نشریه مهندسی ژنتیک و ایمنی زیستی
سال یازدهم شماره 2 (پیاپی 22، پاییز و زمستان 1401)

Ascochyta blight disease of chickpea plants caused by Ascochyta rabiei is one of the important agents that reduce the yield of this crop around the world. In this study, the effect of separate and combined application of two arbuscular mycorrhizal fungi (AMF) including Glomus versiform and Glomus fasciculatum, and four plant growth promoting rhizobacteria (PGPR) including Bacillus subtilis BS, Bacillus velezensis JPS19, Bacillus pumilus INR7 and Alcaligenes faecalis 1624 for controlling the Ascochyta blight of chickpeas was investigated under greenhouse conditions. The fungicide chlorothalonil, which was used for comparison, was the most effective in reducing the disease. All biological treatments reduced the severity of the disease compared to the diseased control, and most of them enhanced the growth parameters (wet and dry weight of roots, wet and dry weight, and the length of foliage) in the presence of the pathogen, except for root length. Compared to the separate application of AMF, some PGPR+AMF combined treatments had a synergistic effect on disease inhibition, enhanced growth, or root mycorrhizal colonization rate, but this effect was not present in all combinations. There was no direct relationship between the amount of mycorrhizal colonization and the reduction of Ascochyta blight; In general, the use of AMF and PGPR, separately and in combination, was effective in reducing the Ascochyta blight disease and enhancing the growth of chickpeas, but the efficiency of the combined inoculation was not always synergistic and depended on the bacterial and mycorrhizal strains used.

Using Ephestia kuehniella larvae as hosts, invert emulsion (IE) and an aqueous suspension (AS) of Beauveria bassiana (isolate IR34-JS2) and Metarhizium anisopliae (isolate IR41-TT1) formulations were compared when stored for three months at either 3 °C or 25 °C. Initially, IE formulations of isolates JS2 and TT1 were 13- and 14-fold more virulent than AS formulations, based on their LC50 values. JS2 LC50 values increased 1.3- and 5.6-fold for the AS and IE formulations, respectively, after 3 months storage at 3 °C, and 1.6 and 7.3-fold after 3 months at 25 °C, whereas values for TT1 increased 2.1- and 6.8-fold for these formulations at 3 °C, and 3.9- and 15.7-fold at 25 °C. Formulation and storage temperature interacted significantly to affect conidial production post-storage. Vegetative growth, conidiogenesis, and conidial germination of both isolates were better preserved at 3 °C than at 25 °C in vitro. The IE formulation preserved vegetative growth capacity better than the AS formulation at both temperatures, and better preserved conidiogenesis at 3 °C, a temperature that also improved TT1 conidial germination in the IE formulation. At 3 °C, the IE formulation yielded a relative speed of kill that was 3.5- and 1.3-fold faster for the JS2 and TT1 isolates, respectively, than the AS formulation. It can be concluded that IE formulations were superior to AS formulations, and that storage at 3 °C will help preserve the biological activity and pathogenicity of these fungi.

Asthenozoospermia is one of the major causes of male infertility, the motility of the sperm is decreased or absent in these men. Male infertility occurs in approximately 50% of infertile couples and among the many genetic causes of infertility, we can mention cytogenetic abnormalities, gene defects, and epigenetic factors. The aberrant mRNA expression of some genes can also impair sperm motility. This research aims to study the difference in expression of the Intraflagellar transport 122 gene (IFT122) and the Ectonucleoside triphosphate diphosphohydrolase 4 gene (ENTPD4) in the semen sample of 20 infertile men with asthenozoospermia and 10 healthy normozoospermic men with Real-time polymerase chain reaction. The results demonstrated that the expression level of the ENTPD4 gene increased (p = 0.01) and the IFT122 gene decreased significantly (p = 0.0001) in the asthenozoospermia group in comparison with the control group. The IFT122 gene plays a role in the assembly and maintenance of flagella, and the ENTPD4 gene hydrolyzes triphosphate nucleotides to diphosphate and monophosphate in energy metabolism. The current study emphases their importance in male infertility mechanism.

Salinity is considered as complex stress and plants show different reactions to this stress based on their genetic structure. Therefore, it is possible to achieve the salinity-tolerant genotype in plants through creating changes in the genetic structure and breeding activities. Tomato is in the group of plants sensitive to salinity stress. Distinct studies have been explained different indicators for tolerance to salt stress in tomato. Identifying a reliable indicator in the early stages of plant growth under salt stress is necessary to evaluate a large number of samples in plant breeding projects. Based on this, in the current project, 10 tomato genotypes were evaluated under salt stress in the form of a randomized complete block design with three replications. The results of variance analysis showed a statistically significant difference between genotypes for the stress tolerance index in the traits of root dry weight (RDW), root fresh weight (RFW), leaf dry weight (LDW), leaf fresh weight (LFW), stem fresh weight (SFW), total dry weight (TDW) and total fresh weight (TFW). The results of cluster analysis and GGEbiplot analysis classified the genotypes into four groups. Based on the results of multiple regression analysis, the index of stress tolerance with total dry weight (STI-TDW) and total fresh weight (STI-TFW) was recognized as a suitable index for evaluating tolerance to salt stress in tomato genotypes. It seems that these index can be used for the screening of tomato germplasms under salt stress for plant breeding projects.

Chrysomphalus dictyospermi (Morgan, 1889) (Hem.: Diaspididae) is one of the most important citrus pests. Since weather conditions in the north of Iran are suitable for this pest, it infects the entire regions in a short period. Various pesticides are widely used to control this pest. These toxins have an adverse effect on human health, ecosystem and reduce the population of natural enemies of pests. The present study aimed to evaluate the effect of Thiamthoxam (Actamia 24% SC) at 0.5, 0.75, Spirotetramat (Movento 100% SC) at 1 per 1000, and Chlorpyrifos (Dorsban 48% SC) at 2 per thousand pesticides on different developmental stages of C. dictyospermi and its biological control agent Chilocorus bipustulatus (Linnaeus, 1758) (Col.: Coccinellidae) in Gilan and Golestan, Iran. In this research, a new formulation of thiamethoxam pesticide named Actamia was used. The results showed that in both provinces, the highest efficiency is related to Actamia and Spirotetramat insecticides with a dose of 1 per 1000 after 14 days. Moreover, the studies showed that these compounds have the most negative effects on C. bipustulatus, and the most important natural enemy of this pest.

Iran is an arid and semi-arid country and more than 70% of its agricultural lands are rainfed. So far, no oilseed plant suitable for different regions of the country has been introduced. Camelina (Camelina sativa L.) is an oily-medicinal plant of the Brassicaceae family, a low-input plant, with low water-fertilizer requirements, resistant to a variety of common diseases and pathogens and suitable for cultivation in grain rotation. In this study, genetic variation of 32 doubled haploid lines of Camelina was evaluated by using 11 REMAP primers. Eight primers produced clear and scorable strips and totally, 74 bands were produced which 59 of them were polymorphic )79/72 %). IRAP1+P6 and IRAP1+P8 primers produced the lowest number of bands (4 bands) and IRAP979+P4 marker produced the most of bands (15 bands). The amount of primer polymorphism varies from 23.69% to 100% and the amount of PIC varies from 0.38 to 0.41. Clustering based on the Jaccard similarity placed the lines in six main groups. According to the principal components analysis, the first two components contributed 21.51% of the variance, which indicated the appropriate coverage of the markers at the genome level. Thus, it seems that the REMAP marker, with its high polymorphism and high distribution in the Camelina genome, is a suitable marker for investigating the genetic diversity in this plant.

With the rising cost of chemical fertilizers and their negative impact on the environment, there is growing interest in the use of beneficial microorganisms to enhance soil and plant fertility. The present study showed that bacterial isolates can produce auxin and solubilized phosphate, which increases germination and plant growth indices under laboratory and greenhouse conditions. To investigate the effects of different nitrogen fertilizer rates on yield and nitrate accumulation in tomato plants, an experiment with eight bacterial treatments and three rates of zero, 300, and 900 kg urea per hectare was set up in a completely randomized factorial trial with three replicates in the greenhouse. Results showed that the growth-promoting bacteria significantly increased shoot dry weight and nitrate concentration in the absence of nitrogen fertilizer compared to the non-inoculated control. Evaluation of nitrate content in the plants showed that excessive fertilization with more than 300 kg of urea may lead to nitrate accumulation in the control plants. In all bacterial treatments, nitrate levels were lower than in the untreated control, even when three times the recommended amount of fertilizer was applied. In conclusion, plant probiotic isolates in integrated nitrogen fertilizer management systems can improve fertilizer efficiency and yield and reduce nitrate accumulation in plants

Seed inoculation with endemic plant growth promoting rhizobacteria (PGPR) is a suitable approach in health management, improving the production and quality of agricultural products. The purpose of this research is to isolate and identify plant growth enhancing bacteria from the rhizosphere of wheat plants in Selseleh city (Iran) and to evaluate the beneficial characteristics of bacterial isolates.  The screening of PGPR isolates was done using tests of the ability to produce indole acetic acid (IAA), siderophore, protease, bacterial swarming  motility, biofilm formation, phosphate solubility and investigating the effect of bacterial isolates on wheat seeds germination in laboratory conditions. Among the 100 bacterial isolates extracted from the soil around the rhizosphere of wheat, the best four isolates were selected. The superior isolates were identified based on their morphological and biochemical characteristics as well as the nucleotide sequence of the 16sDNA region as Pseudomonas sp., Pseudomonas brassicacearum, Exiguobacterium sp and Acinetobacter calcoaceticus. In this research, Pseudomonas sp. strain has the highest IAA production (5.59 µg ml-1), siderophore production (2.35 cm), protease production (1.7 cm) and phosphate dissolution (390 µg ml-1) among four bacterial isolates. The highest percentage of inhibiting the growth of pathogenic fungus Fusarium graminearum, the cause of Fusarium blight disease of wheat spike, was related to P. brassicacearum isolate, which was evaluated as 49.33%.

The high nutritional value has made potato the fourth most important food source after wheat, rice and corn worldwide. In this study, in order to identify and investigate the expression pattern of the most significant genes involved in the synthesis of flavonoids at different potato tuber developmental stages, the RNA sequencing data was obtained from three different potato tuber development stages, namely; initiation of stolon formation, stolon swallowing and initiation of tuber formation. In order to validate the expression of identified genes involved in the biosynthesis of flavonoids in potato tuber (62 genes), the expression of significant genes were evaluated by using qRT-PCR method. The results of this study showed that at the stolon swallowing stage, 10 and 11 genes had a significant increase and decrease in expression, respectively. Comparing the stolon swallowing stage with initiation of stolon formation, 7 and 20 genes showed a significant increase and decrease in expression. At the initiation of tuber formation, it was found that 14 genes had a significant decrease in expression. In total, 4 key genes CYP98A3, ACT, SAT and BEAT were identified with significant changes among developmental stages. The amount of flavonoid in the three developmental stages was also significantly increased with the transition of developmental stages. The average of flavonoid content was 1.9, 7.2 and 24.8 mg/gFW for tree developmental stages, respectively. Since CYP98A3, ACT, SAT and BEAT are key genes involved in the biosynthesis of secondary metabolites in the potato tuber, they can be considered as possible candidate genes for alteration of flavonoids content in potato.

Bacterial canker is one of the most devastating diseases on the stone fruit trees. This disease is caused by a gram-negative bacterium called Pseudomonas syringae pv. syringae. Consecutive use of antibiotics and copper compounds has caused the emergence of new resistance races. One of the most promising replacement compounds is the use of bacteriophages. In this research, 56 soil samples were collected from the suspected trees of having bacterial canker from northwestern of Iran. In order to check the presence of phage particles, double-layer soft-agar technique was used to purify individual phage plaques. A total of 75 phage isolates, all of which had clear plaques, were isolated from the samples, among them, five phages with the highest lysing capability were selected for electron microscopy and greenhouse studies. Among the selected phages, three phages showed morphological similarity to Myoviridae, Tectividae and Microviridae families. Although all five phages were effective in reducing the growth of bacterial population in liquid culture medium, significant differences were observed between them. The cocktail prepared from the mixture of five phages showed a much stronger effect than the individual phages. The results of the greenhouse tests showed that these phages effectively reduce the development of the pathogen inside the bean and can reduce the bacterial symptoms in the treated plant by 90%. The five isolated phages in this research showed acceptable results in the control of the agent of bacterial canker of the stone fruit trees in the laboratory and in greenhouse experiments, and their actual formulation is recommended at the regional level.

Potato (Solanum tuberosum L.) (2n=4x=48), is a tetraploid and heterozygous crop. This plant is the world's most important food crop after rice, wheat and corn. According to the current pressure of increasing population, potato is believed to be a vital crop to meet the food need of the growing population. Although conventional breeding approaches have improved potato yield, tetrasomic inheritance makes potato research and breeding difficult through traditional crossbreeding. By specific applications of genome editing, one or a few traits can be added to a commercial variety, hence crossbreeding method can be avoided. In recent years, genome editing via the CRISPR-Cas9 system, by providing simple and robust new technologies, has helped plant scientists to accelerate different plant breeding processes. With advances being made, the insertion, expression or silencing of economically important genes is being used to improve potato production and the quality traits of current potato varieties. Furthermore, genome sequence information coupled with established genetic transformation and regeneration procedures make potato a strong candidate for genetic engineering. The purpose of this article, is to review the researches done on potato using the CRISPR-Cas9 system, in order to improve traits and increase crop productivity.

The causative agent of scab disease or potato scab, which are different species of the genus Streptomyces, has a relatively wide host range. This disease has caused a lot of economic damage in most of the cultivating areas. Researches on the virulence mechanisms of plant-pathogenic Streptomyces spp. have shown the importance of the thaxtomin phytotoxins as main pathogenicity determinants produced by several species. In addition, other phytotoxic specialized metabolites such as coronafacoil, Concanamycin and FD-891 along with the production of phytohormones and secretory proteins may have a role in the development or severity of the disease caused by species related to this genus. There are wide range of pathogenic factors in the species related to the Streptomyces genus. This phenomenon shows the potential of the species of each region to accept pathogenic genes and create new species, which is very important and decisive from the disease management point of view. The purpose of this review is to gain an understanding of the molecular mechanisms of plant pathogenicity to use improved management methods to control potato scab disease and other plant diseases caused by species related to this genus.