IFAB   27864
INSTITUTO DE INVESTIGACIONES FORESTALES Y AGROPECUARIAS BARILOCHE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Circadian clocks, temperature and Patagonian forest ecology
Autor/es:
MARTINEZ-MEIER, A; MARCHELLI, P; HEER, K; ESTRAVIS-BARCALÁ, M; GONZALEZ-POLO, M; ZIEGENHAGEN, B; YANOVSKY, M; BELLORA, N; CAGNACCI, J; OPGHENOORTH, L; ARANA, MV
Reunión:
Workshop; EMBO Workshop: Integrative biology ? From molecules to ecosystems in extreme environments; 2019
Resumen:
The Andean-Patagonian region comprises one of the most singular forestry ecosystems of the planet and constitutes one of the last frontier forests of its type. In this region, Nothofagaceae, a monotypical family in the order Fagales, dominates in generally hostile environments, inhabiting almost all the narrow forestry landmass of the Patagonian Andes. This region will be affected by increasing temperatures according to climate change (CC) predictions. In this context, a fundamental question is how trees will cope with these changes, given their low population turnover.Here we explored the hypothesis that the upper thermal limit for clock functioning influences thermal adaptation in Nothofagus obliqua and N. pumilio. These are two emblematic tree species of the Patagonian forests, which constitute examples of extremes of adaptation of closely related species to altitude, inhabiting non-overlapping thermal niches. We show that the circadian clocks of both species are out of their compensation range at 34°C. In diurnal conditions, at 31°C, daily oscillation in the expression of the homolog clock gene NoTOC1 is maintained in N. obliqua, which inhabits warmer and lower altitudes of the mountains but is lost in N. pumilio, which inhabits higher and colder habitats. Experiments across an altitudinal gradient show that the expression of NpTOC1 in N. pumilio is affected in warmer and lower environments out of its distribution range, and this is associated with reduced accumulation of dry weight, chlorophyll and survival. This behavior is not evident in N. obliqua seedlings grown in higher environments out of their natural range. Taken together, our results provide the first evidences in favor that performance of circadian clock at different temperatures contribute to physiological adaptation to the local thermic environment. This phenomenon might influence the ability of N. obliqua and N. pumilio to respond to increasing temperatures such as those predicted by CC.