Exclusion, Amelioration, Tolerance: An investigation of the physiological basis for tolerance in serpentine Mimulus guttatus
Year: 2014
Type: dissertation
Abstract: As sessile organisms, plants must cope with a variety of abiotic stress factors, including the mineral composition of soil.In serpentine soils, the low calcium-to-magnesium ratio has been shown to limit the growth and survival of many plant species.Some species are adapted to serpentine, employing a variety of physiological mechanisms.However the physiological basis for tolerance has not been clearly defined.Populations of Mimulus guttatus are found growing on and off of serpentine soil and were used here to identify a potential mechanism conferring tolerance to serpentine-adapted populations.Using a combination of soil and hydroponic culture reciprocal transplants, it was demonstrated that the serpentine and non-serpentine populations were differentially adapted to their native soils and thus ecotypes of M. guttatus.Biomass and photosynthetic rates of non-serpentine M. guttatus are dramatically reduced in low Ca:Mg conditions relative to the serpentine ecotype.Root and shoot concentrations of calcium (Ca) and magnesium (Mg) reflect external treatment conditions and indicate that tolerance to low Ca:Mg in the serpentine ecotype is not due to exclusion of Mg.Leaf expansion and photosynthetic rates of excised Many thanks to Professor Elizabeth Van Volkenburgh, who, as my advisor, provided unwavering support of my research
Author: Emily Palm
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Life on land
Open Access status: green
Funder: National Science Foundation
OpenAlex ID: W2565261809