Iranian Journal of Genetics and Plant Breeding
Volume:10 Issue: 2, Oct 2021

Transcription factors are known as factors having the ability to simultaneously activate several genes in plant and animal genomes. Because of their significance in responding to environmental stresses like salinity, drought, temperature changes, etc., a group of these transcription factors known as DREB1/ CBF (Dehydration-Responsive Element Binding Protein 1/ C-repeat binding factor) gene family has been extensively studied in various plant species. In this research, considering the particular and well-stablished role of the genes of this family in cold stress in plants, Viola tricolor (wild pansy), as a cold resistant species, was chosen to identify this gene family. For this purpose, viola plants in the multi-leaf stage were gradually transferred to a -8 °C chamber and subjected to subfreezing treatment for 18 h. Using bioinformatics analysis based on NCBI database, the initial identification of the AP2/ ERF (APETALA2/ Ethylene-Responsive Factor) conserved region in the genes of the members of this family was carried out and the consensus sequence was used for primer design. The sequencing result revealed considerable sequence similarity in this region with genes found in other plant species. Thus, as predicted, this work established the presence of the DREB1 gene family in V. tricolor. The closest species to V. tricolor was also determined by drawing the phylogenetic tree based on the identified region. The gene expression pattern analysis revealed a significant increase in expression of this gene under cold stress conditions.

Barley yellow rust is one of the important barley diseases in the world. However, the importance of this disease has recently increased in Iran. The main aim of the present study was to identify the sources of resistance to this disease in a collection of Iranian barley genotypes provided from the National Plant Gene Bank of Iran (NPGBI). For this purpose, a set of 128 accessions of the north and northwest regions of Iran were assessed in terms of resistance components such as disease severity, infection type and coefficient of infection under natural incidence of the disease in the field of Ardebil Research Station as a hotspot region for barley yellow rust during 2019-2022 cropping seasons. The results indicated a considerable genetic diversity among the tested genetic materials in response to this disease. A moderate correlation was observed between the evaluations of different years. The accessions were separated into five groups using cluster analysis, and the second group with 41 members with the lowest infection coefficient average was identified as the most resistant group. The results of this research showed the high capacity of the collection to identify sources of resistance to barley yellow rust disease. The identified resistant germplasm can be used in breeding programs for resistance to this disease.

Lentil (Lens culinaris) is the third most important grain legume in the world after chickpeas and peas. Ascochyta blight (AB) caused by Ascochyta lentis, is one of the most damaging diseases of this crop worldwide. In this study response of 169 lentil genotypes against AB was appraised in the greenhouse and field conditions based on randomized complete block design (RCBD). Field screening was carried out in the growing season of 2019-2020 at Shirvan-Chardavol Agricultural Research Station, Ilam province, Iran. Conidial suspension with concentration of 1×106 spore per mL was used for artificial infection in the greenhouse condition. Analysis of variance discovered significant differences among studied genotypes in response to the pathogen. There were no detected resistant genotypes among the studied lentil germplasm against AB in either environments. In the field condition, the majority of genotypes were identified as resistant while in the greenhouse condition most of the genotypes retained susceptible responses. Regarding AUDPC and disease severity characteristics, genotypes “G121”, “G132”, and “G139” were recognized as resistant in both field and greenhouse coditions. Classification of lentil genotypes by using Ward algorithm in both conditions resulted in 4 heterotic groups. The identified resistant genotypes can be useful in the breeding program of interested susceptible lentil genotypes by the backcross approach. Also, the identified heterotic groups can consider in parental selection for mapping QTLs related to resistance to the disease.

Cold tolerance in wheat is one of the most important factors effective in the field of winter damage in Iran. Freezing and laboratory tests were carried out in the greenhouse and plant breeding laboratory of Mohaghegh Ardabili University in 2018-20 to achieve the set goals. The plant materials used included 45 promising durum wheat lines. Durum wheat genotypes were planted in a randomized complete block design with three stress levels. The results of the variance analysis of LT50 showed a significant difference between the genotypes at the probability level of 1%. LT50 varied between -0.754 and -26.609 values. The survival percentage of plants decreased with increasing stress. In clustering based on the LT50, the genotypes were divided into 5 groups. The dendrogram obtained from the cluster analysis based on all the traits divided lines in the control level, -8 °C, -10 °C, and -12 °C into 8, 6, 9 and 7 different groups. Four factors were identified in the control level, 5 in the first stress, 6 in the second stress, and 5 in the third stress level. To evaluate the relationship between the measured traits and RAPD molecular markers, stepwise multiple regression analysis was performed and significant relationships were observed. LT50 showed a correlation with 9 markers. Finally, according to the tests conducted, lines 1, 2, 3, 4, 5, 6, 7, 8, 10, and 23 were recognized sensitive lines and lines 11, 12, 13, 14, 15, 17, 18, 19, 21, 29, 31 and 27 were recognized as resistant.

For more than half of the world’s population, rice (Oryza sativa L.) is the primary source of nutrition. Rice production must expand by at least 25 percent by 2030 to feed the world’s ever-increasing population. As climate change and arable land loss take a tremendous toll on the world’s food supply, genetic advancements in rice would be crucial for alleviating the yield gap. We must first obtain extensive information on the genetic diversity of the Oryza spp. gene pool, the association between diverse alleles and critical rice characteristics, and the systematic exploitation of the rich genetic diversity using approaches that employ expertise in rice breeding procedures. The vast genetic diversity of rice cannot be represented by a single genome. To produce variants that are more tolerant to adverse weather conditions, a multi-national rice genome sequencing project was launched on May 28, 2014. Genes associated with drought tolerance, disease resistance, and pest resistance in rice could be identified using the above mentioned genetic information. Using diverse germplasm resources and high-throughput genome sequencing projects, rice genomics has made great progress toward applying basic research advances to understanding agronomic traits. It is important to remember that many important genes are missing from the previous sequencing projects, and many useful genes are present in native and traditional populations that cannot be retrieved without gene sequencing.

Melioidosis is a common disease between human and animals caused by Burkholderia pseudomallei. There is currently no effective vaccine for it. The aim of this research was to express blf1 gene in tobacco plants. By transforming the pBI121 vector into Agrobacterium tumefaciens, the blf1 gene was transferred to the tobacco plants and the primary transgenic plants were obtained. The explants obtained from the transgenic plants were used to induce hairy roots. The presence of the blf1 gene was investigated in the obtained hairy roots by PCR and Western blot analysis. The titer of antigen production was measured by ELISA technique. The insertion of the blf1 gene construct into pBI121 vector containing the ctxB gene was confirmed by PCR. The tobacco explants inoculated with A. tumefaciens were cultured on the MS medium containing benzyl-aminopurine (BAP) and 1-naphthalene acetic acid (1 -NAA). After callus formation and seedling regeneration, the seedlings with active meristems were transferred onto the hormone-free medium for rooting and transgenic tobacco plants containing the blf1 gene were produced. By preparing an explant of transgenic plants by A. rhizogenes, inoculum and hairy roots were obtained. In hairy roots, the presence of blf1 gene was confirmed using PCR and its expression was confirmed by Western blotting. By using the ELISA technique, the titer of BLF1 antigen production in the total soluble protein of hairy roots was determined to be 0.56%.