دکتر علیرضا عباسی

Leaf rust, caused by the pathogenic biotrophic fungus Puccinia triticina (Pt), is one of the most destructive wheat diseases worldwide and its negative impact on crop yields is exacerbated by higher temperatures due to climate change. Ascarosides are nematode pheromones with resistance-inducing activities against microbial pathogens and pests in various crops. We investigated the effect of ascaroside ascr#18, the major ascaroside of plant-parasitic nematodes, on infection of cv. Boolani wheat (Triticum aestivum L.) with the virulent Pt race PKTTS. After spraying with ascr#18 in the micromolar concentration range 24 hours before inoculation with fungal uredospores, the number of rust pustules on ascr#18-treated wheat leaves was greatly reduced, by 55 to over 80%, showing that ascr#18 can induce resistance in wheat to Pt. Pretreatment with ascr#18 also further enhanced the expression of defense marker genes PAL and Chitinase 3 in response to Pt as compared with untreated Pt-infected plants. Our results are consistent with and further extend previous reports that ascr#18 triggers plant immunity and primes plant for protection against pathogens. Given its broad protective effects at very low concentrations as compared to chemical resistance inducer, such as salicylic acid mimics, argue that it is an interesting tool for strengthening environmentally friendly, sustainable plant production.

Safflower (Carthamus tinctorius L.) is one of the most important oilseed crops in the world, which has gained great importance in Iran due to its high tolerance to drought and salinity. Two important factors in the development of safflower cultivation are the increase of oil yield and early maturity. Considering that the most important step in plant breeding is creating diversity and using this diversity in selection, in this experiment, a large number of safflower genotypes were evaluated in terms of important quantitative and qualitative traits.

In this study, 160 local and imported genotypes were evaluated in the form of an augmented design with three controls (introduced cultivars Goldasht, Padideh and Golmehr) in five replicates as winter cultivation, and traits such as flowering date, Plant height, number of branches, spininess, seed yield, oil percentage, 1000 seed weight, seed protein content and fatty acid profile including percentage of palmitic, stearic, oleic, linoleic and linolenic acids were investigated.

The results showed the existence of a range of 23 days for flowering date, a range of 95 cm in plant height and a range of 16% in the amount of seed oil. Also, a large variation was observed in seed yield and other evaluated traits. The results showed that the amount of seed protein in some tested genotypes was up to 20%, which is very important in terms of the nutritional value of meal. Examining the fatty acid profile with the help of GC showed that 24 genotypes had oleic acid content higher than 55%. The results of partial correlation showed that the genotypes with the highest percentage of oleic and palmitic acid usually have the highest percentage of oil and there is a strong negative correlation between oleic and linoleic, so that the decrease or increase of one is associated with the increase or decrease of the other. High oil percentage was observed only in thorny genotypes and no significant correlation was observed between oil percentage and seed protein content, so that genotypes with high oil percentage and high seed protein percentage were observed at the same time.

Overall, the results of this study showed that there is a great diversity between the collected genotypes, which can be used in breeding programs.

The research was conducted to study changes in expression pattern of some genes involved in drought tolerance due to the problem of terminal drought stress in rainfed lentil agriculture in Iran.

In order to identify the consensus sequence of the coding sequence (CDS) of selected lentil genes; Aquaporin PIP2, Fructose bisphosphate aldolase, Oxygen-evolving enhancer protein2, WRKY1 and Xyloglucan endotransglucosylase/hydrolase, expressed sequence tag (EST) and reads were identified through similar ortholog sequences in other leguminosae plants. 90, 60 and 30 percent of field capacity were considered as control, medium and severe stress respectively. RNA was extracted from both control and severe drought stress treated plants leaf samples, cDNA was synthesized from RNA samples. Expression profiles of the genes, were determined via real time PCR technique. To represent the effect of drought stress on lentil plant, some morphological, physiological and biochemical characteristics were measured.

Characteristics like plant height, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight, relative water content, leaf area index, chlorophyll and protein content decreased due to drought stress, leaf trichome density, electrolyte leakage index, proline and carbohydrate content, malondialdehyde and hydrogen peroxide increased in drought stress. Analysis of real time PCR demonstrated expression of AQUAPIP2، FBA and WRKY1 genes were increased and expression of XTH and OEE2 genes were decreased under severe drought stress condition.

The results show that AQUAPIP2, FBA and WRKY1 genes are involved in drought tolerance. Due to higher expression of AQUAPIP2 and WRKY1 genes in the tolerant genotype, reduction of RWC in this genotype is less. Less increase in hydrogen peroxide in the tolerant genotype, partly influenced by higher expression of AquaPIP2 gene and higher activity of antioxidant enzymes, which was influenced by higher expression of AquaPIP2 gene in tolerant genotype than susceptible genotype. The increase in carbohydrate content in both genotypes was partially affected by FBA gene expression.

To study the effect of miRNA and PGPR on drought tolerance, Sadri and Yas bean genotypes were subjected to drought conditions (FC = 90%, 60% and 30%) and bacterial treatments (no bacteria, isolates B1, B2 and mixture 2 bacterial isolates), using CRD design with three replications in a factorial arrangement, Drought stress was applied five weeks after planting (for 10 days) and second trifoliate and root were used for sampling. The results showed that PGPRs lead to membrane stability, root development, etc. To identify the potential miRNAs involved in drought stress, the publicly available EST sequences of the plant were obtained from NCBI and blasted against the previously known Plant miRNAs. Ultimately, five distinguished potential miRNAs were acquired in the plant (belonging to four families: miR408, miR5021, miR5565e and miR9559). Candidate miRNAs were involved in growth, stress tolerance, etc. miR9559-3P expression decreased in drought and bacterial inoculation conditions in drought sensitive and tolerant plants. However, in the absence of bacterial inoculation, the expression of miR9559-3P was higher in sensitive plants. miR9559-3P might increase sensitivity to drought stress by negatively regulating role and targeting a higher percentage of target genes in sensitive plants. However, the tolerant plant with a special regulatory display and reduced expression of miR9559-3P reduced the degradation of miR9559-3P transcripts, increased the expression of the target gene and improved stress tolerance. Since PGPR modulate miRNA expression and lead to drought tolerance and increase plant yield, using these bacteria as biofertilizer can be a suitable alternative method of chemical fertilizer.

Given the importance of salinity at the germination stage, this study was carried out with the aim of ‎investigating the diversity of germination traits in bread wheat 91 cultivars and 204 landraces along with ‎three control varieties (Sistan, Narin, and Arg) under salinity (60 and 120 mM NaCl) as a factorial ‎experiment in a completely randomized design with two replicates in petri dishes. There was a high ‎diversity between wheat genotypes in terms of shoot and root length of seeding, shoot-to-root length ‎ratio, germination index, and seed vigor under both sat stress conditions; while germination energy and ‎germination percentage had low variation. There was a positive significant correlation between all the ‎traits (except the root length of seeding and the shoot-to-root length ratio) under all three conditions ‎‎(control, 60 and 120 mM NaCl). From the factor analysis, the PC1 and PC2 under 60 mM NaCl ‎treatment were named as seedling weight and germination percentage, respectively. Under 120 mM ‎NaCl treatment, PC1 and PC2 were named as germination percentage and seedling weight, respectively. ‎Based on the biplot, IP624925, IP628189, and IP624838 landraces and ADL, AFLAK, KHAZAR1, and ‎RIJAW cultivars were identified as superior genotypes under 60 mM NaCl treatment. Moreover, ‎IP627103, IP624596, IP626566, IP625433, and IP628189 landraces and Shiroodi and Dastjerdi ‎cultivars were selected as superior genotypes under 120 mM NaCl treatment. Overall, the selected ‎genotypes were identified as genetic material with the potential of salinity tolerance based on ‎multivariate statistical analysis. ‎

In order to study of genetic diversity and classify barley cultivars under optimal and limited irrigation conditions an experiment was evaluated on 138 barley cultivars using alpha latis design with two replications at research field of Tehran University. Result of analysis of variance showed that there are highly significant differences among cultivars in studied traits which reveal high genetic variation among the cultivars. According to stepwise regression and path analysis, under optimal irrigation condition, seed number per plant and biological yield, and under limited irrigation condition biological yield and harvest index were the most important traits affecting grain yield. Factor analysis showed that in both optimal and limited irrigation conditions four factors were selected, which explained 80.33 and 79.93% of the changes, respectively. In both cases, the first factor was named as the performance factor explanation the most data changes. According to the biplot diagram, in optimal condition, cultivars 54, 57, 37, 103, 31, 30, 2 and 29 , and in limited irrigation, cultivars 130, 127, 124, 97, 122, 99, 29 and 55 which were at a high level in terms of the first and second factors, were selected as superior cultivars. Cluster analysis in n under optimal and limited irrigation conditions grouped cultivars into four and five clusters respectively. Which the results of cluster analysis confirmed grouping cultivars based on biplot diagram.

Glycine max is one of the important oilseed plants in all of the world. One of the problems of G. max production is seed deterioration and low germination and vigor during seed storage and before planting time. To investigate the effects of deterioration on seed and the effects of salicylic acid and ethylene on the improvement of the deteriorated seed of G. max were conducted accelerated aging test for 0, 6 and 10 days and a natural aging test for 6 months. After aging conditions, seeds were imbibed with 50 M salicylic acid and 10 M ACC (precursor of ethylene) for 6 hours at 25 °C. Also, a bach of seed after the natural and accelerated aging test was used without any hormonal treatment as a control seed (called dry seed). Germination percentage, the enzyme activity of catalase, superoxide dismutase, glutathione peroxidase, total protein, and malondialdehyde were measured. Gene expression of CTR1 and NPR1 were investigated on dry seed and under imbibitions of water, salicylic acid and ACC at 6, 12 hours with the Q-RT-PCR method. Seed germination decreased. Amount malondialdehyde increased and total protein decreased. Enzyme activities of catalase, superoxide dismutase and glutathione peroxidase were decreased. and electrical conductivity increased with the progress of aging. Gene expression varied on different days and different hours. Salicylic acid and ACC had different effects on measured traits. All together aging caused disturbing of seed physiology and salicylic acid and ACC were not able to improve deteriorated soybean seed.

Abiotic stresses have major impacts on crop growth and yield. Investigation of biochemical properties and enzymatic activity of different plant genotypes under drought stress conditions can identify tolerant genotypes to abiotic stresses. In the present study, the effect of drought stress on the activity of antioxidant and biochemical enzymes at leaves of 10 bean genotypes at different water stress levels was investigated as a factorial experiment in a randomized complete block design with three replications in the research greenhouse of University of Tehran. Compared to normal moisture conditions, when drought stress increased, the total protein content decreased and Khomein genotype had the lowest total protein content among other genotypes at 25% of field capacity stress. The highest catalase activity was observed at COS-16 genotype (0.196 mg/min protein) at irrigation level of 75% of field capacity, ascorbate peroxidase (0.226 mg/min protein) at 50% of field capacity and guaiacol peroxidase at the irrigation level of 75% of the field capacity (0.293 mg/min protein). Increasing the activity of polyphenol oxidase enzyme and proline content in severe stress compared to normal moisture conditions showed that increasing the content of these two enzymes can be a reason for increasing plant tolerance to drought stress. COS-16 genotype had the highest polyphenol oxidase activity (0.183 mg/min protein) at 25% of field capacity. Also, increasing trend of malondialdehyde content in leaves was observed under severe stress. Based on the results, among the studied genotypes, COS-16 was identified as tolerant genotype and Khomein genotype was drought sensitive.

Blackleg caused by Leptosphaeria maculans is one of the important diseases widely affecting canola production worldwide. Effectiveness of three plant defence related genes transferred from pea (Pisum sativum) to canola was tested against blackleg in two experiments. In the first experiment, three transgenes including PR10.1, Chitinase, and DRR206 were transferred from transgenic Wester variety into four commercial cultivars (Apollo, Sentry, OAC Triton, and MillenniUM 03) via backcrossing to examine the effects of different genetic backgrounds on disease response. In the second experiment, to study the effect of gene pyramiding on level of disease resistance, three transgenic Wester lines were crossed. Cotyledon inoculation was performed for indoor disease screening tests of blackleg. DRR206 in Sentry and Chitinase×DRR206 appeared to be the best combinations conferring disease resistance. Overall, DRR206 had the highest impact on disease, probably due to delayed infection development. Promising lines of this research could be utilized in breeding programs and cultivar release projects after field trials.

This study has been conducted to recognize some of the physiological mechanisms related to the storage in different wheat cultivars as a split-plot experiment in a randomized complete blocks design with three replications at the experimental farm of Agriculture and Natural Resources ofUniversity of Tehran in Karaj, during two crop years of 2014-2016. Experimental treatments consisted of 22 wheat cultivars as the main plots and gibberellic acid (GA3) at two levels (0 mg/L (control) and 100 mg/L) as the sub plots. Results showed that gibberellic acid spraying significantly increased stem dry and specific weights, leaf area, chlorophyll and grain yield in different wheat cultivars in both experimental years. Among these traits, the shoot dry weight had the highest response to gibberellic acid spraying. There was also a significant positive correlation between stem dry and stem specific weights and remobilization in different cultivars under gibberellic acid spraying condition. Shabrang and Dez cultivars had the highest storage related traits (stem dry and specific weights) under gibberellic acid spraying condition which resulted in higher grain yield. These cultivars had the highest grain yield due to higher stem reserves remobilization capacity. In this study, exogenous application of gibberellic acid has generally strengthened the stem storage capacity, source strength and yield in different wheat cultivars.

Medicinal plants have many applications in the treatment of humans, among which chamomile is one of the most valuable and widely used medicinal plants in the world. One of the most important breeding programs is the recognition of genetic diversity for the initial evaluation of plant masses. For this purpose, a study of genetic diversity and classification of experimental chamomile ecotypes was designed and implemented.

25 native and foreign ecotypes of chamomile were evaluated in a randomized complete block design with four replications in the research farm of German Pharmaplant. Some of these ecotypes were collected from their natural growing areas and some were chamomile cultivars. For this purpose, some morphological, phenological and essential traits were evaluated.

The results of analysis of variance showed that the difference between ecotypes in terms of all traits was significant at the level of 1% probability and showed great genetic diversity between traits. The results of phenotypic correlations and comparison of the mean of the studied traits showed that the traits of essential oil percentage, flower diameter, number of flowers and shoot weight were among the important and effective traits on essential oil yield. Slovakia, Izeh (2) and Poland had the highest fresh and dry shoot weight, flower diameter and essential oil yield, but Izeh (1) and Darrehshahr had the highest percentage of essential oil. According to the results of factor analysis, three factors were selected that explained 85.79% of the changes. The first factor, which justified the highest percentage of data changes, was named as the essential oil yield factor, which after drawing a biplot based on two components, Izeh (2) and Poland ecotypes were identified as superior ecotypes. Cluster analysis also classified the ecotypes into four groups, which performed well in differentiating the ecotypes based on the desired traits, and confirmed the distribution of the ecotypes based on the biplot diagram.

The results showed that the essential oil percentage, flower diameter, number of flowers and shoot weight were important and effective traits on essential oil yield. Due to the fact that diversity for these traits was observed among the studied ecotypes, so screening to increase these traits can increase yield. Slovakia, Izeh (2) and Poland had the highest fresh and dry shoot weight, flower diameter and essential oil yield, but Izeh (1) and Darrehshahr ecotypes had the highest percentage of essential oil.

Identification the sources of seedling and adult plant resistance genes is important for gene pyramiding, gene deployment, and developing durable wheat cultivars to control the leaf rust with Puccinia triticinea Erickss agent. In this study, 218 Iranian wheat genotypes collected from different regions were cultivated in one-meter lines in the experimental farm of Golestan Agricultural Research Station in Ahwaz during 2019-2020 and treated with Khouzestan leaf rust prevalent pathotypes including LR-98-8, LR-98-5, LR-94-5 and LR-9-4. Seedling reactions with five prevalent pathotypes were carried out in a randomized complete block design with two replications in the greenhouses of the Cereal Pathology Unit of Seed and Plant Breeding Institute, Karaj. To evaluate resistance, we used Infection Type (IT), AUDPC (Area Under Disease Progression Curve), Final Disease Severity(FDS) and Coefficient Infection (CI) indices. The results showed that 10 percent and 7 percent of the genotypes are resistant in greenhouse and field conditions, respectively. In the adult plant stage, the responses of 23 genotypes were moderately resistant (MR) and 14 genotypes were moderately susceptible (MS). The correlation coefficients between the final disease severity, with the coefficient infection and rAUDPC were 0.989 and 0.949, respectively. Finally, 30 genotypes with the desired characteristics, ie final disease severity between 0-40%, coefficient of infection between 0-40 and rAUDPC between 0-30% were selected as the suitable genotypes. Cluster analysis classified the genotypes into four groups: susceptible (S), moderately susceptible (MS), moderately resistant (MR) and resistant (R).

Drought stress is one of the important non-biological stresses for plants such as beans because it affects the growth, development and yield of the plant. Therefore, identification of drought tolerant genotypes is very important. One of the effective ways in identifying drought tolerant genotypes is biochemical investigation and relative genes expression involved in drought stress. Therefore, the present study was performed on a number of bean genotypes including Khomein, COS-16, D81083 and KS-10012 as factorial complete randomized block design. Drought stress was applied at the levels of severe stress (25% field capacity), mild stress (75% field capacity) and normal irrigation (100% field capacity) and then the relative water content, electrolyte leakage, proline, malondialdehyde and gene expression (NCED, CDPK1, PIP1 and NAC) were evaluated. Results showed that the highest and lowest electrolyte leakage traits belonged to Khomein genotypes with 77.66% and COS-16 with 25%, respectively. The highest relative water content of leaf belonged to COS-16 genotype at mild stress of 80.66% and the lowest to khomein genotype at severe stress of 25%. Increasing trend of proline content was observed in all genotypes from 100% of irrigation to mild and severe stresses. Also, increasing trend of malondialdehyde was observed in severe stress compared to control, on the other hand, Khomein genotype with the highest malondialdehyde rank a and COS-16 genotype with the lowest malondialdehyde genotype f were considered with Tukey test. Relative increase of NCED, NAC and CDPK1 gene expression was observed in severe stress compared to mild stress. Different relative expression of PIP1 gene was also observed at different stress levels (75% and 25% of field capacity). In general, it can be concluded that among the genotypes studied, COS-16 had the highest and Khomein genotype had the least tolerance to drought stress.

Tocopherols (Vitamin E) are an important group of organic compounds that realize vital activities in plant cells. They protect the photosynthetic system from photooxidation damages and prevent the lipid peroxidation of the chloroplast membrane. The presence of this plant organic compound in human nutrition is essential. In this research, six genes involved in the biosynthesis pathway of vitamin E including HPPD/ PDS1, VTE5, HPT/ VTE2, VTE3/ APG1/ IE35, TC/ VTE1, γ-TMT/ VTE4 and their products are identified in lentil plant using databases and bioinformatics software. After this identification, genes are implemented for breeding purposes of lentil through traditional breeding or modern biotechnology methods. According to the phylogenetic tree obtained by the MEGA 7 program, it was observed that most of these genes in the lentil have high homology to legume plants such as chickpea and alfalfa. In addition, the prediction of the presence of conserved domains revealed that the HPPD protein had two domains and one subdomain, and each of the proteins γ-TMT and VTE3 had only one conserved domain. Moreover, the results of the proteins description using ProtParam tool showed that the highest frequency with respect to the amino acids belonged to leucine, serine and glycine; by contrast, selenocysteine and pyrrolysine had the lowest frequency. The use of the DeepLoc-1.0 program predicted that only HPPD proteins were soluble in the cytoplasm, while five other proteins were located in the intermembrane space.

Here, the seeds of 10 different species of the Yarrow (Achillea spp.) originated from geographically different regions of Iran were planted in the greenhouse of medicinal garden of Hamedan (2017-2018), and subsequently phytochemical variation of the essential oils of each individual species collected before and after flowering were assessed using GS-MS. Before flowering, overall, 27 metabolites were detected, among which 1,8-cineol, artemesia alcohol, artemesia ketone, camphor, germacrene-D, linalool, Terpineol and nerolidol were the superior. The maximum amounts of 1,8-cineol was observed in A. alepica, A. eriophora, A. biberstinii, A. filipendula, and A. nobilis, while both A. alepica and A. eriophora contained the highest amounts of camphor. Meanwhile, here, the maximum amounts of Germacrene D were acquired in A. tenuifolia (43.19%) and A. wilhelmsii (47.03%). Upon flowering, overall, 78 metabolites were detected, among which Cubenol, Eucalyptol, Camphor, germacrene-D, sabinol, trans-Nerolidol, Chamazulene, Chamazulene, and 2-Cyclohexen-1-ol, 1-methyl-4-(1-methylethyl)-, cis- were the superior. Based on cluster analysis and PCA constructed by the metabolite data of before and after flowering, all the 10 species of the genus Achillea were respectively grouped into three and four distinguished categories. Lastly, the results indicated that both quantity and quality of chemical composition of yarrow essential oils could be influenced by species under study, various growth and development stages, genetic background and possibly geographical/climatological factors, and that there is an acceptable phytochemical variation among them.

This project was carried out to study and classify the lentil (Lens culinaris Medik) genotypes during germination and seedling establishment, in Greenhouse and in two stages. First stage was carried out with 43 genotypes and Mardom cultivar of lentil in 4 levels of salinity and 3 replications in factorial experiment in as a completely randomized design in a combination of non-saline and saline soil in the 1, 2-1, 1-1 and 1-2 weight ratios (respectively non-saline soil and saline soil). Second stage was carried out with 3 genotypes and Mardom cultivar of lentil in 4 levels of salinity of NaCl (0, 60, 120, 180 mM) and 3 replications in a factorial experiment based on a completely randomized design. In this project, some morphological characteristics as well as the content of chlorophyll a and b, carotenoids and proline were evaluated. Analysis of the results showed that as the salinity increased, morphological traits in most genotypes were significantly damaged. For clustering genotypes in the first experiment, cluster analysis and principal component analysis was carried out and genotypes were classified in four different groups. 4 genotypes for second experiment were selected according to the results of cluster analysis. Results showed that there was high diversity in lentil genotypes in response to salt stress, and we can use this diversity in cultivars breeding programs.

To optimize tomato (Solanum Lycopersicum) plant tissue culture condition, the effect of 13 different hormonal combinations and two explants of cotyledon and hypocotyl on the regeneration rate of three Newton, Infinity and Defines cultivars were investigated. Experiments were conducted in a factorial based on a completely randomized design with three replications. The highest shoot number (11.9 shoots per explant) was obtained for Defines cultivar on MS medium containing the hormones of TDZ=0.68, NAA=0.1milligrams per liter and cotyledon explant. Plant defense responses against environmental factors are one of the inhibitor factors of explants regeneration in plant tissue culture. Calcium ion signaling is one of the primary events and, of course, the most important event in plant defense response against pathogens, Therefore, the effect of verapamil as a calcium channel blocker was investigated on the plant defense response. For this purpose, inoculation was performed using Agrobacterium tumefaciens strain LBA4404 and based on optimized tissue culture condition. The effect of verapamil in four concentrations of 0, 50, 100 and 200 milligrams per liter was investigated in a co-culture medium. Results showed that the use of verapamil in comparison with the control sample reduced the plant defense response. Also, the use of 50 milligrams per liter of verapamil increased the amount of regeneration.

Water Water deficit especially after heading is one of the most effective factors of wheat yield loss in Iran and across the world and identifying the physiological traits related to plant resilience is of great importance in screening for tolerant varieties. The objective of this study was to evaluate the variation in stem reserves accumulation capacity and its relationship with remobilization in some wheat cultivars. 22 wheat cultivars were cultivated in a split plot design with three replications, full irrigation and 40% of field capacity being main plots. The amount of accumulation and remobilization was estimated by measuring internodes weight and stem soluble carbohydrates content (WSC). Significant genotypic variation among cultivars was observed under both normal and drought conditions. Maximum accumulation was found in lower internodes followed by peduncle and penultimate using dry weight measurement method. In WSC measurement method, however, maximum accumulation was observed in penultimate followed by lower internodes and peduncle. Cultivars ranking based on accumulation was also different in two methods. Drought stress caused decline in internodes weight, WSC and yield and remobilization efficiency. The specific stem weight had the highest correlation with remobilization. Significant correlation was found between grain yield and remobilization, specific stem weight and WSC.

Hormonal changes of Aeluropus littoralis (Gouan) Parl. halophyte under none- stress, moderate and severe salinity stress condition (0, 250, and 600 mM NaCl, respectively) at four time-courses (3, 6, 12, 24 h) were studied. The results showed that the Abscisic acid (ABA) content increased after one day at all stress levels, however, Gibberellic acid (GA3) levels also significantly decreased under severe stress compared to mild stress. The level of Salicylic acid (SA) decreased slightly compared to the control at the beginning of mild stress condition, but in severe stress, this decrease was more noticeable. Jasmonic acid (JA) content was not different at the first of stress, but with increased stress time, its content increased and in severe stress, it was more than mild stress and in mild stress, it was more than the control. It seems that the plant needs at least 24 hours to respond to stress because in the first time (3 hours) the content of hormones changed compared to the control, which indicates the perception of stress, but in continues the levels of the hormone had limited changes, and within 24 hours, the plant produced a completely different response to its hormonal content than the control. In conclusion, the results of this study will be useful in providing a deeper understanding of the hormonal mechanism of salinity tolerance.

MicroRNAs(miRNAs) are a group of small non-coding RNAs of approximately 18 - 24 nucleotides that play a negative role in post-transcriptional changes in eukaryotes. The miRNAs are then loaded onto the argonate family proteins (AGO) to form a protein complex (RISC). The primary activity of the RISC complex is to direct the mature miRNA to the target RNA and to stop protein production (Megah et al., 2018). miRNAs are involved in response to abiotic stresses in plants such as drought; several miRNA families have been reported in response to drought stress in rice, tomato, Arabidopsis, Medicago truncatula, peach, barley and wheat (Akdogan et al., 2015). The purpose of this study was to identify new microRNAs and their role in suppressing and preventing expression of some of their target genes in rapeseed.

A total of 38589 known mature miRAN sequences were downloaded from the miRBase database. The miRNA sequences were used as known sequences to find conserved miRNAs based on homology search for miRNAs with rapeseed GSS sequences.103369 GSS for rapeseed was downloaded from NCBI database. Mature miRNA sequences were uploaded to the BLASTn algorithm to search for homology with rapeseed GSSs in Linux. The miRNA sequences as known sequences and the GSS sequences as sequences were compared with each other for homology search. GSSs with mature miRNA sequences up to four mismatches were selected as candidates (Zhang, 2005). GSS sequences were used instead of EST sequences because miRNAs can generate GSS sequences in addition to EST sequences. Consequently, GSSs were sequenced between the BLASTx miRNA sequences and the GSS coding sequences were deleted and only non-coding GSS sequences remained (Karimi et al., 2017). Mfold software was used to predict the secondary structure of candidate miRNAs (Vivek, 2018). ath-miR5021 and ath-miR8175 from Arabidopsis, bol-miR9410 and bol-miR9411 from wild cabbage and cas-miR11592 from Camelina sativa were selected from the psRNATarget website (Dai and Zhao, 2011.

For miR5021: The NST1 target gene encodes a protein called Stress response protein NST1, which plays a role in regulating secondary wall thickness in plants and preventing its destruction against a variety of stresses (Mitsuda et al., 2005). For miR9410: The HST gene is one of the target genes that encodes an enzyme called Shikimate O-hydroxycinnamoyltransferase in plants, which participates in the phenylpropanoid biosynthesis and heat stress control in plants, propanoids as secondary metabolites during developmental stages. The plant is synthesized in response to stress conditions (Lukasik et al., 2013).

Types of microRNAs and their role in suppressing target genes during live and abiotic stresses in barley, wheat, soybean, cucumber, alfalfa, olive, rice have been reported (Ozhuner et al., 2013). In this study, we tried to identify new microRNAs and their role in suppressing target genes for the first time in rapeseed. The results of this study showed that among the newly identified microRNAs, miR5021 and miR9410 families play an important role in suppressing NST1 and HST target genes, respectively, especially during stress in canola.. Therefore, identifying the molecular mechanism of these microRNAs and their target genes can help us in selecting drought and heat resistant varieties for rapeseed. A study of microRNAs for boron stress tolerance in leaves and roots of barley showed that of the four new microRNAs identified, miR408 was more involved in regulating cell signaling in leaves than the other three microRNAs (Ozhuner et al., 2013). Also, no response has been reported in hybrid and maize inbred lines for miR172 under drought and salt stress conditions (Kong et al., 2010). Therefore, understanding the cellular regulation mechanism for new microRNAs, including how to regulate the activity pathway of antioxidant enzymes such as superoxide dismutase in organs such as leaves, roots and shoots of canola, requires further investigation.

MicroRNAs can be used as a new molecular tool alongside existing classical breeding methods to improve the genetic status of plants to promote tolerance to a variety of biotic and abiotic stresses in plant breeding.

Glycine max is one of the most important oilseeds plant in all of the word. One of the problems of G. max production is seed deterioration and low germination and vigor during seed storage and before planting time. In order to investigate the effects of seed deterioration on germination and the effects of salicylic acid and ethylene on improvement of deteriorated seed of G. max several experiments were conducted. Accelerated aging test for 0, 6 and 10 days and natural aging test for 6 months were the main effects. After aging conditions, seeds were imbibed with 50 M salicylic acid and 10 M ACC (precursor of ethylene) for 6 hours at 25 °C. Also seeds after natural and accelerated aging test were used without any hormonal treatment as control seed (called dry seed). Germination percentage, electrical conductivity and gene expression of αMY1, βMY1, were investigated on dry seed and under imbibition of water, salicylic acid and ACC for 6, 12 hours using Q-RT-PCR method. Seed germination decreased and electrical conductivity increased with progress of aging. Gene expression varied in different days and different hours. Salicylic acid and ACC had different effects on measured trait. All together aging caused disturbing of seed physiology and salicylic acid and ACC were not able to improve deteriorated soybean seed.

Acidification of cell wall is the most valid cause of fast cell expansion. Expansins are a kind of wall loosening protein that can expand wall through pH changes. In this study AtEXPB2 genewas transferred to tobacco plant. Regenerated plants were cultured in selective medium (contained kanamycin) then transgenic plants were selected and afterward transmitted to greenhouse. To confirm transgenic plant DNA was extracted from them and PCR was down via specific primer of AtEXPB2. Seed was collected from transgenic plants and seed of three transgenic lines were cultured in MS selective medium. Transgenic seedlings tolerate medium which contain kanamycin. Subsequently some of these seedlings were grown in greenhouse and others were grown in Hoagland nutrient solution for evaluating root morphology. The results indicated that transgenic lines had bigger organs in most of the measured traits. For example capsule number, total seed weight, root length, root fresh weight and so on were increased in transgenic lines in comparison to wild type plant. These results suggested a specific role for this gene as a common growth regulator that could be used to produce transgenic plants with larger organs as well as tolerant to stresses like drought and salinity.

The aim of this study to evaluate the response of wheat cultivars to salt stress on some physiological and biochemical characteristics and more understand about the mechanisms of resistance to salinity and access to tolerance genetic resources. To evaluate the effects of different concentrations of salinity (control and 16 dS m-1) on morphological and physiological aspects of 5 wheat cultivars, an experiment was conducted using a randomized complete block design with factorial treatments in three replications. The results showed that salt stress causes a significant reduction in shoot and root dry matter, the concentration of K+ and K+/Na+ ratio of different varieties of wheat and this reduction was more severe in higher levels of salinity. The sodium content of the plant increased in high salinity. so that the negative correlation (-.828) between the concentration of sodium ions shoot and shoot and root dry matter. In addition, salt tolerant cultivars compared with the susceptible cultivars showed high K+/Na+ ratio in shoot and root keep better performance in salinity stress. So K+/Na+ showed significant positive correlation (0.747) with the shoot dry matter. salt tolerant cultivars transfer Less sodium in their shoot. shoot K+ ion concentration was positively correlated (.747) with shoot dry matter. The observed negative correlation between sodium concentration and the chlorophyll content (-0.946) indicate that the plant metabolism has been adversely affected by salinity stress.

Leaf rust caused by Puccinia triticina Eriks. is the most widespread and regularly occurring rust on wheat. Genetic resistance is the most economical approach of preventing yield losses due to leaf rust. To evaluate the resistance of 320 wheat genotypes at seedling stage to four leaf rust isolates, an experiment was carried out using randomized complete block design with two replications in the greenhouse conditions of the cereal pathology unit of Seed and Plant Improvement Institute in Karaj, Iran. To evaluate the resistance, two components of infection type and latent period, were used. Analysis of variance showed that there was highly significant differences between the genotypes for each of the two components. Dehdasht, Dena, Karaj-2, Khazar-1, Sepahan and Parsi and seven landraces were resistant to all isolates at seedling stage. The correlation between infection type and the latent period was negative and significant. Cluster analysis classified the genotypes into three clusters: susceptible, moderately susceptible to moderately resistant, and resistant to immune. More than 78 percent of the genotypes were in susceptible cluster. Identified resistant genotypes, especially landraces, can be used as sources of resistance to leaf rust in wheat breeding programs.