial with two factors (spray treatments at 10 levels and samplind dates at 5 levels) with 3 replications. There were ten spray treatments including kaolin 5%, P at two concentrations (1 and 2%), K at two concentrations(1. 5 and 3%), kaolin 5%+ P 1%, kaolin 5%+P 2%, kaolin 5%+ K 1. 5%, kaolin 5%+ K 3% and the control (use of distilled water). Foliar application of above treatments were performed in mid June when embryo growth started (the maximum demand for photoassimilates). Photosynthetic parameters (photosynthesis and transpiration rate, stomatal conductance and sub stomatal CO2 concentration), chlorophyll fluorescence parameters (Fv/Fm and PI), photosynthetic pigments (chlorophyll a, b and total and total carotenoids) were measured in 5 stages (the first stage was one day after spray treatments and the others were performed with one week interval). The results showed that non of treatments could improve photosynthesis parameters except Ci while chlorophyll fluorescence parameters were improved by kaolin treatments and photosynthetic pigments were increased by most of experimental treatments. The result also showed that photosynthesis and transpiration rate and stomatal conductance were increased with time whereas sub-stomatal CO2 concentration was decreased. Chlorophyll fluorescence indices and photosynthetic pigments were also increased with time. Totally, the effect of experimental treatments on photosynthetic parameters was less than we expectated.

The medicinal plant bitter apple (colocynth) belongs to Cucurbitaceae family. To study the effect of phenylalanine and tryptophan amino acids on morphological and physiological characteristics of Citrullus colocynthis L., an investigation was conducted according to a completely randomized block design with four treatments and three replications in the University of Zanjan, Iran. The studied factors included different levels of phenylalanine and tryptophan (0, 0. 5, 1, 2 mM). According to the results, phenylalanine and tryptophan very significantly affected the majority of the studied traits including plant length, fresh and dry weight of foliage, seed yield, weigh of 1000 seeds, chlorophyll, total phenol and flavonoid contents (p≤ 0. 01). The maximum content of total phenol and flavonoid were reached to 16. 94 and 7. 31 mg/100 g fresh weight in the concentration of 1 mM phenylalanine compared to the control with 10. 72 and 4. 04 mg/ 100 g fresh weight respectively. Also, yield of fruit and antioxidant activity were affected significantly by the amino acid treatments (p≤ 0. 05). The maximum fruit yield was 8930. 6 kg/ha at the concentration of 0. 05 mM tryptophan compared to 6344. 4 kg/ha in control. In conclusion, various levels of tryptophan and phenylalanine can effectively improve morphological and physioloogical characteristics and hence production of this crop. To achieve the best performance, application of 2 mM phenylalanine for maximum yield of foliage, 1 mM of the two amino acids for phytochemical characteristics and 0. 5 mM of the two amino acids for fruit yield, depending on the aim, can be recommended.

Drought is one of the most important environmental stresses that limits plant growth through effects on physiological processes. In order to evaluate spraying growth regulators on some physiological traits and water use efficiency of potato under drip irrigation system, a study was conducted at the research farm in Malayer during 2015 growing seasons. The experiment was conducted as a split-plot scheme based on randomized complete block designs with three replications. Different drip irrigation intervals (once every day, once every 2 days, once every 3 days, once every 4 days, once every 5 days and once every 6 days) and sprinkler irrigation (once every 6days) were considered as a main plots and substrate foliar application of growth regulators with four levels, including epibrassinolide, gibberellic acid, acetylsalicylic acid and the control treatment (distilled water) were considered as a subplots. Results showed that with an increase in drip irrigation intervals, the amount of water use efficiency and protein content as well as the amount of proline, sugar solution of leaf and tuber and potassium concentration increased significantly. The activity of antioxidant peroxidase and superoxide dismutase enzymes on potato seemed to increase as the irrigation frequency increased. The highest enzymatic activities were obtained from once every5 and 6days drip irrigation intervals. Foliar applications of growth regulators were effective in reducing hazard effects of drought stress via the increase in photosynthetic pigments and antioxidant enzymes. Foliar application of growth regulators increased the amount of peroxidase and superoxidase enzymes by 25% and 10%. Foliar application of growth regulators was effective in reducing the effects of stress caused by irrigation period prolongation whereas significantly increased water use efficiency, leaf protein content, proline, leaf and sugar solution of potassium, photosynthetic pigments, and antioxidants. Also, increasing the irrigation interval reduced the total chlorophyll content as well as carotenoid by 33% and 45% compared to the control and increased the activity of peroxidase and superoxide dismutase enzymes by 50% and 41% in potato. Foliar application of growth regulators increased the total chlorophyll content by 11%. The effect of epibrassinolide was higher than other growth regulators.

Melatonin (N-acetyl-5-methoxytryptamine) as a plant growth regulator, is a natural compound that has been known to exist in a large variety of plant species in roots, leaves, fruits and seeds. In order to investigate the effect of melatonin on some physiological characteristics of chickpea seed and seedling (Arman cultivar) under salinity stress, a factorial experiment was conducted based on a completely randomized design with four replications in 2017 at the Yasouj University. The factors included melatonin at concentrations of without-prim, 0, 25, 50, 75, 100 and 125 μ M as the first factor, and different levels of salinity included 0, 25, 50, 75 and 100 mM sodium chloride, as the second factor. The results showed that in salinity levels of 100 and 50 mM, melatonin with concentration of 100 μ M increased the seedling proline. In non stress conditions, priming with 25, 75 and 100 μ M melatonin increased seedling potassium content. Also, in 100 mM salinity stress, priming with 50 and 75 μ M melatonin increased potassium content in the seedling. Priming reduced the sodium content of seedling at salinity levels of 100 and 75 mM by 25 and 75 μ M melatonin concentrations respectively. Overall, the results of this study showed that chickpea tolerate salinity stress at germination stage up to 100 mM, and the use of melatonin at these stage due to salinity tolerance had not a significant effect on the physiological indices of the seeds, and only hydropriming in this condition compared to the non-primed by helping to absorb water by the plant has had a positive effect on the physiological process during germination.

The most important of growth phase of plants such as soybean coincide in the summer, which is usually exposed to stresses such as heat, and drought. It can supposed that the use of external component such as vitamins and melatoninto reduce the negative effects of stresses on plants and therefore increase yield. This study wase conducted as a factorial experiment based on completely randomized block design in three replications. Treatments including melatonin foliar application (0, 0. 1 and 0. 2 mM) and vitamins B group (0, thiamine, riboflavin, niacin, pantothenic acid and pyridoxine 100 mg / L). Effects of melatonin and vitamin B on total dry weight, yield, plasma membrane stability, leaf relative water content, chlorophyll a and b, carotenoids, flavonoids and anthocyanins were significant. Most of the traits were studied including seed yield, relative water content and chlorophyll in 0. 2 mM melatonin solution with pantothenic acid were significantly increased. The effect of pyridoxine was also significant. With increasing concentrations of melatonin with non-presence of vitamin B, the percent of protein and seed oil increased. Foliar application of 0. 1 and 0. 2 mM melatonin increased grain yield increased by 27% and 84%, respectively. According to the results of this experiment combination of Pantothenic acid and 0. 2 mM melatonin yield, plasma membrane stability, leaf relative water content, chlorophyll a and b, flavonoids and anthocyanins significantly increased.

In order to investigate and compare the allelopathic effects of Eucalyptus (E. globuhus Labill) leaf aqueous extract and leaf mulch on corn (Zea mays) and prosomillet (Panicum miliaceum), a factorial experiment was conducted in a completely randomized design with three replications at Ferdowsi University of Mashhad. The experiment was carried out to evaluate the allelopathic effects of leaf aqueous extract (5, 10, 15 and 20 g L-1 ) and leaf mulch (3 and 5% v/v) on some morphological, physiological and biochemical characteristics of the examined seedlings. Eucalyptus leaf extract (in most cases) and leaf mulch reduced the height of shoot, the total length of root as well as the dry weight of shoot and root. Also, the highest reduction percentage of these traits was observed under the application of 20 g L-1 aqueous extract on prosomillet. When treated with aqueous extracts, the Chl a, Chl b and total Chl, carotenoid contents and chlorophyll stability coefficient of corn seedling showed an incremental increase (in comparison to the control). Whereas, all photosynthetic traits of prosomillet decreased following the application of aqueous extracts and leaf mulch. Under both type of treatments, an increase and decrease of membrane stability coefficient were observed in corn and prosomillet, respectively. Although the highest accumulation of malondialdehyde was obtained in treated prosomillet seedling, the seedling of corn could significantly prevent the peroxidation of membrane lipids against the stress caused by leaf extract and mulch. Another result of this study was more increase effect of aqueous extract and mulch on total phenolic content of corn than prosomillet. Although both type of treatments decreased total protein content of corn and weed, the application of extract could have a better boundary between the sensitivity of species against the allelopathic stress. A significant reduction of nitrate reductase activity in prosomillet was recorded following the application of extracts and mulch. According to the results, leaf aqueous extract or mulch had different effects on biochemical, physiological and developmental traits of crop and weed. Considering the allelopathic potential of Eucalyptus leaf extract and leaf mulch on corn and prosomillet; it is recommended that aqueous extract can be an ideal candidate (compared to leaf mulch) as a natural herbicide to control prosomillet in corn fields.

Drought stress is one of the imperative limiting factors to plant growth and yield in dry conditions. Abscisic acid (ABA) is one of the most important plant regulators that plays a key role in many physiological and morphological responses under drought conditions. This experiment was carried out to evaluate the interaction between drought stress and ABA on the activity of phenylalanine ammonia-lyase (PAL) and some antioxidant enzymes in dragonhead (Dracocephalum moldavica). This research was conducted as split plot based on complete random block design at research farm of University of Zanjan, during 2016 growth season. Three moisture regimes (well-watered, moderate drought with delay irrigation up to-0. 8MPa and severe drought with delay irrigation up to-1. 5MPa) were set as main plots and five ABA concentrations (0, 5, 10, 20 and 40 µ M) were sets as subplots. The results of this study showed that the effect of watering regimes, ABA and interactions between watering regimes and ABA was significant for PAL, catalase (CAT), ascorbate peroxidase (APX) as well as peroxidase (POD) activity, lipid peroxidation, leaf area, total dry weight, plant height and seed yield. Without ABA application, moderate and severe drought stress, increased up to 15. 02 and 30 percent PAL activity, 28. 02 and 25. 44 percent CAT activity, 48. 81 and 35. 55 percent APX activity and 77. 83 and 88. 3 percent POD activity compared to the well-watered condition. Also, exogenous ABA application increased lipid peroxidation and antioxidant enzymes activity compared to the control (no ABA application). Without ABA application the moderate and severe drought stress, reduced seed yield by 19. 69 and 31. 02 percent, respectively, compared to the well-watered condition. There was a decreasing trend in seed yield in response to an increase in ABA concentration. The amount of seed yield reduction in plants treated with different concentrations of ABA, 5. 18-14. 69 percent under well-watered conditions, 4. 22-20. 74 percent under moderate drought conditions and 4. 37-33. 83 percent under severe drought conditions compared to the non-treated plants.

Since supplemental UV-B radiation can provide a simple and economical alternative to increase phenolic compounds in plants, we evaluated the dynamic biological responses of Alo vera L. plants to different UV-B doses (10 and 30 kJ m − 2 − 1 day ). The experiment was performed on the basis of Completely Randomize Design with 4 independent replications. Under high light conditions (600 µ mol m − 2 − 1 s ), UV-B radiation at 30 kJ m − 2 − 1 day caused significant damaging effects in the Alo plants in terms of leaf biomass. This reduction of leaf biomass was coupled with lower values of photosynthetic performance index (PIabs) as well as higher levels of malondialdehyde (MDA). However, when plants were grown at 10 kJ, UV-B-induced increase of proline and soluble sugar content was detected in Alo leaves. In addition, plants treated with 10 kJ m − 2 − 1 day UVB dose manifested a significant phenol content enhancement compared to the control plants. Most importantly, a significant correlation was observwd between accumulation of leaf phenolic compound and their antioxidant potential, when UV-B radiation was applied at 10 kJ. Our data suggested that an improved accumulation of phenolic compounds could be achieved when UV-B radiation was applied at 10 kJ within 21 days. This can be used to apply UV-B radiations to improve the nutritional quality of Alo leaves by increasing accumulation of phenolic compounds, without affecting the efficiency of photosynthetic apparatus.

Salinity stress is one of the environmental factors that limits plant growth and development and has negative effects on morphological and physiological parameters of plants. Therefore, various compounds have been used to reduce the harmful effects of this stress. According to previous studies, metal nanoparticles have both negative and positive effects on different plant species. The aim of this study was to investigate interaction effects of different concentrations of ZnO nanoparticle and NaCl on morphological parameters, photosynthetic pigments and protein content in Ardestanian and Mashhadian cultivar of Fenugreek. Factorial experiment was performed in a completely randomized design with three replications and three levels of ZnO nanoparticle (0, 1000 and 3000 ppm) and four levels of NaCl (0, 75, 150 and 225 mM) were used. The results showed that salinity stress significantly decreased shoot and root fresh weight, as well as the percentage of relative root water content at 225 mM NaCl in both cultivars. The highest fresh weight of shoot in Mashhadian cultivar was observed in the interaction of 75 mM NaCl and 1000 ppm of ZnO nanoparticle. In general, ZnO nanoparticles improved fresh and dry weight in both cultivars. In Ardestanian cultivar, the highest amount of phenol was observed in the concentration of 3000 ppm of nanoparticle and 225 mM NaCl, also, the highest flavonoid content was observed in the interaction of 3000 ppm of nanoparticle and 150 mM NaCl. The highest photosynthetic pigments were observed at interaction of 75 mM NaCl and 3000 ppm of nanoparticle in two cultivars. Also, Increasing the concentration of nanoparticle led to a significant increase in carotenoids in both cultivars. The most antioxidant activity based on IC50 was in Mashhadian cultivar and in the interaction of 225 mM NaCl and 3000 ppm of nanoparticle. The results of this study showed that the application of ZnO nanoparticle under salt stress improved plant growth.