Adnan A, Mavinic DS, Koch, FA (2003) Pilot-scale study of phosphorus recovery through struvite crystallization-examining to process feasibility. Journal of Environmental Engineering and Science 2: 315-324.
Adetunji AT, Lewu FB, Mulidzi R, Ncube B (2017) The biological activities of β-glucosidase, phosphatase, and urease as soil quality indicators: A review. Journal of Soil Science and Plant Nutrition 17: 794-807.
Ahern CP, Staff IA (1994) Symbiosis in cycads, the origin and development of coralloid roots in Macrozamia communis (Cycadaceae). American Journal of Botany 81: 1559-1570.
Ahsan N, Marian M, Suga H, Shimizu M (2021) Lysinibacillus xylanilyticus strain GIC41 as a potential biostimulant. Microbes and Environments 36: 1-10.
Bamigboye SO, Tshisikhawe MP (2020) The impacts of bark harvesting on a population of Encephalartos transvenosus (Limpopo cycad), in Limpopo province, South Africa. Biodiversitas 21: 8-13.
Barea J, Pozo MJ, Azcòn-Aguilar C (2005) Microbial co-operation in the rhizosphere. Journal of Experimental Botany 56: 1761-1778.
Brenner ED, Stevenson DW, Twigg RW (2003) Cycads: Evolutionary innovations and the role of plant-derived neurotoxins. Trends in Plant Science 8: 446-452.
Buscot F, Varma A (2005) Microorganisms in Soils: Roles in Genesis and Functions. Springer Science Business Media, vol 3. Berlin/Heidelberg, Germany, pp. 422
Chang ACG, Chen T, Li N, Duan J (2019) Perspectives on endosymbiosis in coralloid roots: Association of cycads and cyanobacteria. Frontiers in Microbiology 10: 1888.
Condamine FL, Nagalingum NS, Marshall CR, Morlon H (2015) Origin and diversification of living cycads: A cautionary tale on the impact of the branching process prior in Bayesian molecular dating. BMC Evolutionary Biology 15: 1-5.
Costa J, Paulsrud P, Lindblad P (1999) Cyanobiont diversity within coralloid roots of selected cycad species. FEMS Microbiology Ecology 28: 85-91.
Cousins SR, Williamson VL, Witkowski ETF (2012) Uncovering the cycad taxa (Encephalartos species) traded for traditional medicine in Johannesburg and Durban, South Africa. South African Journal of Botany 78: 129-138.
Cousins SR, Williamson VL, Witkowski ETF (2013) Sifting through cycads: A guide to identifying the stem fragments of six South African medicinal Encephalartos species. South African Journal of Botany 84: 115-123.
Dehgan B (1983) Propagation and growth of cycad-A conservation strategy. Proceedings of the Florida State Horticultural Society 96: 137-139.
De Mandal S, Singh SS, Kumar NS (2018) Analysing plant growth promoting Bacillus sp. and related genera in Mizoram, Indo-Burma biodiversity hotspot. Biocatalysis and Agricultural Biotechnology 15: 370-376.
Donaldson JS (2003) Cycads status survey and conservation action plan. IUCN/SSC Cycad Specialist Group. IUCN Gland, Switzerland and Cambridge, United Kingdom, pp. 26-89.
Donaldson JS (2008) South African Encephalartos species. NDF Workshop Case Studies 1: 1-21.
Erdei B, Coiro M, Miller I, Johnson KR, Griffith PM, Murphy V (2019) First cycad seedling foliage from the fossil record and inferences for the Cenzoic evolution cycads. Biology Letters 15: 1-6.
Fisher JB, Vovides AP (2004) Mycorrhizae are present in cycad roots. Botanical Review 70: 16-23.
Golding JS, Hurter PJH (2003) A red list account of Africa’s cycads and implications of considering life-history and threats. Biodiversity and Conservation 12: 507-528.
Grobbelaar N, Hattingh W, Marshall J (1986) The occurrence of coralloid roots on the South African species of the Cycadales and their ability to fix nitrogen symbiotically. Suid-Afrikaanse Tydskrif vir Plant en Grond 52: 467-471.
Gupta G, Parihar SS, Ahirwar NK, Snehi SK, Singh V (2015) Plant growth promoting rhizobacteria (PGPR): current and future prospects for development of sustainable agriculture. Journal of Microbial and Biochemical technology 7: 96–102.
Gutiérrez-García K, Bustos-Díaz ED, Corona-Gómez JA, Ramos-Aboites HE, Sélem-Mojica N, Cruz-Morales P, Pérez-Farrera MA, Barona-Gómez F, Cibrián-Jaramillo A (2019) Cycad coralloid roots contain bacterial communities including Cyanobacteria and Caulobacter spp. that encode niche-specific biosynthetic gene clusters. Genome Biology and Evolution 11: 319–334.
Haas D, Dѐfago G. (2005) Biological control of soil-borne pathogens by fluorescent pseudomonads. Nature Reviews Microbiology 3: 307-319.
Hepler PK, Vidali L, Cheung AY (2001) Polarized cell growth in higher plants. Annual Review of Cell and Developmental Biology 17: 159-187.
Hu W, Coomer TD, Loka DA, Oosterhuis DM, Zhou Z (2017) Potassium deficieny affects the carbon-nitrogen balance in cotton leaves. Plant Physiology and Biochemistry 115: 408-417.
Hutchings A (1996) Zulu medicinal plants. Natal University press, Pietermaritzburg, South Africa.
Jeffries P, Gianinazzi S, Perotto S, Turnau K, Barea J (2003) The contribution of arbuscular mycorrhizal fungi in sustainable maintenance of plant health and soil fertility. Biology and Fertility of Soils 37: 1-16.
Keppel G (2002) Low genetic variation in pacific cycad conservation concerns for Cycas seemannii (Cycadaceae). Oryx 36: 41-49.
Kipp MA, Stüeken EE, Gehringer MM, Sterelny K, Scott JK, Forster PI, Strӧmberg CAE, Buick R (2019) Exploring cycad foliage as an archive of the isotopic composition of atmospheric nitrogen. Gebiology 18: 152-166.
Kong Z, Deng Z, Glick BR, Wei G, Chou M (2017) A nodule endophytic plant growth promoting Pseudomonas and its effects on growth, nodulation, and metal uptake in Medicago lupulina under copper stress. Annals of Microbiology 67: 49-58.
Laidlaw MJ, Forster PL (2012) Climate predictions accelerate decline for threatened Macrozamia cycads from Queensland, Australia. Biology 1: 880-894.
Li Q, Liu S, Li Y, Hao T, Chen S (2022) Nitrogen fixation by Paenibacillus polymyxa WLY78 is responsible for cucumber growth promotion. Plant and Soil 473: 507-516.
Lindblad P (2009) Cyanobacteria in symbiosis with cycads. Microbiology Monographs 8: 225-233.
Liu D, Liberton M, Yu J, Pakrasi HB, Bhattacharyya-Pakrasi M (2018) Engineering nitrogen fixation activity in an oxygenic phototroph. American Society for Microbiology 9: e01029-18.
Lu J, Yang F, Wang S, Ma H, Liang J, Chen Y (2017) Co-existence of Rhizobia and diverse non-rhizobial bacteria in the rhizosphere and nodules of Dalbergia odorifera seedlings inoculated with Bradyrhizobium elkanii, Rhizobium multihospitium-like and Burkholderia pyrrocinia-like strains. Frontiers in Microbiology 8: 2255.
Ma Y, Jiang H, Wang B, Zhou G, Yu S, Peng S, Hao Y, Wei X, Liu J, Yu Z (2009) Carbon storage of cycad and other gymnosperm ecosystems in China: Implications to evolutionary trends. Polish Journal of Ecology 57: 635-646.
Magadlela A, Kleinert A, Dreyer LL, Valentine AJ (2014) Low phosphorus conditions affect the nitrogen nutrition and associated carbon costs of two legume tree species from a Mediterranean-type ecosystem. Australian Journal of Botany 62: 1-9.
Magadlela A, Kleinert A., Steenkamp ET, Valentine AJ (2016) Variable P supply affects N metabolism in legume tree, Virgilia divaricata, from nutrient-poor Mediterranean-type ecosystems. Functional Plant Biology 43: -297.
Makaure BT, Aremu AO, Magadlela A (2022) Soil nutritional status drives the co‑occurrence of nodular bacterial species and arbuscular mycorrhizal fungi modulating plant nutrition and growth of Vigna unguiculata L. (Walp) in grassland and savanna
ecosystems in KwaZulu‑Natal, South Africa. Journal of Soil Sciences and Plant Nutrition: 1-16.
Mankga LT, Yessoufou K, Mugwena T, Chitakira M (2020) The cycad genus Cycas may have diversified from Indochina and occupied its current ranges through vicariance and dispersal events. Frontiers in Ecology and Evolution 8: 1-13.
Marler TE, Calonje M (2020) Two cycad species affect the Carbon, Nitrogen, and Phosphorus content of soils. Horticulturae 6: 24.
Marler TE, Lindstrӧm A (2018) Inserting cycads into global climate nutrient relations datasets. Plant Signalling and Behavior 13: e15475781-e15475786.
Marler TE, Lindstrӧm A (2021) Leaf nutrient relations of cycads in common garden. Tropical Conservation Science 14: 1-10.
Martínez-Hidalgo P, Hirsch AM (2017) The nodule microbiome: N2-fixing rhizobia do not live alone. Phytobiomes Journal 1: 70-82.
Matzner E (1992) Factors controlling Al-activity in soil solution in an acid forest soil of the German soiling area. Journal of Plant Nutrition and Soil Science 155: 333-338.
Míguez-Montero MA, Valentine A, Pѐrez-Fernández MA (2020) Regulatory effect of phosphorus and nitrogen on nodulation and plant performance of leguminous shrubs. AoB Plants 12: 1-11.
Nackley LL, Midgley GF, De wet Bӧsenberg J, Donaldson JS (2018) A cycad’s non-saturating response to carbon dioxide enrichment indicates Cenzoic carbon limitation in pre-historic plants. Austral Ecology 43: 447-455.
Pecundo MH, Chang ACG, Chen T, Cruz TEED, Ren H, Li N (2021) Full length 16S rRNA and ITS gene sequencing revealed rich microbial flora in roots of Cycas spp. In China. Evolutionary Bioinformatics 17: 1-16.
Peix A, Ramírez-Bahena MH, Velázquez E, Bedmar EJ (2015) Bacterial associations with legumes. Critical Reviews in Pant Science 34: 17-42.
Shay PE, Winder RS, Trofymow JA (2015) Nutrient-cycling microbes in coastal Douglas-fir forests: regional-scale correlation between communities, in situ climate, and other factors. Frontiers in Microbiology 6: 1–13.
Sinsabaugh RL, Moorhead DL (1994) Resource allocation to extracellular enzyme production: a model for nitrogen and phosphorus control of litter decomposition. Soil Biology and Biochemistry 26: 1305- 1311.
Sithole N, Pѐrez-Fernández M, Magadlela A (2019) Nutritional status of soils from KwaZulu-Natal nodulate symbiotic interactions and plant performance in Vigna unguiculata L. (Walp.). Applied Soil Ecology 142: 1-7.
Raimondo DC, Donaldson JS (2003) Responses of cycads with different life histories to the impacts of plant collecting: Simulation models to determine important life history stages and population recovering times. Biological Conservation 11: 345-358.
Raimondo D, von Staden LV, Foden W, Victor JE, Helmen NA, Turner RC, Kamundi, DA, Manyama PA (2009) Red list of South African plants, Strelitzer 25, South African National Biodiversity Institute, Pretoria.
Ravele AM, Makhado RA (2009) Exploitation of E. transvenosus outside and inside Mphaphuli cycad nature reserve, Limpopo province, South Africa. African Journal of Ecology 48: 105-110.
Roodt D, Lohaus R, Sterck L, Swanepoel RL, van de Peer Y, Mizrachi E (2017) Evidence for an ancient whole denome duplication in the cycad lineage. PLoS ONE 12: 1-8.
Taylor R, Williams M, Sistani K (1991) N2 fixation by soybean-Bradyrhizobium combinations under acidity, low P and high Al stresses. Plant and Soil 131:293-300.
Valentine AJ, Benedito VA, Kang Y (2011) Legume nitrogen fixation and soil abiotic stress: from physiology to genomics and beyond. Annual Plant Reviews 42: 207-248.
Vance CP (2001) Symbiotic nitrogen fixation and phosphorus acquisition. Plant nutrition in a world of declining renewable resources. Plant Physiology 127: 390-398.
Verma P, Yadav AN, Khannam KS, Kumar S, Saxena AK, Suman A (2016) Molecular diversity and multifarious plant growth promoting attributes in Bacilli associated wheat Triticum aestivum L. rhizosphere from six diverse agro-ecological zones in India. Journal of Basic Microbiology 56: 44-58.
Verma P, Yadav AN, Khannam KS, Saxena AK, Suman A (2017) Potassium-solubilizing microbes: diversity, distribution, and role in plant growth promotion. In: Panpatte, D., Jhala, Y., Vyas, R., Shelat, H. (eds), Microorganisms for green revolution. Microorganisms for Sustainability, vol 6. Springer, Singapore, pp. 125-149.
Xu X, Du X, Wang F, Sha J, Chen Q, Tian G, Zhu Z, Ge S, Jiang Y (2020) Effects of potassium levels on plant growth, accumulation and distribution of carbon and nitrate metabolism in apple dwarf rootstock seedlings. Frontiers in Plant Science 11: 904.
Yessoufou K, Bamigboye SO, Daru BH, van der Bank M (2014) Evidence of constant diversification punctuated by a mass extinction in the African cycads. Ecology and Evolution 4: 50-58.
Yousuf J, Thajudeen J, Rahiman M, Krishnankutty SP, Alikunj AA, Abdulla MH (2017) Nitrogen fixing potential of various heterotrophic Bacillus strains from a tropical estuary and adjacent coastal regions. Journal of Basic Microbiology 57: 922-932.
Zheng W, Song T, Bao X, Bergman B, Rasmussen U (2002) High cyanobacterial diversity in coralloid roots of cycads revealed by PCR fingerprinting. FEMS Microbiology Ecology 40: 201-222.