Document Details
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Document Type |
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Thesis |
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Document Title |
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Isolation, Characterization and Identification of Endophytes from Some Plants Growing in Hot spring area at Gumiqa in Saudi Arabia عزل وتوصيف وتعريف الاندوفايتس من بعض النباتات النامية في منطقة العين الحارة بغميقة في المملكة العربية السعودية |
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Subject |
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Faculty of Science |
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Document Language |
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Arabic |
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Abstract |
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Endophytes represent a diverse group of microorganisms that make symbiotic associations with plants, these microorganisms supposed to affect the ecology of plants, by frequently enhancing the capacity of the host plant to survive and resist environmental and biological stresses through production of beneficial bioactive compounds. Recently, the demand for increasing the agriculture production by using endophytes as bio-fertilizers and bio-pesticides, have caused a resurgence of interest in finding new endophytes that have the ability to produce unique biological substances products. Several researchers have extensively studied the diversity and beneficial characteristics of endophytes in different plant ecologies. However, a little knowledge is available on diversity, and interaction of endophyte communities in plants struggling for existence in extreme environments. Therefore, the present study was focused on isolation, characterization, and identification of endophytes from four different plants growing at Hot spring, Gumiqa in Saudi Arabia. A total of 117 endophytic bacteria and 57 endophytic fungi were obtained from different organs (leaves, stems, and roots) of four plants Heliotropium pterocarpum, Datura innoxia, Ammannia baccifera, and Prosopis juliflora. Fifty bacterial and fifteen fungal isolates that exhibited differences in phenotypic aspect were subjected to molecular analysis by using partial 16S rDNA gene sequencing for bacteria and ITS for fungi. The phylogenetic analysis revealed that the majority of endophytic bacterial isolates belonged to γ-protobacteria (55 %), β-protobacteria (12 %), α-protobacteria (8 %), Firmicutes (18 %), Actinobacteria (4 %), and Bacteroidetes (2 %), and the majority of endophytic fungal isolates belonged to Ascomycota (99 %), and Basidomycota (1 %), with various species. Among the endophyte isolates, only 28 bacteria, and 11 fungi were selected for screening of plant growth promotion and controlling plant against pathogens, in vitro. Among these isolates, (24 bacterial isolates) produced ammonia, (18 bacterial and 8 fungal isolates) solubilized of phosphate, with solubilizing index ranged (1.2 to 1.4) for the bacterial isolates and (1.04 to1.13) for the fungal isolates, (17 bacterial and 8 fungal isolates) produced siderophore to acquire iron. In addition, the bacterial isolates produced variable amounts of phytohoromnes, such as gibberellic acid (GA) ranged from 0.001±0.001 to 0.445±0.08 mg/ml broth, and indole acetic acid (IAA) ranged from 0.001±0.001 to 0.056±0.01 mg/ml broth. Most of the isolates (22 bacterial isolates) were able to utilize 1-aminocyclopropane-1-carboxylic acid (ACC) as sole source of nitrogen on experimental plate, these bacterial isolates deaminated ACC and produced a quite appreciable amount of α-ketobutyrate with ACC deminase activity ranged from 0.005±0.02 to 0.107± 0.02 mmol.〖mg〗^(-1) h^(-1). Furthermore, the endophytes (11 bacterial and 2 fungal isolates) showed antibacterial activity against at least one of the test human pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa). Also, all the bacterial and fungal isolates exhibited antifungal activity against at least one of the plant pathogens (Fusarium oxyspourum, Talaromyces funiculosus, Curvularia khuzestanica, and Curvularia sp.). In addition, all the bacterial and fungal isolates produced different extracellular enzymatic activities, including: cellulase, pectinase, amylase, lipase, chitinase, and protease. In this study, interesting observations were found for each endophyte isolate. The bacterial isolates Sphingomonas koreensis, which isolated from Ammannia baccifera, and Prosopis juliflora, and Kocuria sediminis, which isolated from Heliotropium pterocarpum, these isolates considered as novel bacterial endophytes. In conclusion, plants growing under extreme conditions harbor a diversity of unique endophytes. These endophytes could be having multiple activities in promoting plant growth and controlling infection against phytopathogens, which lead to be used as biological products for plants. Thus, bioprospecting needs to search for other unique plant ecologies in Saudi Arabia to isolate more novel endophytes with bioactive compounds that can be used in the agricultural, industrial and environmental fields. |
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Supervisor |
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Prof. Dr. Magda Mohammed Aly |
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Thesis Type |
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Doctorate Thesis |
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Publishing Year |
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1443 AH
2022 AD |
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Co-Supervisor |
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Dr. Amal Yahya Aldhebiani |
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Added Date |
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Tuesday, December 20, 2022 |
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Researchers
| مدى فيصل عشكان | Ashkan, Mada Faisal | Researcher | Doctorate | |
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