Short-term UV-B radiation affects photosynthetic performance and antioxidant gene expression in highbush blueberry leaves
Short-term UV-B radiation affects photosynthetic performance and antioxidant gene expression in highbush blueberry leaves
Authors
Inostroza Blancheteau, Claudio
Acevedo, Patricio
Loyola, Rodrigo
Arce Johnson, Patricio
Alberdi, Miren
Reyes Diaz, Marjorie
Acevedo, Patricio
Loyola, Rodrigo
Arce Johnson, Patricio
Alberdi, Miren
Reyes Diaz, Marjorie
Authors
Date
Datos de publicaciĆ³n:
10.1016/j.plaphy.2016.06.019
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Abstract
The impact of increased artificial UV-B radiation on photosynthetic performance, antioxidant and SOD activities and molecular antioxidant metabolism responses in leaves of two highbush blueberry (Vaccinium corymbosum L. cv. Brigitta and Bluegold) genotypes was studied. Plants were grown in a solid substrate and exposed to 0, 0.07, 0.12 and 0.19 W m(-2) of biologically-effective UV-B irradiance for 0 -72 h. Our findings show that net photosynthesis (Pn) decreased significantly in Bluegold, accompanied by a reduction in the effective quantum yield (phi PSII) and electron transport rate (ETR), especially at the highest UV-B irradiation. On the other hand, Brigitta showed a better photosynthetic performance, as well as a clear increment in the antioxidant activity response that could be associated with increased superoxide dismutase activity (SOD) in the early hours of induced UV-B stress in all treatments. At the molecular level, the expression of the three antioxidant genes evaluated in both genotypes had a similar tendency. However, ascorbate peroxidase (APX) expression was significantly increased (6-fold) in Bluegold compared to Brigitta. Thus, the reduction of Pn concomitant with a lower photochemical performance and a reduced response of antioxidant metabolism suggest that the Bluegold genotype is more sensitive to UV-B radiation, while Brigitta appears to tolerate better moderate UV-B irradiance in a short-term experiment. (C) 2016 Elsevier Masson SAS. All rights reserved.