Effects of high temperature coupled with high light on the balance between photooxidation and photoprotection in the sun-exposed peel of apple

Abstract

The sun-exposed peel of 'Gala' apple with or without sunburn was compared in terms of photooxidation and photoprotection, and a controlled experiment was conducted to probe the initial responses of PSII to high light and high temperature. The content of carotenoids, lutein and xanthophylls on a chlorophyll basis was higher in the sunburned peel although they were lower expressed on a peel area basis. Significant loss of beta-carotene and neoxanthin was observed relative to chlorophylls in the sunburned peel. O(2) evolution rates and the activity of key enzymes in the Calvin cycle were lower in the sunburned peel, but the activity of these enzymes decreased to a lesser extent than the O(2) evolution rates. The activity of antioxidant enzymes in the ascorbate-glutathione cycle and the level of total ascorbate, total glutathione, and reduced glutathione were higher in the sunburned peel. However, the sunburned peel had higher H(2)O(2) and malondialdehyde contents. Fruit peels treated with high temperature (45 degrees C) alone showed a clear "K" step in their chlorophyll fluorescence transients whereas high temperature coupled with high light (1,600 micromol m(-2) s(-1)) led to the disappearance of the "K" step and a further decrease in F (V)/F (M) (similar to what was observed in the sunburned peel). We conclude that high temperature coupled with high light damages the PSII complexes at both the donor and acceptor sides. Although both the xanthophyll cycle and the antioxidant system are up-regulated in response to the photooxidative stress, this up-regulation does not provide enough protection against the photooxidation.

Prevention of New Cork Spot-like Physiological Disorder in ‘Kurenainoyume’ Apples by Pre-harvest Fruit Bagging

“…Schrader et al (2001) reported that sunburn was induced by both high skin temperature and solar radiation. Intense sunlight induces thermal dissipation and antioxidation by upregulating the xanthophyll and ascorbate-glutathione cycles, respectively (Chen et al, 2008(Chen et al, , 2009Cheng, 2003, 2004). However, when this upregulation is inadequate, a physiological disorder is induced by photooxidation (Chen et al, 2008).…”

“…Intense sunlight induces thermal dissipation and antioxidation by upregulating the xanthophyll and ascorbate-glutathione cycles, respectively (Chen et al, 2008(Chen et al, , 2009Cheng, 2003, 2004). However, when this upregulation is inadequate, a physiological disorder is induced by photooxidation (Chen et al, 2008). In this study, the temperature inside the paper bag did not differ significantly among treatments (Table 5).…”

Physiological adaptive mechanisms of plants grown in saline soil and implications for sustainable saline agriculture in coastal zone

“…1). O-J-I-P transient has been accepted as a reliable and popular tool in photosynthetic research, especially to study PSII behavior in recent years (Wen et al 2005;Strauss et al 2007;Toth et al 2007;Yang et al 2007;Chen et al 2008;Rapacz et al 2008;Yan et al 2008Yan et al , 2011Li et al 2009;Mehta et al 2010;Rapacz et al 2010;Jedmowski et al 2013). O, J, I and P are a sequence of phases in the kinetics of fast fluorescence rise, and environmental stress often provokes the occurrence of K phase in this transient, suggesting the damage to oxygen-evolving complex in donor side of PSII (Strasser et al 2004).…”

Influencia Del Uso De Malla Perla Y Roja en Las Condiciones Micro-Climáticas, Daño Por Sol Y Desarrollo De Color De Frutos en Huertos De Manzanos Cvs. Gala Y Fuji

“…Una mayor PaR total bajo la malla Perla podría indicar una mayor actividad fotosintética en la planta, asociada a un aumento del contenido de clorofila en las hojas (DO amaRaNte et al, 2011), puesto que la radiación y su intensidad están en relación directa con la actividad de los fotosistemas y su inhibición en la piel de la fruta por un exceso de radiación u otro factor ambiental como altas temperaturas (CHeN et al, 2008). la menor PaR bajo malla Roja respecto a la malla Perla (Fig.…”

“…el efecto positivo de la malla Perla sobre la mayor coloración de frutos, puede ser explicado por la mayor proporción de luz difusa que se generó bajo esta malla (Figura 4 C y D), lo que favorece la mayor disponibilidad de luz en sectores más sombríos del árbol (SHaHak et al, 2014), favoreciendo la síntesis de antocianinas en frutos, ya sea directamente como mecanismo de foto-protección (FelICettI y SCHRaDeR, 2008;CHeN et al, 2008), o indirectamente al favorecer una mayor disponibilidad de carbohidratos producto del incremento en la capacidad fotosintética en las hojas de los árboles expuestas a una mayor proporción de luz difusa (BaStIaS et al, 2012 Jaboticabal -SP InfluencIa del uso de malla Perla y roja en las condIcIones ... …”