Elevated CO2 Atmosphere Minimizes the Effect of Drought on the Cerrado Species Chrysolaena obovata

Author(s)

Oliveira, Vanessa F. ^{[1, 2, 3]} ; Silva, Emerson A. ^[1] ; Carvalho, Maria A. M. ^[1]

Affiliation

^[1] Univ Mogi das Cruzes, Sao Paulo - Brazil

^[2] Inst Bot, Nucleo Pesquisa Fisiol & Bioquim, Sao Paulo - Brazil

^[3] Inst Bot, Programa Posgrad Biodiversidade Vegetal & Meio Am, Sao Paulo - Brazil

• Document type: Journal article
• Source: FRONTIERS IN PLANT SCIENCE; v. 7, JUN 14 2016.
• Web of Science Citations: 1

Abstract

Chrysolaena obovata stores inulin in the rhizophores, associated with drought tolerance. While crop plants are widely studied concerning the interactive effects of high {[}CO2] and drought, few studies reported these effects in native species. Here, we evaluated the combined effects of these factors on water status and fructan metabolism in C. obovata, a native Cerrado species. Two lots of plants were kept at 380 and 760 ppm CO2 in open top chambers. In each, {[}CO2] plants were divided into four groups and cultivated under different water availability: irrigation with 100 (control), 75 (low), 50 (medium), and 25% (severe drought) of the water evapotranspirated in the last 48 h. In each, water treatment plants were collected at 0, 9, 18, and 27 days. On day 27, all plants were re-watered to field capacity and, after 5 days, a new sampling was made. Water restriction caused a decrease in plant moisture, photosynthesis, and in enzymes of fructan metabolism. These changes were generally more pronounced in 25% plants under ambient {[}CO2]. In the later, increases in the proportion of hexoses and consequent modification of the fructan chain sizes were more marked than under high {[}CO2]. The results indicate that under elevated {[}CO2], the negative effects of water restriction on physiological processes were minimized, including the maintenance of rhizophore water potential, increase in water use efficiency, maintenance of photosynthesis and fructan reserves for a longer period, conditions that shall favor the conservation of this species in the predicted climate change scenarios. (AU)

• FAPESP's process: 05/04139-7 - Carbohydrates of tropical species as modulators of ecophysiological processes and as environmental stress response markers
• Grantee: Marcia Regina Braga
• Support Opportunities: Research Projects - Thematic Grants