فصلنامه گیاه و زیست فناوری ایران
سال هجدهم شماره 3 (پاییز 1402)

The Law on Protection, Restoration, and Management of Soils in Iran was approved in 2019. This law consists of 44 articles and 127 notes and aims to protect biodiversity, improve soil quality, and enhance environmental health. According to this law, the Environmental Protection Organization can issue warnings to polluters to take necessary actions to remove and remediate contamination sources, restore the soil, and compensate for the damage caused within a certain deadline. If stakeholders object to the warning or order issued by the organization, they can request an extension of the mentioned deadline from the organization once. The Environmental Protection Organization is responsible for identifying soil-polluting units and documents such as soil pollution tests, reports from industry representatives, and reports from the Environmental Protection Organization on the status and extent of soil contamination are admissible as evidence in court. Determining the deadline for removing and remedying contamination sources is difficult due to complex and variable factors in the process of discharging pollutants and their impact on soil and the environment. The type, chemical and physical composition, amount, type and characteristics of the soil, weather conditions, and environmental and geographical differences are all important in determining a specific deadline. For each type of pollutant, specific analyses must be performed to determine an appropriate removal and remediation deadline. Therefore, no specific deadline or time frame exists in the reviewed resources, and giving a specific time is impossible due to the frequency of factors. Ultimately, removal and remediation of contamination sources must take place in the shortest logical and practical time possible, and failure to do so will result in heavy penalties for the polluter.

Frequent and excessive use of antibiotics has caused the resistance of pathogenic bacteria to common antibiotics. Considering this issue, researchers are looking for new methods to replace antibiotics, which can be referred to as antimicrobial peptides (AMP). Therefore, the aim of the present study was bioinformatic investigation of the effect of his taq addition on the antibacterial activity of plant beta-defensin peptide and clone this peptide gene in the expression vector pAMJ1653 in Lactococcus lactis bacteria. The third structure of beta defensin peptide with his-taq was predicted through I-TASSER and verified by SAVE 6 and prosA software. Finally, molecular docking was performed through Cluspro software between beta defensin with /without his-taq sequence and Escherichia coli LPTD antigen. In the exprimental section, beta defensin gene was used along with his-taq sequence and secretion signal in pGEM-DFF replication vector and DH5α replication host. After plasmid extraction and enzymatic digestion by Sap1 and Sal1 enzymes, plant beta defensin gene was homogenized into pAMJ1653 expression vector and transferred into Lactococcus lactis strain 1543 bacteria using electroporation method. The positive colonies containing the recombinant vector were checked by PCR colony method and finally enzymatic digestion was performed. In the bioinformatics part, the third structure of beta defensin was predicted with acceptable accuracy. Docking results showed that beta defensin peptide with/without his-taq is in contact with LPTD antigen in the right position. In the laboratory section, it was shown that the gene encoding plant betadefensin was successfully cloned in the pAMJ1653 expression vector

This study was conducted in order to investigate the efficiency of antioxidant systems of cotton mutant genotypes under irrigation water salinity conditions in the form of split plots based on a randomized complete block design with three replications. The treatments included irrigation with salinities of 4 (control), 8 and 12 ds.m-1 as main plots and two or three Shayan genotypes, mutant LM1673 and LM-1303 as sub-plots. The results showed that salinity increased the amount of hydrogen peroxide and malondialdehyde in cotton cultivars, and then the amount of enzymatic and non-enzymatic antioxidants also increased. The increase in the production of hydrogen peroxide and malondialdehyde in salinity of 12 decisiemens/m decreased the chlorophyll index, especially in sensitive cultivars. Also, the results showed that the highest amount of nonenzymatic antioxidants such as proline, ascorbic acid, phenol, flavonoid and anthocyanin was obtained in the irrigation conditions with salt water with a salinity of 12 ds.m-1 . The highest level of catalase enzyme activity was in LM-1303 cultivar and at the salinity level of 12 ds.m-1 . The highest level of activity of superoxide dismutase and glutathione reductase enzymes was obtained in the salinity treatment of 8 ds.m-1 . Based on the results, it was found that the variety LM-1303 has the most sensitivity to salinity stress, and in irrigation water salinity, due to the increase in lipid peroxidation caused by the production of hydrogen peroxide and malondialdehyde, the amount of nonenzymatic antioxidants and the amount of activity of enzymatic antioxidants for overcoming oxidative stress increases

Sweet pepper is a rich source of antioxidant compounds such as phenolic compounds, vitamin C and carotenoids. Environmental factors such as nutrition affect the growth, fruit yield, and fruit quality of pepper. This study was conducted in the form of a randomized complete block design with three replications and four fertilizer treatments. Fertilizer treatments include NPK 20:20:20 chemical fertilizer at the rate of 6 grams per 6 square meters, Arghavan biofertilizer at the rate of 72 ml per 6 square meters, and combined treatment of NPK chemical fertilizer and Arghavan biofertilizer at the rate of half of each two fertilizers and the control treatment. The obtained results showed that the combination of Arghavan biological fertilizer and NPK chemical fertilizer significantly increased the average values of vegetative growth traits such as plant height, stem diameter, fresh and dry weight of stem, fresh and dry weight of roots, relative water content, Leaf chlorophyll index, total leaf chlorophyll content, leaf carotenoid content, single fruit weight, and fruit yield compared to the control treatment and in many traits such as stem diameter, stem fresh and dry weight, root fresh and dry weight, single fruit weight, length And fruit diameter, fruit yield, chlorophyll index, carotenoid content were equal to chemical fertilizer treatment. By using the combination of Arghavan biofertilizer and chemical NPK, the physiomorphological indicators of bell pepper increased. Also, by using Arghavan biofertilizer, you can reduce the use of chemical fertilizer, which is a move in the direction of sustainable agriculture, releasing blocked food in the soil and reducing the environmental pollution.

This experiment was conducted to study the effect of seed pretreatment by salicylic acid under drought and salinity stress conditions on germination and growth characteristics of Badrashbo seedlings in 1400 at Islamic Azad University, Khorramabad branch. This study was conducted as two separate experiments with common pretreatment of salicylic acid and separate treatments of drought and salinity stress. Both experiments were conducted as a factorial in a completely randomized design with three replications. The treatments of the first experiment included salicylic acid at 3 levels (0, 0.1 and 0.5 mM) and drought at 4 levels (0, -0.1, -0.3 and -0.5 MPa). The treatments of the second experiment included salicylic acid at 3 levels (0, 0.1 and 0.5 mM) and salinity at 4 levels (0, -0.2, -0.4 and -0.8 MPa). At the end of 12 days of counting, germination and growth characteristics of seedlings were evaluated. The results showed that in both experiments, the effects of the factors on the characteristics of percentage and speed of germination, length of root and shoot, and seed germ were significant. Among the levels of salicylic acid, pretreatment with 0.5 mM concentration had the highest percentage and germination rate, root length, shoot length and seed germ. In the non-drought treatment, pre-treatment with salicylic acid did not lead to a significant increase in the examined traits compared to no pre-treatment, and in the drought stress treatment, the pre-treatment caused a significant increase in all the examined traits. Also, among the levels of salicylic acid, pretreatment with a concentration of 0.5 mM produced the highest percentage and germination rate. In the absence of salinity and drought stress, salicylic acid with a concentration of 0.1 mM had the longest root and shoot length, and the increase in salinity and drought caused the increase in the concentration of salicylic acid to have a negative effect on root length. In general, the results showed that pretreatment of seeds with salicylic acid in areas prone to drought and salt stress can accelerate the germination of fennel seeds and lead to an increase in the percentage of seed germination .

In order to investigate the effect of salicylic acid foliar application on the vegetative and physiological traits and the amount of essential oil of peppermint plant (Mentha piperita L.) under salinity stress conditions, a factorial experiment was conducted based on a completely randomized design in three replications in a greenhouse located in the north of Iran. The treatments included Foliar spraying of salicylic acid (zero, 50 and 100 mg/l) and salinity stress (zero, 50, 100 and 150 mg/l of sodium chloride) were the salinity stress at the six-leaf stage twice a week in the form of irrigation and foliar spraying of salicylic acid. It was applied in three stages of the four-leaf stage at a time interval of 10 days. The results showed that all the evaluated traits were significant at the level of 1 and 5%, increasing the salinity steress reduced all the evaluated traits except proline and salicylic acid foliar application had a positive effect on improving these traits under stress conditions. Fresh and dry weight of shoots and roots, plant height, total chlorophyll and essential oil percentage in salicylic acid treatment 100 mg/l and control salinity level and maximum root length in salicylic acid treatment 100 mg/l and the salinity level of 50 mg/l were obtained. Also, the highest content of phenol and flavonoids was observed in the treatment of salicylic acid 50 mg/l and the salinity level of 50 mg/l, and in the treatment of salicylic acid 100 mg/l and the salinity level of 150 mg/l the highest proline was observed. Therefore, according to the results of the present study, foliar application of salicylic acid at a concentration of 100 mg/l can be recommended to reduce the negative effects of salinity stress on peppermint.