Effect of cold acclimation on the photosynthetic performance of two ecotypes of Colobanthus quitensis (Kunth) Bartl.

Abstract

The effects of cold acclimation of two ecotypes (Antarctic and Andes) of Colobanthus quitensis (Kunth) Bartl. Caryophyllaceae on their photosynthetic characteristics and performance under high light (HL) were compared. Non-acclimated plants of the Antarctic ecotype exhibited a higher (34%) maximal rate of photosynthesis than the Andes ecotype. In cold-acclimated plants the light compensation point was increased. Dark respiration was significantly increased during the exposure to 4 degrees C in both ecotypes. Cold-acclimated Antarctic plants showed higher Phi(PSII) and qP compared with the Andes ecotype. In addition, the Antarctic ecotype exhibited higher heat dissipation (NPQ), especially in the cold-acclimated state, which was mainly associated with the fast relaxing component of non-photochemical quenching (NPQ(F)). By contrast, the Andes ecotype exhibited a lower NPQ(F) and a significant increase in the slowly relaxing component (NPQ(s)) at low temperature and HL, indicating higher sensitivity to low temperature-induced photoinhibition. Although the xanthophyll cycle was fully operational in both ecotypes, cold-acclimated Antarctic plants exposed to HL exhibited higher epoxidation state of the xanthophyll cycle pigments (EPS) compared with the cold-acclimated Andes ecotype. Thus, the photosynthetic apparatus of the Antarctic ecotype operates more efficiently than that of the Andes one, under a combination of low temperature and HL. The ecotype differences are discussed in relation to the different climatic conditions of the two Colobanthus.

Simulation of CO2 Fluxes in European Forest Ecosystems with the Coupled Soil-Vegetation Process Model “LandscapeDNDC”

“…For example, the inter-site differences for model parameters involved for photosynthetic activity i.e., AMAXB, PSNTOPT, between boreal and temperate pine forests are large. Site-specific calibration for "nitrogen dependency of photosynthesis" (AMAXB) results in a higher value (in average 50%) in boreal compared to temperate pine stands which is in accordance with experimental findings [118]. Acclimation to local environmental conditions has been reported for pine [22], spruce [23] beech [24] and other tree species [21,25].…”

Changes in soluble carbohydrates in polar Caryophyllaceae and Poaceae plants in response to chilling

“…In the Antarctic, only two species grow: Colobanthus quitensis (Caryophyllaceae) and Deschampsia antarctica (Poaceae). C. quitensis and D. antarctica have developed unique anatomical structures which enable them to adapt to severe climates, including xerophytic leaves (Romero et al 1999), structural plasticity of chloroplasts and mitochondria (Giełwanowska 2003;Giełwanowska and Szczuka 2005) as well as organs with highly effective photosynthetic function at low temperatures (Bravo et al 2007). Survival at sub-zero temperatures is probably conditioned by the accumulation of protective proteins (Bravo and Griffith 2005;John et al 2009), fats (Zúñiga et al 1994), sugars and polyols (Montiel and Cowan 1993;Zúñiga et al 1996).…”

Optimización de parámetros para la propagación in vitro de Colobanthus quitensis (Kunth) Bartl.

“…Aunque no evaluamos el efecto de las poblaciones, más estudios son requeridos para dilucidar a qué se puede deber esta respuesta diferencial, así como para definir el medio y condiciones de cultivo óptimo para la regeneración in vitro para cada población de C. quitensis. Varios estudios han mostrado adaptaciones morfofisiológicas y hasta diferenciación ecotípica en estudios con individuos de C. quitensis de diferentes procedencias (Gianoli et al 2004, Bravo et al 2007, Bascuñán et al 2010, 2012, Cordero 2012, esto podría relacionarse con condicionamientos genéticos y fisiológicos de esta especie de acuerdo a su procedencia.…”