نشریه زیست شناسی کاربردی
سال سی و چهارم شماره 4 (زمستان 1400)

Plants pre-treatment with various chemicals has often been used to diminish salinity stress impact on plants. In the present study, we used foliar spray of two antioxidant compounds (β -carotene and gallic acid) before the stress, to study interactive effect of antioxidants and salinity stress in seedlings of Lepidium sativum L. Our results showed growth indices, relative water content (RWC), chlorophyll a, chlorophyll b and chlorophyll a/b were negatively affected by 25 mM NaCl. The results obtained in the present study showed the beneficial effects of the pre-treatments of two antioxidants in of Lepidium sativum L. seedling under non salinity stress condition with respect to increasing root dry weight, RWC, photosynthetic pigments and the content of carbohydrate. The results suggested that foliar spray of β -carotene and gallic acid could considerably diminish NaCl-caused stress on Lepidium sativum L. seedlings, probably due to higher accumulation of plant biomass, photosynthetic pigments, RWC and carbohydrate content, as well as significant reduction of H2O2 and malondialdehyde (MDA) content. Collectively, it could be concluded that, the accumulation of osmotic metabolites and the intensification antioxidant systems during β -carotene and gallic acid -mediated pretreatments can diminish the deleterious effects of reactive oxygen species (ROS) induced by NaCl stress through preventing the lipid peroxidation and scavenging cytotoxic H2O2. Therefore, usage of antioxidant compounds as a pretreatment under salinity stress may be advantageous for increasing biomass and osmotic adjustment in Lepidium sativum L. seedlings

Phosphate fixation by chemical fertilizers, in addition to being costly, carries environmental risks. Today, fertile phosphate biofertilizer 2 contains two types of phosphate-solubilizing bacteria, decomposes insoluble phosphorus compounds and thus absorbable for the plant. The aim of this study was to evaluate the effect of fertile biofertilizers 2 Pseudomounas putida (Strain P13) and Pantoea aggilomerans (Strain P5) (only once at the beginning of the growing season) and potassium phosphate in three concentrations (0, 1.2 mM, 5 mM) (Until the end of the growing season,once a week with irrigation) on some developmental characteristics of Arabidopsis thaliana in greenhouse conditions, 15 hours of light, temperature 25 ° C, light intensity of 6000 lux was done in a randomized design. After cell-histology, slides were observed under a light microscope. The results showed a significant reduction in wood vascular density in the stems of plants treated with 5 mM and 1.2 mM potassium phosphate compared to the other two treatments. Also, 5 mM potassium phosphate increased the tunica layers and the special wall thickness of the tetrads. Cell proliferation of ovule primordium, pre-embryo, and suspensor was observed in plants treated with biofertilizer and 5 mM phosphate. Treatment with biofertilizer showed the highest average number of seeds produced. The application of fertile biofertilizer 2 in this experiment, with effects similar to potassium phosphate, increased the quantitative and qualitative yield of Arabidopsis. Biofertilizer can be effective as a safe alternative to increase soil productivity and plant growth in sustainable agriculture and minimize environmental pollution.

The use of chemical compounds to increase and maintain vegetative and reproductive growth in horticultural products has become common. Humic acid is an organic substance that stimulates growth due to the release of nutrients. In this study, the effect of humic acid with concentrations of 50 and 100 mg/L in two stages 30 and 45 days after flowering, were sprayed on pistachio trees of Akbari cultivar. Then, characteristics such as leaf area, chlorophyll index, branch length and diameter of the current year, percentage of hollow, split rate, percentage of deformed fruits, fruit weight, cluster weight and number of fruits per cluster, and yield were studied. The results showed that the highest leaf area, length and branch diameter were related to pistachio trees with 100 mg /L humic acid in 30 days after full flowering stage. The lowest percentage of hollow was observed in fruits treated with humic acid 50 mg /L. The highest cluster weight and number of fruits per cluster was observed in trees treated with humic acid 100 mg /L. The highest cluster weight and number of fruits per cluster was observed in trees treated with humic acid 100 mg /L. Increased yield and fruit weight in both treatments were observed with increasing humic acid concentration up to 100 mg/L. The percentage of deformed fruits in control fruits increased in both stages of foliar application compared to fruits treated with humic acid.

Polyhydroxy alkanoates are biodegradable and biocompatible polymers produced by a wide range of bacterial strains. In the present study, the natural strain of Bacillus cereus producing polyhydroxybutyrate-co-valerate (PHBV) copolymer with high productivity isolated from starch effluent was used. In order to produce, starch effluent was studied as a cheap and expensive culture medium. Then, by examining the effective factors, the optimal composition of the culture medium was evaluated and in order to achieve higher productivity, the culture method with high cell density was evaluated. The results showed that the mean maximum production of PHBV using the platelet-Berman test design method (culture medium related factors) was about 3.07 g / l (59.5% of cell dry weight). Subsequently, by optimizing culture with high cell density, the production rate increased to 4.45 g / l (more than 72% of dry cell weight). Therefore, it can be concluded that the high-density cell culture method has a significant effect on increasing the productivity of PHBV production by B. cereus. Due to the use of cheap culture medium and the cost of wastewater, the importance of these results is twofold and shows the potential for production on an industrial scale.

The purpose of this study, allelopathic potential assessment of aqueous extract of root, stem, leaf and flower organ of Fumaria parviflora weed on morpho-physiological and biochemical characteractics of Lolium rigidum seedling in hydroponic culture. First, 5% suspension was prepared separately from the organs with help of distilled water and then the resulting suspension solution (extract) was applied on 7 day old of seedlings of Lolium rigidum. Based on the results, various organs of Fumaria parviflora had significant inhibitory effect on growth indices of root length and seedling dry weight, content of chlorophyll b and carotenoids of Lolium rigidum. In most cases, the most inhibitory effect was related to leaf and flower organ extract. But content of prolin, soluble sugar and phenolic compounds were increased compared to control. The greatest increase in these compounds were obtained under leaf and flower organs of Fumaria parviflora. Therefore, by identifying the components of Fumaria parviflora and experiment on other species, maybe be a candidate for production of natural herbicide or proposed a model for the synthesis of herbicides.

In order to investigate the genetic diversity and the heritability of oil and protein content of seed in lines of sesame under different irrigation regimes and mycorrhizal fungi, 8 lines of sesame were studied in three separate experiments as factorial split plot layout based on a randomized block complete design with three replications in research field of Agricultural Research Center, West-Azerbaijan in 2015 and 2016 cropping seasons. The main plots (factor A and B) consisted of three different irrigation regimes and factor B included three levels: two species of mycorrhiza fungi Glomus mosseae, Glomus intraradices and non-inoculated (control). Sub plots (factor C) consisted of eight sesame lines. Studied traits were including oil percentage and yield, protein percentage and yield, nitrogen percentage and chlorophyll index. Under optimum irrigation conditions, the maximum heritability was observed for protein percentage (0.88) and chlorophyll index (0.79) in inoculation with mycorrhizal fungi G. mosseae. Also, under moderate drought stress, the highest heritability was observed in chlorophyll index (0.70) and protein percentage (0.63) in inoculation with mycorrhizal fungi G. mosseae. In nine different environments of experiment, the maximum genetic variation of traits was observed for chlorophyll index, oil yield and protein yield. In all three irrigation conditions, the most phenotypic, genetic and environmental variance was observed in traits of chlorophyll index and protein yield. Therefore, with selecting traits such as chlorophyll index and protein percentage in breeding programs would improve oil and protein yield.

Today bioremediation by microalga is an effective method to remove radionuclides and heavy metals from wastewater. Bioremediation of radionuclides and heavy metals is an efficient method of treating heavy metal contaminated effluents. In this study, the bioremediation of uranium from aqueous solutions was evaluated using live microalgae Chlorella vulgaris in a batch system. The Plackett-Burman method by Minitab statistical software was used to screen for effective factors such as initial uranium concentration, temperature, time, pH and amount of biomass on the removal of uranium by C. vulgaris. The results showed that the initial uranium concentration and pH factors were statistically effective by software. Optimization of effective factors in uranium bioremediation was evaluated by the response surface methodology (RSM). To determine the main effects and interaction of factors affecting uranium removal by C. vulgaris, central composite design (CCD) was used. The experimental data were then processed and the equation was evaluated to match the experimental data, and then the optimal removal values were determined. Finally, the results showed that C. vulgaris in optimal conditions proposed by Design-Expert software can remove 99.63% of existing uranium from aqueous solutions containing 7.1 mg / l uranium with pH 4.3.

Bacillus thuringiensis var. kurstaki (Btk)is used for control of sugar beet army worm larvae, Spodoptera exigua Hb. in large-scale. Using high doses for more effective control increases the likelihood of developing resistance. The use of plant and physical compounds with this bacterium as an effective method to reduce the dose of Btk and increase its effect is of great importance and place in integrated pest management programs. Therefore, in order to reduce the use of Btk and increase its efficiency in mixing with silica nanoparticles and Neemarin to control the larvae of the second larval of sugar beet in labratory condition were evaluated. The LC50 value by probit analysis of different concentrations of Btk, silica nanoparticles and neemarin after 24, 48 and 72 hours (2252.39, 3219.22, 1608.15), (1483.31, 1852.49, 793.35) and (724.78, 982.28, 393.71) mg. L.-1 were obtained, respectively. The highest and lowest mortality in the treatment of Btk combination with neemarin (LC25, NE+LC25, Bt) (%66) and the control treatment (distilled water) (%2) after 75 h were observed. Also in the assessment of damage according to the mean of treatments, the most damage in the control treatment (%55.3) and the least damage in the treatment of Btk combination with neemarin (LC25, NE+LC25, Bt) (%15) after 5 day were obtained. In this study, due to the increase in Btk efficiency in combination with neemarin, the combination of these two factors in order to manage resistance and sustainable control of sugar beet army worm larvae and susceptible pests is recommended.

The purpose of the current study was to investigate the effect of carbon nanotubes on morphological traits of two wild pistachio species and compare them with common treatments including cold and acid sulfuric 65% in a completely randomized design with eight treatments and 10 replicates. The results showed that application of carbon nanotubes with concentrations of 25 and 75 mg / L significantly improved the morphological and biomass traits of the two species of wild pistachio including (Pistacia atlantica Desf ) and (P. khinjuk Stocks) in comparison with the acid and cold treatments. The highest increase in root, stem height and collar diameter was observed in the 25 mg / L treatment. The highest root length and dry and fresh root biomass were observed in Khinjuk under 75 mg/L nano carbon treatment. The highest concentration of leaf magnesium was observed in P. atlantica after 10 and in P. Khinjuk after 100 mg/L treatments. The phosphorus content in leaves of the two wild pistachio species was stable under the all treatments. The leaf potassium in P. atlantica was the highest under 10, 25, and 50 mg/L treatment and it was the highest in leaves of P. Khinjuk under 75 mg/L treatment. Although the current research proved the positive impacts of carbon nanotubes on growth of the wild Pistachio species, the further research can be suggested to find strategies for enhancing the growth of wild pistachio species to commercialize the products of these valuable species.

L-asparaginase is an enzyme that catalyzes the hydrolysis of asparagine into aspartic acid and ammonia and is one of the most important enzymes in the pharmaceutical and food industries. The goal of this study was the isolation and identification of asparaginase producing endophytic fungi from Salvia nemorosa and the determination of their enzyme activities. In this study, different species of endophytic fungi were isolated from healthy leaves of S. nemorosa. A qualitative assay of asparaginase enzyme was performed on asparagine agar medium and its quantitative assay was performed on Czapexdox's medium by spectroscopic method with Nessler reagent. Morphological and molecular investigations indicated that the obtained isolates belonged to genera of Alternaria, Stemphylium Talaromyces, and Linnemannia . Different species were shown to be able to produce the asparaginase by creating a pink to a red color zone. Alternaria alternata was selected as the best enzyme-producing isolate by producing 2.34 U/mg asparaginase in Czapexdox's medium, and could be considered as a potential source for enzyme production.