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Full-Text Articles in Life Sciences
Impacts Of Nutrient Enrichment On Native And Non-Native Plants In Serpentine Soil, Amber R. Williams, Mary Devlin, N. Rajakaruna
Impacts Of Nutrient Enrichment On Native And Non-Native Plants In Serpentine Soil, Amber R. Williams, Mary Devlin, N. Rajakaruna
STAR Program Research Presentations
Serpentine soil, derived from serpentinite, California’s state rock, is characterized by its harsh nature - due to its low levels of essential nutrients and exceptionally high levels of toxic heavy metals.In California, serpentine soils are characterized by high levels of plant endemism and rarity. Plants occurring in serpentine soil exhibit extreme tolerance of harsh soil conditions, and are typically out-competed in ‘normal’ soils due to the cost associated with physiological specialization. Atmospheric nutrient deposition is contributing to a greater invasion of non-native grass species on serpentine soils, outcompeting the native species and threatening them with local extinction. Our greenhouse study …
Inducing Ni Sensitivity In The Ni Hyperaccumulator Plant Alyssum Inflatum Nyárády (Brassicaceae) By Transforming With Cax1, A Vacuolar Membrane Calcium Transporter, Rasoul Ghasemi, Hoorieh Share, Roza Sharif, Robert S. Boyd, Nishanta Rajakaruna
Inducing Ni Sensitivity In The Ni Hyperaccumulator Plant Alyssum Inflatum Nyárády (Brassicaceae) By Transforming With Cax1, A Vacuolar Membrane Calcium Transporter, Rasoul Ghasemi, Hoorieh Share, Roza Sharif, Robert S. Boyd, Nishanta Rajakaruna
Biological Sciences
The importance of calcium in nickel tolerance was studied in the nickel hyperaccumulator plant Alyssum inflatum by gene transformation of CAX1, a vacuolar membrane transporter that reduces cytosolic calcium. CAX1 from Arabidopsis thaliana with a CaMV35S promoter accompanying a kanamycin resistance gene was transferred into A. inflatum using Agrobacterium tumefaciens. Transformed calli were subcultured three times on kanamycin-rich media and transformation was confirmed by PCR using a specific primer for CAX1. At least 10 callus lines were used as a pool of transformed material. Both transformed and untransformed calli were treated with varying concentrations of either calcium (1–15 mM) or …
Sympatric Serpentine Endemic Monardella (Lamiaceae) Species Maintain Habitat Differences Despite Hybridization, Kathleen M. Kay, Suzie Woolhouse, Brett A. Smith, Nathaniel S. Pope, Nishanta Rajakaruna
Sympatric Serpentine Endemic Monardella (Lamiaceae) Species Maintain Habitat Differences Despite Hybridization, Kathleen M. Kay, Suzie Woolhouse, Brett A. Smith, Nathaniel S. Pope, Nishanta Rajakaruna
Biological Sciences
Ecological differentiation and genetic isolation are thought to be critical in facilitating coexistence between related species, but the relative importance of these phenomena and the interactions between them are not well understood. Here, we examine divergence in abiotic habitat affinity and the extent of hybridization and introgression between two rare species of Monardella (Lamiaceae) that are both restricted to the same serpentine soil exposure in California. Although broadly sympatric, they are found in microhabitats that differ consistently in soil chemistry, slope, rockiness and vegetation. We identify one active hybrid zone at a site with intermediate soil and above-ground characteristics, and …
Diversity And Functional Traits Of Lichens In Ultramafic Areas: A Literature Based Worldwide Analysis Integrated By Field Data At The Regional Scale, Sergio E. Favero-Longo, Enrica Matteucci, Paolo Giordani, Alexander G. Paukov, Nishanta Rajakaruna
Diversity And Functional Traits Of Lichens In Ultramafic Areas: A Literature Based Worldwide Analysis Integrated By Field Data At The Regional Scale, Sergio E. Favero-Longo, Enrica Matteucci, Paolo Giordani, Alexander G. Paukov, Nishanta Rajakaruna
Biological Sciences
While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a …
Lessons On Evolution From The Study Of Edaphic Specialization, Nishanta Rajakaruna
Lessons On Evolution From The Study Of Edaphic Specialization, Nishanta Rajakaruna
Biological Sciences
Plants adapted to special soil types are ideal for investigating evolutionary processes, including maintenance of intraspecific variation, adaptation, reproductive isolation, ecotypic differentiation, and the tempo and mode of speciation. Common garden and reciprocal transplant approaches show that both local adaptation and phenotypic plasticity contribute to edaphic (soil-related) specialization. Edaphic specialists evolve rapidly and repeatedly in some lineages, offering opportunities to investigate parallel evolution, a process less commonly documented in plants than in animals. Adaptations to soil features are often under the control of major genes and they frequently have direct or indirect effects on genes that contribute to reproductive isolation. …