The chilling tolerance of doubled haploid (DH) maize plants selected and regenerated from microspores exposed to prooxidants, paraquat or tert-butyl hydroperoxide was determined by monitoring cold-induced changes in the photosynthetic electron transport, CO2 assimilation processes and chlorophyll breakdown in young leaves after cold treatment (8°C for 5 days). The results were compared to those of the non-selected DH line and the original hybrid plants. Chilling stress caused a great reduction in the Fv/Fm, qP and ΔF/Fm’ fluorescence parameters, related to the photosynthetic electron transport processes, and in carbon assimilation, and resulted in chlorophyll breakdown. These changes were less extensive in the selected DH plants, which showed elevated antioxidant capacity both at ambient and at low temperature. Among the antioxidant enzymes tested, the activity of GR and GST was induced by chilling stress to the greatest extent. Correlations between cold-induced changes in the photosynthetic apparatus and the antioxidant capacity of the plants suggested that the better protection against oxidative stress induced by the elevated antioxidant capacity of the plants contributed to protecting the photosynthetic apparatus from cold.
Allen, D. J., Ort, D. R. (2001): Impacts of chilling temperatures on photosynthesis in warm-climate plants. Trends Plant Sci., 6, 36–42.
Ort D. R., 'Impacts of chilling temperatures on photosynthesis in warm-climate plants' (2001) 6Trends Plant Sci.: 36-42.
Ort D. R.Impacts of chilling temperatures on photosynthesis in warm-climate plantsTrends Plant Sci.200163642)| false
Darkó, É., Fodor, J., Dulai, S., Ambrus, H., Szenzenstein, A., Király, Z., Barnabás, B. (2011): Improved cold and drought tolerance of doubled haploid maize plants selected for resistance to prooxidant tert-butyl hydroperoxide. J. Agron. Crop Sci., in press.
Fryer, M. J., Andrews, J. R., Oxborough, K., Blowers, D. A., Baker, N. R. (1998): Relationship between CO2 assimilation, photosynthetic electron transport, and active O2 metabolism in leaves of maize in the field during periods of low temperature. Plant Physiol., 116, 571–580.
Baker N. R., 'Relationship between CO2 assimilation, photosynthetic electron transport, and active O2 metabolism in leaves of maize in the field during periods of low temperature' (1998) 116Plant Physiol.: 571-580.
Baker N. R.Relationship between CO2 assimilation, photosynthetic electron transport, and active O2 metabolism in leaves of maize in the field during periods of low temperaturePlant Physiol.1998116571580)| false