مجله پژوهش های ژنتیک گیاهی
سال نهم شماره 2 (پاییز و زمستان 1401)

Plastid engineering gives numerous benefits for the next generation of transgenic technology, consisting of the convenient use of transgene stacking and the production of high expression levels of recombinant proteins. Designed ankyrin repeat proteins (DARPin) are relatively small non-immunoglobulin scaffold proteins that bind to their specific target with high affinity. The G3 is a type of DARPin designed to bind to the HER2 tyrosine kinase receptor (human epidermal growth factor receptor 2). We previously developed a bioprocess for the production of DARPin G3 in tobacco chloroplasts as an imaging agent in HER2 over-expressed cancers. In this study, we analyzed the expression and homoplasmic stability of DARPin G3 gene in vegetative and generative T1 generation of transplastomic tobacco plants. The presence of DARPin G3 gene in the next generation of transplastomic plants was confirmed with specific primers by PCR analysis. Southern blot analysis confirmed the homoplasmic status of transplastomic plants. The western blot analysis confirmed the accumulation of the DARPin G3 in the chloroplasts of next generation of transplastomic plants. The DARPin G3 protein content was estimated around 33% by ELISA in chloroplast total soluble protein (TSP) of the transplastomic plants. Results confirmed that the DARPin G3 gene in vegetative and generative T1 generation of transplastomic tobacco plants was stably and highly expressed.

Salinity stress affects morpho-physiological and biochemical traits of plants. The transgenic Bt plants play a significant role in pest control, but their response and ability to cope with environmental stresses still need to be evaluated. Therefore, effect of salinity stress at 0, 50, 100, 150, and 200 mM on morphological, physiological, and molecular traits of T3 transgenic tomato plants containing cry1Ab gene (CH-Falat-Bt) was investigated and compared with that of the non-transgenic control (CH-Falat). Evaluation of the morphological traits (leaf area, root length, fresh and dry weight of roots) at different salinity levels revealed that CH-Falat-Bt transgenic plants are more tolerant to salinity stress compared to CH-Falat non-transgenic plants. The chlorophyll content at 150 and 200 mM salinity levels was 12 and 9% plants, respectively. Moreover, the amount of RWC, carotenoids, proline and soluble sugars increased significantly in transgenic plants as salinity levels increased. The relative expression of SOS1 and SOS2 genes showed a significant increase in all salinity levels in CH-Falat-Bt transgenic plants compared to CH-Falat non-transgenic plants. The amount of electrolyte leakage in the transgenic plants was significantly reduced compared to the non-transgenic plants. The results of morphological, physiological, and molecular investigations of CH-Falat-Bt transgenic plants confirmed that the undesirable effects of salinity stress on transgenic plants is much less than non-transgenic ones. in general CH-Falat-Bt transgenic plants are more tolerant to different applied salinity levels than the wild variety.

The various medicinal functions of Yarrow have made it an important medicinal plant in medicine. Also, yarrow is a rich source of antioxidants and flavonoids that protect plants from the harmful effects of active oxygen species. The aim of this study was to investigate the effect of salicylic acid treatment on the expression pattern of two genes (aox2 and pal2) involved in the production of antioxidants and flavonoids in Yarrow plant. For this purpose, a factorial experiment was conducted in a completely randomized design including salicylic acid at two levels (0 and 50 mM) as the first factor and sampling time with two levels (24 and 48 hours) as the second factor in the greenhouse of the Faculty of Agriculture. First, the yarrow plant was subjected to hormonal treatment in Johnson's hydroponic environment, and 24 and 48 hours after the treatment, leaf tissue sampling was done. The results of qRT-PCR showed that salicylic acid stimulation significantly decreased the expression of two genes in the path of producing antioxidants in yarrow. The lowest relative expression of studied genes occurred 48 hours after treatment with salicylic acid. In general, the use of salicylic acid triggers molecular processes that result in the plant responding by changing the expression level of genes encoding antioxidants and flavonoids; therefore, it is suggested to use other stimulants such as jasmonic acid to investigate the expression of genes encoding antioxidants and flavonoids in future researches.

Soybean is the promising oilseed in the face of protein and oil shortage. In this study 16 advanced soybean genotypes, in terms of seed yield and yield components were evaluated using multivariate statistical methods. This experiment was carried out in the form of randomized complete block design (RCBD) in the research farm of Ardabil Agricultural and Natural Resources Research Center (Moghan) for two consecutive years (2017-2018). Combined analysis of variance emphasized the statistically significant differences for seed yield, yield components and growth period among these soybean genotypes. Based on the mean comparison results, G1, G5 and G11 genotypes had the highest grain yield, longest growth period was observed in G1, G16 and G6 genotypes and highest number of seeds per m2 was belonged to G1, G16 and G9 genotypes. The broad sense heritability for plant height, seed yield and number seed in m2 were 0.92.07, 75.31 and 79.25 percentage, respectively. Also, the results showed that there was a positive and significant correlation between seed yield and leaf area of per plant, growth period, number of seeds per m2 and number of pods per plant. Genotypes were classified into four distinct groups in cluster analysis and the Ward method. The results of principal component analysis and biplot confirmed by the clustering results, too.G1, G2, G5 and G11 genotypes belong to the first group from cluster analysis with higher seed yield and number of seed per m2, and these genotypes are recommended in future breeding programs.

Drought stress is one of the main environmental factors that affects growth and productivity of crop plants, including lentil. In the course of evolution evolution, crucial genetic regulations mediated by non-coding RNAs (ncRNAs) have emerged in plant in response to drought and other abiotic stresses. In the present study, after identifying lncRNAs within the expression profile of lentil, RNA-seq data and real-time PCR analyses were employed to examine the expression pattern of some of the identified lncRNAs under drought stress. Additionally, psych R package was used to generate the lncRNAs-DEGs co-expression network. A total of 3590 lncRNA sequences were identified in lentils transcriptome. Numerous lncRNAs were co-expressed with genes involved in circadian rhythm regulation, zinc ion response, photosynthetic photoreaction, and ion homeostasis. The LCUL_evgLocus_104392, LCUL_evgLocus_99066 and LCUL_evgLocus_61876 sequences were differentially expressed in response to drought stress. Examining the co-expression of these sequences with differentially expressed genes in response to drought stress, led to the identification of metabolic pathways associated with these sequences. In this study, lncRNA sequences were identified for the first time in lentil, and provided useful insights into the function of lncRNA in plant resistance to drought stress. The lncRNAs-DEGs co-expression network can lead to a better understanding of drought response mechanisms in lentil.

Tomato is the second most important vegetables, after potato, which has the highest area of cultivation worldwide. Acording to FAO statistics, Iran is the sixth producer of tomato cultivation in the world. However, more than 95 percent of vegetable seeds are imported into the country. The present study was conducted in order to evaluate commercial imported hybrids (8320, Eden, Matin and Xaman) and the F2 and F3 generations resulting from their self-breeding. In this regard, after the production of F2 and F3 generations, three generations (F1, F2 and F3) together with the control variety (Early Orbana y) were evaluated in the research farm of Seed and Plant Improvement Institute, Karaj, Iran, based on a randomized complete block design with four replications during 2019-2020. The analysis of variance showed that the difference among genotypes for single plant yield, days to flowering, average single fruit weight, number of fruits harvested and acidity (pH), was significant at the level of 1% probability and total soluble solids (TSS) was significant at the level of 5%. The results of the mean comparison showed that the highest mean of single plant yield belonged to 8320 F1 (10920/10g), the highest days to flowering was observed in Xaman F2 (47.01 days), the highest mean weight of single fruit was observed in Xaman F1 (115.50 g), the highest number of fruits harvested was in Xaman F1 (106.62), the highest amount of total soluble solids was in Matin F3 generation (4.96) and the lowest amount of acidity (pH) was in 8320 F1 (4.10). The results of estimating genetic parameters showed that most of the evaluated traits had high genetic and phenotypic variances, but a slight difference was observed between the coefficient of phototypic variation and the coefficient of genotypic variation, which indicates a small effect of environment on the control of these traits. Higher variance of dominance than additive variance in most traits caused the degree of dominance to be greater than one, Therefore, the possibility of control of traits by genes with dominance or over-dominance effects is high, and in order to improve these traits, the methods for hybrid development are suggested.

Luffa (Luffa cylindrica) is a plant from the Cucurbitaceae family that grows mostly in tropical and subtropical regions, as well as in most regions of Iran. In this research, the genetic diversity of nine native and non-native genotypes of L. cylindrica was investigated through the evaluation of the chloroplast trnH-psbA intergenic region (IGS). After sampling the young leaves, DNA extraction was performed by using the Dellaporta method, and PCR was conducted by using IGS intergenic region primers. After sequencing of the amplified products, their quality was determined using Chromas software and then aligned using ClustalW method by BioEdit and MEGA7 softwares. Next, the dendrogram of phylogenic relationships was drawn and the matrix of the difference and similarity of the sequences were determined. In the present research, by analyzing the relationships between studied samples, based on the trnH-psbA (IGS) marker, a strong intraspecies variation was observed in native and non-native L. cylindrical genotypes. The genetic distance matrix between the samples examined in this research ranged from 0 to 6.865 with an overall average distance of 2.53. The average value of synonymous and non-synonymous substitutions (dN/dS) for the IGS sequence was ds/dn = 0.68, which indicates positive and pure line selections in the process of natural selection of studied genotypes. The results of this research showed that trnH-psbA is a suitable marker for evaluation of the intraspecific diversity of luffa species.

Chickpea (Cicer arietinum L.) is one of the most important crops in the world. After bean and pea, chickpea is the most important cold season legume. Weeds are one of the most important threats to chickpea production worldwide. Due to the sensitivity of chickpea to herbicides, the majority of herbicides are used pre-emergence and the use of post-emergence herbicides is limited, and therefore weeds cause a significant decrease in chickpea yield. Therefore, herbicide-tolerant chickpea cultivars that have a higher flexibility for post-emergence herbicide application are needed to improve the chickpea yield. In this study, using seed bioassay and PCR method, resistance mechanism of Iranian chickpea cultivars to Pursuit herbicide was investigated. The results showed a significant genotypic and phenotypic variation among Iranian chickpea cultivars for tolerance to the Pursuit herbicide. The results did not show a difference between the target genes of Pursuit herbicide, ALS1 and ALS2, in all investigated cultivars with that of the reference sequences in the GenBank. This proves that the resistance observed in different chickpea cultivars to the herbicide Pursuit is not associated with the target site resistance mechanism and probably follows a non-target resistance mechanism. The superior genotypes of this study (Bivanij, Aksou, Mansour, TDS-Maragheh90-400 and TDS-Maragheh90-358) can be recommended to farmers and also suggested as parents to produce natural herbicide resistant chickpea plants in breeding programs.

To determine the ideal genotypes in terms of the quantity and quality of fruit, 32 genotypes of greengage were evaluated in a randomized complete block design with three replications at the research station of Horticultural Research Institute in Karaj during two cropping seasons 2018 and 2019. To evaluate the genotypes and to determine the ideal genotype, 26 traits related to fruit, fruiting and yield were used. Combined variance analysis of data showed that the genotype source of variation was significant for all studied traits at the level of 0.01 probability level. ASIIG index showed that the genotypes CodR, Cod100, Malayer, and Gojeh Siah are the best and most desirable genotypes with an index higher than 55%, respectively. Also, Cod98, Cod99, Gojeh Baghi Qasr Dasht, Gojeh Qomi, and Gojeh Holandi with ASIIG index higher than 49% were ranked next. The grouping of genotypes using ASIIG method diagrams, the genotypes CodR, Cod100, Cod98, Cod99, Gojeh Malayer, Gojeh Siah, and Gojeh Baghi Qasr Dasht were located in the ideal quartile. Using cluster analysis, the genotypes CodR, Cod100, black, and Malayer as well as completely ideal hypothetical genotype (+) were placed in a group at a distance line of 0.018. According to the results of this study, seven genotypes CodR, Cod100, Cod98, Cod99, Gojeh Malayer, Gojeh Siah, and Gojeh Baghi Qasr Dasht were selected as the ideal genotypes in terms of fruit quantity and quality. Finally, due to the high benefits of the ASIIG index, it was suggested that this index can be used in other horticultural products to determine the ideal genotype.

Environmental stress is one of the main factors that reduce the growth and performance of crops and threatening human food security. This study was conducted in order to investigate the effect of drought stress on the changes in biochemical traits and the level of expression of a MYB transcription factor gene in two wheat cultivars (Tajan and Zagros), under drought stress. The experiment was conducted as a factorial based on a completely randomized design with 3 replications. Drought treatments were applied at three levels of 40, 70 and 100% of field capacity 4 weeks after germination. Twenty days after the application of stress, leaves and roots were sampled in order to investigate the expression of MYB genes and measuring some biochemical traits. The results of examining the chlorophyll content under stress showed that the content of chlorophyll a and b decreased with increasing of stress intensity in different genotypes. The rate of reduction of chlorophyll a and b in Tajan genotype under severe stress was higher than Zagros genotype. Also, TBARM content under severe drought stress was significantly higher than moderate stress condition and this increase was seen in Tajen genotype more than Zagros genotype. qRT-PCR analysis showed that the MYB genes showed an increase in expression under drought stress. Furthermore, Zagros genotype, which is considered as a tolerant cultivar to drought stress, had a higher MYB expression level than Tajan cultivar for both genes, suggesting this cultivar for future breeding programs, also considering the importance MYB family genes during drought stress, the results can be used in molecular breeding and pyramiding breeding projects.