Increasing atmospheric CO2 and canopy temperature induces anatomical and physiological changes in leaves of the C-4 forage species Panicum maximum

Autor(es)

Habermann, Eduardo ^[1] ; Barrera San Martin, Juca Abramo ^[1] ; Contin, Daniele Ribeiro ^[1] ; Bossan, Vitor Potenza ^[1] ; Barboza, Anelize ^[1] ; Braga, Marcia Regina ^[2] ; Groppo, Milton ^[1] ; Martinez, Carlos Alberto ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, FFCLRP, Dept Biol, Ribeirao Preto, SP - Brazil

^[2] Inst Bot, Dept Plant Physiol & Biochem, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 14, n. 2 FEB 19 2019.
• Citações Web of Science: 5

Resumo

Changes in leaf anatomy and ultrastructure are associated with physiological performance in the context of plant adaptations to climate change. In this study, we investigated the isolated and combined effects of elevated atmospheric CO2 concentration ({[}CO2]) up to 600 mu mol mol(-1) (eC) and elevated temperature (eT) to 2 degrees C more than the ambient canopy temperature on the ultrastructure, leaf anatomy, and physiology of Panicum maximum Jacq. grown under field conditions using combined free-air carbon dioxide enrichment (FACE) and temperature free-air controlled enhancement (T-FACE) systems. Plants grown under eC showed reduced stomatal density, stomatal index, stomatal conductance (g(s)), and leaf transpiration rate (E), increased soil-water content (SWC) conservation and adaxial epidermis thickness were also observed. The net photosynthesis rate (A) and intrinsic water-use efficiency (iWUE) were enhanced by 25% and 71%, respectively, with a concomitant increase in the size of starch grains in bundle sheath cells. Under air warming, we observed an increase in the thickness of the adaxial cuticle and a decrease in the leaf thickness, size of vascular bundles and bulliform cells, and starch content. Under eCeT, air warming offset the eC effects on SWC and E, and no interactions between {[}CO2] and temperature for leaf anatomy were observed. Elevated {[}CO2] exerted more effects on external characteristics, such as the epidermis anatomy and leaf gas exchange, while air warming affected mainly the leaf structure. We conclude that differential anatomical and physiological adjustments contributed to the acclimation of P. maximum growing under elevated {[}CO2] and air warming, improving the leaf biomass production under these conditions. (AU)

• Processo FAPESP: 14/26821-3 - Análise comparativa das relações hídricas em espécies forrageiras C3 e C4 submetidas a elevado nível de CO2 e aquecimento em sistema TROP-T-FACE
• Beneficiário: Eduardo Habermann
• Linha de fomento: Bolsas no Brasil - Mestrado
• Processo FAPESP: 08/58075-8 - Miniface climate-change impact experiment to analyze the effects of elevated CO2 and warming on photosynthesis, gene expression, biochemistry, growth, nutrient dynamics and yield of two contrasting tropical forage species
• Beneficiário: Carlos Alberto Martinez y Huaman
• Linha de fomento: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático