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Showing 6 results for Khademi
Hadi Karimbeigi, Farhad Nazarian-Firouzabadi, Mitra Khademi, Elham Mousav,
Volume 3, Issue 1 (9-2016)
Abstract
Oilseed rape (Brassica nupus L), a member of Brassicaceae family, is an important crop regarding oil production worldwide. Brassicaceae is an economically important family of flowering plants with about 350 genera and more than 3000 species. Eleven pairs of single sequence repeat (SSR) primers were used to identify the genetic diversity among 21 oilseed rape genotypes. Results of SSR molecular marker analysis revealed that SSR primers produced a total number of 76 scorable bands of which 46 (60.5%) bands were polymorphics. The average number of bands for each primer and genotype was 6.9 and 3.6, respectively. Both CB10036B and Na10A09 primers produced 10 and Cb10403 primer produced 4 polymorphic bands, respectively. UPGMA cluster analysis based on Dice similarity matrix showed that Zarfam and Gerinimo genotypes had the highest (0.99%) and Licord and KS-11 genotypes had the lowest (0.72%) similarity. Both Iranian and foreign genotypes were grouped together in one major cluster, indicating presumably they may have the same origin and/or common pedigree. Results of AMOVA analysis within and between groups (spring – Autumn) revealed that almost 97% of total genetic diversity belonged to within group genotypes.
Mitra Khademi, Farhad Nazarian-Firouzabadi,
Volume 6, Issue 1 (9-2019)
Abstract
Recently, new molecular breeding and genetic engineering approaches have emerged to overcome the limitations of conventional breeding methods in generating disease-resistance transgenic plants. The use of antimicrobial peptides (AMPs) to produce transgenic plants resistant to a wide range of plant pathogens has achieved great success. Among huge number of AMPs, Dermaseptin B1 (DrsB1), an antimicrobial cationic 31 amino acids peptide, exhibits significant antimicrobial activities towards a wide range of pathogens. In order to increase the antimicrobial efficacy of DrsB1, the DrsB1 encoding DNA sequence was either fused to the N- or C-terminus of the sequence encoding chitin-binding domain (CBD) of Avr4 gene from Cladosporium fulvum and constructs (CBD-DrsB1 and DrsB1-CBD) were used for tobacco leaf disk Agrobacterium-mediated transformation. Polymerase chain reaction (PCR), semi-quantitative RT-PCR and SDS-PAGE analysis indicated the integration of transgenes in tobacco genome and expression of the recombinant genes in transgenic plants, respectively. The antimicrobial activity of extracted recombinant peptides were assessed against a number of plant and human pathogens. Both recombinant peptides had statistically significant (P<0.01) inhibitory effects on the growth and development of fungi pathogens. Also, CFU test result showed that extracted recombinant peptides from transgenic plants, had a relatively high inhibitory effect on plant pathogens. The CBD-DrsB1 recombinant peptide demonstrated a higher antibacterial activity, whereas the DrsB1-CBD recombinant peptide performed a greater antifungal activity. In addition, the expression of DrsB1-CBD recombinant peptide significantly inhibited R.solani fungal infection in comparison with Pythium sp. interestingly, fungi with a higher amount of cell wall chitin were more vulnerable to recombinant peptides, suggesting recombinant peptides present a higher affinity for cell wall chitin. Owing to the high antimicrobial activity and novelty of recombinant peptides, this strategy for the first time, could be used to generate transgenic crop plants resistant to devastating plant pathogens.
Ali Dowlatshah, Ahmad Ismaili, Hadi Ahmadi, Karim Khademi, Daryoush Goudarzi,
Volume 7, Issue 2 (3-2021)
Abstract
Plant breeding researches is based on genetic diversity and evaluation of genetic diversity is also one of the most important steps in introduction of new cultivars. In this study, genetic diversity of 25 grass pea genotypes was studied based on randomized complete block design with three replicates in Khorramabad (Iran). Analysis of variance showed significant differences among genotypes for most of traits. Mean comparison showed that genotype IF1312 with the highest grain yield and genotypes IF1332 and IF471 with the highest dry and fresh forage yield had the best yield. Principal component analysis showed that the first 3 factors explained 62.64% of total variance. Based on cluster analysis, genotypes IF1307, IF1872 and IF471 with the highest grain and forage yield are belonged to one cluster. REML method was used to estimate genetic correlation and heritability of different traits. The highest amount of heritability (0.87) was estimated for number of immature grains and the least heritability (0.10) was estimated for total dry weight. Grain yield had a high and positive genetic correlation with forage yield, and biomass, percentage of leaf and dry forage yield also had a high and positive genetic correlation with fresh forage yield. Totally, genotype IF1307 had the best performance for most of traits compared to the other genotypes and had an acceptable forage yield among genotypes.
Mitra Khademi, Marzih Varasteh-Shams, Farhad Nazarian-Firouzabadi,
Volume 9, Issue 1 (9-2022)
Abstract
Hairy and adventitious roots are efficient systems for expressing recombinant proteins. In the present study, the amount of DrsB1-CBDAvr4 recombinant protein in hairy and adventitious root systems was compared. To this end, the effect of different factors on the optimization of culture conditions to obtain adventitious and hairy roots was evaluated in three separate experiments by assessment of biomass production in T1 transgenic plants expressing DrsB1-CBDAvr4 recombinant protein. The efficacy of Agrobacterium rhizogenesis in producing hairy roots was ensured using rolC gene specific primers. The insertion of DrsB1-CBDAvr4 recombinant peptide transgene in the genome of hairy and adventitious roots was confirmed by PCR analysis. Also, the level of DrsB1-CBDAvr4 protein was measured in hairy and adventitious roots by ELISA analysis. Analysis of the variance of data showed that the highest number of roots and the longest roots were obtained in MS media supplemented with 1 mg/L NAA and 0.5 mg/L IBA. The results of adventitious root biomass showed that liquid MS medium containing 1 mg/L of NAA hormone had a significant effect (P <0.01) on biomass production. More biomass was obtained in MS medium supplemented with 1mg/L NAA, whereas a lower fresh and dry weight was obtained in a 1/4 MS medium with no NAA. The results also showed that ATCC15834 strain with MS media supplemented with 3% sucrose, 10 minutes inoculation time was high efficiency to induce hairy roots in tobacco plants. The results of ELISA analysis showed that clones obtained from both roots showed a significant difference in terms of total protein content. The amount of recombinant protein from hairy roots was much higher than that of adventitious roots.
Zahra Zarindast , Farhad Nazarian-Firouzabadi, Mitra Khademi,
Volume 10, Issue 1 (9-2023)
Abstract
Expression of antimicrobial peptides (AMPs) in plants to resist plant pathogens as well as to produce novel AMPs for pharmaceutical applications has recently received much consideration. alfAFP, a defensin cationic peptide synthesizing in alfalfa seeds, exhibits a strong antimicrobial activity. In order to facilitate alfAFP access to the pathogen’s membrane and increase the activity of the alfAFP peptide, the alfAFP encoding sequence was fused to the C-terminal of a chitin-binding domain (CBD) from a rice chitinase encoding gene. First, the antimicrobial properties of the recombinant peptide were assessed using bioinformatics tools. Next, the pGSA1285 expression vector harboring the CBD-alfAFP heterologous DNA was transformed into Agrobacterium rhizogenes for hairy root (HR) production in tobacco. The presence of transgene, transcription, and the expression of recombinant peptide in the HRs were confirmed by PCR and semi-quantitative RT-PCR analysis, respectively. Bioinformatic analysis was used to predict the antimicrobial activity of the alfAFP recombinant peptide. The results of the 3D structure analysis revealed a β-sheet and an α-helix structure that corresponded well with the structure of plant defensins. A Knottin functional domain was also recognized, suggesting that the recombinant peptide retains its antimicrobial activity. The results of the in vitro antimicrobial activity of the alfAFP recombinant peptide using CFU test showed that the recombinant peptide had significant inhibitory effects on Pseudomonas syringae pathogen. Therefore, the chitin-binding domain provided a better access of the recombinant peptide to the pathogenic bacterial cell wall through binding to peptidoglycan, and probably the recombinant peptide was able to target the plasma membrane with better efficiency. The results of this study suggested that the expression of the CBD-alfAFP recombinant peptide in crop plants and HRs can be a promising approach to producing pathogen-resistant plants as well as to produce new recombinant pharmaceutical AMPs.
Fatemeh Hatami, Farhad Nazarian-Firouzabadi, Seyed Sajad Sohrabi, Mitra Khademi,
Volume 11, Issue 1 (9-2024)
Abstract
Saffron (Crocus sativus L.) is not only one of the most expensive food products in Iran and the world but also holds a special place among Iran's export and industrial products. Since saffron is propagated only through corms, preventing the contamination of corms as “seed” with devastating pathogens is crucial to maintaining the quality and yield of the saffron. Hence, investigating the genetic mechanisms associated with the response of the saffron plant to fungal pathogens such as fusarium wilt rot (Fusarium oxysporum) is of great importance. Given that plants express a wide range of resistance genes to defend themselves, the role of genes related to the PTI (Pattern-Triggered Immunity) pathway, such as those in the LysM-RLK family, is crucial in pathogen resistance. Therefore, studying the transcriptome of saffron corms infected with the pathogen Fusarium oxysporum is important for identifying and investigating the genes belonging to the RLP and RLK gene families. Plants express a wide range of resistance genes to respond to pathogens attacks. Among different gene families associated with PTI pathway, the LysM-RLK family plays an important role in resistance to pathogens. Therefore, in this study, the transcriptome of saffron corms infected with the Fusarium oxysporum was studied to identify and investigate the genes belonging to the RLP and RLK gene families. According to the results of this study, a total of 45 genes encoding PTI pathway receptors were identified in the saffron transcriptome, with 40 sequences belonging to the RLP (Receptor-like proteins) family and 5 sequences to the RLK (Receptor-like kinases) family. The expression analysis of some main RLP and RLK family members showed that the highest expression was related to the sequences of Contig 41583 (RLP) and Contig 61879 (RLK) in the saffron stigma and corms, respectively. Furthermore, the expression of the selected genes in the infected corms significantly increased compared to the control healthy corm. Additionally, the expression levels of the target genes (Contig 41583 and Contig 61879) assessed using qRT-PCR indicated higher expression in corms 72 hours post-infection compared to 48 hours post-inoculation. These results suggest that RLK proteins play a crucial role in the interaction between saffron and the pathogen, particularly due to the presence of the LysM motif. Since LysM motif binds to chitin oligomers of fungal cell walls of certain fungi and oomycetes, it triggers plant immune responses. Overall, the findings of this study are significant for understanding the specific nature of the plant-pathogen relationship and can contribute to insights into the PTI immune pathway.
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