TITLE:
Effects of Low Temperature and Low Light on Physiology of Tomato Seedlings
AUTHORS:
Yubo Yang, Lingdi Dong, Linqi Shi, Jinghua Guo, Yonggang Jiao, Haizheng Xiong, Ryan William Dickson, Ainong Shi
KEYWORDS:
Enzyme Activity, Malondialdehyde, Osmotic Potential, Peroxidases, Proline, Physiological Condition, Soluble Sugar, Stress Tolerance, Superoxide Dismutase
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.2,
February
20,
2020
ABSTRACT: The physiological changes and the mechanism of
stress tolerance in tomato were studied under
low temperature and low light conditions. Two growth chamber experiments
evaluated three temperatures regimes under standard and relatively low
illumination levels with three tomato genotypes. Both experiments used a
completely randomized split-plot design (CRD), with temperature regime as the main plot and tomato genotype as the
split-plot. The three tomato varieties were “Fenyan No.1”, “SV0313TG”, and “Ousa”. In both experiments, activity of superoxide dismutase (SOD) and
peroxidases (POD) in tomato seedlings decreased under low temperature regime and the combination of low temperature and
low light. Decreasing temperature had the
greatest effect on the increase in enzyme activity. Decrease in POD activity was the greatest under low light and low temperature. The
concentration of malondialdehyde (MDA) in plant tissue also decreased under low
temperature (20°C/10°C day/night) compared to the standard temperature control (25°C/16°C day/night), but increased at 15°C/5°C day/night
temperatures in both experiments and was the greatest under the lowest light and temperature
conditions. In both experiments, proline concentrations were the greatest under the
standard light intensity (30,000 lux), and proline concentrations increased as
temperature decreased. The content of soluble sugar decreased under only low temperature stress but increased under
double stresses. The relative value of osmotic potential increased a little
under low temperature stress but decreased
under double stresses.