Moderate warming increases PSII performance, antioxidant scavenging systems and biomass production in Stylosanthes capitata Vogel
| Autor: | Andre Rodrigues, Fernanda Tomita Manchon, Matheus E. Bianconi, Andressa Uehara Approbato, Lucas Curtarelli, Maria Teresa Oliverio Lemos, Carlos Alberto Martinez, Laís Mara Caetano da Silva, Tathyana Rachel Palo Mello, Leticia Santos |
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| Rok vydání: | 2014 |
| Předmět: |
Biomass (ecology)
Antioxidant Photosystem II Chemistry medicine.medical_treatment MUDANÇA CLIMÁTICA food and beverages Plant Science Photosynthesis Malondialdehyde Horticulture chemistry.chemical_compound Capitata Botany medicine Leaf area index Agronomy and Crop Science Ecology Evolution Behavior and Systematics Legume |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | 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 °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 °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. |
| Databáze: | OpenAIRE |
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