The physiological response of different tobacco varieties to chilling stress during the vigorous growing period

Tobacco is be sensitively affected by chilling injury in the vigorous growth period, which can easily lead to tobacco leaf browning during flue-curing and quality loss, however, the physiological response of tobacco in the prosperous period under low temperature stress is unclear. The physiological response parameters of two tobacco varieties to low temperature stress were determined. The main results were as follows: (1) For tobacco in the vigorous growing period subjected to low-temperature stress at 4-16 degrees C, the tissue structure of chloroplast changed and photosynthetic pigments significantly decreased compared with each control with the increase of intensity of low-temperature stress. (2) For tobacco in the vigorous growing period at 10-16 degrees C, antioxidant capacity of the protective enzyme system, osmotic adjustment capacity of the osmotic adjusting system and polyphenol metabolism in plants gradually increased due to induction of low temperature with the increase of intensity of low-temperature stress. (3) Under low-temperature stress at 4 degrees C, the protective enzyme system, osmotic adjusting system and polyphenol metabolism of the plants played an insignificant role in stress tolerance, which cannot be constantly enhanced based on low-temperature resistance at 10 degrees C. This study confirmed that under the temperature stress of 10-16 degrees C, the self-regulation ability of tobacco will be enhanced with the deepening of low temperature stress, but there is a critical temperature between 4 and 10 degrees C. The self-regulation ability of plants under low temperature stress will be inhibited.

Automated summary

This study found that tobacco exhibits different physiological responses to low-temperature stress during the vigorous growth period. The antioxidant enzyme system, osmotic adjusting system, and polyphenol metabolism in tobacco gradually increased in response to low temperature stress at 10-16 degrees Celsius. However, under low temperature stress at 4 degrees Celsius, the capacity for stress tolerance in plants did not significantly improve.