فصلنامه فرآیند و کارکرد گیاهی
سال نهم شماره 6 (پیاپی 40، Feb and Mar 2020)

Chromium-VI would impose detrimental effects morphological, physiological, and metabolic in plants. This study aimed to research the impact of citric acid (0, 2.5 and 5 mM), on different the morphological and physiological characteristics of garden cress exposed to chromium-VI stress (0, 1, and 10 mM). Results showed that some growth parameters, chlorophyll, carotenoids, and DPPH activity decreased under chromium, while anthocyanine increased. Also, results showed that the use of citric acid improved the parameters affected by chromium so that the addition of citric acid (2.5, and 5 mM) with chromium (10 mM) significantly enhanced some growth parameters, chlorophyll, carotenoids while a similar increase was observed in the combination of 1 mM chromium and 2.5 mM citric acid, 5 mM citric acid in combination with 1 mM chromium reduced some growth parameters, chlorophyll, carotenoids. The addition of 2.5 and 5 mM citric acid along with chromium 1 and 10 mM significantly decreased anthocyanin content, as compared to chromium alone. Besides, our results showed that citric acid 2.5 and 5 mM alleviated this adverse effect of chromium 1 and 10 mM on DPPH activity. The results also showed that at high chromium concentrations in the soil, the rate of accumulation of this metal in the shoot parts is declining. This means that the transfer from the root to the shoot will increase under the affection of citric acid at high chromium concentrations but in low concentrations of chromium, citric acid reduced the concentration of chromium in the shoot parts considering the chromium uptake and translocation factor results, garden cress in low chromium concentrations, it is suitable for phytoremediation, but in high chromium concentrations, it is not recommended for phytoremediation. Hence, the citric acid played this role through the regulation of the antioxidant system to diminish the toxicity of chromium-VI.Chromium-VI would impose detrimental effects morphological, physiological, and metabolic in plants. This study aimed to research the impact of citric acid (0, 2.5 and 5 mM), on different the morphological and physiological characteristics of garden cress exposed to chromium-VI stress (0, 1, and 10 mM). Results showed that some growth parameters, chlorophyll, carotenoids, and DPPH activity decreased under chromium, while anthocyanine increased. Also, results showed that the use of citric acid improved the parameters affected by chromium so that the addition of citric acid (2.5, and 5 mM) with chromium (10 mM) significantly enhanced some growth parameters, chlorophyll, carotenoids while a similar increase was observed in the combination of 1 mM chromium and 2.5 mM citric acid, 5 mM citric acid in combination with 1 mM chromium reduced some growth parameters, chlorophyll, carotenoids. The addition of 2.5 and 5 mM citric acid along with chromium 1 and 10 mM significantly decreased anthocyanin content, as compared to chromium alone. Besides, our results showed that citric acid 2.5 and 5 mM alleviated this adverse effect of chromium 1 and 10 mM on DPPH activity. The results also showed that at high chromium concentrations in the soil, the rate of accumulation of this metal in the shoot parts is declining. This means that the transfer from the root to the shoot will increase under the affection of citric acid at high chromium concentrations but in low concentrations of chromium, citric acid reduced the concentration of chromium in the shoot parts considering the chromium uptake and translocation factor results, garden cress in low chromium concentrations, it is suitable for phytoremediation, but in high chromium concentrations, it is not recommended for phytoremediation. Hence, the citric acid played this role through the regulation of the antioxidant system to diminish the toxicity of chromium-VI.Chromium-VI would impose detrimental effects morphological, physiological, and metabolic in plants. This study aimed to research the impact of citric acid (0, 2.5 and 5 mM), on different the morphological and physiological characteristics of garden cress exposed to chromium-VI stress (0, 1, and 10 mM). Results showed that some growth parameters, chlorophyll, carotenoids, and DPPH activity decreased under chromium, while anthocyanine increased. Also, results showed that the use of citric acid improved the parameters affected by chromium so that the addition of citric acid (2.5, and 5 mM) with chromium (10 mM) significantly enhanced some growth parameters, chlorophyll, carotenoids while a similar increase was observed in the combination of 1 mM chromium and 2.5 mM citric acid, 5 mM citric acid in combination with 1 mM chromium reduced some growth parameters, chlorophyll, carotenoids. The addition of 2.5 and 5 mM citric acid along with chromium 1 and 10 mM significantly decreased anthocyanin content, as compared to chromium alone. Besides, our results showed that citric acid 2.5 and 5 mM alleviated this adverse effect of chromium 1 and 10 mM on DPPH activity. The results also showed that at high chromium concentrations in the soil, the rate of accumulation of this metal in the shoot parts is declining. This means that the transfer from the root to the shoot will increase under the affection of citric acid at high chromium concentrations but in low concentrations of chromium, citric acid reduced the concentration of chromium in the shoot parts considering the chromium uptake and translocation factor results, garden cress in low chromium concentrations, it is suitable for phytoremediation, but in high chromium concentrations, it is not recommended for phytoremediation. Hence, the citric acid played this role through the regulation of the antioxidant system to diminish the toxicity of chromium-VI.

Cold stress is an ‎important limiting factor for cereal production. Barley is a host species for arbuscular mycorrhizal fungi (AMF) with a high genetic diversity in response to cold stress. In order to explore the mechanisms for the ameliorative effect of AMF under cold stress, an experiment was undertaken using completely randomized block design with three factors including temperature treatment, AMF inoculation and plant cultivar. Two spring barley cultivars with different cold tolerance (‘Reyhan’ as tolerant and ‘Torkaman’ as susceptible) were inoculated with two AMF species (Diversispora versiformis and Rhizophagus irregularis) and grown under chilling (CH, 5 °C) and freezing (FR, ‒5 °C) temperatures for three weeks. Dry matter production, photosynthesis rate, and membrane ‎integrity parameters decreased, while the antioxidant defense and the synthesis of phenolics ‎were activated under CH stress. Inoculation of plants with AMF alleviated the adverse ‎effects of CH stress on growth and membrane parameters, while exacerbated CH effect on ‎the antioxidant system and phenolics accumulation. Plants could not survive FR stress when ‎they were not cold acclimated through prior exposure to CH treatment, unless they were ‎inoculated with AMF which results in survival rates almost similar to cold-acclimated plants. Our results suggested that AMF alleviated CH stress through ‎reducing H2O2 and improving membrane integrity while the ‎substituting effect of AMF for cold acclimation and increasing FR survival was mediated by the activation of antioxidant ‎defense and phenolics synthesis and accumulation of proline.

Understanding the relationships between biochemical contents and morpho-phenological aspects of a plant during life cycle would be helpful for doing precise agricultural practices through its cultivation. In the present study, various biochemical parameters were evaluated in relation to bulb storage, shoot growth and florogenesis in Iranian lily (Lilium ledebourii var. Kelardasht Salehi1). Ten plants from each sampling were examined at intervals of 10 days throughout an annual life cycle. Results showed that starch hydrolysis commenced in the late stage of storage and reached the maximum level at flower initiation time. It was concomitant with the increase of amylase activity, indicating that the change of starch content in the bulbs is regulated by amylase. The accumulation of soluble carbohydrates in the bulbs during shoot growth and stem elongation period (from 50 days after planting to the next 50 days) did not result from starch hydrolysis. A great deal of starch accumulation occurred mainly just during ten days before shoot withering. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the protein bands during bulb storage were different from those after planting. Moreover, it also revealed that a certain protein was expressed in bulb at anthesis stage. Our results recommend that the protection of aerial organs until complete withering seems to be necessary for higher energy reservation in the bulbs of L. ledebourii.

Drought stress influences seed germination and seedling growth of many plants. Seed coating is technique of covering seeds with adhesive agents to improve seed performance and plant establishment and could be used to alleviate the negative effects of osmotic stress. In order to solve the problem of low germination and poor vigor of sweet corn under osmotic stress conditions (0, -0.3, -0.6 and -0.9 MPa), film coating with different concentration of sodium alginate (NaAlg) (0, 1 and 2%) were performed. Results showed that osmotic stress reduced percentage and rate of germination, seedling length, seedling vigor index and soluble protein content and also increased the content of proline and soluble sugars. In all levels of osmotic stress, coating with NaAlg 1% improved germination and biochemical indices of sweet corn seeds compared to NaAlg 0 and 2%- and non-coated seeds. The highest percentage of germination (67 %) was related to osmotic potential of 0 MPa and the lowest germination percentage (36 %) was observed in the osmotic potential of -0.9 MPa. The highest (19.17 mg g-1 FW) and the lowest (6.68 mg g-1 FW) amount of soluble protein were obtained from NaAlg 1% at 0 MPa and NaAlg 0% at -0.9 MPa, respectively. The results suggested that seed coating with NaAlg 1% could serve as an appropriate treatment to increase the germination and early seedling growth of sweet corn under osmotic stress conditions.

The experiment was conducted in factorial test based on a completely randomized design with three replications in greenhouse of Isfahan University of Technology of Iran. Lettuce seedlings were exposed separately to the exhaust emissions in three different exposure times (10, 20 and 30 days) and after the exposure time, their morphological, physiological and anatomical traits were measured and compared with morphological, physiological and anatomical traits of control plants. Results obtained in lettuce, showed significant increases in traits including catalase, ascorbate peroxidase, guaiacol peroxidase, proline, electrolyte leakage, relative water content and number of stomata and significant decreases in photosynthetic factors, leaf area, height, aerial fresh and dry weight and length of stomata in lettuce plants which were exposed to gases for 30 days, compared to controls. Significant increase in the photosynthetic rate, stomatal conductance, CO2 intracellular concentration and leaf area of lettuce seedlings were exposed to emissions for 10 days, most likely, indicate the nutritional role of output gases from generator in the short period time of exposure. It was observed that the anatomical features of contaminated samples have been changed by gases in 30-days exposure plants compared to others. The results showed that the exposure of lettuce plants to gases, especially 30-days exposure, caused morphological, physiological and anatomical reactions due to contaminants that could be considered these reactions as the adaptation of these plants to the stress of contamination, in order to adapt or to deal with stress conditions and thus to survive the plant under pollution stress conditions.

The aim of the present research is to investigate the profile of amino acid of Chlorella vulgaris supplemented with some plant amino acid and oil extracts. The bioactive oil and amino acid from four Iranian medicinal plants, namely Oliveria decumbens, Thymus kotschyanus, Trachyspermum ammi, and Zataria multiflora were obtained. The LC-MS / MS analysis demonstrated that the major amino acids component of Chlorella vulgaris were alanine (30.4 mg/g), glycine (23.2 g/g), glutamic acid (22.7 mg/g), aspartic acid (21.1 mg/g), arginine (20.9 mg/g), leucine (18.9 mg/g), lysine (16.5 mg/g), phenylalanine (14.0 mg/), serine (13.0 mg/g), asparagine (12.7 mg/g), valine (12.6 mg/g),  isoleucine (11.5 mg/g), and tyrosine (11.0 mg/g). The major fatty acids of the plants considered are 9, 12, 15-octadecatrienoic acid, 9, 12-octadecadienoic acid, 9-octadecenoic acid, and hexadecanoic acid but with different concentrations. The major non-fat components (lipophilic monoterpenoid) detected in the oils were thymol and carvacrol with different concentrations. Vegetable oils mainly composed of polyunsaturated fatty acids and reduced amino acid contents in Chlorella vulgaris. The main amino acids from plant-derived protein hydrolysate were aspartic acid, glycine, glutamic acid, leucine, alanine, lysine, arginine, serine, phenylalanine, valine, proline, and histidine but with a different level.  Vegetable amino acids mainly composed of functional amino acids and significantly enhanced amino acid production in Chlorella vulgaris. Zataria multiflora, Trachyspermum ammi and Thymus kotschyanus amino acid supplementations as nitrogen and carbon sources also exhibited the same and better effects on the amino acid profile compared to the Oliveria decumbens amino acid supplementation.

Common purslane is a warm season plant which had a lot of medicinal properties. An experiment was conducted as a split plot design arranged  in completely randomized block design with three replications in the research field of Agricultural Sciences and Natural Resources University of Khuzestan during 2015-2016. In this experiment, the main plots consisted of four levels of irrigation intervals (5, 10, 15 and 20 days), and the sub-plots included four different types of fertilizers (no fertilizer, chemical fertilizer, chicken manure, and cow manure). The results indicated that five-day irrigation interval exhibited the best results for the most of the traits. Among different types of fertilizers, chemical fertilizer and chicken manure had relatively the highest dry weight of plant, stem, leaf, stem length, number of sub-stems and leaf protein content. The results of this study revealed that in semi arid region such as Khuzestan with low rainfall, the 10-day irrigation interval could be an appropriate alternative for 5-day irrigation interval. Chicken manure not only provide the highest yield, but also it can reduce the amount of chemical fertilizer inputs to the purslane farms.  In addition to an acceptable yield, it can be a great step towards environmental health and, finally sustainable agriculture through reducing application of chemical fertilizers.