Moderate warming increases PSII performance, antioxidant scavenging systems and biomass production in Stylosanthes capitata Vogel

Autor(es)

Martinez, Carlos Alberto ^[1] ; Bianconi, Matheus ^[1] ; Silva, Lais ^[1] ; Approbato, Andressa ^[1] ; Lemos, Maria ^[1] ; Santos, Leticia ^[1] ; Curtarelli, Lucas ^[1] ; Rodrigues, Andre ^[1] ; Mello, Tathyana ^[1] ; Manchon, Fernanda ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Biol, FFCLRP, BR-14040901 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL AND EXPERIMENTAL BOTANY; v. 102, p. 58-67, JUN 2014.
• Citações Web of Science: 14

Resumo

Stylosanthes capitata Vogel is an important forage legume in tropical and subtropical regions. To study the response of S. capitata to the moderate warming expected as a result of climate change, plants were subjected to elevated temperature (2 degrees C increase over the ambient temperature) in a temperature free-air controlled enhancement (T-FACE) facility. Photosystem II (PSII) performance, the activity of antioxidant enzymes, the chlorophyll index, the leaf area index (LAI) and the aboveground biomass production were evaluated. The maximum PSII quantum yield (Fv/Fm) and the quantum yield of regulated energy dissipation Y (NPQ) were not affected by the warming. However, we observed a significant increase in the electron transport rate (ETR), the non-photochemical energy dissipation (NPQ), the effective PSII quantum yield Y(II) and the coefficient of photochemical quenching (qP) in the warmed leaves compared with the control leaves. In contrast, a significant reduction in the quantum yield of the relative reduction state of QA (1-qP) and non-regulated power dissipation Y(NO) was observed in the warmed leaves. The increase in ETR under moderate warming was associated with the increase (31%) in chlorophyll content. The activities of antioxidant enzymes increased in the leaves of the warmed plants, but the malondialdehyde (MDA) content of the leaves was not affected by warming, suggesting that higher levels of the antioxidant defense system induced by warming may improve the protection of photosynthesis against oxidative damage and attenuate the destructive effects of reactive oxygen species. As a result of warming, leaf area index (LAI) and biomass production increased by 32% and 16%, respectively. The improved PSII functioning of the warmed leaves-of S. capitata may reflect their capacity to acclimate better to warming growth conditions. We conclude that the warming induced by increasing the temperature by 2 degrees C, under non stressing conditions, was beneficial for the physiology and for the biophysical and physiological processes involved in plant growth of S. capitata, suggesting that slight increases in the leaf temperature may benefit some plants, especially those in tropical environments. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• 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