Arbuscular mycorrhizal fungi persist in dying Euphorbia ingens trees
- Vivas, M, Crous, C J, Dames, Joanna F, van der Linde, J A, Coetzee, M P A, Roux, J
- Authors: Vivas, M , Crous, C J , Dames, Joanna F , van der Linde, J A , Coetzee, M P A , Roux, J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440465 , vital:73784 , https://doi.org/10.1016/j.sajb.2017.12.009
- Description: Forest declines have been reported with increasing regularity during the last decade and are expected to increase due to the ongoing environmental changes. During adverse environmental conditions, plant symbioses with mycorrhizas can help to reduce plant stress. Mycorrhizas are symbiotic associations between fungi and roots of living plants. Plants offer carbohydrates to the fungus and the fungus improves the acquisition of nutrients and water to the plant. Specifically, arbuscular mycorrhizal (AM) fungi are the most abundant mycorrhizas. In South Africa, there are increasing reports describing the decline of native Euphorbia ingens trees. This study analysed the presence and abundance of AM fungal colonisation in the roots of E. ingens trees, and the number of AM fungal spores in the surrounding soil, with the aim to improve the understanding of the rapid decline of these trees. AM fungal colonisation and spores in relation to the soil properties were also analysed. Soil and root samples were collected from different rates of declining E. ingens trees at three sites in South Africa. AM fungal colonisation of the roots was assessed and fungal spores in the surrounding soil were enumerated. Soil phosphorus, mineral nitrogen and pH were analysed from the soil samples. The results showed that AM fungi are associated with E. ingens trees. AM abundance was influenced by site specific properties and not by E. ingens health. Moreover, the level of soil NO3− and soil texture significantly influenced AM colonisation in roots and the number of spores enumerated. These preliminary findings provide background information for further research into the large-scale decline of E. ingens populations in South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Vivas, M , Crous, C J , Dames, Joanna F , van der Linde, J A , Coetzee, M P A , Roux, J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440465 , vital:73784 , https://doi.org/10.1016/j.sajb.2017.12.009
- Description: Forest declines have been reported with increasing regularity during the last decade and are expected to increase due to the ongoing environmental changes. During adverse environmental conditions, plant symbioses with mycorrhizas can help to reduce plant stress. Mycorrhizas are symbiotic associations between fungi and roots of living plants. Plants offer carbohydrates to the fungus and the fungus improves the acquisition of nutrients and water to the plant. Specifically, arbuscular mycorrhizal (AM) fungi are the most abundant mycorrhizas. In South Africa, there are increasing reports describing the decline of native Euphorbia ingens trees. This study analysed the presence and abundance of AM fungal colonisation in the roots of E. ingens trees, and the number of AM fungal spores in the surrounding soil, with the aim to improve the understanding of the rapid decline of these trees. AM fungal colonisation and spores in relation to the soil properties were also analysed. Soil and root samples were collected from different rates of declining E. ingens trees at three sites in South Africa. AM fungal colonisation of the roots was assessed and fungal spores in the surrounding soil were enumerated. Soil phosphorus, mineral nitrogen and pH were analysed from the soil samples. The results showed that AM fungi are associated with E. ingens trees. AM abundance was influenced by site specific properties and not by E. ingens health. Moreover, the level of soil NO3− and soil texture significantly influenced AM colonisation in roots and the number of spores enumerated. These preliminary findings provide background information for further research into the large-scale decline of E. ingens populations in South Africa.
- Full Text:
- Date Issued: 2018
Morphological and symbiotic root modifications for mineral acquisition from nutrient-poor soils
- Kleinert, Aleysia, Benedito, V A, Morcillo, R J L, Dames, Joanna F, Cornejo-Rivas, P, Zuniga-Feest, A, Delgado, Mabel, Muñoz, Gaston
- Authors: Kleinert, Aleysia , Benedito, V A , Morcillo, R J L , Dames, Joanna F , Cornejo-Rivas, P , Zuniga-Feest, A , Delgado, Mabel , Muñoz, Gaston
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448640 , vital:74748 , https://doi.org/10.1007/978-3-319-75910-4_4
- Description: Plants have the ability to form vast root systems with lengths measuring up to several kilometers and branch roots numbering in millions. These expansive root systems provide plants with a large surface area for water and nutrient uptake from the surrounding soil. Roots also have further equally important functions to fulfil such as vegetative reproduction, hormone biosynthesis, photoassimilate storage, and the establishment of symbiotic relationships with microorganisms. Root systems have evolved several adaptations to aid them in maximizing nutrient uptake. These adaptations can be morphological such as changes in the root architecture or formation of cluster roots or may be symbiotic associations with mycorrhizae or nitrogen-fixing bacteria. Improvement of nutrient acquisition and use by plants is imperative for economic, humanitarian, and environmental reasons, and a better understanding of the processes governing root adaptations would enable us to adapt fertilizer and pesticide programs. In this chapter, we will focus on both morphological (cluster roots) and symbiotic root adaptations (associations with ectomycorrhizae, arbuscular mycorrhizae, and nitrogen-fixing bacteria) to soil nutrient deficiencies.
- Full Text:
- Date Issued: 2018
- Authors: Kleinert, Aleysia , Benedito, V A , Morcillo, R J L , Dames, Joanna F , Cornejo-Rivas, P , Zuniga-Feest, A , Delgado, Mabel , Muñoz, Gaston
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448640 , vital:74748 , https://doi.org/10.1007/978-3-319-75910-4_4
- Description: Plants have the ability to form vast root systems with lengths measuring up to several kilometers and branch roots numbering in millions. These expansive root systems provide plants with a large surface area for water and nutrient uptake from the surrounding soil. Roots also have further equally important functions to fulfil such as vegetative reproduction, hormone biosynthesis, photoassimilate storage, and the establishment of symbiotic relationships with microorganisms. Root systems have evolved several adaptations to aid them in maximizing nutrient uptake. These adaptations can be morphological such as changes in the root architecture or formation of cluster roots or may be symbiotic associations with mycorrhizae or nitrogen-fixing bacteria. Improvement of nutrient acquisition and use by plants is imperative for economic, humanitarian, and environmental reasons, and a better understanding of the processes governing root adaptations would enable us to adapt fertilizer and pesticide programs. In this chapter, we will focus on both morphological (cluster roots) and symbiotic root adaptations (associations with ectomycorrhizae, arbuscular mycorrhizae, and nitrogen-fixing bacteria) to soil nutrient deficiencies.
- Full Text:
- Date Issued: 2018
Purification and characterization of an amyloglucosidase from an ericoid mycorrhizal fungus (Leohumicola incrustata)
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440405 , vital:73780 , https://doi.org/10.1186/s13568-018-0685-1
- Description: This study aimed to purify and characterize amyloglucosidase (AMG) from Leohumicola incrustata. AMG was purified to homogeneity from cell-free culture filtrate of an ERM fungus grown in a modified Melin–Norkrans liquid medium. The molecular mass of the AMG was estimated to be 101 kDa by combining the results of Sephadex G-100 gel filtration, sodium dodecyl sulphate–polyacrylamide gel electrophoresis, and zymography. The Km and kcat values were 0.38 mg mL−1 and 70 s−1, respectively, using soluble starch as a substrate. The enzyme was stable at 45 °C (pH 5.0), retaining over 65% activity after a pre-incubation period of 24 h. The metal inhibition profile of the AMG showed that Mn2+ and Ca2+ enhanced activity, while it was stable to metals ions, except a few (Al3+, Co2+, Hg2+ and Cd2+) that were inhibitory at a concentration higher than 5 mM. Thin layer chromatography revealed that only glucose was produced as the product of starch hydrolysis. The amylase from L. incrustata is a glucoamylase with promising characteristics such as temperature stability over an extended period, high substrate affinity and stability to a range of chemicals. Also, this study reports for the first time the possibility of using some culturable ERM fungi to produce enzymes for the bio-economy.
- Full Text:
- Date Issued: 2018
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440405 , vital:73780 , https://doi.org/10.1186/s13568-018-0685-1
- Description: This study aimed to purify and characterize amyloglucosidase (AMG) from Leohumicola incrustata. AMG was purified to homogeneity from cell-free culture filtrate of an ERM fungus grown in a modified Melin–Norkrans liquid medium. The molecular mass of the AMG was estimated to be 101 kDa by combining the results of Sephadex G-100 gel filtration, sodium dodecyl sulphate–polyacrylamide gel electrophoresis, and zymography. The Km and kcat values were 0.38 mg mL−1 and 70 s−1, respectively, using soluble starch as a substrate. The enzyme was stable at 45 °C (pH 5.0), retaining over 65% activity after a pre-incubation period of 24 h. The metal inhibition profile of the AMG showed that Mn2+ and Ca2+ enhanced activity, while it was stable to metals ions, except a few (Al3+, Co2+, Hg2+ and Cd2+) that were inhibitory at a concentration higher than 5 mM. Thin layer chromatography revealed that only glucose was produced as the product of starch hydrolysis. The amylase from L. incrustata is a glucoamylase with promising characteristics such as temperature stability over an extended period, high substrate affinity and stability to a range of chemicals. Also, this study reports for the first time the possibility of using some culturable ERM fungi to produce enzymes for the bio-economy.
- Full Text:
- Date Issued: 2018
The potential use of treated brewery effluent as a water and nutrient source in irrigated crop production
- Taylor, Richard P, Jones, Clifford L W, Laing, Mark D, Dames, Joanna F
- Authors: Taylor, Richard P , Jones, Clifford L W , Laing, Mark D , Dames, Joanna F
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440476 , vital:73785 , https://doi.org/10.1016/j.wri.2018.02.001
- Description: Brewery effluent (BE) needs to be treated before it can be released into the environment, reused or used in down-stream activities. This study demonstrated that anaerobic digestion (AD) followed by treatment in an integrated tertiary effluent treatment system transformed BE into a suitable solution for crop irrigation. Brewery effluent can be used to improve crop yields: Cabbage (Brassica oleracea cv. Star 3301), grew significantly larger when irrigated with post-AD, post-primary-facultative-pond (PFP) effluent, compared with those irrigated with post-constructed-wetland (CW) effluent or tap water only.
- Full Text:
- Date Issued: 2018
- Authors: Taylor, Richard P , Jones, Clifford L W , Laing, Mark D , Dames, Joanna F
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440476 , vital:73785 , https://doi.org/10.1016/j.wri.2018.02.001
- Description: Brewery effluent (BE) needs to be treated before it can be released into the environment, reused or used in down-stream activities. This study demonstrated that anaerobic digestion (AD) followed by treatment in an integrated tertiary effluent treatment system transformed BE into a suitable solution for crop irrigation. Brewery effluent can be used to improve crop yields: Cabbage (Brassica oleracea cv. Star 3301), grew significantly larger when irrigated with post-AD, post-primary-facultative-pond (PFP) effluent, compared with those irrigated with post-constructed-wetland (CW) effluent or tap water only.
- Full Text:
- Date Issued: 2018
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