IBAM   22618
INSTITUTO DE BIOLOGIA AGRICOLA DE MENDOZA
Unidad Ejecutora - UE
artículos
Título:
UV-B IMPAIRS GROWTH AND GAS EXCHANGE IN GRAPEVINES GROWN IN HIGH ALTITUDE
Autor/es:
BERLI F.; ALONSO R.; BRESSAN-SMITH R.; BOTTINI R.
Revista:
PHYSIOLOGIA PLANTARUM
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2012 p. 1 - 14
ISSN:
0031-9317
Resumen:
We previously demonstrated that solar ultraviolet-B (UV-B) radiation levels in high altitude vineyards improve berry quality in Vitis vinifera cv. Malbec, but also reduce berry size and yield, possibly as a consequence of increased oxidative damage and growth reductions (lower photosynthesis). The defense mechanisms toward UV-B signal and/or evoked damage promote production of antioxidant secondary metabolites instead of primary metabolites. Purportedly, the UV-B effects will depend on tissues developmental stage and interplay with other environmental conditions, especially stressful situations. In this work, grapevines were exposed to high solar UV-B (+UV-B) and reduced (by filtering) UV-B (−UV-B) treatments during three consecutive seasons, and the effects of UV-B, developmental stages and seasons on the physiology were studied, i.e. growth, tissues morphology, photosynthesis, photoprotective pigments, proline content and antioxidant capacity of leaves. The +UV-B reduced photosynthesis and stomatal conductance, mainly through limitation in gas exchange, reducing plant’s leaf area, net carbon fixation and growth. The +UV-B augmented leaf thickness, and also the amounts of photoprotective pigments and proline, thereby increasing the antioxidant capacity of leaves. The defense mechanisms triggered by +UV-B reduced lipid peroxidation, but they were insufficient to protect the photosynthetic pigments per leaf dry weight basis. The +UV-B effects depend on tissues developmental stage and interplay with other environmental conditions such as total radiation and air temperatures.