Effects of PEG simulated drought stress on root physiology of Seriphidium transiliense seedlings at different ages

To elucidate the response of the root system of Seriphidium transiliense seedlings at different ages to varying drought stress intensities in physiological characteristics, one- and two-month-old seedlings of potted S. transiliense were evaluated. PEG-6000 was used to simulate drought stress, and the stress gradients were set as 0 (CK), –0.3, –0.6, –0.9, and –1.2. The results showed that with an increase in stress intensity, the root activity of the one-month-old seedlings decreased, while that of two-month-old seedlings increased first and then decreased. while the contents of proline (Pro), malondialdehyde (MDA), and soluble sugar (SS) increased gradually. The content of soluble protein (SP) and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased first and then decreased. Except for MDA, the changes of the above indexes were greater in two-month-old seedlings than in one-month-old seedlings. In summary, the root activity of S. transiliense seedlings decreased under drought stress, responding to the stress by accumulating a large number of osmotic adjustment substances and increasing antioxidant enzyme activities. The drought resistance of two-month-old seedlings was stronger than that of one-month-old seedlings.