Е.С. Холопцева, В.В. Таланова.
Влияние низкой температуры и кадмия на интенсивность фотодыхания проростков пшеницы
Keywords: Triticum aestivum L.; low temperature; cadmium; photorespiration; stomatal conductance
The effects of separate and combined exposure to a low hardening temperature (4°C) and cadmium sulfate (100 μM) on the visible photorespiration rate in the leaves of winter wheat seedlings (Triticum aestivum L.) were investigated. It was found that the temperature of 4°C causes a significant decrease in stomatal conductance and CO2 content in leaf intercellulars already in the initial period of the treatment (1–5 h). This effect persists for 7 days of the experiment. The rate of photorespiration sharply decreased in the first 1–5 hours of cold exposure. But then, it gradually increased due to a low CO2 concentration and exceeded the initial level after 4–7 days. In contrast, cadmium had virtually no effect on stomatal conductance and CO2 concentration in the intercellular spaces in the first hours of exposure, and after 4–7 days it led to a slight decrease in these indices. At the same time, after a small decline in the first hours of exposure the rate of photorespiration returned to the initial level. The combined impact of 4°C temperature and cadmium led to a decrease in stomatal conductance, CO2 content in the intercellular spaces, and the rate of photorespiration on the first day. After that, the first two indicators remained at a reduced level, whereas the photorespiration rate returned to its original value. It was concluded that by maintaining an elevated level of photorespiration in the leaves under the impact of low temperature simultaneously with a decrease in stomatal conductance and CO2 content in intercellular spaces wheat plants protect their cells from the oxidative stress developing under these conditions.
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