Inserting cycads into global nutrient relations data sets

Marler, Thomas E.; Lindström, Anders J.

doi:10.1080/15592324.2018.1547578

Cited by 10 publications

(7 citation statements)

References 51 publications

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“…In the process, the cattle deposit dung and urine, enriching the forest soils. According to [27], the chemical composition of rhizosphere soils in the root and litterfall zone may be altered by cycads. Thus, rhizosphere soils were collected directly beneath the selected plants and along the dripline of the leaf canopy.…”

Section: Study Sites and Speciesmentioning

confidence: 99%

Exploring the Influence of Ecological Niches and Hologenome Dynamics on the Growth of Encephalartos villosus in Scarp Forests

Motsomane,

Suinyuy,

Pérez-Fernández

et al. 2024

Soil Systems

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Information on how bacteria in plants and soil, along with extracellular enzymes, affect nutrient cycling in Encephalartos villosus growing in phosphorus deficient and acidic scarp forests is lacking. Bacteria in coralloid roots, rhizosphere, and non-rhizosphere soils were isolated to determine the potential role of soil bacterial communities and their associated enzyme activities in nutrient contributions in rhizosphere and non-rhizosphere soils. The role of soil characteristics and associated bacteria on E. villosus nutrition and nitrogen source reliance was investigated. Encephalartos villosus leaves, coralloid roots, rhizosphere, and non-rhizosphere soils were collected at two scarp forests. Leaf nutrition, nitrogen source reliance, soil nutrition, and extracellular enzyme activities were assayed. A phylogenetic approach was used to determine the evolutionary relationship between identified bacterial nucleotide sequences. The clustering pattern of isolated bacterial strains was primarily dictated by the ecological niches from which they originated (rhizosphere soil, non-rhizosphere soil, and coralloid roots), thus indicating that host-microbe interactions may be a key driver of this pattern, in line with the hologenome theory. There were insignificant differences in the phosphorus and nitrogen cycling enzyme activities in E. villosus rhizosphere and non-rhizosphere soils in both localities. Significantly positive correlations were recorded between nitrogen and phosphorus cycling enzymes and phosphorus and nitrogen concentrations in rhizosphere and non-rhizosphere soils. Additionally, more than 70% of the leaf nitrogen was derived from the atmosphere. This study challenged the conventional expectation that environmental filters alone dictate microbial community composition in similar habitats and revealed that host-microbe interactions, as proposed by the hologenome theory, are significant drivers of microbial community structuring. The isolated bacteria and their plant growth promoting traits play a role in E. villosus nutrition and nitrogen source reliance and secrete nutrient cycling enzymes that promote nutrient availability in rhizosphere and non-rhizosphere soils.

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Section: Study Sites and Speciesmentioning

confidence: 99%

Exploring the Influence of Ecological Niches and Hologenome Dynamics on the Growth of Encephalartos villosus in Scarp Forests

Motsomane,

Suinyuy,

Pérez-Fernández

et al. 2024

Soil Systems

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“…Cycads are ancient gymnosperms that have persisted through many extinction events, survived competition with fast-growing angiosperms and environmental stresses such as drought and nutrient de ciencies (Brenner et al, 2003;Marler and Lindstrӧm, 2018;Erdei et al, 2019). The Zamiaceae and Stangeriaceae are the most diverse cycad families in South Africa (Cousins et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Encephalartos villosus relies on atmospheric nitrogen than soil derived nitrogen to maintain growth in nutrient-deficient and acidic soils

Motsomane¹,

Suinyuy²,

Magadlela

2023

Preprint

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Background Encephalartos villosus is a forest understory dwarf cycad growing in nutrient-deficient and acidic soils due to their association with plant growth promoting bacteria. This study investigated the effects of soil characteristics (pH, nutrition, total cation, and exchange acidity) on cycad-microbe symbiosis and the nitrogen (N) source preference of E. villosus growing in Rhebu and Oceanview, Eastern Cape, South Africa. Methods Coralloid roots and leaf material from targeted E. villosus individuals in both locations were analysed for N isotope, total plant N, and total plant phosphorus (P). Results Plant growth promoting bacteria were associated with E. villosus growing in Rhebu and Oceanview. The culturable bacteria strains isolated from the coralloid roots of E. villosus growing in Rhebu and Oceanview with N-fixing traits were Lysinibacillus fusiformis, Rhizobium huautlense, Stenotrophomonas sp., Enterobacter cloacae, and Paenibacillus polymyxa. Encephalartos villosus growing in Rhebu and Oceanview effectively fixed more than 70% of its total N from the atmosphere. Less than 25% of the total N utilized by E. villosus was derived from the soil. There were no significant variations in the leaf number, length, total N, and P in E. villosus growing in Rhebu and Oceanview. Conclusions The findings of this study revealed that E. villosus maintains growth and plant nutrition in nutrient-deficient and acidic soils by establishing symbiotic associations with plant growth-promoting bacteria and relying mostly in atmospheric N.

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“…As a group, cycads remain the most threatened plants worldwide [1][2][3]. Much interest in cycad gardening and species conservation has created a need for practical knowledge that greatly exceeds the actual knowledge that has accumulated from applied research [4,5]. Therefore, cycad conservationists often lack the information that is needed to inform management decisions [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Reporting of leaf nutrient concentrations for various gymnosperms such as cycads has been accruing, but most cycad species remain unstudied within this research agenda [5]. Moreover, the methods that underpin leaf sampling protocols have not been defined adequately for the plant group.…”

Section: Introductionmentioning

confidence: 99%

Distribution of Elements along the Rachis of Cycas micronesica Leaves: A Cautionary Note for Sampling Design

Marler

Krishnapillai

2019

Horticulturae

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Cycas micronesica K.D. Hill trees on the island of Yap were used to determine the influence of position along the leaf rachis on macro- and micro-nutrient concentrations and how leaf age affected the results. The outcomes revealed improvements to sampling protocols for future cycad leaf research. The concentration of every element except carbon and copper was influenced by leaflet position along the rachis. Most elements exhibited similar patterns for the oldest and youngest leaves on a tree, but the influence of position along the rachis for nitrogen, phosphorus, calcium, zinc, and boron was highly contrasting for old versus young leaves. The elements with the greatest variability along the rachis were potassium, phosphorus, manganese, and zinc, with the difference in basal and terminal leaflets as great as four-fold. Sampling leaflets at one position on a cycad leaf may generate inaccurate elemental concentration results for most essential nutrients other than carbon and copper. We have added position of sampled leaflets within leaves as a mandatory component of what is recorded and reported for future cycad leaf tissue analyses. Leaflets that span the full length of the rachis should be included in cycad leaf samples that are collected for tissue analysis.

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Inserting cycads into global nutrient relations data sets

Cited by 10 publications

References 51 publications

Exploring the Influence of Ecological Niches and Hologenome Dynamics on the Growth of Encephalartos villosus in Scarp Forests

Exploring the Influence of Ecological Niches and Hologenome Dynamics on the Growth of Encephalartos villosus in Scarp Forests

Encephalartos villosus relies on atmospheric nitrogen than soil derived nitrogen to maintain growth in nutrient-deficient and acidic soils

Distribution of Elements along the Rachis of Cycas micronesica Leaves: A Cautionary Note for Sampling Design

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