Physiological Integration and inducible Crassulacean Acid Metabolism: Possible Drought Stress Response Mechanisms in the California Invasive Clonal Plant Carpobrotus edulis

Event Center BC

Carpobrotus edulis, an introduced succulent species, poses a serious threat to native plant communities in coastal Mediterranean habitats around the world, including the California coast. C. edulis produces new plants (ramets) which are physically connected by stolons (horizontal stems). Previous studies demonstrate the ability of C. edulis to switch from C3 to Crassulacean Acid Metabolism (CAM) photosynthesis, allowing the plant to save water when exposed to droughted conditions. As well, previous studies have shown improved performance in C. edulis stolon connected ramets. Presumably, this improved performance occurs through sharing resources like water. A previous study in 2013 on seasonal microclimate effects on phenology and plant physiology for C. edulis at the San Clemente State Beach (SCSB) did not detect CAM induction for C. edulis in any of the seasonal micro-climates. The aim of this study is to establish C. edulis cuttings from the SCSB population at California State University San Bernardino (CSUSB) and expose the plants to controlled drought stress for hydrologically connected and isolated ramets in an outdoor growing facility under the warm summer conditions of inland southern California. These results may help to more completely understand the drought tolerance mechanisms involved with C. edulis and its invasive ecology.