title: Changes in net photosynthesis, chlorophyll fluorescence and xanthophyll cycle interconversions during freeze-thaw cycles in the Mediterranean moss Leucodon sciuroides.
abstract: The tolerance to freezing and thawing of Leucodon sciuroides, a moss growing in mountainous areas of the Mediterranean (south-east Spain), was investigated by means of CO2gas exchange, modulated chlorophyll (Chl) a fluorescence and pigment analysis by high-performance liquid chromatography. Evidence is presented for freezing-induced decreases in CO2fixation that enhance non-radiative dissipation of absorbed light energy, a process which protects the photosynthetic apparatus. The photosynthetic apparatus of L. sciuroides remained fully recuperable after freezing, as indicated by the recovery of photosynthetic CO2fixation and Chl fluorescence parameters to pre-freezing values during thawing. The rapid recovery of photosynthesis activity during thawing in L. sciuroides suggests that this moss is capable of tolerating freeze-thaw cycles in a manner similar to that found at higher latitudes or in the Antarctic. The resistance of the photosynthetic apparatus of this moss to freezing might be achieved, at least partially, through the employment of dissipative pathways, such as non-radiative dissipation of absorbed light energy.
authors.affiliation: Departament de Biología Vegetal, Facultat de Ciències Biológiques, Universitat de València, c/Dr. Moliner 50, E-46100 Burjassot (València), Spain, , , , , , ES.
authors.forename: Vicente I
authors.initials: VI
authors.lastname: Deltoro
authors.affiliation: Departament de Biología Vegetal, Facultat de Ciències Biológiques, Universitat de València, c/Dr. Moliner 50, E-46100 Burjassot (València), Spain, , , , , , ES.
authors.forename: Ángeles
authors.initials: Á
authors.lastname: Calatayud
authors.affiliation: Estación Experimental de Aula Dei (CSIC), Department of Plant Nutrition, Avda. Montañana 177 Box 202, E-50080 Zaragoza, Spain, , , , , , ES.
authors.forename: Fermin
authors.initials: F
authors.lastname: Morales
authors.affiliation: Estación Experimental de Aula Dei (CSIC), Department of Plant Nutrition, Avda. Montañana 177 Box 202, E-50080 Zaragoza, Spain, , , , , , ES.
authors.forename: Anunciacion
authors.initials: A
authors.lastname: Abadía
authors.affiliation: Departament de Biología Vegetal, Facultat de Ciències Biológiques, Universitat de València, c/Dr. Moliner 50, E-46100 Burjassot (València), Spain, , , , , , ES.
authors.forename: Eva
authors.initials: E
authors.lastname: Barreno
keywords: Chlorophyll a fluorescence; Downregulation; Freezing tolerance; Key words Bryophytes