JXB Advance Access published online on May 12, 2006
Journal of Experimental Botany, doi:10.1093/jxb/erj136
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Horticulture and Landscape Architecture, Washington State University, Pullman, WA 99164-6414, USA
* To whom correspondence should be addressed. Photo-oxidative stress was imposed under natural solar radiation on exposed and shaded sections of detached fruit of immature green tomato (Lycopersicon esculentum Miller=Solanum lycopersicum L.) mutants (anthocyanin absent,
Received September 30, 2005
Accepted January 24, 2006
RESEARCH PAPER
Physiological and biochemical responses of fruit exocarp of tomato (Lycopersicon esculentum Mill.) mutants to natural photo-oxidative conditions
Carolina A. Torres 1 *,
Preston K. Andrews 1,
and
Neal M. Davies 2
2 Department of Pharmaceutical Sciences and Pharmacology, Washington State University, Pullman, WA 99164-6534, USA
Carolina A. Torres, E-mail: carolinat{at}paceint.com
Abstract 
-carotene, Delta, and high pigment-1) and their nearly isogenic parents (‘Ailsa Craig’ and ‘Rutgers’). After 5 h exposure to high solar irradiance, either with or without ultraviolet (UV) radiation, surface colour changes, pigment composition, photosynthetic efficiency, antioxidant metabolites and enzyme activities, and selected flavonoids and antioxidant proteins in exocarp tissue were evaluated. The imposed photo-oxidative stress reproduced the symptoms observed on attached fruit. Both high temperature and solar irradiance caused fruit surface discoloration with faster degradation of chlorophyll (Chl) than carotenoids (Car), leading to an increase in the Car/Chl ratio. Surface bleaching was mostly caused by visible light, whereas elevated temperatures were mostly responsible for the inactivation of photosynthesis, measured as decreased Fv/Fm. Ascorbate, glutathione, and total soluble protein concentrations decreased in the exocarp as the duration of exposure increased. Specific activities of superoxide dismutase, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase (MDHAR), glutathione reductase (GR), and catalase increased with exposure, suggesting that these proteins were conserved during the imposed stress. GR protein expression remained stable during the imposed stress, whereas, MDHAR protein expression increased. Quercetin and kaempferol concentrations increased rapidly upon exposure, but not to UV radiation, suggesting rapid photo-protection in response to visible light; however, naringenin synthesis was not induced. The apparent increased tolerance of hp-1 fruit is discussed.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  S. Mintz-Oron, T. Mandel, I. Rogachev, L. Feldberg, O. Lotan, M. Yativ, Z. Wang, R. Jetter, I. Venger, A. Adato, et al. Gene Expression and Metabolism in Tomato Fruit Surface Tissues Plant Physiology, June 1, 2008; 147(2): 823 - 851. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. A. Felicetti and L. E. Schrader Changes in Pigment Concentrations Associated with the Degree of Sunburn Browning of 'Fuji' Apple J. Amer. Soc. Hort. Sci., January 1, 2008; 133(1): 27 - 34. [Abstract] [Full Text] [PDF]
|
|