Plasticity to simulated shade is associated with altitude in structured populations of Arabidopsis thaliana

Plants compete for photosynthesis light and induce a shade avoidance syndrome [SAS] that confers an important advantage in asymmetric competition for light at high canopy densities. Shade plasticity was studied in a greenhouse experiment cultivating Arabidopsis thaliana plants from 15 populations spread across an altitudinal gradient in the northeast area of Spain that contain a high genetic variation into a reduced geographical range. Plants were exposed to sunlight or simulated shade to identify the range of shade plasticity. Fourteen vegetative, flowering and reproductive traits were measured throughout the life cycle. Shade plasticity in flowering time and dry mass was significantly associated with the altitude of population origin. Plants from coastal populations showed higher shade plasticity indexes than those from mountains. The altitudinal variation in flowering leaf plasticity adjusted negatively with average and minimum temperatures, whereas dry mass plasticity was better explained by negative regressions with the average, maximum and minimum temperatures, and by a positive regression with average precipitation of the population origin. The lack of an altitudinal gradient for the widest number of traits suggests that shade light could be a driver explaining the distribution pattern of individuals in smaller geographical scales than those explored here. Low red/far-red [R/FR] ratio of the light environment provides an early and unambiguous warning of the presence of competing vegetation. This paper focuses on the study of the shade avoidance syndrome in structured populations of Arabidopsis thaliana originated in an altitudinal gradient of the Northeastern of Spain. Plasticity to shade of two important fitness traits, like flowering and aerial dry biomass, were associated with the altitudinal gradient of population origin being plants collected in the coast more plastic than those from the mountains. The clinal variation of the shade plasticity index was negatively associated with temperature for both traits and positively with precipitation for dry biomass, suggesting that these climatic parameters could be relevant for light adaptation in these populations.

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Bibliographic Details
Main Author: Botto, Javier Francisco
Format: Texto biblioteca
Language:spa
Subjects:SPAIN, SHADE TOLERANCE, SHADE AVOIDANCE SYNDROME, PHYTOCHROMES, PHENOTYPIC PLASTICITY, LOCAL ADAPTATION, LIGHT, GEOGRAPHICAL REGION, GENETIC VARIATION, ARABIDOPSIS THALIANA, ANGIOSPERM, ALTITUDINAL GRADIENT, ALTITUDE, ,
Online Access:http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=47217
http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=
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Summary:Plants compete for photosynthesis light and induce a shade avoidance syndrome [SAS] that confers an important advantage in asymmetric competition for light at high canopy densities. Shade plasticity was studied in a greenhouse experiment cultivating Arabidopsis thaliana plants from 15 populations spread across an altitudinal gradient in the northeast area of Spain that contain a high genetic variation into a reduced geographical range. Plants were exposed to sunlight or simulated shade to identify the range of shade plasticity. Fourteen vegetative, flowering and reproductive traits were measured throughout the life cycle. Shade plasticity in flowering time and dry mass was significantly associated with the altitude of population origin. Plants from coastal populations showed higher shade plasticity indexes than those from mountains. The altitudinal variation in flowering leaf plasticity adjusted negatively with average and minimum temperatures, whereas dry mass plasticity was better explained by negative regressions with the average, maximum and minimum temperatures, and by a positive regression with average precipitation of the population origin. The lack of an altitudinal gradient for the widest number of traits suggests that shade light could be a driver explaining the distribution pattern of individuals in smaller geographical scales than those explored here. Low red/far-red [R/FR] ratio of the light environment provides an early and unambiguous warning of the presence of competing vegetation. This paper focuses on the study of the shade avoidance syndrome in structured populations of Arabidopsis thaliana originated in an altitudinal gradient of the Northeastern of Spain. Plasticity to shade of two important fitness traits, like flowering and aerial dry biomass, were associated with the altitudinal gradient of population origin being plants collected in the coast more plastic than those from the mountains. The clinal variation of the shade plasticity index was negatively associated with temperature for both traits and positively with precipitation for dry biomass, suggesting that these climatic parameters could be relevant for light adaptation in these populations.