جستجوی مقالات مرتبط با کلیدواژه "اندوفیت" در نشریات گروه "بیوتکنولوژی و ژنتیک گیاهی"

alfalfa with the scientific name Medicago sativa is the most important fodder plant in Iran and many parts of the world. This plant is known as the queen of fodder plants due to its high nutritional value and the possibility of planting in different climates. The aim of the current research is to isolate and identify endophytic bacteria from alfalfa roots and investigate their antagonistic effects on human pathogenic bacteria.
The sterilized alfalfa root pieces, after being crushed, were cultured in Tyoglycollate Broth and Muller Hinton Broth liquid culture media for enrichment. After liquid cultures, culture was done on Muller Hinton agar, eosin methylene blue and McConkey agar. Endophytic bacteria were identified by gram staining method and biochemical tests. The antagonistic activity of isolated bacteria was investigated by steric crossing and bilayer methods. From the bacteria with antagonistic effects, DNA extraction was performed and with the use of universal primer, 16SrRNA gene was amplified. The PCR product was sequenced and a phylogeny tree was drawn.
The results showed that alfalfa endophyte bacteria had antagonistic activity and finally, two endophytes were investigated in terms of molecular identity, which belonged to Enterobacter and Pseudomonas genera.
Based on the results, endophytic bacteria have a great diversity and significant antibacterial effects.

Different genera of fungi coexist in Elaeagnus angustifolia plant. These fungi are able to produce some valuable extracellular enzymes, from a research and economic perspective. In this research, the presence of endophytic fungi and some of their enzymatic properties were investigated in Elaeagnus angustifolia tree. Sampling was performed from healthy tissues (leaf, fruit, Branch and bark) of Elaeagnus angustifolia trees of Hamedan city Initial identification of fungi was conducted using fungal identification keys. After isolation and purification, endophytic fungi were examined for the presence of some extracellular enzymes. Forty seven fungal isolates of different genera, such as Aspergillus, Penicillium, Fusarium, and Alternaria were isolated. The results showed that the activity of proteases, cellulase, pectinase and catalase enzymes of different fungi were different. No lipase activity was proven in these fungi. Amylase activity in these fungi showed that the enzyme activity varied depending on the type of consumed substrate. This is the first report of isolation of fungal endophytes of Elaeagnus angustifolia tree.

Enzymes are noble metabolites which extensively utilize in different industries. Currently, the production of enzymes by microorganisms is one of the best and most effective methods for the production of these enzymes. Hydrolytic enzymes are one of the most important enzymes that produced by various microorganisms, including endophytes.

In order to investigate the presence of endophytic fungi from two plants Euphorbia esula L. and Chenopodium album L, in summer of 1395, six different plants parts including flowers, leaves, seeds, roots, crowns and stems were sampled from healthy plants in Hamadan province. After fungal purification, the presence of extracellular hydrolytic enzymes such as amylase, catalase, protease, cellulase, pectinase, and xylanase were investigated by adding the corresponding substrate in the endophytic fungal culture medium.

After sterilizing the surface of collected plants and transferring samples to Potato Dextrose Agar culture media, a total of 31 endophytic fungi were isolated. The results showed that 84% of fungal isolates had amylase, 81% catalase, 71% protease, 61% cellulase, 39% pectinase and 26% xylanase activity. Morphological studies of the isolated fungi showed that some them belongs to the Fusarium, Alternaria and Trichoderma spp.

The results obtained in this study showed that endophytic fungi isolated from Euphorbia esula L. and Chenopodium album L, plants are capable of in vitro production of various enzymes. Among them, the presence of important enzymes like cellulase, pectinase and protease in some isolates, emphasis the significance of results. Based on the vast application and magnitudes of these enzymes in different industries, the importance of these fungi and demands for more experiments on enzyme activity arespecified.

Endophytes are known as a potential source of active natural compounds for use in medicine, agriculture, and industry. Medicinal plants are valuable sources for the study of endophytes. One of the most important medicinal and industrial plants in Iran is the Barije; Ferula gummosa.boiss, whose endophytes have not been studied yet. 

In this study, 20 bacterial isolates were isolated from different organs of the plant. Endophytes were identified using morphological and then molecular characteristics. The antioxidant properties of endophytic extracts were investigated by degradation of free radicals DPPH (DiPhenyl-1-Picryl Hydrazyl free radical).  

The R4 bacterium with the IC50 value of 2.5 mg / ml had the highest and the SK6 bacterium with an IC50 value of 8.8 mg / ml had the lowest antioxidant activity. The molecular identification of R4 bacteria revealed 98% similarity to the bacterium Rahnella aquatilis. It was also observed by phytochemical analysis that endophytic extracts with phenolic compounds exhibit significant antioxidant activity.  

Barije has different bacterial endophytes with different antioxidant properties. One of these bacteria is Rahnella aquatilis, which has high antioxidant properties. The presence of phenolic compounds in the extract of this bacterium is probably related to its antioxidant properties.

Nitrogen is one of the most important elements needed by plants, but plants are unable to reduce atmospheric nitrogen into ammonia and use it directly for its growth. Nitrogen fixing microorganisms, with the process of nitrogen fixation, provide the nitrogen required for plant utilization and play an important role in soil fertilization. The aim of this study was to evaluate nitrogen fixation in endophytic microorganisms isolated from root nodules of alder (Alnus subcordata) and Russian olive (Elaeagnus angustifolia) in Golestan province. A total of 50 nodule specimens were collected and cultured on nitrogen-free medium. Microorganisms were identified using biochemical and molecular tests. Nitrogen fixation of isolates was also evaluated using acetylene reduction and gas chromatography (GC). The two genera of Streptomyces badius strain BL225 and Actinomadura citrae strain DSM 43461 were identified as endophytic actinobacteria, Cladosporium cladosporioides strain F1 and Cryptococcus victoriae strain p41A001 were found as Ascomycota and Basidiomycota phyla of fungal endophytes, respectively. Cladosporium cladosporioides strain F1 and Cryptococcus victoria strain p41A001 had a high ability in nitrogen fixation. The root nodules of alder (A. subcordata) and Russian olive (E. angustifolia) carry the endophytic microorganisms with nitrogen fixation ability, therefore, the endophytes can be used as biocontrol agents in agriculture.

Endophytes are symbiont microorganisms within apoplast or symplast of plants that promote growth, control phytopathogens, increase plant resistance to stress and improve plant growth conditions. The aim of this study was identification of endophytes from six rice cultivars in Khouzestan province and assessment of their effects on growth of the host plant. For this purpose, a suspension was prepared from sterilized seeds, and their endophytes were isolated in LB broth. The ability of isolates in nitrogen fixation, auxin production and phosphate solubilizing was discovered. The seeds of Champa cultivar were then infected by endophytes and growth and physiologic outcomes of this treatment were studied. As a result of this study six endophytes belong to Bacillus, Staphylococcus and Erwinia genus were isolated from them only the Erwinia sp. was able to fix N2, dissolve phosphate and produced auxin more than others. Treatment with Erwinia sp. significantly increased the fresh and dry weight of aerial parts and root and aerial part length and density of hair roots. The auxin and carbohydrate content of treated rice with Erwinia sp. had significant difference than control. No significant difference was observed for chlorophyll a and b chlorophylls in different treatments and untreated plants produced more a and b chlorophylls. While there was significant difference for carotenoid between endophyte treated samples and untreated ones. Finally based on the obtained results it can be suggested that Erwinia sp. as an endophyte has significant effect on increasing of Champa cultivar performance and improvement main characteristics of this cultivar.

Rhizoctonia rot disease is one of the most important diseases of crop plants and has a worldwide distribution. Despite the relative effects of certain chemicals to control the disease, it seems that biological control is one of the appropriate methods of control. Beauveria bassiana is an endophytic fungus that can colonize a wide range of plants in a systemic manner and enhance plant resistance. In this study the ability of three strains of B. bassiana fungus for control of cotton damping- off were investigated. Results showed that the isolates used, in addition to their endophytic activities, can significantly reduce the disease severity in plants. Based on the result of greenhouse studies and measurement of peroxidase activity and total plant protein, the KJ24 isolate at a concentration of 107 spores/ml was found to be the most suitable treatment to control the disease. It appears that this ability is due to the stimulation of plant growth. Moreover, concentrations of 107 spores/ml of isolates TS7 and TS12, were also able to significantly reduce the severity of the disease. Based on the observed increase of total protein in plants treated with these isolates, the reduction of disease could be due to the induction of plant resistance by these isolates.