Showing 11 results for Pathogen
Asad Masoumiasl,
Volume 2, Issue 1 (3-2013)
Abstract
There are some strategies for adaptation to environmental changes in plants, including a range of molecular-biochemical and also intent or induced mechanisms. The proper response of plant is occurred when it receives extracellular signals and transfers those inside the cell. Ethylene, identified as a plant hormone which regulates the plant reactions under some circumstances. Ethylene production has been enhanced in response to biological stresses like plant infection by pathogens or herbivores attack. Most of induced defense genes are regulated by transduction pathways signal. The biosynthesis pathway of ethylene from the amino acid methionine has been studied well. In this pathway, the produced ethylene activates the resistant genes resulting to incidence of plant resistance. The responsible genes in rice and also the ethylene-expressed resistance genes have been discussed in this review.
Mohammad Abdollahi,
Volume 2, Issue 1 (3-2013)
Abstract
Most nematodes are free-living. They live in oceans, fresh waters and soil and feed on bacteria, fungi and other nematodes. Some are predators and some are parasites of plants and animals. Some of the latter group are insect-associated. There are different types of relations between insects and nematodes. Beneficial nematodes that cause disease in insects are referred to as “entomopathogenic” and have the ability to kill the insects. Entomopathogenic nematodes from the genera Steinernema and Heterorhabditis have proven to be the most effective as biological control organisms. Only the infective juvenile stage of entomopathogenic nematodes will survive in the soil, find and penetrate insect pests. In this paper, different types of association between nematode and insect with emphazing on entomopathogenic nematode species have been reviewed.
Saeid Tabein, Seyed Ali Akbar Behjatnia,
Volume 3, Issue 2 (9-2014)
Abstract
In addition to the full-length viral DNA genome, various types of smaller specific DNA molecules have been isolated from plants infected by DNA viruses. These DNAs are usually derived from viral genomes by different ways or have non-viral genome sequences. Some of these DNA have no significant effect on the virus cycle and on the incidence and progression of the disease, while some of them inducing the viral disease symptoms. These components that are known as satellite, defective and defective interfering DNAs, depend on helper viruses for replication, encapsidation and movement in plants. Satellites have no significant homology with the helper virus genome. However, they are required for inducing disease symptoms. While defective and defective interfering DNAs exhibit high homology with the genome of helper viruses, only defective interfering DNAs have ability to interfere with virus replication and with disease symptom induction and development. In this paper, the characteristics of these subviral DNAs and the possible mechanisms by which they are generated and transmitted in virus infected plants are discussed.
Banafsheh Safaiefarahani, Reza Mostowfizadeh-Ghalamfarsa,
Volume 6, Issue 1 (2-2017)
Abstract
Safaiefarahani B. & Mostowfizadeh-Ghalamfarsa R. 2017. Phytophthora spp. interspecific hybrids and their danger for agriculture. Plant Pathology Science 6(1): 33-46.
Interspecific hybridization is an important evolutionary process contributing to adaptation and speciation. During the last decade, advances in the molecular taxonomy techniques have led to increasing the number of descriptors interspecific hybrids in the genus Phytophthora. In Phytophthora hybrids, inheriting and recombining genes from both parents may result in increased aggressiveness and broader host range compared with either parent. Some Phytophthora natural hybrids have also been reported in Iran to date. Consequently, identification, pathogenicity and host range tests of these hybrids as well as preventing the formation of new hybrids before experiencing large economic losses are recommended for management of plant diseases caused by this fungal-like organisms.
Zabihollah Azami-Sardooei , Abdolrahman Mirzaei , Farnaz Fekrat ,
Volume 6, Issue 1 (2-2017)
Abstract
Nowadays, control of plant pathogens and weeds is more difficult and expensive than in the past. In last decades, due to adoption of inappropriate management methods and excessive use of agrochemicals, the soil fauna and flora threatened. Accordingly, many of ecologists and plant pathologists tried to find some alternative methods of pest and pathogen control. Soil solarization is of these approaches that is widely used against soil pathogens. This is an ecofriendly and safe as well as low cost and efficient method which can be used to control the plant pathogens, pests and weeds. As a part of integrated pest management program, this approach applies the ecological principles to protect the environment and reduce the hazards of pesticides. In this review, we have described the history and benefits of soil solarization and also the principles of this method
Soraya Mirzapour, Mostafa Darvishnia, Eidi Bazgir, Hossein Mirzaei Najafgholi,
Volume 9, Issue 2 (8-2020)
Abstract
Mirzapour S, Darvishnia M, Bazgir E, Mirzaei Najafgholi H (2020) Pathogenic variation of
Didymella rabiei isolates causing Chickpea blight in three western provinces of Iran. Plant Pathology Science 9(2):1-13. DOI: 10.2982/PPS.9.2.1
Introduction: Chickpea blight, caused by Didymella rabiei, is the most limiting factor in chickpea production areas in the world, including the western provinces of Iran. The aim of this study was to investigate the pathogenic diversity of the isolates collected from western provinces of Iran (Ilam, Lorestan and Kermanshah) on differential lines of chickpea, as well as the relationship between pathogenic diversity of the isolates and their geographical origins. Materials and Methods: During the 2017-18 chickpea growing season, samples of infected plants were collected from fields in western provinces and transferred to the laboratory. Then 100 pure isolates of D. rabiei were obtained. Based on the location of collection, the isolates were divided into 20 groups. Based on the morphological characteristics, one isolate from each group was selected as a representative for greenhouse experiments. The pathogenic diversity of theses 20 isolates was assessed on eight differential lines of chickpea. The factorial experiments were performed in a completely randomized block design under greenhouse conditions. Results: The results of analysis of variance showed that there was a significant difference between differential lines and isolates at a probability level of p<0.01. Based on the response of the differential lines, the pathogenic isolates were grouped into three pathogenic groups, including pathogenic group 1 (weakly aggressive), group 2 (aggressive or moderately aggressive), and group 3 (highly aggressive). The isolates from Kermanshah and Lorestan Province were classified into Group 1 and the Ilam isolates into Groups 1, 2 and 3. The greatest severity of the disease was found in three isolates of Ilam province. The variety ILC3996 showed the highest resistance to all isolates. Conclusion: D. rabiei isolates from three western provinces of Iran are divided into three pathogenic groups: 1 (low aggressive), 2 (moderately aggressive), and 3 (highly aggressive). Highly aggressive isolates identified in Ilam province can be used in chickpea breeding programs to produce resistant cultivars to the disease.. The wild variety ILC3996 has resistant genes against these pathogenic groups and showed resistance to all of these isolates.
Dorna Forghani, Eidi Bazgir, Mehdi Nasr Esfahani, Mostafa Darvishnia,
Volume 9, Issue 2 (8-2020)
Abstract
Forghani D, Bazgir E, Nasr Esfahani M, Darvishnia M (2020) Pathogenicity severity of Iranian isolates of Rhizoctonia solani in Burren potato cultivar. Plant Pathology Science 9(2):63-72. DOI: 10.2982/PPS.9.2.63.
Introduction: Rhizoctonia solani Kühn is a soil borne fungus that causes stem canker and black scurf and severely damages crop in various potato growing areas in Iran. The aim of this study was to investigate the pathogenicity of various fungal isolates from different potato growing areas in Iran on the Burren cultivar. Material and Methods: In this study, The pathogenicity of 70 isolates of Rhizoctonia solani from major potato growing areas in Iran including the provinces of Ardabil, Isfahan, Fars, Kurdistan, Kerman, Lorestan and Hamedan was investigated on the potato cultivar ‘Burren’ in completely randomized design experiment under greenhouse conditions. Results: The analysis of variance showed that the pathogenicity of the isolates was very different at probability level of 1% is significant, and therefore they were divided into different groups. Conclusions: The isolates of Ardabil-1, Ardabil-5, Isfahan-14, Fars-26, Fars-29, Kurdistan-34, Kurdistan-39, Kurdistan-40, Kerman-47 and Hamedan-66 had the highest pathogenicity, while the isolates Fars-21, Isfahan-20, Hamedan-65 and Isfahan-18 showed the lowest pathogenicity, respectively.
Eisa Nazerian, Sahar Sayad,
Volume 10, Issue 1 (2-2021)
Abstract
Nazerian E, Sayad S (2021) Control methods of plant pathogens in irrigation system. Plant Pathology Science 10(1): 117-127. Doi: 10.2982/PPS.10.1.117.
Many plant pathogens can spread into irrigation water in farms, gardens or greenhouses and cause disease in various crops. So far, a large number of plant pathogens including 43 fungal-like organisms, 27 fungi, eight bacteria, 26 viruses and 13 nematodes have been isolated and reported from water sources and water transmission systems. In many greenhouses, various pesticides are used to prevent the spread and control of these pathogens, which imposes costs, soil or water pollution, and the possibility of resistance in pathogens. Different methods of water treatment to control aquatic pathogens in the irrigation system using chemicals such as chlorine, chlorine dioxide, copper, silver and ozone, physical methods such as water filtration, heat, ultraviolet rays and the use of biosurfactants such as rhamnolipid and nitrapyrin, are described in this article.
Aminallah Tahmasebi,
Volume 10, Issue 1 (2-2021)
Abstract
Tahmasebi A (2021) The role of ubiquitin in plant-virus interactions. Plant Pathology Science 10(1):141-152. Doi: 10.2982/PPS.10.1.141.
Plant viruses cause major losses to agricultural crops worldwide. Plants react to the virus infections via several defense mechanisms, such as ubiquitination. Ubiquitin (Ub) and ubiquitin proteasome system (UPS) play key role in the function modification and degradation of proteins in plants. Ub attachment to the cellular proteins alters the stability, the cellular establishment or activity of the target protein. The key role of UPS has been revealed in defense mechanisms and other plant processes. Viruses as obligate intracellular parasites have evolved mechanisms to interfere UPS. In some cases, it has been shown that viral proteins were targeted by this system. Ubiquitination plays an important role in plant–virus interaction which can lead to plant resistance or pathogenicity in the host plant. Therefore, further understanding of UPS and its role in plant-virus interaction can develop novel methods to increase resistance to viral infections in plants.
Maryam Khezri, Mahmoud Reza Karimi Shahri, Abolghasem Ghasem,
Volume 12, Issue 1 (3-2023)
Abstract
Khezri, M., Karimi Shahri, M. R., & Ghasemi, A. (2023). Bacterial rot disease of saffron corm and leaf. Plant Pathology Science, 12(1), 74-83. Doi: 10.2982/PPS.12.1.74
Saffron is one of the valuable agricultural products and its dried stigma is used as medicine and is known as a precious spice. Infection of the plant's reproductive organs plays an important role in the spread of pathogens. The saffron is reproduced via corms, and using healthy and pathogen-free corms is the best and most effective strategy to prevent the spread of soil-borne pathogens in new areas and fields. Saffron corm rot disease is caused by some fungal and bacterial pathogens. Burkholderia gladioli pv. gladioli is the causal agent of saffron leaf and corm rot disease. The bacterium survives in the soil for a long time, and it is transmitted through the infected soil, farming tools, and corms. In recent years, this disease has been reported from Khorasan Razavi province. In this article, along with introducing the bacterial disease of saffron leaves and corms rotting, strategies to prevent the occurrence and spread of the disease have been presented.
Saeedeh Dehghanpour Farashah,
Volume 12, Issue 2 (9-2023)
Abstract
Dehghanpour Farashah S (2023) Defense responses by nitric oxide in plant-pathogen interaction. Plant Pathology Science 12(2):130-142.
The control of diseases in agriculture often relies on pesticides and chemical fertilizers, which negatively affect the rhizosphere natural microflora and ecosystem balance. Today, researchers are looking to replace these chemicals with other environment friendly agents to improve agricultural production and control plant pathogens. Research on the interaction of nitric oxide (NO) with plant pathogens has shown that NO is a key messenger in the response of plants to biotic and abiotic stresses. Due to the role of NO in the regulation of plant defense genes, especially through programmed cell death, it has attracted the attention of many plant pathologists. Although NO plays an important role in the hypersensitive reaction in response to various biotic and abiotic stresses, it has been found that NO also plays a role in regulating the expression of genes related to non-specific resistance. In this review, the role of nitric oxide in plant-pathogens interaction has been investigated.
